Nota van inspraak

12-6-2023

AA en Hunze

geluid

Het is net of er elk moment een vliegtuig wil DEE 3.1 landen en dat 24u per dag!!

13-6-2023

AA en Hunze

geluid

hard zoeven met pieken

14-6-2023

Borger Odoorn geluid

Doordat de wind uit het noordoosten komt en de zon volop warmte geeft, hebben wij s' avonds de ramen open om te ventileren. Hierdoor horen ik de windmolens, dit is vervelend om in slaap te komen.

14-6-2023

Borger Odoorn geluid

14-6-2023

AA en Hunze

slagschaduw

De rh 1.5 maakt weer vreselijk laaiwaai. Kijk er eens na of luister mee naar het vreselijk lawaai Wij ondervinden al weer geruime tijd elke ochtend enige slagschaduw op onze gevel veroorzaakt door turbine OM 2.4 De stilstandsvoorziening op deze turbine is ca. twee weken geleden niet meer van kracht. De slagschaduw treedt op tussen 7.30 en 8.00 uur in de ochtend en bij een oostelijke windrichting (NO tot ZO) en hieraan tegenovergesteld natuurlijk.

29-6-2023

AA en Hunze

geluid

6-7-2023

AA en Hunze

slagschaduw

9-7-2023 15-7-2023 16-7-2023

AA en Hunze AA en Hunze AA en Hunze

geluid geluid geluid

zeurderige en jengelende tonen

DEE 1.1, DEE 1.2 en DEE 1.3 Laagfrequent geluid. DEE 3.1 of OM 1.1 Zondag 11 juni jl. had ik lawaai overlast van 2 OM 1.1, OM turbines m.n. OM1.1 en OM 1.2. Het geluid 1.2 dat ik hoorde is te vergelijken met een vliegtuig die niet doorvliegt. DEE 3.1

RH3.4, RH3.5 en OM1.6

RH 1.5

OM 2.4

Je hoort steeds krakend geluid dat is heel erg OM2.3, storend. OM2.4 en OM2.5 Vandaag, 6 juli, weer slagschaduw over de OM2.4 gehele woning! Tijd 7.45 uur. Snerpend, constant variërend geluid RH3.5 snerpend geluid, onregelmatig RH3.5 hard zoevend repeterend RH3.5

30-7-2023

AA en Hunze

geluid

Snerpend geluid, soms krakend hard zoevend repeterend zie vorige keer Geluid van een mega harde gasbrander die aan en uit gaat. Om gek van te worden .

RH3.5

1-8-2023 3-8-2023 16-8-2023

AA en Hunze AA en Hunze AA en Hunze

geluid geluid geluid

17-8-2023

AA en Hunze

geluid

19-8-2023

Borger Odoorn geluid

Hard zoevend met pieken, zware gasbrander hard, zwaar en bulderend geluid wieken

20-8-2023

Borger Odoorn geluid

hele hoge tonen

22-8-2023

Borger Odoorn geluid

zoevend geluid wieken, hele hoge pieptoon

23-8-2023

Borger Odoorn geluid

hard, zwiepend geluid wieken, hele hoge pieptoon

24-8-2023

Borger Odoorn geluid

hele hoge doordringende, zeurderige pieptoon, zwiepend geluid wieken

25-8-2023

Borger Odoorn geluid

hele hoge pieptoon

23-8-2023

AA en Hunze

geluid

Dat de windmolens dag en nacht een dreunend geluid maken is inmiddels een status quo. Maar de ene dag, en vooral nacht, als het verder stil is, maken ze soms veel meer herrie dan anders. Zoals afgelopen nacht, en deze ochtend, Het gedreun gaat door alles heen, zelfs oordoppen.

24-8-2023

AA en Hunze

geluid

26-8-2023

Borger Odoorn geluid

27-8-2023

Borger Odoorn geluid

28-8-2023

Borger Odoorn geluid

29-8-2023

Borger Odoorn geluid

rubberachtig geluid dat in de wijde omtrek te Om2.2 horen was hard bulderend geluid wieken DEE 1.1, DEE 1.2 en DEE 1.4 tikkende en klapperende wieken, heel hard DEE 1.1, DEE zwiepend geluid wieken, hele hoge pieptoon 1.2 en DEE 1.3 ratelend geluid wieken, hele hoge pieptoon DEE 1.1, DEE 1.2 en DEE 1.2 ratelend geluid wieken, hoge pieptoon DEE 1.1, DEE 1.2 en DEE 1.1

RH3.5 RH3.5 RH3.5

RH3.5 en RH3.4 DEE 1.1, DEE 1.2 en DEE 1.3 DEE 1.1, DEE 1.2 en DEE 1.3 DEE 1.1, DEE 1.2 en DEE 1.3 DEE 1.1, DEE 1.2 en DEE 1.3 DEE 1.1, DEE 1.2 en DEE 1.3 DEE 1.1, DEE 1.2 en DEE 1.3 Om2.2

30-8-2023

Borger Odoorn geluid

ratelend geluid wieken, hoge pieptoon

31-8-2023

Borger Odoorn geluid

hard zwiepend geluid wieken, hele hoge pieptoon

1-9-2023

Borger Odoorn geluid

zwiepend geluid wieken, zeurderige en jengelende geluiden, hele hoge pieptoon

2-9-2023

Borger Odoorn geluid

hele hoge pieptoon

4-9-2023

Borger Odoorn geluid

zoevend geluid wieken, hele hoge jengelende, zeurderige tonen

4-9-2023

AA en Hunze

5-9-2023

Borger Odoorn geluid

Vandaag maakt OM 2.2 in ieder geval sinds 12.00 uur een hard slepend, rubberachtig krakend geluid zoevend geluid wieken, ratelend geluid wieken

5-9-2023

AA en Hunze

slagschaduw

5-9-2023

AA en Hunze

geluid en slagschaduw

6-9-2023

Borger Odoorn geluid

7-9-2023

Borger Odoorn geluid

8-9-2023 26-9-2023

AA en Hunze AA en Hunze

geluid geluid

11-10-2023 1-1-2024

AA en Hunze AA en Hunze

geluid slagschaduw

17-1-2024

AA en Hunze

geluid

geluid

DEE 1.1, DEE 1.2 en DEE 1.0 DEE 1.1, DEE 1.2 en DEE 1.1 DEE 1.1, DEE 1.2 en DEE 1.2 DEE 1.1, DEE 1.2 en DEE 1.3 DEE 1.1, DEE 1.2 en DEE 1.3 OM2.2

DEE 1.1, DEE 1.2 en DEE 1.3 OM2.3

Op dit moment hebben wij last van slagschaduw in de woning. Dit wordt veroorzaakt door OM 2.3. Dit is niet de eerste keer. Eerder echter gingen de molens netjes uit als er zon was. Er is de hele dag al volop zon, de molen moet dus 'weten' dat hij uit moet gaan. De windturbines OM 02 t/m 05. OM2.2 t/m Maken krakend en rare geluiden. Dat er een OM2.5 mitrailleur afgaat. We hebben weer overlast van slagschaduw. Vanaf 19.00u volgens mij van windturbine OM 05. Dit is behoorlijk irritant. hard zwiepend geluid wieken, hele hoge DEE 1.1, DEE pieptoon 1.2 en DEE 1.3 hard, zoevend en zwiepend geluid wieken, DEE 1.1, DEE hele hoge tonen. 1.2 en DEE 1.3 Hard zoevend met bijgeluid RH3.5 OM 2.2 maakt nu al weer zeker een half uur OM2.2 een afschuwelijk rubberachtig geluid. Hard zoevend met pieken Slagschaduw in de woonkamer (stroboscopisch effect) Snerpend en zoevend geluid

RH3.5 OM 2.7 RH 3.5

1-2-2024

AA en Hunze

geluid en slagschaduw

Wij wonen aan ......... en hebben al zo lang de windmolens er staan ontzettend veel last van ze maken lawaai je kan de ramen niet open hebben want dan kunnen we door het lawaai er niet van slapen ook als we buiten zijn horen we ze dat is erg irritant en we hebben ook last van de slagschaduw het is vreselijk al dat lawaai dat ze maken we hopen dat u iets met klachten gaat doen.

1-2-2024

AA en Hunze

slagschaduw

brief over slagschaduw

SUBJECTIEVE KLACHTEN EN COPINGSTRATEGIEËN VAN MENSEN MET GERAPPORTEERDE LAAGFREQUENT GELUIDSWAARNEMINGEN Samenvatting van de resultaten van de tweede publicatie

Lfg als omgevingsstressor De perceptie van laagfrequent geluid (Lfg), hetzij door het horen van een laag bijv. bromgeluid of door het voelen van bijv. trillingen, kan verschillende effecten hebben op personen. Terwijl sommige mensen er geen of weinig last van hebben, kunnen anderen er ernstig last van hebben en serieuze beperkingen in hun dagelijks leven ervaren. Dit laatste geldt naar schatting voor ongeveer 2% van de Nederlandse volwassen bevolking. Als we naar het onderzoek over dit onderwerp kijken, is er nog veel onbekend, vooral als het gaat om de ervaring van Lfg in de algemene bevolking (in plaats van onderzoek naar bijvoorbeeld specifieke beroepsgroepen). Om meer inzicht te krijgen in de ervaringen van mensen die Lfg waarnemen

in

hun

dagelijks

leven,

is

de

afdeling

Klinische

en

Ontwikkelingsneuropsychologie van de Rijksuniversiteit Groningen in 2018 een onafhankelijk onderzoek begonnen.

Recent onderzoek Na een eerste publicatie waarin de Lfg waarnemingen, Lfg-gerelateerde klachten, en de karakteristieken van mensen die Lfg waarnemen werden onderzocht, hebben we nu enkele specifieke klachten geanalyseerd en de manier waarop mensen hiermee omgaan. We hebben specifiek gekeken naar slaap, vermoeidheid, cognitie, depressieve klachten, en stress. Ons onderzoek wilde antwoord geven op de volgende onderzoeksvragen:

1

2

Welke klachten rapporteren personen

Wat voor copingstrategieën

met Lfg-waarnemingen en hoe ernstig

gebruiken mensen met

zijn deze klachten?

Lfg-waarnemingen?

Methodes van onderzoek Eindresultaten

Vragenlijsten: Alle deelnemers vullen uitgebreide vragenlijsten in over slaap,

vermoeidheid,

cognitie,

depressieve

klachten,

Naast het vergelijken van welke groep meer klachten

stress en coping (ongeveer 1 uur invultijd). Deze

heeft, hebben we ook het aantal

vragenlijsten zijn specifiek ontwikkeld, gevalideerd, en

individuen met bovengemiddelde

veelvuldig gebruikt om deze klachten in detail te meten.

klachten berekend.

Groepsvergelijkingen:

Subjectieve ervaringen:

Een grote groep van 420 Lfg waarnemers werd vergeleken

Wij hebben ons gericht op de subjectieve ervaringen van

met een grote groep van 410 Lfg niet-waarnemers. Beide

mensen die Lfg waarnemen. Vaak zijn er (nog) geen Lfg

groepen

en

metingen ter plaatse verricht of metingen kunnen geen Lfg-

opleidingsniveau. Dus, als we verschillen zien tussen de

bron aanwijzen. Maar mensen kunnen uiteraard nog steeds last

groepen,

hadden betekent

hetzelfde dat

dat

geslacht, de

Lfg

leeftijd

waarneming

hebben van Lfg ook als de bron niet kan worden vastgesteld.

waarschijnlijk de factor is die verantwoordelijk kan zijn

Daarom is het doel van dit onderzoek om Lfg ervaringen te

voor het verschil.

beschrijven, ook los van een succesvolle meting.

1

RESULTATEN WELKE KLACHTEN RAPPORTEREN PERSONEN MET LFG–WAARNEMINGEN EN HOE ERNSTIG ZIJN DEZE KLACHTEN?

Slaap Als we naar slaap kijken, zien we dat veel problemen

Goede slapers Slechte slapers

Goede slapers Slechte slapers

21%

45%

werden gerapporteerd door de Lfg-waarnemers. We classificeerden ongeveer 3 op de 4 mensen als slechte slapers. Verrassend genoeg rapporteerden ook niet Lfg-waarnemers veel slaapproblemen en de helft van

79%

de deelnemers in deze groep gaf aan slechte slapers

55%

te zijn. De gebieden die het meest beïnvloed leken te zijn bij Lfg-waarnemers waren de kwaliteit van slaap

Lfg-waarnemers

Lfg niet-waarnemers

en het functioneren overdag na slaap.

Vermoeidheid

Cognitie Ook als het gaat om het cognitief functioneren (d.w.z. geheugen, aandacht en executief functioneren (bijv. plannen en het houden van overzicht)) zagen we dat tot 76% van de Lfg-waarnemers boven gemiddeld

We

observeerden

dat

Lfg-waarnemers

meer

vermoeidheid ervaren dan mensen zonder Lfgwaarnemingen. Tot 58% van de Lfg-waarnemers gaf boven gemiddeld veel vermoeidheid aan ten opzichte

van

ongeveer

26%

van

de

niet-

waarnemers.

problemen ervaarden in vergelijking met 33% van de niet-waarnemers. De meeste problemen werden genoemd op het gebied van aandacht. Maar meer dan de helft van de Lfg-waarnemers rapporteerde ook boven gemiddelde problemen met het geheugen en executieve functies.

Depressieve symptomen We vonden dat Lfg-waarnemers meer depressieve symptomen rapporteerden dan niet-waarnemers. Vijf tot vijftien procent van de Lfg-waarnemers rapporteerden matig tot ernstige symptomen van

Stress

depressie ten opzichte van slechts 0 tot 1 procent van de niet-waarnemers. Hierbij moet wel worden

We stelden hogere stressniveaus vast bij Lfg-

opgemerkt dat niet-waarnemers met een diagnose

waarnemers in vergelijking met niet-waarnemers. In

van depressie niet mochten deelnemen.

totaal gaf 62-78% van de Lfg-waarnemers aan boven gemiddeld veel stress te ervaren ten opzichte van 30% van de niet-waarnemers. Hierbij gaven sommige Lfgwaarnemers aan vaker stressvolle evenementen te ervaren in het dagelijkse leven, terwijl andere Lfgwaarnemers aangaven stressvolle evenementen als meer intens te ervaren.

2

RESULTATEN WAT VOOR COPINGSTRATEGIEËN GEBRUIKEN MENSEN MET LFG-WAARNEMINGEN?

Omgaan met klachten Omdat het moeilijk kan zijn om Lfg te detecteren, te

Resultaten

erkennen of uit te schakelen, kan het belastend zijn om met Lfg in het dagelijks leven om te gaan. We

Over het algemeen zagen we dat zowel Lfg-

hebben daarom ook gekeken hoe de deelnemers aan

waarnemers

als

het onderzoek in het algemeen met problemen

vergelijkbare

combinatie

omgaan.

'actieve

copingstrategieën gebruiken. We vonden echter

probleemgerichte coping', waarbij men actief probeert

wel dat sommige Lfg-waarnemers veel meer

stressoren te vermijden of te verminderen, 2) 'steun

gebruik maakte van steun zoeken. Ook strategieën

zoeken', zoals hulp, advies of begrip zoeken, en 3)

zoals plannen maken en zelf afleiding worden iets

'vermijdingsgedrag', acties die erop gericht zijn te

meer gebruik door sommige Lfg-waarnemers.

We

keken

hierbij

naar

1)

niet-waarnemers van

een

dezelfde

ontsnappen aan of zich los te maken van de stressor en de gevolgen ervan.

VOORTZETTING VAN HET ONDERZOEKSPROJECT VAN DE RIJKSUNIVERSITEIT GRONINGEN.

Samenvatting In deze publicatie vonden we dat mensen die Lfg waarnemen op alle gebieden meer klachten hebben dan de deelnemers die Lfg niet waarnemen. Hoewel onze onderzoeksresultaten deels overeenkomen met wat eerdere studies hebben gevonden, geeft ons studie ook aan dat er veel verschillen zijn tussen Lfg-waarnemers en dat het type en de ernst van klachten individueel veel kan verschillen. Verder laten onze resultaten ook zien dat er nog veel behoefte is aan verder onderzoek om meer duidelijkheid te krijgen over bijvoorbeeld de relaties tussen klachten of naar het succes van copingstrategieën bij Lfg-klachten.

De

huidige

samenvatting

beschrijving van

de

is

een

publicatie

beknopte "Subjective

Na deze resultaten werken we nu aan de analyse van

ons

derde

complaints and coping strategies of individuals with

verschillende

reported

deelnemers

Low-Frequency

Noise

Perceptions",

onderzoek.

We

voerden waarbij

cognitieve

tests

uit,

verschillende

tests

gericht

op

geschreven in het Engels en gepubliceerd in het

aspecten van aandacht, geheugen en executieve

"Journal of Clinical Medicine". Het volledige artikel is

functies voltooiden. Zodra deze derde publicatie is

vrij toegankelijk en te downloaden hier onder:

afgerond, zal een soortgelijke samenvatting en link naar de resultaten worden gedeeld.

Het onderzoeksteam, Kristina Erdelyi, MSc., Dr. Anselm Fuermaier, Dr. Lara Tucha, Prof. dr. Oliver Tucha, Dr. Janneke Koerts

https://www.mdpi.com/2077-0383/13/4/935

Groningen, 27-02-2024

Journal of

Clinical Medicine Article

Subjective Complaints and Coping Strategies of Individuals with Reported Low-Frequency Noise Perceptions Kristina H. Erdelyi 1 , Anselm B. M. Fuermaier 1 , Lara Tucha 2 , Oliver Tucha 1,2,3 and Janneke Koerts 1, * 1

2 3

*

Department of Clinical and Developmental Neuropsychology, Faculty of Behavioral and Social Sciences, University of Groningen, 9712 TS Groningen, The Netherlands; k.h.erdelyi@rug.nl (K.H.E.) Department of Psychiatry and Psychotherapy, University Medical Center Rostock, 18147 Rostock, Germany Department of Psychology, National University of Ireland, W23 F2H6 Maynooth, Ireland Correspondence: janneke.koerts@rug.nl

Abstract: Background: Subjective everyday hindrances associated with low-frequency noise (LFN) can be high; however, there is still a lot unknown about experienced complaints. This study aims to investigate (1) subjective complaints and (2) coping strategies of individuals reporting everyday hindrances from LFN. Methods: Cognition, depressive symptoms, sleeping, fatigue, stress, and coping questionnaires were administered to participants sampled for their LFN complaints (LFN1 = 181), LFN complainants derived from a community sample (LFN2 = 239), and a comparison group without LFN complaints (CG = 410). Results: Individuals reporting LFN perceptions reported complaints in all domains and showed a higher proportion of above average symptom severity compared to the CG. Most complaints were reported by the LFN1 group, the least by the CG. However, on some sleeping, fatigue, and stress-related variables, a similar or even higher symptom severity was observed in the LFN2 group. Further, all groups used a similar combination of multiple coping strategies, although the LFN1 group scored higher on support seeking. Conclusions: There might be differences in the complaint severity between different LFN subgroups and future investigations of primary and secondary complaints are necessary.

Also, more research about the use and success of coping strategies for LFN-related hindrances are needed for clear conclusions. Citation: Erdelyi, K.H.; Fuermaier, A.B.M.; Tucha, L.; Tucha, O.; Koerts, J. Subjective Complaints and Coping

Keywords: low-frequency noise; LFN; complaints; cognition; depressive symptoms; sleep; fatigue; stress; coping

Strategies of Individuals with Reported Low-Frequency Noise Perceptions. J. Clin. Med. 2024, 13, 935. https://doi.org/10.3390/ jcm13040935 Academic Editor: Stéphane Bouchard Received: 23 December 2023 Revised: 26 January 2024 Accepted: 29 January 2024 Published: 6 February 2024

Copyright: © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

1. Introduction 1.1. Low-Frequency Noise (LFN) While the effects of noise pollution are widely researched and its various adverse effects are recognized [1–3], there is still a lot unknown about LFN. LFN is defined as noise at low frequencies between 20 and 100/125 Hz by the Dutch Institute for Public Health [4]. Sounds below 20 Hz are defined as infrasound [4]. However, definitions can vary and some definitions of LFN encompass wider frequency ranges (e.g., between 10 Hz and 200 Hz in [5]). The primary sources of LFN are man-made, such as traffic, ventilation, or household and industrial installations. The rapid growth of industrialization is also accompanied by a rising number of concerns and LFN-related complaints [4,6,7]. LFN is most commonly perceived by hearing a deep humming, rumbling, or engine-like sound, but bodily vibrations or other kinds of non-auditory perceptions are also reported [5,6,8]. LFN is only perceived consciously by a proportion of the general population; however, it is not yet clear how big this proportion is and why some individuals report LFN perceptions and others do not. Prevalence estimations for the proportion of the general population perceiving LFN in various studies range between 2% to up to 34% with an estimated pooled prevalence of 10.5% [9]. Moreover, it is not yet clear why some individuals seem to be more annoyed by LFN than others.

In terms of experienced annoyance, the Dutch

J. Clin. Med. 2024, 13, 935. https://doi.org/10.3390/jcm13040935

https://www.mdpi.com/journal/jcm

J. Clin. Med. 2024, 13, 935

2 of 31

Institute for Public Health estimates that 2% of the Dutch adult population experiences severe annoyance, and 8% experiences some annoyance from LFN [4]. Complaints reported in relation with LFN perceptions can be manifold and can have considerable effects on the daily functioning and health of those reporting LFN perceptions. They can encompass various physical (e.g., cardiovascular complaints, or nausea), psychological (e.g., annoyance, stress, sleeping problems), cognitive (e.g., concentration difficulties), or social (e.g., work incapacity, relationship problems) domains [5,6,8,10]. However, more systematic research has to be conducted on which complaints occur most frequently, on which complaints can be directly associated with LFN exposure, on influencing (non-acoustic) factors, and on possible primary or secondary complaints. Also, it is still unclear to what extent objectively measured LFN exposure aligns with subjectively measured LFN perceptions. Previous research has utilized these two concepts to different extents. The present study focuses on a systematic investigation of complaints in the cognitive and psychological domains in relation to subjective LFN perceptions. 1.2. Cognitive Complaints Reported in Relation to LFN Cognitive functions, including attention, memory, and executive functions, are necessary for activities of daily life.

They are also among the most commonly reported LFN-related complaints, especially concentration difficulties [5,6,8,10,11]. Difficulties can occur in so-called attention functions, such as the selection or awareness of specific stimuli while disregarding interruptive stimuli or the regulation of the intensity of awareness [12]. Subjective reports of concentration difficulties in surveys in relation to LFN ranged from 7.5 to 17% [13], over 43 to 44% [6], and up to 67% [8] of research participants. Still, research trying to objectify subjective attention difficulties shows incongruous results. While some studies suggested worse attention performance during LFN exposure [10,14–16], other studies observed better or similar performance during LFN exposure [17–19]. When looking at memory, i.e., the ability to encode, retain, retrieve, and reactivate information [20], there is to our knowledge hardly any research aiming to explore subjective or objectively measured memory complaints in relation to LFN. In a treatment study [21], on average participants with reported LFN perceptions stated before treatment that the noise leads them to forget things some of the time (answer ‘2’ on a 5-point scale from ‘0 = not at all’ to ‘4 = most of the time’).

Considering objective memory measurements, two studies suggested worse memory functioning [14,19], of which one has also found some memory variables with no relation between LFN exposure and memory [19]. A third group of cognitive functions are executive functions, a group of complex, higher-order functions especially relevant for cognitively demanding tasks. These metacognitive processes generate, synchronize, coordinate, or withhold activity and involve processes like planning, working memory, the inhibition of responses, or the ability to shift quickly between tasks [22,23]. There is to our knowledge no research specifically aiming at investigating subjective executive functions in relation to LFN. Studies using objective performance tests focused mainly on inhibition and working memory. Again, some studies showed worse performance [15,16,24,25], while others suggested better [17,18,26], or no differences in performance [10,27] related to LFN exposure. Notably, a recent meta-analysis suggests that a negative impact of LFN exposure on cognition is observed only on higherorder cognitive functions, such as logical reasoning, mathematical calculation, and data processing, compared to basic functions in the areas of attention, memory, and executive functions [28].

In conclusion, there is still a lot unknown about the effects of LFN on cognition, especially in terms of memory and executive functions. Evidence of subjective complaints is currently stronger compared to objectively measured cognitive functioning, which does not allow for firm conclusions, yet [29]. Subjective complaints have mainly been investigated in terms of attention functions, although these investigations were often conducted using single items or open questions.

J. Clin. Med. 2024, 13, 935

3 of 31

1.3. Psychological Complaints Reported in Relation to LFN 1.3.1. Depression The impact of mental disorders on quality of life and years lived with disability can be high. Depression currently ranks as one of the most common and most impactful disorders [30]. Although many of the reported complaints from LFN are also complaints associated with depression (such as depressed mood, sleeping problems, fatigue, concentration difficulties), research investigating the association between LFN and depression is scarce and provides conflicting results. Indications for increased depressive symptoms were found in a questionnaire study, which observed that 30% of LFN complainants showed moderately severe and severe depression symptom severity compared to 5% of a matched comparison group living in the same building block [31]. Further, in a treatment study, 53% of the participants reported that LFN made them feel depressed before treatment [32]. In a follow-up study [21], participants with reported LFN perceptions stated on average that the noise made them feel depressed some of the time (answer ‘2’ on a 5-point scale from ‘0 = not at all’ to ‘4 = most of the time’) before treatment. However, other studies provide conflicting results. Road traffic noise exposure in the low-frequency ranges was not found to correlate with a diagnosis of depression [33].

Also, research on wind turbine noise, a possible source of LFN, did not find correlations between depressive symptoms and noise exposure [34]. Finally, similar proportions of participants who reported experiencing depression living in areas of high (19%) and low (18%) assumed LFN exposure were observed in [35]. In conclusion, evidence of subjective reports of depression or depressed mood in association with LFN seems to be stronger compared to research trying to link reports of depression to LFN exposure. However, the research using subjective LFN reports has to be reviewed carefully due to partly unstandardized measures or small sample sizes. With the high impact of depression on everyday life, a standardized investigation of depressive symptoms in individuals reporting to be affected by LFN in their daily life is necessary. 1.3.2. Sleep Among the most commonly reported and also the longest and most extensively studied complaints are sleeping problems and disturbed rest. Various case, pilot, field, survey, and experimental studies, as well as reviews, investigated the role of LFN or of noise with LFN components on sleep, e.g., [4,9,11,21,32,36,37]. In terms of subjective complaints, the proportion of individuals reporting sleeping problems related to LFN in surveys ranged from 13 to 22% [13], over 54 to 77% [8], 82 to 89% [31], and up to 83% [6].

Further, significantly higher sleep disturbances, difficulties falling asleep, and tension in the morning were reported from individuals annoyed by LFN compared to individuals not annoyed by LFN [13]. Research utilizing both subjective questionnaires and objective measures of sleep shows contradicting findings. From two similar sleep laboratory studies with nocturnal LFN exposure and cortisol measurements [38,39], only one found altered, flat cortisol levels 30 min after awakening [38]. This was related to lower sleep quality and negative mood. Further, this research observed longer reported times to fall asleep [38], which was also not found in the follow-up study [39]. In this latter study [39], higher tiredness in the morning, lower social orientation, and negatively affected mood were observed in relation to LFN [39], but no change in the number of nocturnal sleep disruptions or morning tension was observed. In a different field study with cortisol measurements, increased night cortisol levels were observed in the first half of the night in children exposed to traffic noise with LFN components [14], which could be associated with decreased sleep quality. Further, higher noise levels in this study were related to more subjective sleeping problems.

Contradictory findings were also observed in a study using actigraphs [40], where participants reported worse sleep quality during LFN exposure; however, objective measurements indicated better sleep. Finally, an experimental EEG study did not find significant sleep differences between nights with and without LFN exposure [41].

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In conclusion, evidence of subjective sleeping difficulties is currently stronger compared to objectively measured sleep disturbances. Further, studies differ regarding which aspects of sleep seem to be affected. Difficulties might thus occur in only some areas of sleep or might differ between subgroups and situations. Notably, previous studies had methodological limitations, such as single-item questions, small effect sizes, unclear noise dose descriptions, or the use of specific subgroups. Considering that good undisturbed sleep is necessary for maintaining good health and daily performance [42], a deeper understanding of sleep and its specific subcomponents in individuals with daily life LFN perceptions is crucial. 1.3.3. Fatigue Although LFN exposure has been commonly associated with sleeping problems, it has also been suggested to induce short periods of sleep [5]. Especially in work conditions, LFN was associated with increased drowsiness, short-term tiredness, and (mental) fatigue ([43,44], see overviews in [5,45]). Further indications for an association between LFN and fatigue complaints can be derived from studies with LFN exposure during mental performance tasks [24,27,46]. Specifically, higher reported mental fatigue was observed with higher LFN levels and with rising cognitive workloads [24].

Further, significant correlations between self-rated tiredness and annoyance due to LFN, impaired working capacity, and response times were found [27]. Notably, higher rated tiredness during a long series of performance tasks was found in relation to both LFN and also non-LFN ventilation noise [46]. Further, sleep laboratory studies [5,38,39] give first indications for an association between LFN and fatigue. A series of laboratory EEG studies by Landström and colleagues (see [5] for an overview) associated ventilation noise with LFN tones with greater fatigue. Also, more tiredness after nights of LFN exposure was observed by [38,39]; however, this only reached significance in one of those studies. While much of the previous research focused on short-term fatigue, little research has considered long-term fatigue reflecting a status of tiredness and diminished functioning [47] in the daily living of affected individuals. Two surveys suggested proportions of individuals reporting fatigue in relation to LFN of 56% [6] and 59% [31]. However, in another survey [8], fatigue did not belong to the five most commonly reported complaints and was included as one of many secondary effects in the ‘other’ category encompassing 39% of the participants. Finally, individuals annoyed by LFN showed significantly higher rated levels of fatigue compared to non-annoyed individuals [13].

Overall, the current findings give indications, but do not allow for clear conclusions on the relation between LFN and everyday fatigue. This might partly be due to the difficulty with defining fatigue and distinguishing it from symptoms of tiredness or drowsiness. Considering the importance of fatigue on daily performance, further research on the frequency, severity, and impact of long-term fatigue in daily life is crucial in individuals with daily LFN perceptions. 1.3.4. Stress Constant LFN has been classified as a background stressor and has been associated with various stress-related complaints, as also described in the previous paragraphs [5,48]. Considering self-reported stress, a proportion of 57% of respondents reported feeling stressed in relation to LFN in [6], and in a small-scale treatment study, 56% of the participants reported feeling distressed due to the noise before treatment [32]. Further, in a follow-up treatment study [21], 31% of the participants were classified as highly stressed, and 41% were classified as moderately stressed before treatment. Contrarily, stress was not among the five most common complaints in the survey by Moller and Lydolf [8], and stress was included in the ‘other’ category with other complaints (encompassing 39% of the participants).

Both self-reported stress and stress measured by cortisol levels, a hormone that can be disrupted by stressful events and which shows elevated levels during short-term stress,

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were included in a task–performance study by [49]. Participants were categorized as having high or low sensitivity to LFN and general noise, and were exposed to LFN and non-LFN. The results suggested that the LFN-sensitive participants reported the highest stress levels during all cognitive tasks and all noise conditions. Also, higher stress levels after LFN exposure were related to participants not feeling in control, regardless of their sensitivity. Further, a small but significant cortisol elevation level during LFN exposure was observed for individuals who were sensitive to noise in general, but not specifically in LFN-sensitive individuals. Surprisingly, these measured cortisol levels did not clearly correlate with the subjective ratings of stress. Another surprising finding was that non-LFN was in general reported to be more stressful than LFN by all participants. These findings suggest that the relationship between LFN exposure, noise sensitivity, and reported short-term stress is not clear yet, and indicate a discrepancy between subjective and objective stress measures. Since the previous results of subjective stress related to LFN are partly based on single-item questions, and since objective measures have focused on short-term stress, a thorough investigation of everyday stress in individuals with daily LFN perceptions is needed.

Moreover, other factors, such as sleep, seem to be influential on experienced stress and need to be considered (as shown in LFN nonspecific research [50] or as indicated by altered cortisol levels observed in the previously described sleep studies [14,38]). 1.4. Coping Coping is a multidimensional term with various interpretations. In social and behavioral sciences, coping refers to the cognitive and behavioral strategies used to manage demanding or stressful situations [51]. Such strategies can be subdivided into different categories. Two major ones are ‘problem-focused coping’, strategies focusing on changing the source of stress, and ‘emotion-focused coping’, strategies addressing the reduction of one’s emotional distress [52]. There are also further theoretical frameworks, such as ‘active problem-oriented coping’, which involve active techniques to avoid or reduce stressors, ‘support seeking’, which involve seeking assistance, advice, or understanding, and ‘avoidance behavior’, which involve actions aiming to escape or disengage with the stressor and its effects [52]. Determining which coping strategies prove to be useful does not only depend on the use of specific strategies, but can also change with the extent of its use or the context. The same coping strategy can be useful in one situation, but not in another situation.

An investigation of the application and success of coping strategies is especially relevant for LFN-associated complaints. First, LFN presents with properties that can make coping more difficult compared to general environmental noise. For example, the source of LFN can often not be found and individuals can have difficulties localizing or defining their LFN perception. This can lead to difficulties with identifying an external stressor. Second, compared to general environmental noise, LFN is usually more invasive, and insulation from the noise is less effective. This can make it complicated to resolve, reduce, or escape the LFN. While LFN seems to be reported as even more annoying than regular noise, others often do not share the same perceptions, and receiving (social) support can thus be challenging for affected individuals. All these properties can make it difficult to find successful coping strategies for the complainants and thus LFN can become a long-term stressor [4,5,36,53]. Notably, environmental noise research suggests that noise exposure can only partly explain noise reactions (such as annoyance). Other non-acoustical factors including personal, contextual, and noise management-related factors also play a highly relevant role in noise reactions and health effects [54–56].

Relevant factors include noise sensitivity, demographic factors, situational and personal circumstances, perceived control, and also coping mechanisms [5,56–59]. Despite the numerous concerns about LFN-related complaints, to our knowledge, coping, as earlier defined, has not been the main focus of previous research. However, studies assessing the ways in which affected individuals react to the noise and treatment studies give some first indications. Specifically, it seems that the majority of individuals

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reporting LFN perceptions try numerous actions to reduce nuisance, thereby often focusing on the external termination of the noise (e.g., using earplugs, masking the sound, switching off suspected sources, or changing or adapting their living location). However, these actions were regularly reported as unsuccessful in reducing nuisance [6,8,60]. Thus, personal or internally focused actions could be promising for reducing LFN-related nuisances. Such actions could be distraction [60] or strategies focusing on living with the sound and managing the experienced hindrances. In a pilot study, the use of electronically emitted masking sounds was effective at reducing complaint severity for most LFN complainants [60]. The authors concluded that this reduction partly stems from participants ‘learning to live with the sound’, and hypothesized multiple underlying mechanisms for the masking effect, including psychological distraction. Further, four treatment studies investigated the success of treatment procedures to reduce LFN-related complaints.

Interventions that seemed to improve the quality of life and quality of coping included the (self-help) coping techniques of different relaxation therapies, [32,61], Neural Linguistic Programming/Visual-Kinaesthetic Dissociation [32], imaginal exposure [32], anchoring [32], cognitive behavioral therapy that focuses, amongst other things, on healthy thinking about sounds [21], desensitization for noise-related stress [21], and sound therapy [61]. Interventions were partly applied on-site and partly at home online or via electronic instructions. Evaluations differed individually regarding what techniques were especially helpful, and interventions were beneficial for some, but not all participants. Interestingly, two studies noted that participants had difficulties with coping, avoided noisy situations, missed out on things they like, and worried about the noise, their future coping abilities, and about making other people feel uncomfortable [21,32]. Notably, the proportion of individuals worried about the noise increased after the therapy sessions (from 67% to 78%) in one study [32]. Therefore, a high need for personal coping strategies targeting, amongst other things, the affected individual’s need to regain control over their personal environments, was recommended.

In summary, current research indicates that affected individuals might commonly apply active problem-oriented strategies, especially focusing on external noise sources with mixed success rates. However, with no clearly identifiable external source or nonescapable LFN perceptions, emotion-focused strategies might be promising in reducing LFN-related hindrances for some individuals. However, the results of the treatment studies have to be viewed with care due to partly small sample sizes, the simultaneous use of multiple interventions that limit the identification of their individual effects, and the use of measures not specifically validated for assessing coping mechanisms. While support seeking strategies have not been specifically investigated in previous research, they have been named as a promising coping component for LFN complaints [32]. Thus, considering that the properties of LFN make successful coping especially difficult, and that there is a large variety of complaints reported by individuals with LFN perceptions, more insight into coping mechanisms is crucial. 1.5. Research Aims and Questions There are currently indications that daily life LFN perceptions could be associated with complaints in the domains of cognition, depression, sleep, fatigue, and stress. However, previous research presents mixed results and is limited.

Therefore, this study aims to, first, investigate those subjective complaints, including complaints associated with cognitive functioning, such as attention, memory, and executive function, depressive symptom severity, different aspects of sleeping difficulties, fatigue symptom severity, and daily stress, using standardized and validated measurement instruments. Furthermore, there is a high need for investigating the coping strategies used in dealing with those complaints. Therefore, the second aim of this study is to provide a multi-faceted investigation of different coping mechanisms applied by LFN complainants. For this, an observational, cross-sectional questionnaire study was conducted comparing complaints and coping strategies between a sample of individuals experiencing LFN-related complaints in their daily life and individuals with no LFN-related complaints. This research is the first, to our

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knowledge, to integrate all those complaints in one study and to provide cross-comparisons between measures in contrast to previous unidimensional research including only one/a few of those domains. This also allows for a comparison between the frequency and extent of multiple complaint domains. Further, this research makes use of large naturalistic groups and an extensive battery of validated measures with big normative groups for better clinical interpretation. Eventually, the following research questions are proposed: 1. 2. 3. 4.

What types and severity of complaints do individuals with LFN perceptions report? Do individuals with LFN perceptions report more complaints compared to individuals with no LFN perceptions? What proportion of individuals with and without LFN perceptions report complaints in a presumably clinically relevant range? What kind of coping mechanisms do individuals with LFN perceptions use compared to individuals with no LFN perceptions?

2. Methods 2.1. Procedure and Participants LFN participants specifically sampled for LFN-related experiences (LFN1 group) were recruited via an online information letter that was distributed by the Stichting Laagfrequentgeluid (www.laagfrequentgeluid.nl, accessed on 11 December 2023), a Dutch volunteer organization with the goal to inform about LFN and to support affected individuals. Interested participants indicated their intention to participate via email. In order to participate, individuals had to be at least 18 years old, have good command of Dutch, and have current LFN perceptions and LFN-related difficulties in their daily life. Having current LFN perceptions was based on participants’ subjective reports and did not depend on a successful sound measurement. Participants received a definition of LFN formulated by the Dutch Institute for Public Health and Environment [4] in an information letter. Further, LFN-related complaints were assessed, first, by asking how often participants experience LFN-related complaints on a 5-point rating scale from 0 ‘never’ to 4 ‘continuously’. Second, participants had to rate the extent of LFN-related hindrances in their daily life between 1 ‘not at all’ and 10 ‘very much’.

After signing up for the research, participants received a paper–pencil version of a battery of questionnaires together with an informed consent form and a form to sign up for a further LFN study. No financial reward was provided. A response rate of 65% was observed with 306 initially interested participants and 200 received questionnaires that arrived between June 2018 and February 2021. Usually, no reason was provided for not returning questionnaires. However, some initially interested participants provided reasons, including the hope for an on-site sound measurement instead of completing questionnaires, or time constraints. From those 200 questionnaires, seventeen participants were excluded for not fulfilling the inclusion and exclusion criteria, and two for having too many missing values (less than 15% filled out). Furthermore, six individuals were not retained in the LFN1 group since they reported LFN complaints to occur ‘never’, or only ‘sometimes’, in addition to a very low extent of hindrance (reported as a one or two). One person was excluded for not providing an answer to these questions. Finally, participants with a significant self-reported psychiatric or neurological disorder (e.g., schizophrenia or epilepsy) that could have confounding effects on sound perceptions or LFN-related psychological and cognitive functioning were excluded (n = 5).

Individuals with psychiatric (n = 32, 18%) or neurological disorders (n = 6, 3%) with assumed low confounding effects on the outcome variables were not excluded (e.g., depression). Individuals with a diagnosis of tinnitus (n = 37, 20%) could participate in the research, since LFN perceptions and tinnitus can be comorbid, and since it is difficult to separate tinnitus patients from LFN-perceiving individuals [5]. Eventually, the final LFN1 group consisted of 179 individuals living in The Netherlands (99%) and two in Belgium (1%). The sex, age, educational level, and marital status of the LFN1 and all comparison groups, as well as the frequency of complaints and extent of hindrances, are depicted in Table 1. Further information about occupational status, living situation, and experienced LFN perceptions can be found in Erdélyi et al. [62].

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Table 1. Demographic characteristics of the LFN1, LFN2, and CG groups. LFN1 (n = 181)

LFN2-SA (n = 131)

LFN2-SB (n = 108)

CG-SA (n = 229)

CG-SB (n = 239)

Females (%) Education (%) Low a Middle High Marital status (%) Married b Unmarried c No partner Partner, living together Partner, not living together Divorced Widowed d

124 (68.5)

93 (71.0)

71 (65.7)

144 (62.9)

158 (66.1)

14 (7.7) 61 (33.7) 106 (58.6)

1 (0.8) 56 (42.7) 74 (56.5)

0 (0) 47 (43.5) 61 (56.5)

3 (1.3) 88 (38.4) 138 (60.3)

2 (0.8) 80 (33.5) 157 (65.7)

87 (48.1) 64 (35.4) 34 (18.8) 26 (14.4) 4 (2.2) 22 (12.2) 6 (3.3)

80 (61.1) 31 (23.7) 13 (9.9) 15 (11.5) 3 (2.3) 16 (12.2) 4 (3.1)

48 (44.4) 35 (32.4) 15 (13.9) 16 (14.8) 4 (3.7) 13 (12.0) 12 (11.1)

124 (54.1) 54 (23.6) 24 (10.5) 22 (9.6) 8 (3.5) 28 (12.2) 23 (10.0)

142 (59.4) 55 (23.0) 32 (13.4) 20 (8.4) 3 (1.3) 24 (10.0) 17 (7.1)

Age in years e

57.4 ± 11.3 (25–87)

54.5 ± 13.5 (18–86)

Mean ± SD (Range) 56.6 ± 13.0 (24–90)

62.7 ± 11.8 (26–89)

62.0 ± 11.5 (25–85)

3.2 ± 0.8 (1–4) 7.3 ± 2.3 (1–10)

1.6 ± 0.9 (0–4) 4.8 ± 1.8 (1–10)

1.7 ± 0.9 (0–4) 4.8 ± 1.8 (1–10)

0.5 ± 0.5 (0–1) 1.3 ± 0.5 (1–2)

0.4 ± 0.5 (0–1) 1.3 ± 0.5 (1–2)

Sex

Frequency of LFN complaints Extent of LFN hindrance

Note: LFN1 = LFN group recruited via LFN foundation, LFN2 = LFN group recruited via online panel, SA = subsample A filling out questionnaires regarding cognition and depressive symptoms, SB = subsample B filling out questionnaires regarding sleep, fatigue, stress, and coping, CG = Comparison group recruited via online panel, a significant group difference between the LFN1 and all other groups based on Chi-square tests. b Includes marriage and registered partnership. Significant group differences between LFN1 and LFN2-SA, LFN1 and CG-SB, LFN2-SA and LFN2-SB, and LFN2-SB and CG-SB based on Chi-square tests. c Significant group difference between LFN1 and LFN2-SA, LFN1 and CG-SA, and LFN1 and CG-SB based on Chi-square tests. d Significant group difference between LFN1 and LFN2-SB, LFN1 and CG-SA, LFN2-SA and LFN2-SB, and LFN2-SA and CG-SA based on Chi-square tests. e Significant difference between LFN1 and CG-SA, LFN1 and CG-SB, LFN2-SA and CG-SA, and LFN2-SB and CG-SB based on Mann–Whitney U tests.

A comparison group was recruited through “PanelInzicht”, a Dutch online research panel gathering research participants from the general public for financial compensation. These participants recruited via ‘PanelInzicht’ consisted of Dutch adults that have good command of Dutch and with similar demographic distributions regarding sex, age categories, and educational categories to the LFN1 group. These categorizations are described in detail in Erdélyi et al., 2023 [62]. Individuals with any self-reported psychiatric or neurological disorder or a diagnosis of tinnitus were not eligible for participation and three participants were excluded due to presumably invalid answer patterns. Since a large number of individuals in this group also reported LFN experiences, this sample was subsequently divided into a group of individuals with LFN-related complaints (LFN2 group) and a comparison group (CG) with (almost) no LFN-related complaints. For this division, the frequency of LFN-related complaints and the extent of their hindrances in daily life were utilized after participants received a definition of LFN. Individuals reporting complaints ‘regularly’, ‘often’, or ‘continuously’ and/or individuals reporting the extent of hindrances as a score of three or higher formed the LFN2 group. Thus, this LFN group has not been sampled specifically for their LFN complaints.

Participants that reported complaints to occur ‘never’ or ‘sometimes’ and also reported the extent of hindrances in their daily life as a score of one or two, were retained as the comparison group (CG). Twelve participants were excluded, since they did not provide an answer to whether they experience LFN-related complaints or hindrances. The final LFN2 group consisted of 239 participants living in The Netherlands (97%) and eight in Belgium (3%). The final CG consisted of 468 participants living in The Netherlands

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(98.5%), six in Belgium (1.3%), and one in Ireland (0.2%). Notably though, the LFN1 group showed a significantly higher frequency of complaints with a large effect size (z = −13.87, p = <0.001, r = −0.68) compared to the LFN2 group (Mdn LFN1 = ‘often’, LFN2 = ‘sometimes’), and a significantly higher extent of hindrance with a large effect size (z = −11.17, p = <0.001, r = −0.55) compared to the LFN2 group (Mdn LFN1 = 8, LFN2 = 4). Because the full questionnaire was too extensive for a regular study at the research panel (about 90 min fill-out time), two subsamples of similar demographic characteristics had to be obtained. Subsample A (SA) filled out the first half of the questionnaire battery (including measures of cognitive functioning and depressive symptoms), and subsample B (SB) filled out the second half (including measures of sleep, fatigue, stress, and coping). This led to the following samples: First, a LFN group that was specifically sampled for their LFN-related complaints (LFN1 = 181). Second, a LFN group that was not specifically sampled for their LFN-related complaints (LFN2 = 239), which was subdivided into LFNSA = 131 and LFN-SB = 108 based on the individuals filling out the first and the second half of the questionnaire.

Third, a comparison group with individuals with no LFN-related complaints (CG = 468), which was subdivided into CG-SA = 229 and CG-SB = 239 based on the individuals filling out the first and second half of the questionnaire. Due to exclusions and the division into a LFN2 group and CG, the distribution of some demographic characteristics differed significantly (Table 1). Specifically, the LFN1 group presented with significantly more low educated individuals compared to all other groups. Further, the LFN1 and LFN2-SB groups presented with significantly less married individuals compared to most other groups, and the LFN2-SB and CG-SA groups presented with significantly more widowed individuals compared to most other groups. Finally, the comparison groups were significantly older than all other groups. For more details, please refer to Tables S1 and S2. All of those significant differences were, however, of a small effect size (based on Cramer’s V and Cohen’s r, see Tables S1 and S2). Only one difference approached a medium effect size (age between the LFN2-SA and CG-SA groups). The potential influence of age, education, and marital status on the outcome variables was investigated. A correlational analysis between age and all outcome variables showed correlations of small size and most correlations demonstrated explained variances (based on R2 ) between less than 1% and 4%.

The effect of low education level on all outcome variables, as investigated with Mann–Whitney U tests, only showed significant differences on two variables measuring stress and coping with small effect sizes. Finally, the effect of marital status (i.e., being married, unmarried, or widowed) was investigated on all outcome variables with Mann– Whitney U tests. Although significant differences were observed between all three marital statuses on at least one variable for the domains of cognition, depressive symptoms, sleep, fatigue, stress, and coping, all differences were of a small effect size. In conclusion, the effect of the observed demographic differences between the groups was assumed to be negligible. Further, the main reason for recruiting similar comparison groups was that LFN complainants in various survey studies [5,6,8] and in our LFN1 group present with older, more female, and more highly educated individuals compared to the general population (i.e., Dutch adult population presenting with an average of 50 years, 51% females, 24% low, 30% middle, and 28% high educated individuals; see [62]). Thus, our comparison group still clearly differs from the demographic characteristics of the general population and resembles the LFN1 group. Accordingly, the five groups were retained for further analysis.

This study is embedded in a large-scale LFN research project at the University of Groningen. Ethical approval for the research project was obtained from the Ethical Committee of Psychology (ECP) affiliated with the University of Groningen, The Netherlands (Registry nr. 17255, PSY-1819-S-0165, PSY-2122-S-004). 2.2. Materials This study is part of a larger research project and investigates cognition, depressive symptoms, sleep, fatigue, stress, and coping. Only these self-report questionnaires are de-

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scribed here. Results of other parts of the research project are published in Erdélyi et al. [62]. Questionnaires were chosen if they were proven to be clinically sensitive at detecting complaints and if they were psychometrically studied and validated. The LFN1 group completed all questionnaires. The LFN2-SA and CG-SA groups filled out the questionnaires measuring cognition and depressive symptoms and the LFN2-SB and CG-SB groups completed the questionnaires measuring sleep, fatigue, stress, and coping. Cognitive functioning was first measured with the 35-item Questionnaire for Complaints of Cognitive Disturbances (FLei) [63]. It measures perceived mental ability where participants provide the frequency of everyday difficulties in the past six months from 0 ‘never’ to 4 ‘very often’. The FLei provides three subscales measuring attention, memory, and executive functioning with 10 items each, and a mental performance sum score consisting of the sum of those scales. The remaining five items focus on visual neglect and will not be taken into account. The FLei scales show high internal consistency (Cronbach’s alphas α ≥ 0.91 [63]). Further, the 75-item Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) [64] was used, where participants rated the frequency of behaviors requiring executive functions in the past month from 1 ‘never’ to 3 ‘often’.

The BRIEF-A provides a summary score between 70 and 210 (Global Executive Composite, GEC), which consists of two indexes. The first one, the Behavioral-Regulation Index (BRI, score between 30 and 90) measures the ability to regulate behavior and emotions appropriately. The second one, the Metacognition Index (MI, score between 40 and 120) measures the ability to solve problems through planning and organization using active working memory. The Dutch BRIEF-A sum score and indexes show high internal consistency (α ≥ 0.92 [65]). A Dutch adult normative group (n = 1600, age 18–65 years) was provided by the questionnaire developers and was used for the computation of percentile scores. Additionally, the BRIEFA entails three validity scales that indicate, first, unusual or possible noncredible response patterns of negative answers (Negativity), second, the extent to which participants give atypical answers (Infrequency), and third, the extent to which participants give inconsistent answers to similar statements (Inconsistency). Depressive symptoms were assessed with the 21-item Beck Depression Inventory (BDIII) [66]. Participants rate the severity of 21 depressive symptoms in the past 2 weeks with an item score of 0 representing the absence of a symptom or no emotional/behavioral change and an item score of 3 representing a high severity of a symptom or emotional/behavioral change.

The Dutch BDI-II provides a sum score, which shows good to excellent internal consistencies in different groups (0.88 ≤ α ≥ 0.92 [67]). According to the manual, individuals scoring between 20 and 28 are considered to show ´moderate´ depressive symptom severity, and individuals scoring 29 or higher to show ´severe´ depressive symptom severity [67]. Sleep was assessed with the 19-item Pittsburgh Sleep Quality Index (PSQI) [68], which measures sleep quality and sleep disturbances in the past month. Participants indicate the time they went to bed and got up in the morning, the number of minutes it took to fall asleep, the hours actually slept, and further rate sleep problems on a scale from 0 to 3 with higher scores indicating more sleep problems. The PSQI provides a global sum score that consists of the seven component scores of sleep quality, sleep latency, sleep duration, habitual sleep efficiency, use of sleeping medication, sleep disturbances, and daytime dysfunction. The PSQI shows good overall internal consistency (α ≥ 0.83); however, the individual coefficients range between 0.35 and 0.76 [68]. The PSQI considers individuals with a global score of ≥5 as bad sleepers.

The severity of fatigue was assessed with the 9-item Fatigue Severity Scale (FSS) [69], which measures the severity of fatigue symptoms on a 7-point Likert scale from 1 ‘totally disagree’ to 7 ‘completely agree’. The FSS provides one sum score, which shows a good test–retest variability of 0.76 in the Dutch version [70]. The cut-off average score of ≥4 was used as an indication of high fatigue. Daily stress was assessed with the Dutch 114-item Alledaagse Problemen Lijst (Everyday Problems List, APLN) [71], which measures the frequency and intensity of daily

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and chronic stressors in the past two months. Participants state whether they had to deal with a daily stressor (yes or no) and if yes, rate the effect of the stressor on their feelings from 0 ’not bad at all’ to 3 ‘quite bad’. The APLN provides three scales, including a frequency score (FREQ) representing the sum of all chosen stressors, an intensity score (INT) representing the average intensity of all selected stressors, and finally a total sum score (TOT) representing the sum of all chosen items with their intensity. These three scores can be computed from all 114 items, and they can also be computed for a selection of items that refer to events that are dependent on the functioning of the person (DEP, 28 items) and a selection of items that refer to events that are not dependent on the functioning of the person (INDEP, 21 items). This leads to a total of 9 APLN scores. The TOT, FREQ, and INT scores present with good test–retest reliability (0.85, 0.87, and 0.76, respectively) [71]. A Dutch norm group (n = 1106) was provided by the questionnaire developers, categorizing percentile scores into ‘very low’, ‘low’, ’normal’, ‘high’, and ‘very high’ categories. Coping was assessed with the 32-item COPE-Easy questionnaire [72], which measures strategies to cope with stress and difficulties.

Participants rate the applicability of strategies from 1 ‘not applicable to me at all’ to 4 ‘very much applicable to me’. The COPE-Easy consists of three dimensions. The first, active problem-oriented coping (APOC), includes the subscales of active coping, suppression of competing activities, planning, positive reframing, and restraint. The second, support seeking coping (SSC), consists of the subscales of instrumental support, focus on venting emotions, and use of emotional support. The third, avoidance behavior (AB), consists of the subscales of self-distraction, denial, and behavioral disengagement. The four coping strategies of religion, humor, acceptance, and substance use are not allocated to any dimension. The dimensions and single strategies of the COPE-Easy show acceptable to good reliability [72]. Further, five of these strategies can be viewed as facets of problem-focused coping (active coping, suppression of competing activities, planning, restraint, and instrumental support) and another five strategies as aspects of emotion-focused coping (positive reframing, use of emotional support, denial, religion, and acceptance). Three strategies were rated as less useful by the questionnaire developers (venting on emotions, self-distraction, and behavioral disengagement). 2.3. Statistical Analysis All statistical analyses were computed with SPSS version 28.