Lakhasly

jp)Association of Sleep Quality and Free Time Leisure Activities inJapanese and British Civil ServantsAli NASERMOADDELI1, Michikazu SEKINE1, Meena KUMARI2, Tarani CHANDOLA2,Michael MARMOT2 and Sadanobu KAGAMIMORI11Department of Welfare Promotion and Epidemiology, Toyama Medical and Pharmaceutical University, Japan and2International Centre for Health and Society, Department of Epidemiology and Public Health, University CollegeLondon, U. K.Abstract: Association of Sleep Quality and FreeTime Leisure Activities in Japanese and British CivilServants: Ali NASERMOADDELI, et al. Department ofWelfare Promotion and Epidemiology, ToyamaMedical and Pharmaceutical University—Sleepdisturbance as a pervasive health problem can directlyaffect the physical and psychological well-being ofindividuals. Factors that positively relate to sleep qualitycan therefore improve healthy functioning. Weexamined whether leisure time activities are associatedwith sleep quality in two culturally different samples ofcivil servants. In this cross-sectional study weevaluated 1,682 Japanese, in Toyama prefecture (T)city, and 6,914 British civil servants from the WhitehallII study undertaken in London. The Japanese versionof Pittsburgh sleep quality index (PSQI-J) was used inT city and Jenkins’ sleep problem scale was used inthe Whitehall II study. Setting a validated cut-off pointof 5.5 for the PSQI-J global score and the upper tertilepoint for the Jenkins’ sleep problem scale, weconducted logistic regression analysis to assess theassociation between leisure time activities and sleepquality. In both populations, those who participated involuntary activities in clubs or organizations weresignificantly less likely to have poor sleep quality withOdds ratios (OR) and 95% confidence intervals(95%CI) of 0.73 (95%CI; 0.56–0.97) and 0.85 (95%CI;0.76–0.95) in Japanese and British civil servants,respectively. Similar findings were apparent for visitingfriends and relatives (ORs 0.60 (95%CI; 0.46–0.80) and0.71 (95%CI; 0.56–0.90) for Japanese and Britishsubjects, respectively). Our findings suggest thatengagement in social leisure activities is associatedwith better sleep quality and consequently bettergeneral well-being.(J Occup Health 2005; 47: 384–390)Key words:Sleep quality, Leisure time activities,Whitehall II study, JapanInvestigations into the determinants of poor sleepquality are important for two major reasons. First,complaints about sleep quality are common and second,poor sleep quality can be an important symptom of manymedical disorders. Sleep problems usually take one ormore of the following forms: delay of sleep onset,difficulty staying asleep, or awakening too early.Inadequate quantity and quality of sleep have long beenobserved to be concomitants of a variety of clinicalmedical and psychiatric conditions. Poor sleep isprospectively associated with an increased risk ofmyocardial infarction, particularly when combined withincreasing resting heart rate1). Poor sleep is alsoprospectively related to fatal accidents at work andaccident risk is considerably increased in relation toirregular work hours2). Good sleep quality has beenassociated with better physical health3, 4) and greaterpsychological well-being5, 6). Therefore, factors that affectsleep quality could also influence the general well-beingof individuals.Daily life pattern contains both positive and negativeconstructs which affect physical and psychological well-being: job stress, effort-reward imbalance, social support,social/leisure activities, family-work interface andpersonal health behaviors.In this study we assessed whether participating indifferent leisure or free time activities was associated withsleep quality in two populations of civil servants. Twoepidemiological scales for measuring sleep, the Jenkinssleep problems scale7) and the Pittsburgh sleep quality 13489585, 2005, 5, Downloaded from https://onlinelibrary.wiley.com/doi/10.1539/joh.47.384 by Cochrane Oman, Wiley Online Library on [19/03/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License
385Ali NASERMOADDELI, et al.: Leisure Activities and Sleep Qualityindex8), were developed to discriminate between goodand poor sleepers and to provide a clinically usefulassessment of a variety of sleep disturbances that mightaffect sleep quality.We assumed that since leisure time activities areculturally specific, external validity of the results couldbe better interpreted if the study were based on dataderived from populations with distinct cultures. In thisregard we assessed the association in the two differentsocieties of Japanese and British civil servants.MethodsSubjectsIn this cross-sectional study we evaluated 2,080 civilservants working in departments related to themunicipality of T city in Toyama Prefecture, Japan, inthe spring of 2001. The response rate was 78.3% as 1,628participants filled in the questionnaire.We divided the civil servants into four groups basedon the classification system used in the national census(1995): 1) Administrative 2) Professional 3) Clerical and4) Protective, Transportation and Telecommunicationservice workers who we put into the Office Supportcategory. We also stratified the age of the participantsinto five groups: 29 or younger, 30–39, 40–49, 50–59and 60 yr or older. This study was in collaboration withthe Whitehall II study9) which was set up to investigatethe degree and causes of the social gradient in morbidityand mortality in a cohort of civil servants in London.From the Whitehall II civil servants, 6,873 (66.7%)subjects (phase 5, 1997) for whom we had completeinformation on sleep problem scores were entered intothe analysis. For the Whitehall II data socio-economicstatus of subjects was determined by grade of employmentof subjects. Grade of employment was obtained by askingall participants to give their civil service grade title. Onthe basis of salary 6 grade categories were assigned.Category one represents the highest status jobs andcategory 6 the lowest. Full details of the screeningexamination for the Whitehall II study are reportedelsewhere9).Income data were not accessible for the participants inthe T city study, and therefore employment categoriesare reported as the socio-economic status.Participants were informed that by answering andreturning the questionnaires, they would be giving us theirinformed consent on data analysis.QuestionnaireWe used the Japanese version of the Pittsburgh SleepQuality index (PSQI-J)10). The PSQI is a self-administered questionnaire, which assesses subjectivesleep quality during the previous month. The PSQIgenerates 7 components (range of score 0–3): sleepquality, sleep latency, sleep duration, habitual sleepefficiency, sleep disturbances, use of sleeping medicationand daytime dysfunction. The sum of these sevencomponent scores produces one global score of subjectivesleep quality. The mean ± standard deviation (SD) forPSQI-J global score was 4.98 ± 2.78. Higher scoresindicate poorer sleep quality. Doi11) reported that a globalPSQI-J score of 5.5 provides an optimal cut-off poi