Association between subjective well-being and sleep among the elderly in Japan

Worldwide prevalence of sleep problems in community-dwelling older adults: A systematic review and meta-analysis

The understanding of the prevalence of sleep problems in older adults can provide a broad and reliable perspective into the occurrence of such issues among older adults. This systematic review and meta-analysis aimed to estimate the worldwide prevalence of sleep problems in community-dwelling older adults. Studies that provide information on the prevalence of sleep problems in community-dwelling older adults (≥60 years) were screened between December 2022 and March 2023. A total of 20,379 studies were identified in database searches, from which 252 were included in this review. These studies covered the last 35 years (from 1988 to 2023) and pooled a sample of 995,544 participants from 36 countries. The most frequent sleep problem worldwide was obstructive sleep apnea (46.0%), followed by poor sleep quality (40.0%), other sleep problems (37.0%), insomnia (29.0%), and excessive daytime sleepiness (19.0%). No significant difference in the prevalence estimates of all sleep problems was observed between the sexes. This systematic review and meta-analysis showed a high prevalence of some sleep problems, mainly obstructive sleep apnea, poor sleep quality, and other sleep problems. Our estimates can be useful for managers and policymakers in planning healthcare strategies for sleep problems aimed at the older population.

Factors contributing to subjective well-being and supporting successful aging among rural Japanese community-dwelling older adults: A cross-sectional and longitudinal study

AIM

We aimed to identify the factors contributing to subjective well-being in community-dwelling older adults in rural Japan. This study explored the relationship among physical and mental health, socioeconomic status, and activity levels with regard to the subjective well-being of older adults.

METHODS

In the Frail Elderly in the Sasayama-Tamba Area study, a cohort investigation of independent older adults in a rural Japanese community, 541 of 844 participants completed a 2-year follow-up survey. Subjective well-being was assessed as a binary based on three factors - "happiness," "satisfaction with life" and "meaning in life" - using a subset of the World Health Organization's Quality of Life questionnaire. The improvement group transitioned from not having subjective well-being during the baseline survey to having subjective well-being during the follow-up survey. Furthermore, we used multivariable log-Poisson regression models to calculate the prevalence ratios of subjective well-being.

RESULTS

The cross-sectional study showed that sleep satisfaction, health services access satisfaction and having a higher-level functional capacity were positively associated with having "happiness" and "satisfaction with life." Furthermore, being aged ≥ 80 years and having financial leeway were positively associated with having "meaning in life." The longitudinal study showed that having a higher-level functional capacity was positively associated with improving "happiness" and "satisfaction with life." Being female was positively associated with improving "happiness" and "meaning in life," and health services access satisfaction and alcohol drinking were positively associated with improving "satisfaction with life" and "meaning in life," respectively.

CONCLUSIONS

These findings offer promising avenues for enhancing the subjective well-being of older adults. Geriatr Gerontol Int 2024; 24: 311-319.

"Wrinkles will only go where the smiles have been": a path analysis of the associations between happiness and health, sleep, physical activities for older people in Abu Dhabi

BACKGROUND

The study aimed to identify the associations of happiness and factors related to physical and mental health, leisure, and sports activities amongst older adults in Abu Dhabi. The sample comprised 1,004 participants in the third Abu Dhabi Quality of Life survey administered in 2019-2020.

METHODS

The analysis used path analysis to develop a model incorporating the specified variables. The path model highlighted all direct and indirect associations between the variables. We also used variance analysis to test the differences in gender, marital status, and education attainment with happiness.

RESULTS

Results show that sleep quality is most associated with happiness and subjective health. In addition, sleeping hours did not show any association with subjective health; but were associated with happiness. The result also confirms that mental health is negatively associated with happiness and subjective health. How often an elderly gets involved in sport and activities for at least 30 min significantly affects subjective health and happiness.

CONCLUSIONS

Happiness of older adults is best understood when we look at both direct and indirect effects using a path model. Their happiness is significantly associated with their subjective health, mental health, participation in sport and activities and sleep quality, Implications of the study were highlighted, along with future research directions.

Association between meaningful activities at home and subjective well-being in older adults with long-term care needs: A cross-sectional study

For this study, we examined whether engaging in meaningful activities at home is associated with subjective well-being (SWB) in older adults with long-term care needs according to their preference for going out. We distributed a self-administered questionnaire to long-term care facilities in Japan and performed a linear mixed-effects model regression analysis of the responses. The dependent variable was SWB, and the independent variables were the number of meaningful home activities, preference for going out, and the interaction between them. In our survey (n = 217), we found that both number of meaningful home activities (B = 0.43; 95%CI: 0.17, 0.70) and its interaction with preference (B = -0.43; 95%CI: -0.79, -0.08) were associated with SWB. These results suggest the importance of engaging in meaningful activities at home for older adults who do not prefer going out. We should encourage older adults to participate in activities that match their preference.

The Impact of Sleep Quality on Subjective Wellbeing Among Older Adults With Multimorbidity: A Moderated Mediation Model

Background

Studies have found that poor sleep quality is negatively associated with subjective wellbeing in older adults, but the mechanisms underlying are unclear. In this study, we aimed to examine the mediating role of negative emotions and the moderating role of perceived social support in the relationship between sleep quality and subjective wellbeing in older adults with multimorbidity.

Methods

A multi-stage random sampling method was used to select a sample of 3,266 older adults aged 60 years and older. The Memorial University of Newfoundland Scale of Happiness (MUNSH), Pittsburgh Sleep Quality Index (PSQI), Depression Anxiety Stress Scales-21 (DASS-21), and Perceived Social Support Scale (PSSS) were used to assess subjective wellbeing, sleep quality, negative emotional states, and perceived social support, respectively. The moderated mediation models were examined using SPSS PROCESS Version 3.3 software.

Results

Sleep quality had a significant direct effect on subjective wellbeing in older adults (β = −0.997, t = −11.783, p < 0.001). Negative emotions partially mediated the effect of sleep quality on subjective wellbeing (ab = −0.608, 95%CI: −0.728, −0.497). The indirect effect was moderated by perceived social support (β = −0.038, 95%CI: −0.062, −0.014, p < 0.001; β = −0.002, 95%CI: −0.004, −0.01, p = 0.008).

Conclusion

Negative emotions increased the negative association between sleep quality and the subjective wellbeing of older adults with multimorbidity, and perceived social support played a moderating role. Psychological and behavioral interventions should be implemented as early as possible to promote mental health and enhance social support level of older adults with multimorbidity, and ultimately improve the subjective wellbeing of older adults.

Associations Among Workplace Bullying, Resilience, Insomnia Severity, and Subjective Wellbeing in Chinese Resident Doctors

BACKGROUND

Although workplace bullying is common among medical workers, its associations with insomnia severity and subjective wellbeing are still unclear. Our study aimed to investigate these associations among resident doctors who are more vulnerable to both workplace bullying and insomnia.

METHODS

We conducted a cross-sectional survey of 1,877 resident doctors from 12 hospitals across 7 administrative regions in China. Workplace bullying, resilience, insomnia severity, and subjective wellbeing were evaluated by the Negative Acts Questionnaire-Revised (NAQ-R), the Chinese version of the Connor-Davidson Resilience Scale-10-item (CD-RISC-10), the Insomnia Severity Index, and the Index of Wellbeing, respectively. Further, a logistic regression analysis was used to analyze factors associated with insomnia. In addition, structural equation modeling (SEM) was applied to examine the associations among workplace bullying, resilience, insomnia severity, and subjective wellbeing.

RESULTS

In the present study, the rates of workplace bullying and insomnia were 51.4 and 33.2%, respectively. Workplace bullying (OR = 1.056, p < 0.001) and poor resilience (OR = 0.957, p < 0.001) were the factors associated with insomnia after controlling the confounding variables. Further, SEM of the present study revealed a direct relationship between workplace bullying and subjective wellbeing (std-β = -0.223, p < 0.001). In addition, insomnia severity (std-β = -0.071, p < 0.001) and resilience (std-β = -0.092, p < 0.001) can individually or collectively (std-β = -0.008, p < 0.001) mediate the indirect associations between workplace bullying and subjective wellbeing. However, resilience was found to act as a moderator only in the direct association between workplace bullying and subjective wellbeing.

CONCLUSIONS

Workplace bullying and poor resilience were the factors associated with insomnia. Further, greater resilience acted as a buffer in the direct association between workplace bullying and subjective wellbeing, whereas both insomnia severity and resilience were critical mediators in the indirect associations between them.

Restless Legs Syndrome: Contemporary Diagnosis and Treatment

Restless legs syndrome (RLS) is characterized by an uncomfortable urge to move the legs while at rest, relief upon movement or getting up to walk, and worsened symptom severity at night. RLS may be primary (idiopathic) or secondary to pregnancy or a variety of systemic disorders, especially iron deficiency, and chronic renal insufficiency. Genetic predisposition with a family history is common. The pathogenesis of RLS remains unclear but is likely to involve central nervous system dopaminergic dysfunction, as well as other, undefined contributing mechanisms. Evaluation begins with a thorough history and examination, and iron measures, including ferritin and transferrin saturation, should be checked at presentation and with worsened symptoms, especially when augmentation develops. Augmentation is characterized by more intense symptom severity, earlier symptom occurrence, and often, symptom spread from the legs to the arms or other body regions. Some people with RLS have adequate symptom control with non-pharmacological measures such as massage or temperate baths. First-line management options include iron-replacement therapy in those with evidence for reduced body-iron stores or, alternatively, with prescribed gabapentin or pregabalin, and dopamine agonists such as pramipexole, ropinirole, and rotigotine. Second-line therapies include intravenous iron infusion in those who are intolerant of oral iron and/or those having augmentation with intense, severe RLS symptoms, and opioids including tramadol, oxycodone, and methadone. RLS significantly impacts patients' quality of life and remains a therapeutic area sorely in need of innovation and a further pipeline of new, biologically informed therapies.

Morale in Old Age and Its Association with Sociodemographic, Social, and Health-Related Factors in Different Age Groups

Morale can be viewed as a future-oriented optimism or pessimism regarding challenges associated with aging and is closely related to subjective well-being. Promoting morale in old age could be considered to have important implications for aging well, and increased knowledge about morale in different stages of old age is needed. Hence, the aim of this study was to investigate factors associated with morale in different age groups among old people. Data were derived from a survey conducted in 2016, as a part of the Gerontological Regional Database (GERDA). The sample consisted of 9,047 individuals aged between 65 and 86 years from Ostrobothnia and Southern Ostrobothnia in Finland, and Västerbotten in Sweden. Morale was measured with the Philadelphia Geriatric Center Morale Scale (PGCMS) and regressed upon a number of sociodemographic, social, and health-related factors using linear regression analyses. The results showed that older age was an independent factor explaining lower level of morale. Additionally, the sociodemographic, social, and health-related variables could explain a large proportion of the variance in morale. Perceived loneliness, having gone through a crisis in life, poor self-rated health, and depression were associated with lower morale, and sleeping well with higher morale, in all age groups. Furthermore, the oldest age groups seem to be more exposed to several risk factors of lower morale identified in this study. Multidimensional interventions targeting especially social and mental health and the oldest-old could therefore be recommended.

Factors associated with poor sleep quality in the Korean general population: Providing information from the Korean version of the Pittsburgh Sleep Quality Index

BACKGROUND

Recently, studies have been conducted to address the research gap in the understanding of poor-quality sleep and its relationship to health outcomes, through the evaluation of sleep quality. The aim of this study was to provide information regarding poor sleep quality based on a nationwide general population sample in Korea.

METHODS

We conducted a cross-sectional study using data from a nationwide sample of 165,193 individuals (males: 44%) aged 19 years or older from the 2018 Korea Community Health Survey. The age range of the participants was 19-107 years (mean: 55.3 ± 17.5). The Korean version of the Pittsburgh Sleep Quality Index (PSQI) was used for assessing sleep quality. Poor sleep quality was defined as a total PSQI score of >5.

RESULTS

The overall prevalence of poor sleepers was 41.0% (males: 35.6%; females: 46.2%). Poor sociodemographic status (illiteracy, low income, and unemployment), poor health behaviors (smoking, high-risk drinking, diabetes, hypertension, non-participation in walking, and obesity), and poor mental health (perceived poor health status, stress, depressive symptoms, and subjective cognitive decline) were all associated with poor sleep quality in both males and females.

LIMITATIONS

As this study relies on self-reported and cross-sectional data, causal inferences cannot be made.

CONCLUSIONS

Poor sleep quality is highly prevalent in females. In addition, poor socio-demographic status, poor health behaviors, and poor mental health were associated with poor sleep quality. The mechanisms underlying sex differences in sleep quality remain to be elucidated, and further studies are required to address this.

Impact of sleep health on self-perceived health status

Although sleep habits have long been recognized as a promoter of health, the World Health Organization 2014 report on non-communicable diseases (NCDs) only listed smoking, alcohol intake, diet and physical activity (PA) as key modifiable risk factors that could enhance health and prevent NCDs. Cross-sectional data on 4385 surveys from the 2015 Catalan Health Survey, representative of the 2015 non-institutionalized Catalan population over age 14, were used to assess and compare the independent associations of low PA (International Physical Activity Questionnaire (IPAQ): low activity); poor diet (PREvención con DIeta MEDiterránea questionnaire (PREDIMED): low-adherent); poor sleep health (Satisfaction, Alertness, Timing, Efficiency and Duration scale (SATED): <8); smoking status; and, alcohol intake (high-risk drinker based on standard drink units) with having a poor self-perceived health status. Logistic regression models adjusted by age, gender, education level and number of comorbidities showed that poor sleep health had the strongest independent association with poor self-perceived health status (OR = 1.70; 95%CI: 1.37–2.12), followed by poor diet (OR = 1.37; 95%CI: 1.10–1.72) and low PA (OR = 1.31; 95%CI: 1.01–1.69). This suggests that sleep habits should be included among the important modifiable health risk factors and be considered a key component of a healthy lifestyle.

Combined Impact of Traditional and Non-Traditional Healthy Behaviors on Health-Related Quality of Life: A Prospective Study in Older Adults

Combined exposure to several healthy behaviors (HB) is associated with reduced mortality in older adults but its impact on health-related quality of life (HRQL) is uncertain. This is a cohort study of 2,388 individuals aged ≥60 recruited in 2000–2001, whose data were updated in 2003 and 2009. At baseline, participants reported both traditional HB (non-smoking, being very or moderately active, healthy diet) and non-traditional HB (sleeping 7–8 h/d, being seated <8 h/d, and seeing friends every day). HRQL was measured with the SF-36 questionnaire at baseline, in 2003 (short-term) and in 2009 (long-term); a higher score on the SF-36 represents better HRQL. Linear regression models were used to assess the association between HB at baseline and HRQL in 2003 and 2009, with adjustment for the main confounders including baseline HRQL. In the short-term, being physically active, sleeping 7–8 h/d, and being seated <8 h/d was associated with better HRQL. Compared to having ≤1 of these HB, the β (95% confidence interval) for the score on the physical component summary of the SF-36 in 2003 was 1.42 (0.52–2.33) for 2 HB, and 2.06 (1.09–3.03) for 3 HB, p-trend <0.001. Corresponding figures for the mental component summary score were 1.89 (0.58–3.21) for 2 HB and 3.35 (1.95–4.76) for 3 HB, p-trend <0.001. Non-smoking, a healthy diet or seeing friends did not show an association with HRQL. In the long-term, being physically active was the only HB associated with better physical HRQL. As a conclusion, a greater number of HB, particularly more physical activity, adequate sleep duration, and sitting less, were associated with better short-term HRQL in older adults. However, in the long-term, being physically active was the only HB associated with better physical HRQL.

Associations of sleep duration and sleep quality with life satisfaction in elderly Chinese: The mediating role of depression

This study investigated whether sleep duration and quality were related to life satisfaction (LS) among older Chinese adults and whether depression mediated those relationships. Cross-sectional data from the aging arm of the Rugao Longevity and Aging Study were used. Sleep duration, sleep quality, depression, LS and covariates were analyzed using logistic regressions. To assess the potential mediation of depression on the association between sleep duration and quality and LS, Aroian tests were used. Of 1756 older Chinese adults aged 70-84 years, 90.7% of the men and 83.3% of the women reported being satisfied with their lives. After adjusting for covariates, older adults who slept ≤6h per night were more likely to suffer from life dissatisfaction compared with those who slept 7-8h (OR=2.67, 95% CI 1.86-3.79), and individuals who slept poorly were almost 2 times (OR=2.91, 95% CI 2.16-3.91) more likely to have life dissatisfaction. The Aroian tests confirmed that these relationships were partially mediated by depression (p<0.001). Between short sleep and LS, the mediating effect of depression accounted for 13.9% of the total effects. Moreover, the mediating effect of depression on the association between sleep quality and LS was 13.3%. Short sleep duration and poor sleep quality were inversely associated with LS, and the relationships were partially mediated by depression. Our study suggests that both sleep and depression status are important factors for LS among the elderly.

Association of chronic insomnia symptoms and recurrent extreme sleep duration over 10 years with well-being in older adults: a cohort study

OBJECTIVES

The extent to which aspects of sleep affect well-being in the long-term remains unclear. This longitudinal study examines the association between chronic insomnia symptoms, recurrent sleep duration and well-being at older ages.

SETTING

A prospective cohort of UK civil servants (the Whitehall II study).

PARTICIPANTS

4491 women and men (25.2% women) with sleep measured 3 times over 10 years and well-being once at age 55-79 years. Insomnia symptoms and sleep duration were assessed through self-reports in 1997-1999, 2003-2004 and 2007-2009.

PRIMARY OUTCOME MEASURES

Indicators of well-being, measured in 2007-2009, were the Control, Autonomy, Self-realisation and Pleasure measure (CASP-19) of overall well-being (range 0-57) and the physical and mental well-being component scores (range 0-100) of the Short Form Health Survey (SF-36).

RESULTS

In maximally adjusted analyses, chronic insomnia symptoms were associated with poorer overall well-being (difference between insomnia at 3 assessments vs none -7.0 (SE=0.4) p<0.001), mental well-being (difference -6.9 (SE=0.4), p<0.001) and physical well-being (difference -2.8 (SE=0.4), p<0.001) independently of the other sleep measures. There was a suggestion of a dose-response pattern in these associations. In addition, recurrent short sleep (difference between ≤ 5 h sleep reported at 3 assessments vs none -1.7 (SE=0.7), p<0.05) and recurrent long sleep (difference between >9 h reported at 2 or 3 assessments vs none -3.5 (SE=0.9), p<0.001) were associated with poorer physical well-being.

CONCLUSIONS

We conclude that in older people, chronic insomnia symptoms are negatively associated with all aspects of well-being, whereas recurrent long and short sleep is only associated with reduced physical well-being.

Restless Leg Syndrome Across the Globe: Epidemiology of the Restless Legs Syndrome/Willis-Ekbom Disease

There are more than 50 epidemiologic studies measuring the prevalence of restless legs syndrome/Willis-Ekbom disease (RLS/WED) across 5 of the 6 inhabited continents (not Australia), most conducted in North America and Europe. Sufficient studies have been conducted in Asia, North America, and Europe to make inferences on RLS/WED prevalence by region. RLS/WED prevalence is thought to be highest in North America and Europe and lower in Asia. These differences across regions may be explained by cultural, environmental, and genetic factors. Future investigation is needed to determine to what extent these factors affect expression of RLS/WED according to world region.

The Association between Short or Long Sleep Times and Quality of Life (QOL): Results of the Korea National Health and Nutrition Examination Survey (KNHANES IV-V)

STUDY OBJECTIVES

Sleep can affect quality of life (QOL). We examined the association between self-reported sleep time and QOL independent of perceived health status and depressive disorder using the EuroQol-5 Dimension (EQ-5D) and a visual analog scale (VAS).

METHODS

We used the nationwide cross-sectional survey data of 28,178 subjects from the Korea National Health and Nutrition Examination Survey (KNHANES) IV-V. Self-reported sleep time was assessed by average hours of sleep per day. QOL was measured using the EQ-5D and VAS. A generalized additive model and multiple linear regression analysis were used to estimate the effect of sleep time on the QOL while adjusting for potential confounding variables.

RESULTS

We found a significant inverted U-shaped relationship between sleep time and QOL using both the EQ-5D and VAS indices. Compared with subjects who slept 7 h/day, Korean men whose sleep time was very short (≤ 4 h/ day) or very long (≥ 10 h/day) had substantially worse QOL (-3.125 in EQ-5D, p < 0.001 and -4.387 on the VAS, p = 0.000 for ≤ 4 h/day; -1.763 in EQ-5D, p = 0.001 and -1.944 on the VAS for ≥ 10 h/day, all p = 0.038). A similar inverted U-shape was observed between sleep time and QOL in Korean women.

CONCLUSIONS

Inappropriate sleep time (either short or long) in both men and women was significantly associated with lower QOL. In particular, such an association was more apparent among persons whose perceived health status was poor.

Prevalence and predictors of poor sleep quality in Korean older adults

The purposes of this study were to evaluate the levels of sleep quality and to examine its related factors in the elderly Korean adults. A cross-sectional research design was used, and 157 adults, aged from 65 to 89, were recruited from five community health centres in Gyeonggi province and Seoul, Korea. All participants were informed about the purpose of the study and were asked to provide demographic characteristics, chronic conditions, self-rated health, pain, depression, life satisfaction and sleep quality. More than 60% of the participants reported having poor sleep quality. Hierarchical multiple regression analysis showed that age, self-rated health, pain and depression were related to poor sleep quality. The findings suggest that it is important to screen regularly for sleep quality, and attention to depression, poor self-rated health and perceived pain were needed to improve sleep quality of older adults.

Effect of adding a sleep dimension to the EQ-5D descriptive system: a "bolt-on" experiment

BACKGROUND AND OBJECTIVE

The generic preference-based measures (GPBMs) of health have been widely used to obtain health utility scores for calculating quality-adjusted life-years (QALYs) for economic evaluations. It has been recognized that GPBMs may miss relevant or important dimensions of health for some specific medical conditions. The objective of this study is to explore the effect of extending the current EQ-5D descriptive system by adding a sleep dimension.

METHODS

A new instrument, EQ-5D+Sleep, is proposed by adding a sleep dimension to the EQ-5D. Based on an orthogonal design, 18 EQ-5D+Sleep states and EQ-5D states were selected and a valuation study was undertaken whereby 160 members of the generic public in South Yorkshire, UK, were interviewed using time tradeoff (TTO). Econometric models have been fitted to the data. Two null hypotheses were tested: 1) the coefficient for the sleep dimension is not significant; and 2) the inclusion of the sleep dimension has no impact on the way people value the original dimensions of EQ-5D.

RESULTS

and

CONCLUSIONS

The results support these two null hypotheses. There seems to be no benefit to adding a sleep dimension to the EQ-5D. Research is required to explore the method of adding dimensions to existing descriptive systems of health.

The association between sleep problems and perceived health status: a Japanese nationwide general population survey

OBJECTIVE

Sleep problems in humans have been reported to impact seriously on daily function and to have a close association with well-being. To examine the effects of individual sleep problems on physical and mental health, we conducted a nationwide epidemiological survey and examined the associations between sleep problems and perceived health status.

METHODS

Cross-sectional surveys with a face-to-face interview were conducted in August and September, 2009, as part of the Nihon University Sleep and Mental Health Epidemiology Project (NUSMEP). Data from 2559 people aged 20 years or older were analyzed (response rate 54.0%). Participants completed a questionnaire on perceived physical and mental health statuses, and sleep problems including the presence or absence of insomnia symptoms (i.e., difficulty initiating sleep [DIS], difficulty maintaining sleep [DMS], and early morning awakening [EMA]), excessive daytime sleepiness (EDS), poor sleep quality (PSQ), short sleep duration (SSD), and long sleep duration (LSD).

RESULTS

The prevalence of DIS, DMS, and EMA was 14.9%, 26.6%, and 11.7%, respectively, and 32.7% of the sample reported at least one of them. At the complaint level, the prevalence of EDS, PSQ, SSD, and LSD was 1.4%, 21.7%, 4.0%, and 3.2%, respectively. Multiple logistic regression analyses revealed that DMS, PSQ, SSD, and LSD were independently associated with poor perceived physical health status; DIS, EDS, and PSQ were independently associated with poor perceived mental health status.

CONCLUSIONS

This study has demonstrated that sleep problems have individual significance with regard to perceived physical or mental health status.

Epidemiology of restless legs syndrome: a synthesis of the literature

Restless legs syndrome (RLS) has gained considerable attention in the recent years: nearly 50 community-based studies have been published in the last decade around the world. The development of strict diagnostic criteria in 1995 and their revision in 2003 helped to stimulate research interest on this syndrome. In community-based surveys, RLS has been studied as: 1) a symptom only, 2) a set of symptoms meeting minimal diagnostic criteria of the international restless legs syndrome study group (IRLSSG), 3) meeting minimal criteria accompanied with a specific frequency and/or severity, and 4) a differential diagnosis. In the first case, prevalence estimates in the general adult population ranged from 9.4% to 15%. In the second case, prevalence ranged from 3.9% to 14.3%. When frequency/severity is added, prevalence ranged from 2.2% to 7.9% and when differential diagnosis is applied prevalence estimates are between 1.9% and 4.6%. In all instances, RLS prevalence is higher in women than in men. It also increases with age in European and North American countries but not in Asian countries. Symptoms of anxiety and depression have been consistently associated with RLS. Overall, individuals with RLS have a poorer health than non-RLS but evidence for specific disease associations is mixed. Future epidemiological studies should focus on systematically adding frequency and severity in the definition of the syndrome in order to minimize the inclusion of cases mimicking RLS.

Evaluation of health-related quality of life using EQ-5D in Takamatsu, Japan

OBJECTIVES

Healthy Japan 21 (Japanese National Health Promotion in the 21st Century) was started in 2000 to promote extension of healthy life expectancy and improve health-related quality of life (HRQOL). The present study aims to describe HRQOL of Japanese subjects using the EuroQol questionnaire (EQ-5D) and investigate the influence of social background, health-related behaviors, and chronic conditions on HRQOL using representatives in Takamatsu, Japan.

METHODS

Data were obtained from a 2005 Takamatsu City health survey mailed to 2,500 randomly selected Japanese individuals in Takamatsu, a medium-sized city. We examined data from 915 Japanese adults. The questionnaire addressed social background, health-related behaviors, chronic conditions, EQ-5D items, and self-rated health. The impact of social background, health-related behaviors, and chronic conditions on Japanese HRQOL was examined through multivariate regression, adjusting for age and sex.

RESULTS

EQ-5D scores decreased with age, particularly for respondents who were unemployed or retired. Adjusting for sex and age, the results showed that age, unemployment/retirement, feeling severe stress, and musculoskeletal and gastrointestinal diseases were significantly associated with decreased HRQOL. Conversely, sufficient sleep (7-8 h/day) and having a hobby were significantly associated with increased HRQOL.

CONCLUSIONS

Information is lacking regarding HRQOL in Japanese populations. This study furthers our understanding of some important determinants influencing Japanese HRQOL, using the EQ-5D in Takamatsu, Japan. Our results also resembled some findings from similar studies in other countries. We hope to use the EQ-5D with other health survey questionnaires to gather more data about HRQOL of Japanese people.