Psychometric assessment of subjective sleep quality using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J) in psychiatric disordered and control subjects

[Alcohol drinking patterns and sleep quality of Japanese civil servants]

OBJECTIVE

The purpose of this study was to clarify whether alcohol drinking patterns were associated with sleep quality.

METHODS

A cross-sectional survey was carried out by self-administered questionnaire in 2008 among 2,118 employees aged 18 to 65 years working in local government in Toyama. After excluding those without relevant data for this study, 661 men and 618 women represented the study population. Logistic regression analysis was used to evaluate whether alcohol drinking patterns (as measured by the frequency, the amount of alcohol per day and the timing of alcohol drinking) were associated with poor sleep quality (as measured by the Pittsburgh Sleep Quality Index), after adjustment for potential confounding factors: age, family structure, work characteristics (as measured by the job-demand-control-support model, shift work and occupational class), chronic disease, body mass index, smoking status and physical activity.

RESULTS

In comparison with men who did not drink, the adjusted odds ratio for poor sleep quality was 0.52 (95%confidence interval: 0.32-0.85) for those who drank alcohol once a week or more, 0.32 (0.13-0.84) for those who drank 1-3 glasses daily, 0.30 (0.13-0.70) for those who drank 7-14 glasses per week, 0.37 (0.17-0.77) for those who drank only at meals. In women, the drinking patterns were not significantly associated with sleep quality.

CONCLUSIONS

The results of this study suggest that some alcohol drinking patterns may affect sleep quality among men who do not use sleeping medicine.

Translating the Pittsburgh Sleep Quality Index into Arabic

This descriptive correlational study describes the translation process and the psychometric testing of the Pittsburgh Sleep Quality Index (PSQI). The PSQI has been successfully translated into Arabic and back-translated into English by 10 Arabic bilingual translators. Then the PSQI is tested in a sample of 35 healthy Arabic bilinguals.The internal consistency reliability for the Global PSQI demonstrates borderline acceptability (Cronbach's alpha = .65). The reliability is further supported by moderate to high correlations between five PSQI components and the global PSQI score (r = .53 to .82, p < .01). Convergent validity is supported by the global PSQI correlating strongly with the Insomnia Severity Index (r = .76) and moderately with the related construct of the Medical Outcome Study Short Form-36 vitality subscale (r = -.33). Further testing of the PSQI is needed in a larger Arabic population, both clinical and healthy populations, living in their native countries.

Validation of the Parkinson's disease sleep scale in Japanese patients: a comparison study using the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale and Polysomnography

OBJECTIVE

Characteristic sleep disturbance in patients with Parkinson's disease (PD) was evaluated using a subjective questionnaire called the PD sleep scale (PDSS). In this study we sought to examine the relationship between the results from the PDSS with those from the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and polysomnography (PSG) in Japanese PD patients.

SUBJECTS AND METHODS

Subjects were 79 PD patients and 79 age and gender matched controls. The length of morbidity in patients with PD was 8.4+/-8.0 years, and their Hoehn and Yahr grade was 2.9+/-1.0. All subjects completed the PDSS, PSQI, and ESS questionnaires, and we compared the results from patients with PD to controls. We also evaluated the correlation among the PDSS, PSQI, and ESS in patients with PD. Moreover, we performed PSG on 33 of 79 PD patients, and examined the correlation between the PDSS and PSG.

RESULTS

PDSS total scores and subscales from patients with PD were significantly lower than those in controls, except for items 3, 8, and 14. PDSS scores had significant internal consistency and significant correlation with PSQI and ESS scores. The total PDSS score also correlated with sleep efficiency as measured by PSG. In subscales of the PDSS, night psychosis was negatively correlated with percentage of REM sleep without atonia on PSG.

DISCUSSION

Based on our comparisons with PSQI, ESS, and PSG, the PDSS appears to be a reliable tool to evaluate the characteristics of sleep disturbances in PD patients.

Effect of a blue-light-blocking intraocular lens on the quality of sleep

PURPOSE

To evaluate whether implantation of a blue-light-blocking intraocular lens (IOL) affects sleep quality.

SETTING

Repatriation General Hospital, Adelaide, Australia.

METHODS

This study comprised patients who had bilateral cataract surgery during the preceding 12 months with implantation of a conventional SI40NB IOL or an AcrySof Natural SN60WF blue-light-blocking IOL. Patients were contacted by telephone at least 6 months after second-eye surgery, and the Pittsburgh Sleep Quality Index (PSQI) questionnaire was administered. Results were compared between groups.

RESULTS

Of the 49 patients, 31 received conventional IOLs and 18, blue-light-blocking IOLs. The mean age of the patients was 80 years +/- 8.1 (SD). The median PSQI score was 6 (interquartile range 3 to 8). There were no statistically significant differences in PSQI scores between the 2 IOL groups (P = .65). This remained true after adjustment for sex, age, medication, and time since surgery.

CONCLUSION

The blue-light-blocking IOL had no effect on the sleep quality of patients, indicating that these IOLs might serve as an alternative to conventional IOLs without a detrimental effect on circadian rhythm.

Associations between sleep disturbance and mental health status: a longitudinal study of Japanese junior high school students

BACKGROUND

A limited number of longitudinal studies have addressed the association between sleep disturbance and mental health status among adolescents. To examine whether each of these is a risk factor for the onset of the other, we conducted a prospective longitudinal study of Japanese adolescents.

METHODS

In 2004, we performed a baseline study of students attending three private junior high schools in Tokyo, and in 2006, a follow-up study was performed on the same population. The mean age of the subjects was 13 years. The Pittsburgh Sleep Quality Index was used to evaluate sleep disturbance, and the 12-item General Health Questionnaire was used to evaluate mental health status.

RESULTS

The subjects were 698 students, of whom 516 were suitable for analysis. The incidence of newly developed poor mental health status during the 2 years leading to the follow-up study was 35.1%. New onset of poor mental health status was significantly associated with new onset of sleep disturbance and lasting sleep disturbance. The incidence of sleep disturbance during the 2 years leading to the follow-up study was 33.3%. New onset of sleep disturbance was significantly associated with new onset of poor mental health status and lasting poor mental health status.

CONCLUSIONS

Sleep disturbance and poor mental health status increase each other's onset risk.

Is a Successful High-K Fitness Strategy Associated with Better Mental Health?

This study examined the associations between a high-K fitness strategy and mental health. These associations were tested on a sample of 1400 disaster workers who had exposure to a singular traumatic event and who underwent psychological evaluations. The results showed that high-K was an important negative predictor of psychopathology, accounting for significant variance in PTSD, general psychopathology, functional disability, anger, and sleep disturbances. Implications of the results are discussed.

Using Rasch analysis to validate the revised PSQI to assess sleep disorders in Taiwan's hi-tech workers

The Pittsburgh Sleep Quality Index (PSQI) is an effective instrument for measuring the quality of sleep in older adults. In this study, we used Rasch analysis to validate the items of the revised PSQI (SC_PSQI) that contribute to a single construct. A total of 3,742 workers agreed to participate in this study. Both the appropriateness of the scoring rubrics and the unidimensionality of the SC_PSQI scale were investigated. All nine items fit the model's expectations rather well. These results indicate that the SC_PSQI with a 0 to 2 scoring scale can be used as a unidimensionality to assess sleep quality.

Prognosis of fatigue and functioning in primary care: a 1-year follow-up study

PURPOSE

Although fatigue is a common presenting symptom in primary care and its course and outcomes often remain unclear, cohort studies among patients seeking care for fatigue are scarce. We therefore aimed to investigate patterns in the course of fatigue and relevant secondary outcomes in a large cohort of patients who sought care for a main symptom of fatigue.

METHODS

We performed an observational cohort study in 147 primary care practices. Patients consulting their general practitioner for a new episode of fatigue were sent questionnaires at 1, 4, 8, and 12 months after baseline. We collected measures of fatigue, perceived health and functioning, absenteeism, psychological symptoms, and sleep using the Checklist Individual Strength, the 36-Item Short Form Health Survey, the Four-Dimensional Symptoms Questionnaire, and the Pittsburgh Sleep Questionnaire Inventory. Patients were classified into 4 subgroups based on fatigue severity scores over time. We assessed patterns in the course of all outcomes in these subgroups and in the total population, and tested changes over time and differences between subgroups.

RESULTS

A total of 642 patients were enrolled in the study. Response rates during follow-up ranged between 82% and 88%. For 75% of the patients, 4 distinct groups could be discerned: 26% of patients had continuously high scores for fatigue, 17% had a fast recovery, 25% had a slow recovery, and 32% initially improved but then had a recurrence of fatigue. Patterns for the secondary outcomes of symptoms and functioning were all similar to the pattern for fatigue within each of the subgroups.

CONCLUSIONS

The findings of this study suggest a longitudinal relationship between the severity of fatigue, impaired functioning, psychological symptoms, and poor sleep. Physicians should be aware that a substantial proportion of patients seeking care for fatigue have these additional health and psychosocial problems.

[Relationships of positive and negative affectivity to sleep quality in Japanese civil servants: 3-year follow-up study]

We conducted this longitudinal study to evaluate the relationships of positive and negative affectivity (Affect Balance Scale) to sleep quality among civil servants. For this study we evaluated 827 civil servants of T city in Toyama prefecture in the springs of 2001 (Baseline) and 2004 with complete information in both phases of the study. Based on the median score at each phase, we divided Affect Balance Scale (ABS) scores into high and low groups. We conducted logistic regression analysis to determine the odds ratios (OR) of 3-yr follow-up sleep quality by baseline and follow-up ABS scores. After adjusting for baseline sleep quality scores, age, sex, employment, job strain, and exercise habits, participants who had high ABS scores were more likely (OR: 3.13, 95% confidence interval (CI): 1.78-5.53) to have better sleep quality than those with low ABS scores at both phases. In addition, participants with low ABS scores at baseline and high ABS scores 3 yr later had better sleep quality (OR: 1.81, 95%CI: 1.02-3.20) than those with low ABS scores at both phases. These findings substantiate the relationships of positive and negative affectivity to sleep quality. Improving the affect balance condition as well as maintaining good affect balance condition may be important determinants of sleep quality in civil servants.

Development of a Japanese version of the Epworth Sleepiness Scale (JESS) based on item response theory

BACKGROUND

Various Japanese versions of the Epworth Sleepiness Scale (ESS) have been used, but none was developed via standard procedures. Here we report on the construction and testing of the developer-authorized Japanese version of the ESS (JESS).

METHODS

Developing the JESS involved translations, back translations, a pilot study, and psychometric testing. We identified questions in the ESS that were difficult to answer or were inappropriate in Japan, proposed possible replacements for those questions, and tested them with analyses based on item response theory (IRT) and classical test theory. The subjects were healthy people and patients with narcolepsy, idiopathic hypersomnia, or obstructive sleep apnea syndrome.

RESULTS

We identified two of our proposed questions as appropriate replacements for two problematic questions in the ESS. The JESS had very few missing data. Internal consistency reliability and test-retest reliability were high. The patients had significantly higher JESS scores than did the healthy people, and higher JESS scores were associated with worse daytime function, as measured with the Pittsburgh Sleep Quality Index.

CONCLUSIONS

In Japan, the JESS provides reliable and valid information on daytime sleepiness. Researchers who use the ESS with other populations should combine their knowledge of local conditions with the results of psychometric tests.

Evaluation of an internet-based self-help program for better quality of sleep among Japanese workers: a randomized controlled trial

The effectiveness of Internet-based self-help programs for insomnia is still unclear. A randomized controlled trial was conducted to evaluate the effect of an Internet-based self-help program for better quality of sleep among adult workers. Forty-three volunteers were recruited and randomly assigned to either an intervention group (n=21) or a waiting-list group (n=22). The intervention group participated in a two-week Internet-based program, including selecting and daily practicing sleep-related target behaviors and monitoring those behaviors along with sleep quality. At the same time, each participant received automatically generated, personalized messages and reports both daily and weekly. A total of 12 intervention group participants and 18 waiting-list group participants completed questionnaires at baseline, post-intervention, and at a 3-wk follow-up. Subjective sleep quality was measured by a self-reported questionnaire developed for this study. The sleep quality score increased in the intervention group at post-intervention, with a significant interaction effect [F(1,28)=5.19, p=0.031]. Sleep-related behaviors also greatly increased in the intervention group at post-intervention, with a significant interaction effect [F(1,28)=7.14, p=0.012]. Sleep-onset latency reduced in the intervention group at follow-up, with a marginally significant effect [F(1,28)=3.52, p=0.071]. The Internet-based self-help program improves subjective sleep quality and sleep-onset latency among adult workers.

Perceived sleep quality of psychiatric patients

This paper aims at acquiring knowledge about the quality of sleep of adult and elderly psychiatric patients who receive clinical or outpatient nursing care, and identifying key factors in perceiving a sleep problem. To do so, a sample of 1699 psychiatric patients were asked whether they perceived a sleep problem and were invited to fill in the Pittsburgh Sleep Quality Index (PSQI) and additional questions. Five hundred and sixty (33%) questionnaires were returned. As a result, we find that 36% of the patients perceived a sleep problem, while the PSQI assessed 66% of the sample as being 'bad sleepers'. Forty-nine per cent of the respondents used sleep medication one or more times a week. Five items of the PSQI were shown to be predictors of a perceived sleep problem. Four of these are insomnia symptoms, while the fifth is the use of sleep medication. Moreover, the patients who used sleep medication most scored significantly worse on all PSQI components than patients who used sleep medication less than once a week. In conclusion, many psychiatric patients perceive a sleep problem and all nurses could be confronted not only with the night-time consequences of this, but also with daytime consequences. Therefore, sleep problems must not be viewed as an isolated problem but must be seen in relation with social functioning.

Usefulness of mindfulness-based cognitive therapy for treating insomnia in patients with anxiety disorders: a pilot study

The objective of this study was to examine the usefulness of a mindfulness-based cognitive therapy (MBCT) for treating insomnia symptoms in patients with anxiety disorder. Nineteen patients with anxiety disorder were assigned to an 8-week MBCT clinical trial. Participants showed significant improvement in Pittsburgh Sleep Quality Index (Z = -3.46, p = 0.00), Penn State Worry Questionnaire (Z = -3.83, p = 0.00), Ruminative Response Scale (Z = -3.83, p = 0.00), Hamilton Anxiety Rating Scale (Z = -3.73, p = 0.00), and Hamilton Depression Rating Scale scores (Z = -3.06, p = 0.00) at the end of the 8-week program as compared with baseline. Multiple regression analysis showed that baseline Penn State Worry Questionnaire scores were associated with baseline Pittsburgh Sleep Quality Index scores. These findings suggest that MBCT can be effective at relieving insomnia symptoms by reducing worry associated sleep disturbances in patients with anxiety disorder. However, well-designed, randomized, controlled trials are needed to confirm our findings.

Sleep disturbances in an arctic population: the Tromsø Study

Background

Prevalence estimates for insomnia range from 10 to 50% in the adult general population. Sleep disturbances cause great impairment in quality of life, which might even rival or exceed the impairment in other chronic medical disorders. The economic implications and use of health-care services related to chronic insomnia represent a clinical concern as well as a pronounced public health problem. Hypnotics are frequently prescribed for insomnia, but alcohol and over-the-counter sleep aids seem to be more widely used by insomniacs than prescription medications. Despite the complex relationship between insomnia and physical and mental health factors, the condition appears to be underrecognized and undertreated by health care providers, probably due to the generally limited knowledge of the causes and natural development of insomnia.

Methods/Design

The Tromsø Study is an ongoing population-based cohort study with five previous health studies undertaken between 1974 and 2001. This protocol outlines a planned study within the sixth Tromsø Study (Tromsø VI), aiming at; 1) describing sleep patterns in a community-based sample representative of the general population of northern Norway, and 2) examining outcome variables of sleep disturbances against possible explanatory and confounding variables, both within a cross-sectional approach, as well as retrospectively in a longitudinal study – exploring sleep patterns in subjects who have attended two or more of the previous Tromsø studies between 1974 and 2009. First, we plan to perform a simple screening in order to identify those participants with probable sleep disturbances, and secondly to investigate these sleep disturbances further, using an extensive sleep-questionnaire. We will also collect biological explanatory variables, i.e. blood samples, weight, height and blood pressure. We plan to merge data on an individual level from the Tromsø VI Study with data from the Norwegian Prescription Database (NorPD), which is a national registry including data for all prescription drugs issued at Norwegian pharmacies. Participants with sleep disturbances will be compared with pair-matched controls without sleep disturbances.

Discussion

Despite ongoing research, many challenges remain in the characterization of sleep disturbances and its correlates. Future mapping of the biological dimensions, natural history, as well as the behavioral and drug-related aspects of sleep disturbances in a representative population samples is clearly needed.

Sleep-disordered breathing in the usual lifestyle setting as detected with home monitoring in a population of working men in Japan

STUDY OBJECTIVES

To examine (1) the prevalence of home-monitored sleep-disordered breathing (SDB) and obstructive sleep apnea syndrome in a Japanese working population and (2) whether home monitoring with a type 3 portable monitor and actigraphy can produce reliable data to analyze SDB in usual lifestyles.

METHODS

A cross-sectional survey using a self-administered questionnaire was conducted on a group of employees at a wholesale company in Osaka, Japan. Examinations by physicians and by sleep monitoring were also performed. Unattended home cardiorespiratory (type 3) sleep studies with actigraphy were conducted for 2 nights to diagnose SDB in 322 subjects. From the baseline questionnaires and sleep diaries, participants were assessed to follow their usual lifestyles during the study (e.g., time in bed, alcohol intake).

RESULTS

Of 466 Japanese male employees, 396 responded to the questionnaire survey (85.0%). Results from 322 male employees aged 23 to 59 (43.8 +/- 8.4 years) were analyzed. Respiratory disturbance index (RDI), calculated from the type 3 portable monitors and actigraphy, was highly reliable with an intraclass correlation of 0.98 for interscorer reliability and with an intraclass correlation of 0.95 for night-to-night reliability. Prevalence of mild (5 < or = RDI < 15), moderate (15 < or = RDI < 30) and severe (RDI < or = 30) SDB in this population were 37.4%, 15.7%, and 6.6%, respectively. The prevalence of obstructive sleep apnea syndrome (RDI > or = 5 and Epworth Sleepiness Scale score > 10) was 17.6%.

CONCLUSIONS

The prevalence of moderate to severe SDB (RDI > or = 15) was 22.3% in this Japanese male working population aged 23 to 59, measured in participant's usual life settings. Unattended home monitoring with type 3 portable monitors and actigraphy was highly reliable and may be suitable for analyzing SDB in the usual lifestyle setting.

Effects of antipsychotic medications on sleep in schizophrenia

Schizophrenia is often accompanied by sleep problems. Evidence exists that these sleep difficulties have significant effects on individuals with this disorder. The mainstay of treatment for this condition is the administration of medications that have effects on neurotransmitter systems, which play an important role in sleep-wake function, including histamine, acetylcholine, serotonin, norepinephrine and dopamine. Little systematic attention, however, has been paid to how the sleep effects of these agents might play a role in the course of treatment, function and quality of life of schizophrenia patients. Schizophrenia medications can improve sleep problems and reverse the sleep architectural derangements that are common among patients with schizophrenia and, therefore, have the potential to improve the quality of life and functional capacity of the patient. Conversely, some sleep-wake effects of these medications can impair patient function and quality of life. In this study, we review the effects of schizophrenia medications and discuss their relevance to optimizing the clinical treatment of people with schizophrenia with regard to sleep-wake function.

Validity of the Pittsburgh Sleep Quality Index (PSQI) among Nigerian university students

OBJECTIVES

Sleep-related problems and detection of them remain largely an unidentified public health issue, especially among university students. This study aims to assess the validity of the Pittsburgh Sleep Quality Index (PSQI) among Nigerian university students.

METHODS

Five hundred and twenty students completed the PSQI, the 12-item General Health Questionnaire (GHQ-12) and questionnaires pertaining to socio-demographic details. The students were then interviewed for the diagnosis of insomnia according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth edition (DSM-IV) and the International Classification of Sleep Disorders, revised criteria (ICSD-R).

RESULTS

The PSQI was of moderate value in screening for insomnia, with the best cut-off score at 5 (sensitivity 0.720, specificity 0.545, overall correct classification rate 0.554). The correlation between the PSQI and the GHQ-12 was 0.252 (p<0.001). A 3-factor model was generated by principal component analysis.

CONCLUSION

The psychometric value of PSQI in screening for insomnia among Nigerian students was moderate compared to what has been obtained in Western cultures. Nonetheless, it is still a useful instrument in the detection of sleep problems in this population.

Psychological factors and insomnia among male civil servants in Japan

OBJECTIVE

This study aims at assessing the relative impact of psychological factors on insomnia among daytime workers.

BACKGROUND

Insomnia affects 5-45% of non-shift workers, making it a serious public health concern.

METHODS

The study population was 3435 male civil servants aged 35 years and over. A self-administered questionnaire survey was conducted in 2002. Annual health examination data compiled in the same year were also obtained. Insomnia was assessed in three domains: difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and poor quality of sleep (PQS). Association of each factor with insomnia was examined by age-adjusted logistic regression models. Factors significantly associated with insomnia in age-adjusted analyses were entered in the stepwise logistic regression models to test the relative impact of each factor.

RESULTS

Prevalence of insomnia was 12.3% (DIS), 20.4% (DMS), and 32% (PQS). In stepwise logistic models, high perceived stress was associated with all types of insomnia with odds ratios (95% confidence interval) of 2.27 (1.58-3.26), 2.15 (1.57-2.95), and 2.96 (2.19-3.99), for DIS, DMS, and PQS, respectively. Poor psychological well-being or not having confidants was also associated with insomnia. Somatic conditions such as illnesses or history of hospitalization were related to DIS and DMS.

CONCLUSIONS

Psychological factors were strongly associated with DIS and PQS after controlling for possible confounders. In dealing with insomnia, such factors must not be neglected.

Sleep and psychiatric disorders: future directions

Understanding of the relationship between co-occurring sleep and psychiatric disorders has undergone a radical change. The longstanding perspective that sleep problems invariably are a symptom of a psychiatric disorder is giving way to understanding that complex bidirectional relationships may exist. This change has opened doors to new directions in research and led to changes in guidelines for clinical practice. This article discusses promising future directions for building on this foundation, including developing lines of research currently underway, studying mechanisms that underlie the relationships between sleep and psychiatric disorders; and developing treatment strategies that target these mechanisms to lead to better treatment of sleep disorders and psychiatric disorders.

Clinical characteristics of Restless legs syndrome in patients with Parkinson's disease

To assess the characteristics, clinical significance and pathology of Restless legs syndrome (RLS) in patients with Parkinson's disease (PD), we studied clinical backgrounds, RLS symptoms, polysomnographic (PSG) variables and therapeutic outcomes in 13 PD patients with RLS (pRLS), and compared them with those of 22 idiopathic RLS patients (iRLS). In all but one pRLS patient, RLS symptoms arose within 5 years of PD onset. pRLS patients had a lower prevalence of family history of RLS, and the age at onset was higher than in iRLS subjects. Scores for the severity scale established by the International Restless Legs Syndrome Study Group (IRLS), the Pittsburgh Sleep Quality Index, and the suggested immobilization test did not differ between groups. However, the periodic limb movements index measured by polysomnogram was smaller in pRLS subjects. After RLS treatment, symptoms improved significantly in both groups; however, pRLS subjects showed higher IRLS scores despite receiving similar doses of RLS medications. The severity of RLS before treatment was quite similar between the two groups, but the response to treatment could be poorer in pRLS than in iRLS. Thus, degeneration of the diencephalospinal dopaminergic pathway due to PD itself and physiological aging could overlap in the pathology of pRLS.

Objectively measured sleep characteristics among early-middle-aged adults: the CARDIA study

Despite mounting evidence that sleep duration is a risk factor across diverse health and functional domains, little is known about the distribution and determinants of sleep. In 2003-2004, the authors used wrist activity monitoring and sleep logs to measure time in bed, sleep latency (time required to fall asleep), sleep duration, and sleep efficiency (percentage of time in bed spent sleeping) over 3 days for 669 participants at one of the four sites of the Coronary Artery Risk Development in Young Adults (CARDIA) study (Chicago, Illinois). Participants were aged 38-50 years, 58% were women, and 44% were Black. For the entire sample, mean time in bed was 7.5 (standard deviation (SD), 1.2) hours, mean sleep latency was 21.9 (SD, 29.0) minutes, mean sleep duration was 6.1 (SD, 1.2) hours, and mean sleep efficiency was 80.9 (SD, 11.3)%. All four parameters varied by race-sex group. Average sleep duration was 6.7 hours for White women, 6.1 hours for White men, 5.9 hours for Black women, and 5.1 hours for Black men. Race-sex differences (p < 0.001) remained after adjustment for socioeconomic, employment, household, and lifestyle factors and for apnea risk. Income was independently associated with sleep latency and efficiency. Sleep duration and quality, which have consequences for health, are strongly associated with race, sex, and socioeconomic status.

Spa resort use and health-related quality of life, sleep, sickness absence and hospital admission: The Japanese civil servants study

OBJECTIVE

To examine whether spa resort use is associated with the health of Japanese employees.

DESIGN

Cross-sectional survey.

PARTICIPANTS

3341 employees (2280 males and 1061 females) aged 20-65 in local government in Japan.

MAIN OUTCOME MEASURES

The physical and mental component summary scores (PCS and MCS) of the Short Form 36 (SF-36), sleep quality as measured by the Pittsburgh Sleep Quality Index (PSQI), sickness leave (> or =7 days in the previous year), and hospital admission in the previous year.

RESULT

The PCS and MCS increased with the frequency of spa resort use in men and women. Less frequent use was associated with poor sleep quality for men and women and sickness leave for men. There was no significant relationship between use frequency and hospital admission.

CONCLUSIONS

Spa resort use may have beneficial effects on physical and particularly mental health. Longitudinal research is necessary to clarify the causality.

Association of sleep quality and free time leisure activities in Japanese and British civil servants

Sleep disturbance as a pervasive health problem can directly affect the physical and psychological well-being of individuals. Factors that positively relate to sleep quality can therefore improve healthy functioning. We examined whether leisure time activities are associated with sleep quality in two culturally different samples of civil servants. In this cross-sectional study we evaluated 1,682 Japanese, in Toyama prefecture (T) city, and 6,914 British civil servants from the Whitehall II study undertaken in London. The Japanese version of Pittsburgh sleep quality index (PSQI-J) was used in T city and Jenkins' sleep problem scale was used in the Whitehall II study. Setting a validated cut-off point of 5.5 for the PSQI-J global score and the upper tertile point for the Jenkins' sleep problem scale, we conducted logistic regression analysis to assess the association between leisure time activities and sleep quality. In both populations, those who participated in voluntary activities in clubs or organizations were significantly less likely to have poor sleep quality with Odds 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 visiting friends and relatives (ORs 0.60 (95%CI; 0.46-0.80) and 0.71 (95%CI; 0.56-0.90) for Japanese and British subjects, respectively). Our findings suggest that engagement in social leisure activities is associated with better sleep quality and consequently better general well-being.

Daily illumination exposure and melatonin: influence of ophthalmic dysfunction and sleep duration

BACKGROUND

Ocular pathology lessens light's efficacy to maintain optimal circadian entrainment. We examined whether ophthalmic dysfunction explains unique variance in melatonin excretion of older adults over and above the variance explained by daily illumination, medical, and sociodemographic factors. We also examined whether ophthalmic dysfunction influences relationships between ambient illumination and melatonin.

METHODS

Thirty older adults (mean age = 69 years; Blacks = 42% and Whites = 58%) of both genders participated in the study. Demographic and health data were collected at baseline. Participants underwent eye exams at SUNY Downstate Medical Center, wore an actigraph to monitor illumination and sleep, and collected urine specimens to estimate aMT6s concentrations.

RESULTS

Hierarchical regression analysis showed that illumination factors explained 29% of the variance in aMT6s mesor. The proportion of variance explained by ophthalmic factors, sleep duration, and race was 10%, 2%, and 2%, respectively. Illumination factors explained 19% of the variance in aMT6s acrophase. The proportion of variance explained by ophthalmic factors, sleep duration, and race was 11%; 17%; and 2%, respectively. Controlling for sleep duration and race reduced the correlations between illumination and melatonin, whereas controlling for ophthalmic factors did not.

CONCLUSION

Ophthalmic exams showed that elevated intraocular pressure and large cup-to-disk ratios were independently associated with earlier melatonin timing. Lower illumination exposure also had independent associations with earlier melatonin timing. Conceivably, ophthalmic and illumination factors might have an additive effect on the timing of melatonin excretion, which in turn might predispose individuals to experience early morning awakenings.

Prevalence and clinical characteristics of restless legs syndrome in Japanese patients with Parkinson's disease

To explore the clinical significance of restless legs syndrome (RLS) in Parkinson's disease (PD) and the causal relationship between these two disorders, we made a comparison of both the prevalence of RLS and the severity of sleep disturbance manifested on the Pittsburg Sleep Quality Index (PSQI) between patients with PD (n=165) and age- and sex-matched control subjects (n=131). The prevalence of RLS diagnosed by clinical interview was significantly higher in PD patients than in control subjects (12% vs. 2.3%). PSQI score was significantly higher in PD patients with RLS than in both patients without RLS and controls. However, PSQI score was not statistically different between the latter two groups. Among the PD patients with RLS, only 2 had a positive family history of RLS. Only 3 PD patients had requested treatment for the disorder. Our results emphasize the etiological link between RLS and PD in a Japanese cohort, and the existence of RLS is thought to be one of the most important factors aggravating sleep disturbance in PD, despite the low RLS severity.

Psychometric Evaluation of the Chinese Version of the Pittsburgh Sleep Quality Index (CPSQI) in Primary Insomnia and Control Subjects

In order to effectively study the population experiencing insomnia, it is important to identify reliable and valid tools to measure sleep that can be administered in the home setting. The purpose of this study was to assess psychometric properties for the Chinese version of the Pittsburgh Sleep Quality Index (CPSQI) in community-dwelling adults with primary insomnia. The CPSQI had an overall reliability coefficient of 0.82 -0.83 for all subjects. "Subjective sleep quality" was the component most highly correlated with the global score. Overall, the CPSQI showed acceptable test-retest reliability over a 14- to 21-day interval with a coefficient of 0.85 for all subjects and 0.77 for primary insomniacs. The two contrasting groups had significantly different global and component scores. A CPSQI of greater than 5 yielded a sensitivity and specificity of 98 and 55% in primary insomniacs vs. controls. A CPSQI of greater than 6 resulted in a sensitivity and specificity of 90 and 67%. Results suggest that the CPSQI is a psychometrically sound measure of sleep quality and disturbance for patients with primary insomnia. It may not be an effective screening tool because of its low specificity, but it can be a sensitive, reliable, and valid outcome assessment tool for use in community-based studies of primary insomnia.

A brief sleep scale for Posttraumatic Stress Disorder: Pittsburgh Sleep Quality Index Addendum for PTSD

Sleep disturbances reflect a core dysfunction underlying Posttraumatic Stress Disorder (PTSD). Specifically, disruptive nocturnal behaviors (DNB) may represent PTSD-specific sleep disturbances. The Pittsburgh Sleep Quality Index Addendum for PTSD (PSQI-A) is self-report instrument designed to assess the frequency of seven DNB. The goal of this study was to examine the psychometric properties of the PSQI-A to characterize DNB in a group of participants with and without PTSD. Results indicate that the PSQI-A has satisfactory internal consistency and good convergent validity with two standard PTSD measures even when excluding their sleep-related items. A global PSQI score of 4 yielded a sensitivity of 94%, a specificity of 82%, and a positive predictive value of 93% for discriminating participants with PTSD from those without PTSD. The PSQI-A is a valid instrument for PTSD applicable to both clinical and research settings.

Quality of sleep in patients with schizophrenia is associated with quality of life and coping

BACKGROUND

While sleep disturbance is widespread in schizophrenia it is less clear whether sleep disturbance is uniquely related to impaired coping and perceived quality of life.

METHODS

We simultaneously assessed sleep quality, symptoms, and coping in 29 persons with schizophrenia or schizoaffective disorder in a post acute phase of illness. Assessment instruments included the Pittsburgh Sleep Quality Index; the Positive and Negative Symptom Scale; the Heinrichs Quality of Life Scale; and the Ways of Coping Scale. Multiple regressions were performed predicting quality of life and coping from sleep quality controlling for age and symptom severity. On a subset of seven subjects non-dominant wrist actigraphy was used as an objective check of their self-reported poor sleep.

RESULTS

Analyses revealed that poor sleep quality predicted low quality of life (r = -0.493; p = .022) and reduced preference for employing positive reappraisal when facing a stressor (r = -0.0594; p = 0.0012). Actigraphy confirmed poor sleep quality in a subset of subjects. They had shorter sleep duration (p < .0005), shorter average sleep episodes (p < .005) and more episodes of long awakening (p < 0.05) than community norms.

CONCLUSION

The results are consistent with the hypotheses that poor sleep may play a unique role in sustaining poor quality of life and impaired coping in patients with schizophrenia. These associations may hold for community controls as well.

CSF iron, ferritin and transferrin levels in restless legs syndrome

The aim of this study is evaluating iron, ferritin, and transferrin in both serum and CSF in patients of restless legs syndrome (RLS), based on the hypothesis that iron deficiency in the central nervous system (CNS) causes the symptoms as a result of the dysfunction of dopaminergic systems. These parameters, polysomnographic sleep measures, and subjective evaluation of the sleep quality were compared in 10 patients of idiopathic RLS (RLS group) and 10 age-matched patients of psychophysiological insomnia without RLS symptoms (non-RLS group). With sleep patterns, sleep latency was longer and sleep efficiency was lower in the RLS group than those in the non-RLS group. Periodic leg movement index in the RLS group was higher than that of the non-RLS group. With serum examination, there were no significant differences for the iron, ferritin, and transferrin values between the both groups. With CSF examination, the iron and ferritin values were lower and the transferrin values were higher in the RLS group than those in the non-RLS group. There was positive correlation between the serum and CSF ferritin levels in the both groups, but the slope of the regression lines for the RLS group was lower than that for the non-RLS group. These results indicate low brain iron concentration caused by the dysfunction of iron transportation from serum to CNS in patients with idiopathic RLS.

An occupational health physician's report on the improvement in the sleeping conditions of night shift workers

This paper reviews briefly our research findings on sleep and health for shift workers at a bakery and a dish factory and aims to give some information on health protection with improved sleep. Our medical examinations revealed that rises in blood pressure (BP) were frequently observed in male bakery workers on the fixed night shift. They took a two-hour nap from 1:00 to 3:00 during the night shifts according to our advice. As a result, their diastolic BP significantly decreased in subsequent years. Women working shifts before 3:00 at a dish factory seemed to show more sleep disturbance, higher daytime sleepiness, and more fatigue than those working shits from 3:00. Total sleep hours taken during the daytime was similar between two groups. Among the dish, factory workers who switched to midnight or night shifts, 70% reported slow recovery from fatigue and 30% felt deteriorated health. These women also reported increased efforts to obtain a deep sleep, probably making up for shortened sleep. Occupational physicians can act to improve shift work conditions through monitoring the health of workers, applying naps, and designing possible schedules to secure deep, sufficient sleep.

A systematic review of patient-reported outcome instruments measuring sleep dysfunction in adults

Sleep dysfunction can manifest in several ways, ranging from insomnia to somnolence, and from disrupted sleep to lack of restful sleep. Measuring sleep dysfunction is an area of active research and there exist a number of patient-reported outcome instruments that measure various aspects of sleep dysfunction. However, these instruments have not been evaluated systematically. We used a conceptual model of sleep that included four physical domains of general interest to patients and investigators, and cover the breadth of this disorder: sleep initiation; sleep maintenance; sleep adequacy; and somnolence. We next considered the additional health-related quality-of-life (HR-QOL) domains of psychological and social functioning, progressing along the continuum to include health perceptions and opportunity. We then conducted a literature review to identify instruments and, using criteria developed by the Medical Outcomes Trust Scientific Advisory Committee, evaluated these instruments for their potential use in measuring sleep dysfunction. Twenty-two instruments were identified. Six instruments were found to include the four physical domains defined a priori (Basic Nordic Sleep Questionnaire, Leeds Sleep Evaluation Questionnaire, Medical Outcomes Study - Sleep Problems Measures, Pittsburgh Sleep Diary, Pittsburgh Sleep Quality Index, Self-Rated Sleep Questionnaire and the Sleep Dissatisfaction Questionnaire). Several additional instruments addressed at least some of the domains and thus may be useful for specific purposes. A few instruments addressed overall HR-QOL, but did not include all four domains of interest (Functional Outcomes of Sleep Questionnaire, Quality of Life in Insomniacs and the Sleep-Wake Activity Inventory). Two instruments had undergone extensive psychometric evaluation (Medical Outcomes Study - Sleep Problems Measures and Pittsburgh Sleep Quality Index), with only the latter reporting information about interpretability. Our review indicates that measuring sleep dysfunction in adults is an area of active research and that much work still needs to be completed, specifically the study of interpretability and the application of patient preferences or item response theory. The specific research focus should dictate instrument selection.

Attachment, Sleep Quality, and Depressed Affect

This study examined the role of attachment insecurity in sleep problems among married adults (N=78 couples). Using the Pittsburgh Sleep Quality Index and structural equation modeling, attachment anxiety was associated with higher levels of self-reported sleep difficulties for men and women, whereas attachment avoidance was not. Depressed affect was included as a control variable, and the effect of attachment anxiety remained significant. Men and women did not differ significantly in the magnitude of the effect of attachment anxiety on sleep quality. In addition, there were no cross-partner effects of attachment insecurity on sleep quality or depressed affect. Implications and future directions are discussed.

An epidemiologic review on occupational sleep research among Japanese workers

Epidemiologic sleep research on Japanese workers has been increasing in recent years. It is timely to give an overview of the sleep issues facing the Japanese working population by reviewing the accumulated epidemiological evidence, which will contribute to the promotion of a sound occupational health policy and the development of occupational sleep research in epidemiology. This paper reviews 24 studies, 13 for non-shift and 11 for shift Japanese workers, identified by using MEDLINE and Japan Cetra Revuo Medicina. The results reviewed are as follows: 1) the prevalence of insomnia and other sleep problems is substantially varied, 5 to 45% for non-shift and 29 to 38% for shift workers, 2) poor sleep quality is related to health, occupational activities and personal relations, 3) the risk or associated factors are identified in pathophysiology (e.g., hypertension), lifestyle behaviors (e.g., diet, alcohol, tobacco), job-related conditions (e.g., job stress, social support, job dissatisfaction, workload, shift schedules) and psychopathology (e.g., depressed mood). The methodological limitations found in the studies and the strategies of future epidemiologic sleep research in workers are discussed.

Clinical correlates of poor sleep quality in posttraumatic stress disorder

Sleep disturbances (SD) are a core clinical feature of PTSD. The goal of the study was to determine the influence of patient-related characteristics, disorder-related characteristics, and psychiatric comorbidity on the severity of SD in PTSD outpatients (n = 367) who were not recruited for a sleep study. Increased severity of SD paralleled increasing overall PTSD severity. The severity of SD did not differ according to gender, age groups, types of trauma, PTSD chronicity, or psychiatric comorbidity. Results suggest that age, gender, and psychiatric comorbidity have minimal impact on sleep quality in this PTSD sample. The inclusion of PTSD patients who were not specifically seeking treatment for SD reinforces the study findings.

Validity of a short insomnia questionnaire: the SDQ

The SDQ is a brief self-report insomnia questionnaire, which permits the rapid evaluation of insomnia based on the DSM-IV and ICSD-R criteria. The SDQ was developed to provide a fast and valid instrument both for the pre-screening of subjects who complain of insomnia and for epidemiological studies based on standardized definitions of this sleep disorder. Two studies were carried out in order to assess the validity of the SDQ as a self-report measure of insomnia. In the first study the convergent validity of the SDQ was assessed with respect to the global score of the Pittsburgh Sleep Quality Index (PSQI) in a sample of general practitioners' patients. The second study assessed the sensitivity and the specificity of the SDQ in discriminating between insomniacs or normal sleepers in a sample of college students who were given an extensive sleep evaluation within an insomnia counseling program. The SDQ classifications have a good convergent validity with the global sleep quality scores of the PSQI and its classifications of students who complain of or who do not complain of problems of insomnia have a sensitivity of 95% and a specificity of 87%. Results indicate that the SDQ is a valid paper and pencil instrument to screen insomnia.

Insomnia causes, consequences, and therapeutics: an overview

There is growing interest in insomnia both from the perspective of recent advances in clinical management as well as research aimed at elucidating its pathophysiology. This theoretical overview of insomnia describes the negative impact, etiological considerations, and pharmacological and behavioral treatments for the disorder, with an emphasis on areas receiving increased research attention. Insomnia, the most prevalent sleep disorder, affects 10-15% of the general population. In population-based studies severe insomnia has been shown to last for a median of 4 years. In addition, insomnia has a significant negative impact on an individual's work, physical, and social performance as well as overall quality of life. Furthermore, the economic cost of insomnia related to lost productivity, work-related accidents, absenteeism, and health-care costs are enormous. There is increasing evidence linking the precipitation of insomnia to stress, and converging evidence from cognitive, endocrine, neurological, and behavioral domains provide clear evidence for hyper-arousal in insomnia. However, there remains no consensus regarding the specific etiological mechanisms of this disorder. Although the pathophysiology of primary insomnia remains an enigma, numerous treatments both pharmacological and behavioral have been developed and found to be efficacious in controlled studies. Despite the wide availability of pharmacological treatments and increased knowledge of behavioral interventions, the vast majority of individuals with insomnia do not appear to be receiving adequate treatment. The inadequate treatment of insomnia leads to several important and under-recognized consequences including subsequent development of psychiatric disease and increased substance use.

The diagnostic validity of the Athens Insomnia Scale

OBJECTIVE

To provide documentation for the diagnostic validity of the Athens Insomnia Scale (AIS), a self-assessment psychometric tool which has previously shown high consistency, reliability and external validity for the evaluation of the intensity of sleep difficulty.

METHODS

The AIS was administered to a total of 299 subjects (105 primary insomniacs, 100 psychiatric outpatients, 44 psychiatric inpatients and 50 nonpatient controls) who were also assessed for the ICD-10 diagnosis of "nonorganic insomnia" blindly in terms of the AIS scores.

RESULTS

176 subjects were identified as insomniacs and 123 as noninsomniacs. Logistic regression of AIS total score against the ICD-10 diagnosis of insomnia demonstrated that a score of 6 is the optimum cutoff based on the balance between sensitivity and specificity. When diagnosing individuals with a score of 6 or higher as insomniacs, the scale presents with 93% sensitivity and 85% specificity (90% overall correct case identification). For this cutoff score, in the general population, the scale has a positive predictive value (PPV) of 41% and a negative predictive value (NPV) of 99%. For the same cutoff score, among unselected psychiatric patients, the PPV was found to be 86% and the NPV 92%. Other cutoff scores can be also considered, however, depending on the importance of avoiding false positive or false negative results; for example, for a cutoff score of 10, the PPV in the general population reaches about 90% without the NPV becoming lower than 94%.

CONCLUSION

The AIS can be utilized in clinical practice and research, not only as an instrument to measure the intensity of sleep-related problems, but also as a screening tool in reliably establishing the diagnosis of insomnia.