Epidemiology of sleep and sleep disorders in The Netherlands.

OBJECTIVE: There is a surging public interest in The Netherlands concerning sleep, sleep disorders and associated health. For a proper perspective, it is necessary to have reliable information on the prevalence of sleep characteristics at the national level. This study set out to assess prevalence rates and key characteristics of sleep and sleep disorders in The Netherlands. METHODS: In 2012, a nationally representative sample of 2089 individuals, aged 18-70 years, responded to a set of 48 questions, including the Holland Sleep Disorders Questionnaire, a validated questionnaire based on the International Classification of Sleep Disorders. RESULTS: Prevalence rates were: 32.1% for a general sleep disturbance (GSD), 43.2% for insufficient sleep, 8.2 for insomnia, 5.3% for circadian rhythm sleep disorder, 6.1% for parasomnia, 5.9% for hypersomnolence, 12.5% for restless legs disorder and limb movements during sleep, 7.1% for sleep related breathing disorder, and 12.2% for the presence of comorbidity, ie, the presence of two or more concurrent sleep disorders. In addition, sleep onset time as well as sleep duration showed U-shaped relationships with GSD prevalence rates, with respectively the 22:00-24:00 period and seven to 8 h as optimal associates. CONCLUSIONS: Sleep disorders and insufficient sleep have a high prevalence. As matter of concern, female adolescents reached the highest prevalence rates for most sleep disorders, insufficient sleep and daytime malfunctioning.

Cross-cultural and comparative epidemiology of insomnia: the Diagnostic and statistical manual (DSM), International classification of diseases (ICD) and International classification of sleep disorders (ICSD).

OBJECTIVE: To compare the prevalence of insomnia according to symptoms, quantitative criteria, and Diagnostic and Statistical Manual of Mental Disorders, 4th and 5th Edition (DSM-IV and DSM-5), International Classification of Diseases, 10th Revision (ICD-10), and International Classification of Sleep Disorders, 2nd Edition (ICSD-2), and to compare the prevalence of insomnia disorder between Hong Kong and the United States by adopting a similar methodology used by the America Insomnia Survey (AIS). METHODS: Population-based epidemiological survey respondents (n = 2011) completed the Brief Insomnia Questionnaire (BIQ), a validated scale generating DSM-IV, DSM-5, ICD-10, and ICSD-2 insomnia disorder. RESULTS: The weighted prevalence of difficulty falling asleep, difficulty staying asleep, waking up too early, and non-restorative sleep that occurred ≥3 days per week was 14.0%, 28.3%, 32.1%, and 39.9%, respectively. When quantitative criteria were included, the prevalence dropped the most from 39.9% to 8.4% for non-restorative sleep, and the least from 14.0% to 12.9% for difficulty falling asleep. The weighted prevalence of DSM-IV, ICD-10, ICSD-2, and any of the three insomnia disorders was 22.1%, 4.7%, 15.1%, and 22.1%, respectively; for DSM-5 insomnia disorder, it was 10.8%. CONCLUSION: Compared with 22.1%, 3.9%, and 14.7% for DSM-IV, ICD-10, and ICSD-2 in the AIS, cross-cultural difference in the prevalence of insomnia disorder is less than what is expected. The prevalence is reduced by half from DSM-IV to DSM-5. ICD-10 insomnia disorder has the lowest prevalence, perhaps because excessive concern and preoccupation, one of its diagnostic criteria, is not always present in people with insomnia.

Comparison of scoring methods for the Brief Insomnia Questionnaire in a general population sample.

OBJECTIVE: The Brief Insomnia Questionnaire (BIQ) is a lay-administered, structured interview to derive insomnia disorders according to the Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR), International Classification of Diseases, Tenth Edition (ICD-10) and research diagnostic criteria/International Classification of Sleep Disorders, Second Edition (RDC/ICSD-2). The concordance between diagnoses derived from the BIQ and clinical interviews was only moderate and the prevalence estimates based on the BIQ were significantly different from estimates based on clinical interviews. We hypothesized that a modification of the scoring algorithm closer to the diagnostic criteria would improve the performance of the BIQ. METHODS: Probability subsample of population-based epidemiological survey respondents (n=2011) completed clinical reappraisal (n=176) interviews. We compared the modified scoring with the original scoring in sensitivity, specificity, positive and negative predictive values, areas under the characteristic curve, and Cohen's kappa to detect DSM-IV-TR, ICD-10 and RDC/ICSD-2 insomnia diagnoses by the BIQ against clinical interviews. RESULT: The diagnostic accuracy was improved with the modified scoring. The areas under the receiver operating characteristic curve for the DSM-IV-TR, ICD-10, RDC/ICSD-2 and any of the insomnia diagnoses ranged from 0.76 to 0.87. Using the modified scoring, there was no significant difference between prevalence estimates based on the BIQ classification and clinical interviews. CONCLUSIONS: The BIQ with modified scoring enhanced case detection and produced more accurate prevalence estimates of DSM-IV-TR, ICD-10 and RDC/ICSD-2 insomnia disorders. With scoring algorithms now extended to DSM-5 and ICSD-3 diagnoses, the BIQ should be more widely used in clinical and research settings.

Validity and reliability of the Brief Insomnia Questionnaire in the general population in Hong Kong.

OBJECTIVES: The Brief Insomnia Questionnaire (BIQ) was first validated in the U.S. for insomnia disorders according to the Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR), International Classification of Diseases, Tenth Edition (ICD-10) and research diagnostic criteria/International Classification of Sleep Disorders, Second Edition (RDC/ICSD-2). We aimed to determine the validity and reliability of a Hong Kong Chinese version of the BIQ to derive the DSM-5 in addition to other insomnia diagnoses in a general population sample. METHODS: Probability subsamples of population-based epidemiological survey respondents (n=2011) completed test-retest (n=120) and clinical reappraisal (n=176) interviews. RESULTS: Short-term test-retest reliability was moderate for most BIQ items (Pearson r>0.40), except for the number of nights with problems staying asleep, amount of time awake, duration of sleep problems and sleep onset latency. The areas under the receiver operating characteristic curve for the DSM-IV-TR, DSM-5, ICD-10 and RDC/ICSD-2 insomnia disorder ranged from 0.76 to 0.86, indicating high individual-level concordance between BIQ and clinical-interview diagnoses. The use of super-normal control and BIQ symptom-level data further improves the diagnostic concordance. Prevalence estimates based on the BIQ dichotomous classification were comparable with estimates based on clinical interviews for the DSM-5, RDC/ICSD-2 and any of the DSM-IV-TR, ICD-10 and RDC/ICSD-2 insomnia disorders. CONCLUSION: The Hong Kong Chinese version of the BIQ generates accurate prevalence estimates for insomnia disorders in the general population. Modification of the BIQ scoring algorithms and use of trained interviewers may further improve its diagnostic performance.

Undiagnosed and comorbid disorders in patients with presumed chronic fatigue syndrome.

OBJECTIVE: To assess undiagnosed and comorbid disorders in patients referred to a tertiary care center with a presumed diagnosis of chronic fatigue syndrome (CFS). METHODS: Patients referred for chronic unexplained fatigue entered an integrated diagnostic pathway, including internal medicine assessment, psychodiagnostic screening, physiotherapeutic assessment and polysomnography+multiple sleep latency testing. Final diagnosis resulted from a multidisciplinary team discussion. Fukuda criteria were used for the diagnosis of CFS, DSM-IV-TR criteria for psychiatric disorders, ICSD-2 criteria for sleep disorders. RESULTS: Out of 377 patients referred, 279 (74.0%) were included in the study [84.9% female; mean age 38.8years (SD 10.3)]. A diagnosis of unequivocal CFS was made in 23.3%. In 21.1%, CFS was associated with a sleep disorder and/or psychiatric disorder, not invalidating the diagnosis of CFS. A predominant sleep disorder was found in 9.7%, 19.0% had a psychiatric disorder and 20.8% a combination of both. Only 2.2% was diagnosed with a classical internal disease. In the total sample, a sleep disorder was found in 49.8%, especially obstructive sleep apnea syndrome, followed by psychophysiologic insomnia and periodic limb movement disorder. A psychiatric disorder was diagnosed in 45.2%; mostly mood and anxiety disorder. CONCLUSIONS: A multidisciplinary approach to presumed CFS yields unequivocal CFS in only a minority of patients, and reveals a broad spectrum of exclusionary or comorbid conditions within the domains of sleep medicine and psychiatry. These findings favor a systematic diagnostic approach to CFS, suitable to identify a wide range of diagnostic categories that may be subject to dedicated care.

Delayed sleep phase disorder in an Australian school-based sample of adolescents.

STUDY OBJECTIVES: To establish the extent to which the developmental changes in sleep timing experienced by Australian adolescents meet the International Classification of Sleep Disorders (ICSD-2) diagnostic criteria for delayed sleep phase disorder (DSPD), and whether adolescents with DSPD engage in poorer lifestyle choices, and are more impaired compared to good sleeping adolescents. METHODS: Three-hundred seventy-four Australian adolescents (mean age 15.6 years, SD 1.0) participants completed a 7-day sleep diary, wore wrist actigraphy, and completed a battery of questionnaires to assess DSPD criteria. RESULTS: The ICSD-2 criteria for DSPD were met by 1.1% (N = 4) of the adolescents sampled. The majority of adolescents (51.9%, N = 194) met one criterion, 14% (N = 52) of the adolescents met 2 criteria, while 33.2% (N = 124) did not fulfill any DSPD criteria. Despite having significantly delayed sleep timing, adolescents who met all criteria for DSPD reported similar lifestyle habits and daytime functioning. However, there were trends for greater alcohol and caffeine consumption, less sport participation, yet more time spent on extracurricular activities (i.e., learning to play a musical instruments for adolescents with DSPD. CONCLUSIONS: Despite the majority of adolescents reporting DSPD symptoms, only a small minority met full diagnostic criteria. Adolescents with DSPD reported similar lifestyle habits and daytime functioning to those with some or no symptoms. Future investigations of non-school-attending DSPD adolescents are needed to confirm the trends for lifestyle behaviors found in the present study.

Reliability and validity of the brief insomnia questionnaire in the America insomnia survey.

STUDY OBJECTIVES: to evaluate the reliability and validity of the Brief Insomnia Questionnaire (BIQ), a fully structured questionnaire developed to diagnose insomnia according to hierarchy-free Diagnostic and Statistical Manual, Fourth Edition, Text Revision (DSM-IV-TR), International Classification of Diseases-10 (ICD-10), and research diagnostic criteria/International Classification of Sleep Disorders-2 (RDC/ICSD-2) general criteria without organic exclusions in the America Insomnia Survey (AIS). DESIGN: probability subsamples of AIS respondents, oversampling BIQ positives, completed short-term test-retest interviews (n = 59) or clinical reappraisal interviews (n = 203) to assess BIQ reliability and validity. SETTING: the AIS is a large (n = 10,094) epidemiologic survey of the prevalence and correlates of insomnia. PARTICIPANTS: adult subscribers to a national managed healthcare plan. INTERVENTION: None MEASUREMENTS AND RESULTS: BIQ test-retest correlations were 0.47-0.94 for nature of the sleep problems (initiation, maintenance, nonrestorative sleep [NRS]), 0.72-0.95 for problem frequency, 0.66-0.88 for daytime impairment/distress, and 0.62 for duration of sleep. Good individual-level concordance was found between BIQ diagnoses and diagnoses based on expert interviews for meeting hierarchy-free inclusion criteria for diagnoses in any of the diagnostic systems, with area under the receiver operating characteristic curve (AUC, a measure of classification accuracy insensitive to disorder prevalence) of 0.86 for dichotomous classifications. The AUC increased to 0.94 when symptom-level data were added to generate continuous predicted-probability of diagnosis measures. The AUC was lower for dichotomous classifications based on RDC/ICSD-2 (0.68) and ICD-10 (0.70) than for DSM-IV-TR (0.83) criteria but increased consistently when symptom-level data were added to generate continuous predicted-probability measures of RDC/ICSD-2, ICD-10, and DSM-IV-TR diagnoses (0.92-0.95). CONCLUSIONS: these results show that the BIQ generates accurate estimates of the prevalence and correlates of hierarchy-free insomnia in the America Insomnia Survey.