Int.J. Behav. Med. DOI 10.1007/s12529-014-9421-7
Internet-Based Survey of Factors Associated with Subjective Feeling of Insomnia, Depression, and Low Health-Related Quality of Life Among Japanese Adults with Sleep Difficulty Sayaka Aritake & Shoichi Asaoka & Tatsuo Kagimura & Akiyoshi Shimura & Kunihiro Futenma & Yoko Komada & Yuichi Inoue
# International Society of Behavioral Medicine 2014
Abstract Background This study was conducted to determine what symptom components or conditions of insomnia are related to subjective feelings of insomnia, low health-related quality of life (HRQOL), or depression. Method Data from 7,027 Japanese adults obtained using an Internet-based questionnaire survey was analyzed to examine associations between demographic variables and each sleep difficulty symptom item on the Pittsburgh Sleep Quality Index (PSQI) with the presence/absence of subjective insomnia and scores on the Short Form-8 (SF-8) and Center for Epidemiologic Studies Depression Scale (CES-D). Results Prevalence of subjective insomnia was 12.2 % (n= 860). Discriminant function analysis revealed that item scores for sleep quality, sleep latency, and sleep medication use on the PSQI and CES-D showed relatively high discriminant function coefficients for identifying positivity for the subjective feeling of insomnia. Among respondents with subjective S. Aritake : S. Asaoka : A. Shimura : K. Futenma : Y. Komada : Y. Inoue (*) Department of Somnology, Tokyo Medical University, 6-7-1 Nishi-shinjuku, Shinjuku, Tokyo 160-0023, Japan e-mail: [email protected] S. Aritake Japan Society for the Promotion of Science, Tokyo 102-8471, Japan S. Aritake : S. Asaoka : Y. Komada : Y. Inoue Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo 151-0053, Japan S. Aritake : T. Kagimura : A. Shimura : K. Futenma : Y. Inoue Department of Psychiatry, Tokyo Medical University, Tokyo 160-0023, Japan S. Aritake Faculty of Sport Sciences, Waseda University, Tokorozawa 359-1192, Japan
insomnia, a low SF-8 physical component summary score was associated with higher age, depressive state, and PSQI items for sleep difficulty and daytime dysfunction, whereas a low SF-8 mental component summary score was associated with depressive state, PSQI sleep latency, sleeping medication use, and daytime dysfunction. Depressive state was significantly associated with sleep latency, sleeping medication use, and daytime dysfunction. Conclusion Among insomnia symptom components, disturbed sleep quality and sleep onset insomnia may be specifically associated with subjective feelings of the disorder. The existence of a depressive state could be significantly associated with not only subjective insomnia but also mental and physical QOL. Our results also suggest that different components of sleep difficulty, as measured by the PSQI, might be associated with mental and physical QOL and depressive status. Keywords Insomnia . Health-related quality of life . Sleep difficulty . Daytime function . Sleep latency . Internet survey
Introduction Symptoms such as difficulty initiating sleep, decreased sleep quality, short sleep duration, and daytime dysfunction are crucial factors of insomnia. However, subjective recognition of the symptoms of insomnia varies across individuals. Several recent studies have reported that insomnia can cause daytime dysfunction, including psychophysiological impairment and elevated fatigue [1, 2], and that it is a known risk factor for developing depression and decreased health-related quality of life (HRQOL) [3–6]. Although a definitive diagnosis of insomnia requires a face-to-face interview by a clinician [7], previous reports have shown that standardized
Int.J. Behav. Med.
questionnaires such as the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index, and the Athens Insomnia Scale can identify sleep difficulty or the presence/absence of insomnia [8–12]. Studies using these questionnaires have shown that more than 20 % of the general population has insomnia symptoms (e.g., difficulty initiating sleep, decreased sleep quality, short sleep duration, and daytime dysfunction) [9, 10]. However, not more than 10 % of the general population seeks treatment for insomnia [13, 14]. This discrepancy suggests that more than half of those with symptoms of sleep difficulty do not subjectively feel that they have insomnia. Thus, it can be speculated that not all symptom components of sleep disturbance might specifically contribute to the increased subjective feeling of insomnia. Previously, we reported that sleep medication use in insomniacs was associated with higher scores of both poor subjective sleep quality and delayed sleep onset [15]. However, to date, the associated factors of subjective feelings of insomnia have remained unexplored. Similarly, the symptom components of sleep disturbance that are associated with depressive state as well as decreased HRQOL have not been identified. Against this background, we conducted an Internet-based survey of a large general population of Japanese adults to examine the associated sleep difficulty symptom items on the PSQI for the presence of subjective feeling of insomnia, decreased daytime HRQOL, and depressive state. For this purpose, the presence/absence of subjective feeling of insomnia was determined using a self-administered binary question.
question, which has commonly appeared in epidemiological studies on the prevalence of subjective insomnia [8–12, 17], and took the presence or absence of subjective insomnia as a dependent variable in discriminant function analysis (DFA) as indicated below: “Do you think that you have been suffering from insomnia for at least 1 month?” The presence of subjective insomnia was determined when the participant answered affirmatively. Participants also completed the Japanese version of the PSQI to assess sleep difficulty [18], the Short Form-8 (SF-8) to evaluate HRQOL [19–22], and the 16-item version of the Center for Epidemiologic Studies Depression Scale (CES-D), a scale often used in epidemiological studies, to evaluate depressive state [23, 24]. The PSQI included the following seven subitems: sleep quality (C1), sleep latency (C2), sleep duration (C3), habitual sleep efficiency (C4), sleep disturbance (C5), use of sleep medication (C6), and daytime dysfunction (C7). According to a previous report on the validity of the Japanese version of the PSQI [18], respondents with a total PSQI score of >5.5 points were defined as having pathological sleep difficulty. For the SF-8, score calculations of domains including general health, physical function, role physical, bodily pain, vitality, social function, mental health, and role emotional were made according to standard methods [19]. The SF-8 physical component summary score was evaluated as an index of physical QOL and the mental component summary score as an index of mental QOL. General population averages for these scores are set at 50 points, and a score of
Internet-Based Survey of Factors Associated with Subjective Feeling of Insomnia, Depression, and Low Health-Related Quality of Life Among Japanese Adults with Sleep Difficulty Sayaka Aritake & Shoichi Asaoka & Tatsuo Kagimura & Akiyoshi Shimura & Kunihiro Futenma & Yoko Komada & Yuichi Inoue
# International Society of Behavioral Medicine 2014
Abstract Background This study was conducted to determine what symptom components or conditions of insomnia are related to subjective feelings of insomnia, low health-related quality of life (HRQOL), or depression. Method Data from 7,027 Japanese adults obtained using an Internet-based questionnaire survey was analyzed to examine associations between demographic variables and each sleep difficulty symptom item on the Pittsburgh Sleep Quality Index (PSQI) with the presence/absence of subjective insomnia and scores on the Short Form-8 (SF-8) and Center for Epidemiologic Studies Depression Scale (CES-D). Results Prevalence of subjective insomnia was 12.2 % (n= 860). Discriminant function analysis revealed that item scores for sleep quality, sleep latency, and sleep medication use on the PSQI and CES-D showed relatively high discriminant function coefficients for identifying positivity for the subjective feeling of insomnia. Among respondents with subjective S. Aritake : S. Asaoka : A. Shimura : K. Futenma : Y. Komada : Y. Inoue (*) Department of Somnology, Tokyo Medical University, 6-7-1 Nishi-shinjuku, Shinjuku, Tokyo 160-0023, Japan e-mail: [email protected] S. Aritake Japan Society for the Promotion of Science, Tokyo 102-8471, Japan S. Aritake : S. Asaoka : Y. Komada : Y. Inoue Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo 151-0053, Japan S. Aritake : T. Kagimura : A. Shimura : K. Futenma : Y. Inoue Department of Psychiatry, Tokyo Medical University, Tokyo 160-0023, Japan S. Aritake Faculty of Sport Sciences, Waseda University, Tokorozawa 359-1192, Japan
insomnia, a low SF-8 physical component summary score was associated with higher age, depressive state, and PSQI items for sleep difficulty and daytime dysfunction, whereas a low SF-8 mental component summary score was associated with depressive state, PSQI sleep latency, sleeping medication use, and daytime dysfunction. Depressive state was significantly associated with sleep latency, sleeping medication use, and daytime dysfunction. Conclusion Among insomnia symptom components, disturbed sleep quality and sleep onset insomnia may be specifically associated with subjective feelings of the disorder. The existence of a depressive state could be significantly associated with not only subjective insomnia but also mental and physical QOL. Our results also suggest that different components of sleep difficulty, as measured by the PSQI, might be associated with mental and physical QOL and depressive status. Keywords Insomnia . Health-related quality of life . Sleep difficulty . Daytime function . Sleep latency . Internet survey
Introduction Symptoms such as difficulty initiating sleep, decreased sleep quality, short sleep duration, and daytime dysfunction are crucial factors of insomnia. However, subjective recognition of the symptoms of insomnia varies across individuals. Several recent studies have reported that insomnia can cause daytime dysfunction, including psychophysiological impairment and elevated fatigue [1, 2], and that it is a known risk factor for developing depression and decreased health-related quality of life (HRQOL) [3–6]. Although a definitive diagnosis of insomnia requires a face-to-face interview by a clinician [7], previous reports have shown that standardized
Int.J. Behav. Med.
questionnaires such as the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index, and the Athens Insomnia Scale can identify sleep difficulty or the presence/absence of insomnia [8–12]. Studies using these questionnaires have shown that more than 20 % of the general population has insomnia symptoms (e.g., difficulty initiating sleep, decreased sleep quality, short sleep duration, and daytime dysfunction) [9, 10]. However, not more than 10 % of the general population seeks treatment for insomnia [13, 14]. This discrepancy suggests that more than half of those with symptoms of sleep difficulty do not subjectively feel that they have insomnia. Thus, it can be speculated that not all symptom components of sleep disturbance might specifically contribute to the increased subjective feeling of insomnia. Previously, we reported that sleep medication use in insomniacs was associated with higher scores of both poor subjective sleep quality and delayed sleep onset [15]. However, to date, the associated factors of subjective feelings of insomnia have remained unexplored. Similarly, the symptom components of sleep disturbance that are associated with depressive state as well as decreased HRQOL have not been identified. Against this background, we conducted an Internet-based survey of a large general population of Japanese adults to examine the associated sleep difficulty symptom items on the PSQI for the presence of subjective feeling of insomnia, decreased daytime HRQOL, and depressive state. For this purpose, the presence/absence of subjective feeling of insomnia was determined using a self-administered binary question.
question, which has commonly appeared in epidemiological studies on the prevalence of subjective insomnia [8–12, 17], and took the presence or absence of subjective insomnia as a dependent variable in discriminant function analysis (DFA) as indicated below: “Do you think that you have been suffering from insomnia for at least 1 month?” The presence of subjective insomnia was determined when the participant answered affirmatively. Participants also completed the Japanese version of the PSQI to assess sleep difficulty [18], the Short Form-8 (SF-8) to evaluate HRQOL [19–22], and the 16-item version of the Center for Epidemiologic Studies Depression Scale (CES-D), a scale often used in epidemiological studies, to evaluate depressive state [23, 24]. The PSQI included the following seven subitems: sleep quality (C1), sleep latency (C2), sleep duration (C3), habitual sleep efficiency (C4), sleep disturbance (C5), use of sleep medication (C6), and daytime dysfunction (C7). According to a previous report on the validity of the Japanese version of the PSQI [18], respondents with a total PSQI score of >5.5 points were defined as having pathological sleep difficulty. For the SF-8, score calculations of domains including general health, physical function, role physical, bodily pain, vitality, social function, mental health, and role emotional were made according to standard methods [19]. The SF-8 physical component summary score was evaluated as an index of physical QOL and the mental component summary score as an index of mental QOL. General population averages for these scores are set at 50 points, and a score of
