[A literature review on the relationship between questionnaires for assessing minor health complaints and health status indices among Japanese people].

Objectives　Minor health complaints related to stress, mental health, sleep, and fatigue are closely associated with each other, and their deterioration may cause lifestyle diseases. The health status of people can be predicted through a questionnaire by exploring the relationship between their state of minor health complaints and objective health status indices. Therefore, we conducted a systematic review of the relationship between a questionnaire on the state of minor health complaints and health status indices among Japanese people who have a high level of stress, which they experience on a daily basis, using epidemiological literature. Additionally, we considered items for the questionnaire which were necessary for an index development.Methods　The PubMed database was searched for papers on "autonomic nervous system," "sleep disorders," "mental health and stress," and "fatigue," using keywords mentioned in previous studies on minor health complaints.　The extracted research papers were screened according to the following inclusion criteria: 1) the participants were healthy Japanese people; 2) descriptions included characteristics of the target population; 3) use of analytic epidemiological study design, intervention studies, and systematic reviews; 4) minor health complaints assessed by a questionnaire; 5) evaluation of the relationship between the questionnaires for minor health complaints and the health index; and 6) written in Japanese or English. Based on this, ten papers were adopted.Results　Of the 10 papers collected, one was a cohort study, three were case-control studies, and six were cross-sectional studies. The participants in five of them were working adults. Reports on three out of six questionnaires on stress, four out of seven on sleep, and all two on comprehensive health status showed significant associations between minor health complaints assessed by the questionnaires and the index for health status. The increase in responses about work-related stress from the questionnaire was associated with an increase in the "risk of developing depression" [odds ratio 2.96 (confidence interval: 1.04-8.42)]. Poor sleep quality was associated with an increase in "changes in autonomic index," "number of comorbidities and the rate of depression," and the "risk of work-related injuries." Moreover, the health score was associated with the "autonomic nervous system index".Conclusion　These results suggest that a questionnaire evaluating minor health complaints should include questions about "stress," "sleep quality," and "comprehensive health status." Since studies that appropriately adopted for risk of bias were limited, it is necessary to further examine these relationships by applying prospective studies such as cohort studies and intervention studies.