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.