*Chronic hepatitis B patients without liver cirrhosis and liver cancer during enrollment. **Healthy volunteers from Osaka Midosuji Rotary Club, Osaka, Japan.
Association (χ2) and prevalence ratio of back pain frequency with independent variables (demographic, socioeconomic, anthropometric, and psychosocial).
Additional file 1. Questionnaires used in the study. Appendix 1a is questionnaire for children and appendix 1b for mothers. These questionnaires were solely developed for this study and it mainly incl