Additional file 1: of Do medical conditions predispose to the development of chronic back pain? A longitudinal co-twin control study of middle-aged males with 11-year follow-up

Table S1. Incidence of Chronic Back Pain over 11-year Follow-up: Associations between medical conditions and incident chronic back pain, in those without physician-assessed back problems at baseline, with analyses stratified by zygosity*. (DOCX 96Â kb