Menstrual and reproductive factors and limitations in activities of daily living: A case–control study within the Japan Public Health Center‐based Prospective Study

Aim Although menstrual/reproductive factors are known to be associated with physical disability, little is known about these associations in relation to activities of daily living (ADL). This study aimed to clarify associations between menstrual/reproductive factors and ADL limitations in peri‐ and postmenopausal women. Study design A nested case–control study of the Japan Public Health Center‐based Prospective (JPHC) Study. Methods The main outcome measure was self‐reported ADL levels in the 10‐year follow‐up questionnaire survey of the JPHC Study conducted between 2000 and 2004 (N = 36 460). Women who “live inside almost independently, but go out with assistance” or had a lower level of activity were considered to have ADL limitations (“cases”), and all others served as controls. Candidate menstrual/reproductive predictors were as follows: menarcheal age, menopausal status, menopausal age, regularity of menses, menstrual cycle, number of pregnancies, age at first pregnancy, number of deliveries, age at first delivery, and breast feeding. Multiple logistic regression analyses were conducted, and odds ratios adjusted for age and past lifestyle were calculated. Results Mean ages of cases (N = 592) and controls (N = 38 656) were 68.3 (SD = 7.6) and 61.1 (SD = 7.7) years, respectively. With respect to menopausal age, groups aged