This study aimed to report lifetime and 4-week low back pain (LBP) prevalence and examine factors associated with chronic LBP and back pain disability over a lifetime in a Japanese adult population. In February 2011, 1,063,083 adults aged 20-79 years registered as internet research volunteers were randomly selected to participate in a questionnaire survey. The data from 65,496 respondents were analyzed to calculate age-standardized lifetime and 4-week prevalence. Chronic LBP and back pain disability were defined as LBP lasting for ≥ 3 months and a consecutive ≥ 4-day-long absence, respectively. Factors associated with chronic disabling back pain over a lifetime were examined by multiple logistic regression modeling. The lifetime LBP prevalence was 83 % and 4-week prevalence was 36 %; majority of the respondents had disability-free LBP. Smoking [adjusted odds ratio (aOR): 1.17; 95 % CI: 1.05, 1.30], lower educational level (aOR: 1.21; 95 % CI: 1.09, 1.34), history of disabling back pain among family members and/or significant others (aOR: 1.46; 95 % CI: 1.27, 1.67), occupational LBP (aOR: 1.34; 95 % CI: 1.16, 1.55), traffic injury (aOR: 2.81; 95 % CI: 2.07, 3.81), compensated work injury (aOR: 2.42; 95 % CI: 1.92, 3.05), radiating pain (aOR: 4.94; 95 % CI: 4.45, 5.48), low back surgery (aOR: 10.69; 95 % CI: 9.02, 12.68), and advice to rest upon back pain consultation (aOR: 3.84; 95 % CI: 3.36, 4.40) were associated with chronic disabling back pain over a lifetime. LBP is common in Japan as in other industrialized countries. The association between the advice to rest and chronic disabling back pain supports recent treatment guidelines emphasizing continuation of daily activities.
