Proposal and Initial Validation of a Brief Questionnaire for Epidemiological Assessment of Low Back Pain

Low back pain (LBP) is one of the most prevalent pain conditions worldwide and a major contributor to disability. Although numerous epidemiological studies have investigated LBP, heterogeneity in pain definitions and assessment indicators has limited comparability across studies. A brief and reproducible questionnaire incorporating core LBP indicators commonly used in pain epidemiology may facilitate consistent assessment of LBP occurrence and impact in population-based research.

We proposed a brief low back pain questionnaire (B-LBPQ) designed to assess the occurrence and characteristics of LBP in epidemiological studies. The B-LBPQ consists of seven items covering current LBP, LBP during the past 12 months, lifetime experience of LBP, pain duration, and pain-related interference with daily activities. A cross-sectional validation study was conducted among 783 Japanese welfare workers aged 20-74 years (mean age: 41.9 years) undergoing routine health checkups. Construct validity was examined by comparing questionnaire-based LBP classifications with scores on the Roland-Morris Disability Questionnaire (RDQ). Internal consistency was assessed using Cronbach's alpha. Test-retest reliability over a 2-week interval was evaluated among 595 participants using kappa statistics, prevalence-adjusted bias-adjusted kappa (PABAK), and weighted kappa coefficients.

Construct validity was supported by significantly higher RDQ scores among participants reporting LBP compared with those without LBP (all p < 0.001). For items with multiple response categories, significant differences and ordered trends in RDQ scores were observed across response categories (all p for trend < 0.001). Internal consistency was acceptable (Cronbach's α = 0.87). Test-retest reliability ranged from substantial to almost perfect, with PABAK values of 0.70-0.85 for dichotomous items and weighted kappa coefficients of 0.65-0.81 for items with three or more categories.

The B-LBPQ demonstrated initial reliability and construct validity in Japanese welfare workers and may be useful for epidemiological assessment of LBP. However, further validation in diverse populations and settings is required.