Objectives To assess the differences in the prevalence and incidence of low back pain (LBP) and associated disability among office workers in Costa Rica, Nicaragua and Spain.

Methods Data were collected at baseline (n=947, 93% response) in November 2007 and at follow-up after 12 months (n=853, 90% response). Six outcome measures were examined: baseline prevalence of (1) LBP in the past 12 months, (2) LBP in the past month and (3) disabling LBP in the past month; and at follow-up: (4) incidence of new LBP in the past month, (5) new disabling LBP and (6) persistent LBP. Differences in prevalence by country were characterised by ORs with 95% CIs, before and after adjustment for covariates.

Results Prevalence of LBP in the past month among office employees in Costa Rica (46.0%) and Nicaragua (44.2%) was higher than in Spain (33.6%). Incidence of new LBP was 37.0% in Nicaragua (OR=2.49; 95% CI 1.57 to 3.95), 14.9% in Costa Rica (OR=0.74; 95% CI 0.41 to 1.34) and 19.0% in Spain (reference). Incidence of new disabling LBP was higher in Nicaragua (17.2%; OR=2.49; 95% CI 1.43 to 4.34) and Costa Rica (13.6%; OR=1.89; 95% CI 1.03 to 3.48) than Spain (7.7%), while persistence of LBP was higher only in Nicaragua.

Conclusions Prevalence of LBP and disabling LBP was higher in Costa Rican and Nicaraguan office workers than in Spain, but the incidence was higher mainly in Nicaragua. Measured sociodemographic, job-related and health-related variables only partly explained the differences between countries, and further research is needed to explore reasons for the remaining differences.