Socioeconomic factors and disability retirement from back pain - A 1983-1993 population-based prospective study in Norway

Study Design. A prospective observational study with an 11-year follow-up p eriod was performed. Objective. To investigate the influence of education and socioeconomic posi tion on the incidence of permanent disability retirement from back pain. Summary of Background Data. Early retirement because of back pain is the ex treme end point of a disabling process that is a great burden to the indivi dual and costly for the society. Groups of employees at particular risk for permanent back pain disability need to be identified. Methods. All employed men and women in Norway between the ages of 20 and 53 years in 1980 were included (n = 1,333,556). Outcome measures were disabil ity retirement from inflammatory back pain (ICD-9 code 720) and noninflamma tory back pain (ICD-9 codes 721 to 724), Results. The 11-year cumulative incidence was 0.15% (n = 1990) far disabili ty retirement from inflammatory back pain and 1.64% (n = 21,829) for noninf lammatory back pain and was somewhat higher in women than in men. Each year of formal education was independently associated with decreased risk for d isability retirement from noninflammatory back pain (odds ratio [OR] = 0.78 ; 95% confidence interval [CI] = 0.77-0.79) and from inflammatory back pain (OR = 0.83; 95%:, CI = 0.81-0.86). Whereas disability from inflammatory ba ck pain was moderately associated with socioeconomic status, there was a co nsistent upward trend in the association between disability retirement from noninflammatory back pain and Tower socioeconomic position. The OR for uns killed workers was 3.1 (95% CI = 2.6-3.7) for men and 2.1 (95% CI = 1.7-2.5 ) for women, as compared with that of higher professionals. Stepwise analys es suggest that the effect of education is not mediated by socioeconomic st atus. Conclusions. The consistent upward trend in the relation of disability reti rement to lower levels of education and socioeconomic position, even for in flammatory back pain, shows that factors related to the occupational and so cial environment play an important role in the disabling process. The stepw ise, monotonic relation between socioeconomic position and disability retir ement from back pain, even at the higher end of the socioeconomic scale, su ggests that the relation between social class and back pain disability cann ot be explained solely in terms of manual versus nonmanual jobs.