Trends of back pain in eastern Finland, 1972-1992, in relation to socioeconomic status and behavioral risk factors.

The aim of this study was to compare the trends in the prevalence of back pain between several population subgroups and to assess the stability of the associations between back pain and its potential risk factors. Five cross-sectional surveys with independent random samples were conducted in two provinces in eastern Finland every fifth year from 1972 to 1992. There were 29,043 respondents aged 30-59 years. The respondents completed a questionnaire that asked about the occurrence of back pain during the preceding month. The prevalence of back pain varied between 46 and 50 percent among men and between 46 and 51 percent among women. In general, the trend for the entire sample was fairly stable, but the prevalence rates seemed to differ considerably between subgroups of the population. Back pain was more prevalent among those with lower education and income, those with blue-collar occupations, and those doing heavy work. The trends were significantly inconsistent (p < 0.05), for example, between the categories according to household income and, among men, between the categories according to body mass index, a suspected risk factor for back pain.