[Chronic low back pain in 40-year olds in 12 Norwegian counties].

In this study, a questionnaire and a short interview were used to estimate the prevalence of chronic low back pain alone and low back pain together with other musculo-skeletal pains among 40-year-old women and men in 12 Norwegian counties (a total of 67,338 persons). On average 2.4% of men and 1.7% of women had only chronic low back pain, while 5.7% of men and 9.2% of women in addition had other pains as well. Persons with low back pain only were approximately equally distributed across the counties. Greater variations across the counties and between the sexes were found in persons with additional pain. The duration of the pain did not vary significantly between the sexes or across the counties, but the duration was on average two years longer in cases of multi-cause pain. Reduced capacity for work because of pain was approximately equally distributed between the sexes and the groups. More women than men were unable to do their daily work. About one third in both groups (more men than women) had been absent from work because of pain during the last year. More women than men in both groups received national insurance benefits. Persons with only low back pains were approximately equally represented across all levels of education and regardless of marital status, while people with multi-cause pain were overrepresented among those with low levels of education and among the divorced.