The purpose of this thesis was to study in a general adult population the prevalence and incidence of back trouble, predictive factors for new episodes of back pain, new sick leave episodes, and factors important for recovery from back pain. The pain drawing method was used in an epidemiological survey to identify pain in the entire back area. The bias that knowledge of back pain history has on the interpretation of pain drawings was studied in a separate study.
The cross-sectional main study population consisted of 2000 individuals aged 20-59 years. A prospective survey was conducted after one year on the study population of factors important for new sick leave, new back pain episodes and recovery and after five years on two age strata of factors important for retaining back health. After ten years the number of disability pensions granted for back pain during the time period was studied. The socio-demographic and work-related factors that predicted disability pension were studied.
The prevalence of back pain was found to be 23%. Back pain with radiation was reported by 40%, according to the pain drawings. Only 4% reported localised neck pain. Sick leave was reported by 12% of those with back pain. The more generalised pain pattern suggested that back pain is more than a local back pain problem.
The one-year incidence of new back pain was 24%. Seventy-nine percent of the episodes lasted less than 2 months. A history of previous back pain predicted new back pain episodes, while stress at work and low work satisfaction was associated factors. Low age, more qualified work tasks and residence predicted recovery from back pain. New sick leave periods were predicted by unqualified work tasks, pain debut at work, previous back pain history and pain at the primary survey.
The clinical findings in the group with pain at the primary survey showed that the absence of tenderness in the trapezium muscle was the strongest predictor of recovery. It was also found that straighter lordosis and restricted mobility in the cervical spine were associated with new sick leaves in the prospective year.
The pain drawing study showed that knowledge of the pain history affected the interpretation and reliability of the pain drawing evaluation.
The five-year survey showed that absence of physical load in the old age group and absence of psychological stress at work in the younger age group predicted retained back health.
The study of disabilities granted on the grounds of back pain during ten prospective years has shown that age over 40, sick leave at the primary survey together with perceiving the work tasks as meaningless predicted disability pension.
The results of this thesis suggest that back pain should be seen as arecurrent problem, where previous episodes strongly predict new episodes. The complex nature of back pain as a health problem suggests that the rehabilitation should be individualised and include both work-related factors as well as a wide range of factors not related to paid work.
Linköping: Linköpings universitet , 2000. , 64 p.
2000-09-29, Berzeliussalen, Universitetssjukhuset, Linköping, 09:00 (Swedish)