Study Design. A 15-year follow-up study.
Objective. To find risk indicators for self-reported sick-listing because of low back trouble and to evaluate which variables were the most important indicators of work incapacity resulting from low back trouble during the follow-up period of 15 years.
Summary of Background Data. The initial data were obtained from a health survey conducted in a general population from the Municipality of Glostrup, Denmark. The follow-up data included information from the Central Person Register, the Early Retirement Pension Register, and a postal questionnaire regarding self-reported sick-listing because of low back trouble.
Methods. An epidemiologic study, in which logistic regression analyses were used for evaluation of the data. The model used consisted of the variable in question, age, gender, and previous experience of low back trouble, along with interactions.
Results. It was found that 22 of 37 variables were risk indicators for later self-reported sick-listing because of low back trouble during the preceding year or the 7 years before the date of follow-up evaluation. In analyzing the most significant variables simultaneously, it was found that information from the initial investigation about sick-listing in general during the previous 10 years, sciatic pain, use of analgesics for low back trouble, previous sick-listing because of low back trouble, and occupation were the most important risk indicators for self-reported work incapacity resulting from low back trouble during the follow-up period of 15 years.
Conclusion. Findings showed that the strongest prognostic indicators of later sick-listing because of low back trouble involve information from the person about previous sick-listing behavior in general and previous experience of low back trouble episodes, especially if these had been accompanied by sciatic pain, use of analgesics, or previous low back trouble sick-listing.
Musculoskeletal disorders are the most frequent long-term diseases in Denmark, and their incidence increased from approximately 13% of all long-term illnesses in 1987 to 15.4% in 1994. 25
Back pain is one of the most frequent musculoskeletal disorders, and, according to a Danish population survey, 40% of the population has had pain or discomfort in the back during the preceding year, and 21% during the previous 14 days. 12
For years it has been known that low back trouble (pain, tenderness, stiffness, and discomfort) is responsible for many lost work days in Denmark, and it is the most common reported symptom in patients with long-term diseases. 2,12,16,26,31,33,36,37 In 1994, back trouble was the primary diagnosis in 9.2% of all disability pension cases in Denmark 35 ; today, approximately every third reported work-related disease in Denmark is a result of back trouble. 16
Low back trouble (LBT) is therefore very expensive for the industrialized societies, but little is known about the risk indicators for LBT's influence on work capacity. Most epidemiologic estimates concerning sick-listing caused by LBT are made for the group of muscular and skeletal disorders as a whole. 12,26,33-35 Therefore, the aim of this 15-year follow-up study was to identify possible risk indicators for sick-listing caused by LBT in a general population group of 30-, 40-, and 50-year-old men and women.