Low back pain, work absenteeism, chronic back disorders, and clinical findings in the low back as predictors of hospitalization due to low back disorders: A 28-year follow-up of industrial employees

Prospective cohort study. To study symptoms, chronic disorders, and clinical findings in the low back, and work absenteeism, as predictors of hospitalization. Socioeconomic and lifestyle factors are associated with back-related hospitalization, but the significance in the working normal population of low back symptoms and clinical findings are not known. The cohort (n = 902) was drawn in 1973 from among employees in the metal industry (n = 2,653). The data were collected by questionnaire and a structured clinical assessment by a physiotherapist. Weight was measured. A sum score of local and radiating low back symptoms (frequency during the past year on a 4-point Likert scale) was categorized as no/yes and no/infrequent/frequent. Local and radiating symptoms were considered also separately. The data were linked with those from the Finnish Hospital Discharge Register during 1973 to 2000. Logistic regression and the Cox proportional hazard models were used. As compared with persons without low back pain, those with frequent or radiating low back pain had an increased risk of hospitalization due to low back disorders (hazard rate ratio (HRR), 3.0; 95% confidence interval (CI), 1.4-6.5, and 3.7; 1.8-7.7, respectively) after adjustment for age, gender, and occupational class. Similarly, clinical findings (HRR, 2.4; 95% CI, 1.3-4.7), back-related absenteeism (HRR, 3.3; 95% CI, 1.6-6.7), and chronic low back disorders (HRR, 2.8; 95% CI, 1.5-5.4) predicted hospitalization. The associations persisted when further adjusted for smoking, body mass index, and distress symptoms at baseline. Frequent or radiating low back symptoms, chronic low back disorders, back-related work absenteeism, and having clinical findings in the low back predicted inpatient hospital care for low back disorders.