DOES SMOKING CAUSE LOW-BACK-PAIN - RESULTS FROM A POPULATION-BASED STUDY

Objectives: To investigate (a) whether there is a causal link between smoking and low back pain (LBP), (b) whether smoking is uniquely assoc iated with symptoms in the lumbar spine and (c) the role of respirator y problems in the possible link between smoking and LBP. Study Design: Data were collected through questionnaires in a cross-sectional study of a representative sample of the general Danish population, consisti ng of 1370 men and women aged 30-50 yr, with a response rate of 69%. B ackground: In some epidemiological studies (mostly those of cross-sect ional design) smoking has been associated with LBP; this association, however, is not consistently present in all reports. Several theories exist that attempt to explain a possible association between the two; only rarely have these theories been systematically tested. However, c ross-sectional data can also be used to obtain answers to questions re lating to causes and mechanisms. Method: A list of expectations was pr oduced that related to three hypotheses previously forwarded in the ep idemiological literature. The fit of the data in the present study was then considered in the light of these expectations. Results: There is evidence in favor of a causal link between smoking and some definitio ns of LBP. Smoking was not uniquely associated with the lumbar spine. Respiratory symptoms seemed to be positively associated with LBP but o nly when linked with smoking. Conclusions: The clinical significance o f these findings is limited, but it needs to be considered in future r esearch. Abstinence from smoking may, however, be a useful means of pr imary prevention of certain types of LBP.