Plausible theories for smoking and back pain: Review of the literature

Background: Back pain is a common musculoskeletal problem with a lifetime prevalence of 80%. Several studies have demonstrated an association between back pain and smoking, revealing smoking as one of few potentially modifiable back pain risk factors. While associations between smoking and back pain have been made, few studies have tested causal hypotheses between smoking and back pain. The aim of this study was to identify plausible hypotheses related to smoking and back pain in the published literature. Methods: PubMed was searched from the earliest month and year available through January 2012. The search terms were “smoking” and “back pain”. Articles were excluded if they did not discuss a potential theoretical relationship between smoking and back pain, were not in English, or unrelated to the lumbar spine. Each hypothesis included in the study was checked for plausibility against Sir Austin Bradford Hill's criteria for causation. Results: There were 514 citations in the initial search. After reviewing the titles and abstracts, 152 full papers were obtained for further review. Several plausible theories were identified. No previous study had summarized the literature pertaining to hypotheses linking smoking and back pain. Conclusion: The results of this review can help to better inform spine pain research by presenting biologically plausible hypotheses pertaining to smoking and back pain to test in future studies.