Susan C. Scott

BACKGROUND: 'Prehabilitation' is an intervention to enhance functional capacity in anticipation of a forthcoming physiological stressor. In patients scheduled for colorectal surgery, the extent to which a structured prehabilitation regimen of stationary cycling and strengthening optimized recovery of functional walking capacity after surgery was compared with a simpler regimen of walking and breathing exercises. METHODS: Some 112 patients (mean(s.d.) age 60(16) years) were randomized to either the structured bike and strengthening regimen (bike/strengthening group, 58 patients) or the simpler walking and breathing regimen (walk/breathing group, 54 patients). Randomization was done at the surgical planning visit; the mean time to surgery available for prehabilitation was 52 days; follow-up was for approximately 10 weeks after surgery. RESULTS: There were no differences between the groups in mean functional walking capacity over the prehabilitation period or at postoperative follow-up. The proportion showing an improvement in walking capacity was greater in the walk/breathing group than in the bike/strengthening group at the end of the prehabilitation period (47 versus 22 per cent respectively; P = 0.051) and after surgery (41 versus 11 per cent; P = 0.019). CONCLUSION: There was an unexpected benefit from the recommendation to increase walking and breathing, as designed for the control group. Adherence to recommendations was low. An examination of prehabilitation 'responders' would add valuable information.

STUDY DESIGN: A structured review of the epidemiologic literature was performed. Thirty-eight studies published in peer-reviewed journals were reviewed. The methodologic strengths and weaknesses of the studies were described and assessed qualitatively. Four studies were excluded because of difficulties in design or interpretation. OBJECTIVES: To provide a systematic analysis of the literature to assess the evidence as to whether smoking is associated with the prevalence and incidence of nonspecific back pain and related outcomes. SUMMARY OF BACKGROUND DATA: Evidence has been gathering regarding the association of smoking with nonspecific back pain and other back disorders, but a comprehensive summary and evaluation of the data have not been published. RESULTS: Positive associations between current smoking and nonspecific back pain were found in 18 of 26 studies in men and 18 of 20 studies in women. For sciatica and herniated discs, there were four of eight and one of five positive studies in men and women, respectively. The majority of these studies were cross-sectional (18 in men and 16 in women), with only a handful of prospective studies. Positive associations between past smoking and nonspecific back pain were reported in five of nine studies in men and five of six studies in women. In addition, increases in the prevalence and/or incidence of nonspecific back pain were found in the majority of studies in which level of consumption was analyzed and reported. An attempt was made to assess whether these results could be artifactual arising from selection bias, confounding bias, publication bias, or errors in measurement. As well, the biologic mechanisms were summarized that have been suggested by various investigators. CONCLUSIONS: The available data are consistent with the notion that smoking is associated with the incidenceand prevalence of nonspecific back pain, but there are too few studies to make any conclusions for the other end points (e.g., sciatica, herniated discs). It cannot be ruled out that the association is a statistical artifact arising from either selection or confounding factors, because the evidence for nonspecific low back pain derives mostly from cross-sectional studies. In addition, it cannot be stated unequivocally that smoking preceded back pain. Long-term follow-up studies are needed to eliminate the possibility that chronic back pain preceded smoking, to better estimate dose-response correlations, and to perform biologic measurements to elucidate possible mechanisms.