Is improved fitness associated with reduced pain intensity in patients with low back pain?
Abstract Introduction: Low back pain (LBP) is a common global health problem and it causes more disability worldwide than any other disease. Despite this, knowledge concerning causes, prevention and effective treatments is lacking. It is a general assumption that LBP is associated with reduced physical capacity, but only few studies have examined this association. Objective: To examine the association between fitness and pain intensity in LBP-patients. Further to examine the association between clinically relevant improved fitness and clinically relevant reduced pain intensity at follow-up based on the patients’ baseline fitness levels. The hypothesis being that the association is most substantial for patients with poor baseline fitness levels at inclusion. Methods: Cohort study with three months’ follow-up based on data from a previous RCT study. The study population consisted of 176 patients with LBP and complete 3 months’ follow-up on fitness and pain. Clinically relevant improved fitness was defined as improved fitness =10% from baseline to follow-up. Clinically relevant change in pain intensity was defined as a reduction =30% on the Numerical Rating Scale. The association was examined by Spearman correlation and logistic regression and presented by OR (95 CI). Results: No correlation between fitness and pain intensity at baseline was found. Also, no association between clinically relevant improved fitness and clinically relevant reduced pain intensity based on the patients’ baseline fitness levels was detected. Conclusions: The study examined the association between fitness and pain intensity in LBP-patients and no association between changes in fitness and pain intensity during the 3 months’ follow-up was seen. The study contributes with evidence based on clinically relevant changes in fitness and pain intensity.