Predictors of stable return-to-work in non-acute, non-specific spinal pain: low total prior sick-listing, high self prediction and young age. A two-year prospective cohort study.
BACKGROUND
Non-specific spinal pain (NSP), comprising back and/or neck pain, is one of the leading disorders in long-term sick-listing. During 2000-2004, 125 Swedish primary-care patients with non-acute NSP, full-time sick-listed 6 weeks-2 years, were included in a randomized controlled trial to compare a cognitive-behavioural programme with traditional primary care. This prospective cohort study is a re-assessment of the data from the randomized trial with the 2 treatment groups considered as a single cohort. The aim was to investigate which baseline variables predict a stable return-to-work during a 2-year period after baseline: objective variables from function tests, socioeconomic, subjective and/or treatment variables. Stable return-to-work was a return-to-work lasting for at least 1 month from the start of follow-up.


METHODS
Stable return-to-work was the outcome variable, the above-mentioned factors were the predictive variables in multiple-logistic regression models, one per follow-up at 6, 12, 18 and 24 months after baseline. The factors from univariate analyzes with a p-value of at most .10 were included. The non-significant variables were excluded stepwise to yield models comprising only significant factors (p < .05). As the comparatively few cases made it risky to associate certain predictors with certain time-points, we finally considered the predictors which were represented in at least 3 follow-ups. They are presented with odds ratios (OR) and 95% confidence intervals.


RESULTS
Three variables qualified, all of them represented in 3 follow-ups: Low total prior sick-listing (including all diagnoses) was the strongest predictor in 2 follow-ups, 18 and 24 months, OR 4.8 [1.9-12.3] and 3.8 [1.6-8.7] respectively, High self prediction (the patients' own belief in return-to-work) was the strongest at 12 months, OR 5.2 [1.5-17.5] and Young age (max 44 years) the second strongest at 18 months, OR 3.5 [1.3-9.1].


CONCLUSIONS
In primary-care patients with non-acute NSP, the strong predictors of stable return-to-work were 2 socioeconomic variables, Low total prior sick-listing and Young age, and 1 subjective variable, High self-prediction. Objective variables from function tests and treatment variables were non-predictors. Except for Young age, the predictors have previously been insufficiently studied, and so our study should widen knowledge within clinical practice.
Lindell
Odd
O
Center for Family and Community Medicine, Karolinska Institutet, Alfred Nobels allé 12, Huddinge, Sweden. odd.lindell@ki.se
Johansson
Sven-Erik
SE
Strender
Lars-Erik
LE
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001294:Attitude to Health; D001416:Back Pain / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D015928:Cognitive Behavioral Therapy / Q000379:methods; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data; D011320:Primary Health Care / Q000706:statistics & numerical data; D011336:Probability; D011446:Prospective Studies; D018582:Sick Leave / Q000706:statistics & numerical data*