Predictive factors for 1-year outcome of low-back and neck pain in patients treated in primary care: comparison between the treatment strategies chiropractic and physiotherapy.

The inability to predict outcome in patients with low back/neck pain leads to inappropriate or unnecessary treatment. The aims of the study were to identify prognostic factors for disability at 1-year follow-up in patients with back pain visiting primary care, and to compare the effect of these in two treatment strategies--chiropractic and physiotherapy. Data were taken from a randomised trial on patients with back/neck pain visiting the general practitioner, in which patients were allocated to chiropractic and physiotherapy as primary management. Three hundred and twenty-three patients, aged 18-60 years, who had no contraindications to manipulation and who had not been treated within the previous month were included in the study. Multiple regression analysis was used to identify prognostic factors. Dependent variables were mean Oswestry score and mean change in Oswestry score at 12-month follow-up. The multiple regression analysis revealed five significant (P < 0.001-0.01) prognostic factors; duration of current episode, Oswestry score at entry, expectations of treatment, number of localisations, and well-being. Besides, the regression coefficients for the significant factors were compared between the two treatment strategies. No significant difference in effect or regression coefficients for the prognostic factors were seen between the two treatment strategies. Twelve per cent of the patients had poor prognostic factors (duration > or = 1 month, more than one localisation, low expectations of treatment and low well-being) at entry. These patients had a mean Oswestry score above 20% at 1-year follow-up. Clinical decision models for the management of patients with back pain visiting primary care that consider prognostic factors need to be implemented and prospectively evaluated.