Objectives: To investigate the course and prognosis of shoulder pain in the first 6 months after presentation to the general practitioner. We separately studied patients with acute, subacute and chronic shoulder pain, as duration of symptoms at presentation has been shown to be the strongest predictor of outcome.
Methods: A prospective cohort study with 6 months follow-up was carried out in The Netherlands, including 587 patients with a new episode of shoulder pain. Patients were categorized as having acute (symptoms <6 weeks), subacute (6-12 weeks) or chronic (>3 months) shoulder pain. The course of shoulder pain, functional disability and quality of life was analysed over 6 months. Patient and disease characteristics, including physical and psychosocial factors, were investigated as possible predictors of outcome using multivariable regression analyses.
Results: Acute shoulder symptoms showed the most favourable course over 6 months follow-up, with larger pain reduction and improvement of functional disability. Patients with chronic shoulder symptoms showed the poorest results. The multivariable regression analysis showed that predictors of a better outcome at 6 months for acute shoulder pain were lower baseline disability scores and higher baseline pain intensity (explained variance 46%). Predictors of a better outcome for chronic shoulder pain were lower scores on pain catastrophizing and higher baseline pain intensity (explained variance 21%).
Conclusions: The results indicate that, besides a different course of symptoms in patients presenting with acute or chronic shoulder pain, predictors of outcome may also differ with psychosocial factors being more important in chronic shoulder pain.