Steroid injections for shoulder disorders: A systematic review of randomized clinical trials

Background. Patients with shoulder disorders are believed to benefit considerably from steroid injections. However, the controversy about their efficacy persists. Aim. The study was designed to assess the efficacy of steroid injections for shoulder disorders. Method. A systematic computerized literature search in Medline (Index Medicos 1/1966-10/1995) and Embase (Excerpta Medica 1/1984-10/1995) was conducted, supplemented with citation tracking of all relevant publications. Studies published before November 1995 were selected if steroid injections were randomly allocated to patients with shoulder disorders and when clinically relevant outcome measures were reported. Because the validity of study outcomes depends heavily on the strength of methodological quality, the methods were assessed systematically by two 'blinded' independent reviewers. This resulted in a method score (maximum 100 points) that was based on four categories: study population, interventions, measurement of effect, and data presentation and analysis. Confidence intervals for the differences between groups in success rates were calculated in order to summarize the efficacy of steroid injections. Results. Only three out of the 16 studies scored more than 50 points, indicating a generally poor quality of methods. Most studies reported small sample sizes. The flaws most often found were incomparability of co-interventions and poor blinding of therapist. The methods assessment was frequently hampered by incomplete information about randomization, prognostic comparability, compliance, outcome measures included, blinding of patients and blinding of outcome measurement. Conclusions. The evidence in favour of the efficacy of steroid injections for shoulder disorders is scarce. The methods of most studies appear to be of poor quality. The few studies that appear to be credible do not provide conclusive evidence about which patients at what time in the course of shoulder disorders benefit most from steroid injections.