Comparison of two recruitment strategies for patients with chronic shoulder complaints.

BACKGROUND Recruiting adequate numbers of participants represents a major problem to the completion of randomised clinical trials in primary care. Information on different recruitment strategies applied in one trial is scarce. AIM To evaluate the application of two recruitment strategies in one trial. DESIGN OF STUDY The study was performed within the framework of a randomised clinical trial on the effectiveness of a behavioural treatment for patients with chronic shoulder complaints. SETTING Thirty-two general practices in the Netherlands. METHOD Patients recruited during a consultation with their GP for chronic shoulder complaints were compared with patients recruited by advertisement in a local newspaper as regards baseline characteristics, withdrawals (drop-outs and losses to follow-up) and post-treatment clinical outcomes. RESULTS Patients recruited by the GPs (n = 83) were similar to those recruited by advertisement (n = 83) in terms of demographic characteristics and clinical outcome measures at baseline, but differed slightly in disease characteristics and treatment preferences. Recruitment strategy was not related to reasons for or numbers of withdrawals. Improvements on outcome measures were greater in patients recruited by the GPs, irrespective of allocated treatment. Results on the clinical effectiveness of treatments at the end of the treatment period or during follow-up were neither modified by recruitment strategy, nor by differences between the two strategy groups in patient characteristics found at baseline. CONCLUSION Using two recruitment strategies did not influence the outcomes on clinical effectiveness in this trial.However, recruitment strategy should be considered as a putative modifying factor in the design of a study.