Applicability and generalisability of published results of randomised controlled trials and non-randomised studies evaluating four orthopaedic procedures: methodological systematic review.

Objective: To compare the reporting of essential applicability data from randomised controlled trials and non-randomised studies evaluating four new orthopaedic surgical procedures.

Data Sources: Medline and the Cochrane central register of controlled trials.

Study Selection: All articles of comparative studies assessing total hip or knee arthroplasty carried out by a minimally invasive approach or computer assisted navigation system.

Data Extraction: Items judged to be essential for interpreting the applicability of findings about such procedures were identified by a survey of a sample of orthopaedic surgeons (77 of 512 completed the survey). Reports were evaluated for data describing these "essential" items and the number of centres and surgeons involved in the trials. When data on the number of centres and surgeons were not reported, the corresponding author of the selected trials was contacted. Results 84 articles were identified (38 randomised controlled trials, 46 non-randomised studies). The median percentage (interquartile range) of essential items reported for non-randomised studies compared with randomised controlled trials was 38% (25-63%) versus 44% (38-45%) for items about patients, 71% (43-86%) versus 71% (57-86%) for items considered essential for all interventions, and 38% (25-50%) versus 50% (25-50%) for items about the context of care. More than 80% of both study types were single centre studies, with one or two participating surgeons.

Conclusion: The reporting of data related to the applicability of results was poor in published articles of both non-randomised studies and randomised controlled trials and did not differ by study design. The applicability of results from the trials and studies was similar in terms of number of centres and surgeons involved and the reproducibility of the intervention.