Short-duration prophylaxis against venous thromboembolism after total hip or knee replacement: a meta-analysis of prospective studies investigating symptomatic outcomes

CRD COMMENTARY: This was a reasonably well-conducted review with some limitations. The review question was fairly well defined, with inclusion criteria relating to the interventions, participants, study designs and outcomes. The studies were identified through searches of electronic databases, supplemented by manual searches of bibliographies and conference abstracts. It is unclear whether relevant non-English language studies were eligible for inclusion. Identification of such studies would be necessary to limit bias. Quality was assured in the selection and data extraction processes through the use of two independent reviewers. While the authors attempted to minimise between-study heterogeneity with the use of pre-specified inclusion criteria, further details of the included studies would have been desirable. For example, the composition of patient cohorts extracted from each study would give the reader an indication of any possible clinical heterogeneity between these groups. Data on the validity of the individual studies included in the review were also lacking. No formal validity assessment was carried out, nor were methodological details relating to the validity of the individual studies given. The authors' conclusions seem to follow from the evidence presented, though the above comments should be considered with regard to the generalisability of the observed results.