Heterogeneity of reporting standards in randomised clinical trials of endovenous interventions for varicose veins

Aims The efficacy of endovenous treatments for venous reflux has been demonstrated in numerous randomised clinical trials, although significant heterogeneity may exist between studies. The aim of this study was to assess the heterogeneity in reporting between randomised clinical trials investigating endovenous treatments for patients with varicose veins. Methods A literature search of the Pubmed, Cochrane and Google Scholar databases was performed using appropriate search terms. Randomised clinical trials published between January 1968 and June 2009 evaluating endovenous interventions for varicose veins were included and relevant abstracts and full text articles were reviewed. Published study reports were evaluated against recommended reporting standards published by the American Venous Forum in 2007. Results Twenty-eight randomised trials fulfilled the inclusion criteria. Median patient age (reported in 20/28 studies) ranged from 33 to 54 years. The CEAP classification was presented in 17/28 studies and the proportion of patients with C2 disease ranged from 6.3% to 83.5%. A total of 31 different outcome measures were utilised. This included 13 different questionnaires, varicose vein recurrence at 38 time points and 30 categories of complications. Duplex ultrasonography was used in 21/28 trials to assess recurrence. Quality of life was only evaluated in 11 studies and the follow-up period ranged from 3 weeks to 10 years. Conclusions Meaningful comparison across randomised studies of endovenous treatments is made difficult by considerable variations in study populations and outcome measures between trials. This highlights the need for the use of prospectively agreed population selection, and reporting standards for outcome measures in randomised clinical assessments of new treatments.