Quality of abstracts of randomized control trials in five top pain journals: A systematic survey

Background The reporting quality of abstracts of randomized control trials (RCTs) is inadequate despite the publication of consolidated standards of reporting trials extension for abstracts (CONSORT-A). We compared the reporting quality of abstracts in pain journals before and after the publication of CONSORT-A. Methods We searched MEDLINE in April-2016 for RCTs published in five pain journals: Pain, Pain Physician, European Journal of Pain, Clinical Journal of Pain and Pain Practice for pre- and post-CONSORT-A period (2005–2007 and 2013–2015). Data were extracted in duplicate from 250 abstracts for compliance with CONSORT-A, and for items known to affect reporting quality: journal endorsement of CONSORT, number of trial centers, sample-size, type of intervention, industry-sponsorship and significance of results. The primary outcome was mean number of items reported and the secondary outcome was the reporting of each item. We used logistic regression and Poisson regression for analyses. Results Most trials were single centric (76%), had sample size <100 (63%), involved pharmacological intervention (59%) and were non-industry funded (70%). The mean number of items reported was better for 2013–2015 (mean difference 0.94; 95% confidence-interval [CI]: 0.50–1.38, p < 0.001). Post-CONSORT-A, trials were more likely to report as randomized in the title (odds ratio (OR) 2.69; 95% CI 1.61–4.49), describe eligibility criteria and settings (OR 2.47; 95% CI 1.35–4.54), provide effect size and precision for primary outcome (OR 2.47; 95% CI 1.19–5.16), inform harms (OR 1.80; 95% CI 1.05–3.07) and report trial registration (OR 5.13; 95% CI 1.44–18.32). Post-CONSORT-A period (incident rate ratio (IRR) 1.15; 95% CI 1.07–1.24), endorsement of CONSORT statement by the journal (IRR 1.08; 95% CI 1.02–1.14), multi-centric studies (IRR 1.14; 95% CI 1.08–1.20), and studies with pharmacological interventions (IRR 1.07; 95% CI 1.02–1.13) were significantly associated with reporting of more items. Conclusions Abstract reporting for trials in pain literature was better in the post-CONSORT-A period, but there is room for improvement.