Consistency between published results and Clinicaltrials.gov protocols: A systematic review of HIV medication adherence interventions, 2009-2013

Background: Improving medication adherence (MA) for persons with HIV (PWH) is essential to ensuring successful progression through the HIV care continuum. Examining how HIV medication adherence outcome measures are planned and reported is important to forming a comprehensive understanding of the available evidence in MA research. Increasingly, there is an emphasis on clinical trials registration to promote transparent reporting of research and to facilitate systematic reviews.  We evaluated MA interventions and their Clinicaltrials.gov protocols to examine potential discrepancies in reporting of HIV MA outcomes.

Methods: We conducted a systematic review of MA interventions published between 2009 and 2013 and searched the Clinicaltrials.gov registry for the corresponding original trial protocols. HIV MA outcome measures were compared for consistency between published studies and trial protocols.

Results: Thirty-one published HIV MA studies were identified, and only 52% (16 studies) of these had protocols available in the Clinicaltrials.gov registry. Among these 16 studies, 56% reported ≥1 outcomes that were not operationalized in the protocol (k=9) and 44% reported a behavioral or biologic MA outcome not included in the original protocol (k=7).  A greater proportion of studies that fully operationalized MA outcomes, compared with studies that did not, reported significant MA intervention effects (71% versus 67%). 

Conclusions: We found numerous inconsistencies between outcomes reported in trial protocols compared with published MA reports. Researchers are encouraged to register their protocols with Clinicaltrials.gov and to report planned outcomes. Ultimately, this will facilitate analyses of available evidence and help to identify effective programs that improve care for PWH.