Introduction: Growing evidence points for the need to publish study protocols in the health field. The aim of this paper was to observe whether the growing interest in publishing study protocols in the broader health field has been translated into increased publications of rehabilitation study protocols.
Evidence acquisition: PubMed was searched with appropriate combinations of Medical Subject Headings up to December 2014. The effective presence of study protocols was manually screened. Regression models analyzed the yearly growth of publications. Two-sample Z-tests analyzed whether the proportion of systematic reviews (SRs) and randomized controlled trials (RCTs) among study protocols differed from that of the same designs for the broader rehabilitation research.
Evidence synthesis: Up to December 2014, 746 publications of rehabilitation study protocols were identified, with an exponential growth since 2005 (r2=0.981; P<0.001). RCT protocols were the most common among rehabilitation study protocols (83%), while RCTs were significantly more prevalent among study protocols than among the broader rehabilitation research (83% vs. 35.8%; P<0.001). For SRs, the picture was reversed: significantly less common among study protocols (2.8% vs. 9.3%; P<0.001). Funding was more often reported by rehabilitation study protocols than the broader rehabilitation research (90% vs. 53.1%; P<0.001). Rehabilitation journals published a significantly lower share of rehabilitation study protocols than they did for the broader rehabilitation research (1.8% vs.16.7%; P<0.001).
Conclusions: Identifying the reasons for these discrepancies and reverting unwarranted disparities (e.g. low rate of publication for rehabilitation SR protocols) are likely new avenues for rehabilitation research and its publication. SRs, particularly those aggregating RCT results, are considered the best standard of evidence to guide rehabilitation clinical practice; however, that standard can be improved in rigor and/or transparency if the publications of rehabilitation SRs protocols become more common.