Methodological Issues in Rehabilitation Research: A Scoping Review

Objective: To identify, synthesize, and categorize the methodological issues faced by the rehabilitation field.

Data sources: A scoping review was conducted using studies identified in MEDLINE, the Cochrane Library, EMBASE, Web of Science, Scopus, Physiotherapy Evidence Database, and Google Scholar up to August 2018.

Study selection: We included all type of publications describing methodological issues in rehabilitation research where rehabilitation is described as a multimodal process. The methodological issues have been categorized and classified.

Data extraction: The synthesis included qualitative and quantitative analysis. To focus the attention on rehabilitation, we post hoc divided in "specific issues" (highly related to, even if not exclusive of, rehabilitation research) and "generic issues" (common in biomedical research).

Data synthesis: Seventy-one publications were included: 68% were narrative reviews, 15% systematic reviews, 7% editorials, 4% meta-epidemiologic studies, and 5% others. Specific methodological issues include the following: problematic application of randomized controlled trials (32%), absent definition of core outcome sets (28%), poor interventions description (22%), weak methodological (conducting) and reporting quality (21%), scarce clinical practice applicability (14%), lack of blinding assessor (10%), inadequate randomization methods or inadequate allocation concealment (8%), and inadequate participants description and recruitment (8%). "Generic" issues included the following: data and statistical description (31%), authors' methodological training (7%), peer review process (6%, n=4), funding declaration (6%), ethical statement (3%), protocol registration (3%), and conflict of interest declaration (1%).

Conclusions: Methodological and reporting issues might influence the quality of the evidence produced in rehabilitation research. The next steps to move forward in the field of rehabilitation could be to evaluate the influence of all these issues on the validity of trial results through meta-epidemiologic studies and to develop specific checklists to provide guidance to authors to improve the reporting and conduct of trials in this field.