IS THE CONCLUSIVENESS OF COCHRANE SYSTEMATIC REVIEWS IN PHYSIOTHERAPY CHANGING OVER TIME? ANALYSIS OF A REPRESENTATIVE SAMPLE OF 100 REVIEWS

A.P. Freire¹, G. Smilanich¹, I. Lemes², M. Elkins³, S. Amin¹, R. Zambelli Pinto⁴

¹Central Washington University, Health Sciences, Ellensburg, United States, ²Sao Paulo University, Medicine, Sao Paulo, Brazil, ³Sydney Local Health District, Centre for Education & Workforce Development, Sydney, Australia, ⁴Federal university of Minas Gerais, Physiotherapy, Belo Horizonte, Brazil

Background: Systematic reviews are vital for clinicians to make accurate conclusions on whether a therapy is going to be beneficial for a patient. Cochrane reviews are regarded as having some of the highest quality of systematic reviews, making them vital to the decision-making process in health care. There still is debate on whether the Cochrane reviews are conclusive and it is unclear whether the conclusiveness is getting better over time.

Purpose: To determine the proportion of conclusive Cochrane reviews relevant to the field of Physiotherapy and to investigate whether the conclusiveness has been increasing over time.

Methods: We have performed a systematic search in the Physiotherapy Evidence Database (PEDro) for Cochrane reviews and extracted a sample of 100 systematic reviews with 50 from two different periods: 2011 to 2015 and another 50 from 2016 to 2020. Two independent reviewers have extracted: year of publication, country, Cochrane Review Group, intervention, comparators, number of RCTs, a cumulative number of patients enrolled and the need for further studies. The Gradings of Recommendations Assessment, Development and Evaluation (GRADE) approach is a method to assess the certainty of the evidence in recent Cochrane Reviews. If available from Cochrane, GRADE data for the primary outcome has been used to assess conclusiveness. For those reviews without GRADE, reviewers have applied the GRADE approach following a set of pre-specified criteria. Cochrane reviews were considered conclusive when the primary outcome in the review provided high certainty of evidence and inconclusive when classified as moderate, low or very low. Differences between conclusive and inconclusive reviews overtime will be analyzed comparing proportions using Fisher’s exact test. Statistical significance established at 5%.

Results: Trials studying the musculoskeletal subdiscipline were the most common for both 2011 to 2015 (34%) and 2016 to 2020 (30%). Overall, 2016 to 2020 presented a higher number of trials (18.54±18.11), but less participants than 2011 to 2015 (4506.54±16180.18). GRADE assessments did not get better over time: as the number of high ratings for primary outcomes decreased from 6% in 2011 to 2015 to 2% in 2016 to 2020. Ratings of moderate evidence remained similar overtime (20%) and the proportion of very low GRADE ratings increased from 34% to 50% over the two time periods. The conclusiveness rates for Cochrane Systematic reviews (at least one primary outcome with a High-GRADE rating) did not changed when comparing both 2011 to 2015 (6%) and 2016 to 2020 (2%). The findings were not statistically different (p = 0.617).

Conclusions: The proportion of conclusiveness of Cochrane Systematic reviews related to the field of Physiotherapy were low and did not change between 2011 and 2020.

Implications: Cochrane Systematic reviews in the field of Physiotherapy might still be inconclusive, therefore more high quality research are still needed to overcome possible barriers for evidence-based practice. Further research must investigate a larger period of time to support the findings of this study.

Funding acknowledgements: Central Washington University.

Keywords:
Cochrane systematic reviews
Physiotherapy
Evidence-based practice

Topics:
Research methodology, knowledge translation & implementation science
Professional practice: other

Did this work require ethics approval? No

Reason: The study is based on methodological quality assessment of previous published materials (secondary data source). Did not required any human evaluations/ contact/ assessments.