Improving Power and Sample Size Calculation in Rehabilitation Trial Reports: A Methodological Assessment

Area of Science:

• Rehabilitation Medicine
• Clinical Trial Methodology
• Biostatistics

Background:

• Randomized controlled trials (RCTs) are crucial for evaluating rehabilitation interventions.
• Accurate sample size calculation is essential for the statistical power and validity of RCTs.
• Previous assessments indicate potential deficiencies in reporting sample size calculations in clinical research.

Purpose of the Study:

• To systematically evaluate the reporting standards of sample size calculations in RCTs focused on mechanical low back pain rehabilitation.
• To assess the completeness of sample size reporting and its evolution over time.

Main Methods:

• A comprehensive search of the Cochrane Database of Systematic Reviews was conducted up to February 2015.
• Included RCTs published between 1968 and 2015 were screened.
• Data on sample size calculation reporting were extracted using a 6-item checklist based on CONSORT 2010 guidelines.

Main Results:

• Sample size calculation was reported in 36.0% (80/222) of eligible RCTs.
• Only 16.3% of these reports provided a complete description of the sample size calculation.
• Reporting completeness has improved since 2005, with more RCTs now reporting sample size calculations compared to those not reporting them.

Conclusions:

• Despite observed improvements, the reporting of sample size calculation and power analysis in rehabilitation RCTs for mechanical low back pain remains insufficient.
• Inadequate reporting hinders the evaluation of the methodological rigor and reliability of these studies.
• Further emphasis on CONSORT guidelines is needed to enhance the transparency and quality of rehabilitation research reporting.