Reporting sample size calculations for randomized controlled trials published in nursing journals: A cross-sectional...

Area of Science:

• Clinical Research
• Nursing Science
• Biostatistics

Background:

• Sample size calculation is critical for the statistical power of randomized controlled trials (RCTs).
• Ensuring adequate power prevents participant over-recruitment and detects significant differences between groups.
• Compliance with sample size calculation reporting in nursing RCTs is not well-documented.

Purpose of the Study:

• To evaluate the reporting standards of sample size methodology in nursing journals.
• To identify the parameters used in sample size calculations for nursing RCTs.
• To assess the adequacy of reported sample size information.

Main Methods:

• A cross-sectional study analyzed RCTs published in 116 nursing journals from January to December 2016.
• Two-arm RCTs were reviewed for the mention and sufficiency of sample size estimation methods.
• Sample sizes were recomputed for RCTs with effect size data and compared to reported values.

Main Results:

• Of 223 included RCTs, 143 (64.1%) reported sample size methodology.
• Among those reporting, only 22 (15.4%) provided all necessary parameters for sample size computation.
• Reporting of significance level (92.3%), power (93.0%), and effect size (58.7%) varied, with only 15.4% providing complete information.

Conclusions:

• A significant proportion of nursing RCTs (36%) fail to report their sample size calculations.
• Inadequate reporting of sample size methodology and parameters is prevalent in nursing RCTs.
• Improved reporting standards are needed to ensure the rigor and reproducibility of nursing research.