Cluster randomized controlled trials (RCTs) are increasingly being used in healthcare research to evaluate interventions at the group level. A recent systematic review by Tokolahi et al. (2015) investigated the quality and reporting of cluster RCTs evaluating occupational therapy interventions. The findings offer valuable insights for practitioners aiming to improve their research skills and contribute to the evidence base in occupational therapy.
Key Findings
The review included 14 studies, highlighting several areas of strength and opportunities for improvement in the conduct and reporting of cluster RCTs:
- Justification for Cluster Design: 79% of studies justified the use of a cluster design, primarily to prevent contamination between study arms.
- Sample Size and Analysis: 79% of studies accounted for clustering in the sample size calculation and analysis, ensuring robust statistical power.
- Baseline Comparisons: Only 50% of studies described baseline comparisons of clusters, which is crucial for identifying potential biases.
- Intercluster Correlation Coefficients (ICCs): Half of the full trials reported an ICC or design effect, essential for determining appropriate sample sizes.
- Risk of Bias: Blinding of participants and personnel was the most frequent source of bias, with 86% of studies at high risk due to unblinded participants.
Recommendations for Practitioners
Based on these findings, practitioners can take several steps to improve the quality and reporting of their research:
- Justify the Use of Cluster Design: Clearly articulate why a cluster design is appropriate for your study to enhance its methodological rigor.
- Account for Clustering: Ensure that clustering is considered in both sample size calculations and data analysis to avoid Type 1 errors.
- Report Baseline Comparisons: Provide detailed baseline comparisons of clusters to identify any imbalances that could affect your results.
- Include ICCs: Report ICCs or design effects to facilitate the calculation of appropriate sample sizes for future studies.
- Minimize Bias: Where possible, implement strategies to blind participants and personnel to reduce the risk of bias.
Encouraging Further Research
The review underscores the importance of high-quality research in occupational therapy. Practitioners are encouraged to engage with the latest methodologies and collaborate with statisticians to enhance the credibility and impact of their studies. By adhering to these recommendations, practitioners can contribute to a more robust evidence base, ultimately improving outcomes for clients.
To read the original research paper, please follow this link: Quality and Reporting of Cluster Randomized Controlled Trials Evaluating Occupational Therapy Interventions.
