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A systematic review finds variable use of the intention-to-treat principle in musculoskeletal randomized controlled
Royes Joseph1, Julius Sim1, Reuben Ogollah1
1Arthritis Research UK Primary Care Centre, Research Institute of Primary Care and Health Sciences, Keele University, Keele, Staffordshire, ST5 5BG, UK.
Objectives:
In randomized trials, the primary analysis should be consistent with the intention-to-treat (ITT) principle and should address missing data appropriately to draw valid inferences. This review focuses on current practices relating to the ITT principle and methods to handle missing data in the major musculoskeletal journals.
Study Design And Setting:
A systematic review of randomized trials published in 2010 and 2011 in five musculoskeletal journals was performed.
Results:
We reviewed 91 trials: 38% performed a full ITT analysis (analyzing outcome data for all randomized participants) and 31% performed a partial ITT analysis (excluding participants with no follow-up data). The overall median dropout was 12%; 60% of trials had more than 10% dropouts, and 32% of trials had more than 20% dropouts. Among those that performed an ITT analysis, the majority adopted a form of single imputation; last observation carried forward was the designated approach in most cases. Mixed models for repeated measures and/or multiple imputations were limited to eight trials.
Conclusion:
It appears that many trials reporting missing data are inappropriately analyzed and may therefore be prone to biased estimates and invalid inferences.
Insights
Many musculoskeletal randomized trials do not properly use the intention-to-treat (ITT) principle or handle missing data, potentially leading to biased results. Improved methods are needed for valid clinical trial inferences.
Area of Science:
- Clinical Trials
- Biostatistics
- Musculoskeletal Research
Background:
- The intention-to-treat (ITT) principle is crucial for valid inferences in randomized trials.
- Appropriate handling of missing data is essential for robust trial analysis.
- Current practices in musculoskeletal journals require examination.
Purpose of the Study:
- To review current practices regarding the ITT principle in musculoskeletal randomized trials.
- To assess methods used for handling missing data in these trials.
Main Methods:
- Systematic review of randomized trials published in 2010-2011.
- Analysis of trials from five major musculoskeletal journals.
Main Results:
- Only 38% of 91 reviewed trials performed a full ITT analysis.
- Median dropout rate was 12%, with over 60% of trials having >10% dropouts.
- Most ITT analyses used single imputation, primarily last observation carried forward; advanced methods were rare.
Conclusions:
- Many musculoskeletal trials appear to inappropriately analyze missing data.
- Inadequate analysis may lead to biased estimates and invalid inferences.
- There is a need for improved adherence to ITT principles and missing data methods.
