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Identifying subpopulations for subgroup analysis in a longitudinal clinical trial
Rahim Moineddin1, Debra A Butt, George Tomlinson
1Department of Family and Community Medicine, University of Toronto, Toronto, Ontario, Canada. rahim.moineddin@utoronto.ca
Contemporary Clinical Trials
|August 23, 2008
Summary
Random effect models identified patient subgroups benefiting most from gabapentin for hot flashes. Higher baseline hot flash severity and serum creatinine levels predicted greater treatment response in postmenopausal women.
Area of Science:
- Clinical Trials
- Biostatistics
- Pharmacology
Background:
- Treatment effects often vary among individuals in clinical trials.
- Identifying patient subgroups with differential treatment response is crucial, especially for borderline or insignificant overall effects.
- Subgroup analysis requires robust methods to identify relevant patient subpopulations.
Purpose of the Study:
- To demonstrate the application of random effect models for identifying subpopulations suitable for subgroup analysis in longitudinal studies.
- To identify patient factors associated with differential treatment effects of gabapentin for hot flashes in postmenopausal women.
Main Methods:
- Utilized data from a double-blind randomized controlled trial.
- Applied multilevel modeling with random effects to analyze longitudinal data.
- Correlated subject-specific treatment effects with baseline patient characteristics.
Main Results:
- Women with higher baseline hot flash severity scores showed greater reduction in symptoms with gabapentin.
- Postmenopausal women with serum creatinine levels above the median exhibited a more significant response to gabapentin compared to placebo.
- Subject-specific treatment effects were successfully estimated and linked to baseline characteristics.
Conclusions:
- The proposed random effect model approach effectively identifies patient factors linked to differential treatment effects.
- Identified factors (hot flash severity, serum creatinine) are potential targets for further clinical investigation.
- This method aids in constructing relevant subgroups for future sub-analysis in clinical trials.
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