Patient symptom diaries are a commonly used method to collect efficacy data in clinical trials such as those for dry eye treatments. Typically, patients are asked to report the severity of several ocular symptoms multiple times per day over the course of a study that may last weeks or even months. Missing data are common, especially when the patients are asked to complete many items or when diaries are collected over many time points. Along with analyzing the observed data only, the missing observations can be imputed based on other available data to obtain statistically plausible values. There are several possible ways to handle the missing diary data, each of which will result in a different statistical outcome. The goal of imputing missing diary data is to use available data to estimate the statistical outcome that would have been achieved with no missing data.
This poster details:
- Various methods to impute missing data
- Results comparing each method using simulated diary data
- Recommendation on how to handle missing data in clinical trials
- Hui-Chun T. Hsu, ScM
- Dale Usner, PhD
- Richard Abelson, PhD