Single-day pain assessments as clinical outcomes: not so fast.

INTRODUCTION

Pain diaries are important tools for clinical trials and optimal assay sensitivity of outcomes derived from these diaries is a worthwhile goal. Jensen and colleagues recently reported results suggesting that single-day diary-based outcomes could possibly be as psychometrically sound as outcomes based on taking the average of many diaries.

MATERIALS AND

METHODS

In this paper, we attempted to replicate those results with several diary data sets.

RESULTS AND DISCUSSION: We come to a different conclusion than that advanced by Jensen and colleagues and conclude that their results were unusual in that very high test-retest reliability among days was found. With our 4 diary data sets we find that aggregating multiple diaries yields more reliable outcomes and improved sensitivity. We suggest that using single-day diaries will often lead to underpowered studies and that pretesting is advised before adopting single-day diaries. We also suggest that other researchers replicate these findings within their diary-based clinical trials.