Challenges in Using Recommended Quality of Life Measures to Assess Fluctuating Health: A Think-Aloud Study to Understand How Recall and Timing of Assessment Influence Patient Responses.

Patients who experience recurrent fluctuations in health are unable to provide meaningful responses about their quality of life when completing quality-of-life measures due to the recall period and timing of assessment. The use of such responses to calculate health state values in economic evaluations to inform resource allocation decisions in fluctuating conditions must be questioned.