Methods for interpreting change over time in patient-reported outcome measures

• Published in: Quality of life research Vol. 22; no. 3; pp. 475 - 483
• Main Authors: Wyrwich, K. W., Norquist, J. M., Lenderking, W. R., Acaster, S.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01-04-2013; Springer Netherlands; Springer Nature B.V
• Subjects: Asthma; Clinical medicine; Clinical outcomes; Clinical trials; Clinical Trials as Topic; Cumulative distribution functions; Data Interpretation, Statistical; Descriptive labeling; Epidemiology; Health care outcome assessment; Health outcomes; Heart failure; Humans; International Cooperation; Medical treatment; Medicine; Medicine & Public Health; Oncology; Outcome Assessment (Health Care) - methods; Patient Satisfaction; Patients; Physicians; Practice Guidelines as Topic; Product development; Public Health; Quality of Life; Quality of Life Research; Questionnaires; Sociology; Time Factors; Transponders; United States; United States Food and Drug Administration; United States; Anchor-based; Distribution-based; Patient-reported outcome; Interpretation; Minimal important difference; Responder definition; Change over time; Quality of life; Cumulative distribution function
• ISSN: 0962-9343; 1573-2649
• DOI: 10.1007/s11136-012-0175-x

Purpose Interpretation guidelines are needed for patient-reported outcome (PRO) measures' change scores to evaluate efficacy of an intervention and to communicate PRO results to regulators, patients, physicians, and providers. The 2009 Food and Drug Administration (FDA) Guidance for Industry Patient-Reported Outcomes (PRO) Measures: Use in Medical Product Development to Support Labeling Claims (hereafter referred to as the final FDA PRO Guidance) provides some recommendations for the interpretation of change in PRO scores as evidence of treatment efficacy. Methods This article reviews the evolution of the methods and the terminology used to describe and aid in the communication of meaningful PRO change score thresholds. Results Anchor- and distribution-based methods have played important roles, and the FDA has recently stressed the importance of cross-sectional patient global assessments of concept as anchor-based methods for estimation of the responder definition, which describes an individual-level treatment benefit. The final FDA PRO Guidance proposes the cumulative distribution function (CDF) of responses as a useful method to depict the effect of treatments across the study population. Conclusions While CDFs serve an important role, they should not be a replacement for the careful investigation of a PRO's relevant responder definition using anchor-based methods and providing stakeholders with a relevant threshold for the interpretation of change over time.