Truthfulness in patient-reported outcomes: factors affecting patients' responses and impact on data quality

The use of patient-reported outcome (PRO) measures in research and clinical care has expanded dramatically, reflective of an increasing recognition of patient-centeredness as an important aspect of high-quality health care. Given this rapid expansion, ensuring that data collected using PRO measures is of high quality is crucial for their continued successful application. Because of the subjective nature of the outcomes assessed, there are many factors that may influence patients' responses and thus challenge the overall quality of the data. In this review, we discuss the multiple factors that may affect patients' responses on PRO measures. These factors may arise during instrument development and administration or secondary to patient-level response behaviors. We further examine the relevant literature to delineate how these factors may impact data quality and review methods for accounting for these factors. Consideration of such factors is critical to ensuring data collected truthfully reflects patients' evaluations and provides accurate conclusions.