Objective: ThyPRO is the standard thyroid patient-reported outcome (PRO). The change in scores that patients perceive as important remains to be ascertained. The purpose of this study was to determine values for minimal important change (MIC) for ThyPRO. Methods: A total of 435 patients treated for benign thyroid diseases completed ThyPRO at baseline and 6 weeks following treatment initiation. At 6-weeks follow-up, patients also completed Global Rating of Change items. For each 0-100 scale, two MIC values were identified: an MIC for groups, using the ROC curve method and an MIC for individual patients, using the reliable change Index. Results: ROC analyses provided group-MIC estimates of 6.3 to 14.3 (score range 0-100). Evaluation of area under the curve (AUC) supported the robustness for 9 of 14 scales (AUC > 0.7). Reliable change index estimates of individual-MIC were 8.0 to 21.1. For all scales but two, the individual-MIC values were larger than the group-MIC values. Conclusions: Interpretability of ThyPRO was improved by the establishment of MIC values, which was 6.3 to 14.3 for groups and 8.0 to 21.1 for individuals. Thus, estimates of which changes are clinically relevant, are now available for future studies. We recommend using MIC values found by ROC analyses to evaluate changes in groups of patients, whereas MIC values identified by a dual criterion, including the reliability of changes, should be used for individual patients, e.g. to identify individual responders in clinical studies or practice.

Patient-reported outcomes (PROs) are increasingly used in clinical practice to improve clinical care. Multiple studies show that systematic use of PROs can enhance communication with patients and improve patient satisfaction, symptom management and quality of life. Further, such data can be aggregated to examine health levels for patient groups, improve quality of care, and compare patient outcomes at the institutional, regional or national level. However, there are barriers and challenges that should be handled appropriately to achieve successful implementation of PROs in routine clinical practice. This paper briefly overviews thyroid-related PROs, describes unsolved quality of life issues in benign thyroid diseases, provides examples of routine collection of PROs, and summarizes key points facilitating successful implementation of thyroid-related PROs in routine clinical practice. Finally, the paper touches upon future directions of PRO research.

Cognitive interviewing techniques proved useful for developing and evaluating momentary items. Researchers should be aware of the applied reference period and of emerging problems when evaluating adapted momentary items, since not all concepts are suitable. We recommend the proposed method in future adaptations of existing instruments.