The Thyroid-Related Quality of Life Measure ThyPRO Has Good Responsiveness and Ability to Detect Relevant Treatment Effects

BACKGROUND AND PURPOSE: Patient-reported outcomes have become important endpoints in comparative effectiveness research and in patient-centered health care. Valid patient-reported outcome measures detect and respond to clinically relevant changes. The purpose of this study was to evaluate responsiveness of the thyroid-related quality of life (QoL) instrument ThyPRO in patients undergoing relevant clinical treatments for benign thyroid diseases and to compare it with responsiveness of the generic SF-36 Health Survey.

METHODS: A sample of 435 patients undergoing treatment completed the ThyPRO and SF-36 Health Survey (Version 2) at baseline and 6 months after treatment initiation. Responsiveness was evaluated in three thyroid patient groups: patients with hyperthyroidism (n = 66) and hypothyroidism (n = 84) rendered euthyroid after medical therapy, and patients with a clinically detectable nontoxic goiter treated with surgery or radioactive iodine and remaining euthyroid (n = 62). Changes in QoL were evaluated in terms of effect size and compared to the changes predicted by clinical experts. The responsiveness of equivalent scales from ThyPRO and SF-36 Health Survey were compared with the relative validity index.

RESULTS: The ThyPRO demonstrated good responsiveness across the whole range of QoL aspects in patients with hyper- and hypothyroidism. Responsiveness to treatment of nontoxic goiter was also demonstrated for physical and mental symptoms and overall QoL, but not for impact on social life or cosmetic complaints, in contrast to clinicians' predictions. For all comparable scales except one, the ThyPRO was more responsive to treatment than the SF-36 Health Survey.

CONCLUSIONS: The ThyPRO was responsive to treatment across the range of benign thyroid diseases. We suggest implementing this measurement instrument as a patient-reported outcome in clinical studies and in clinical management.