Evaluating the burden of endogenous Cushing's syndrome using a web-based questionnaire and validated patient-reported outcome measures.

INTRODUCTION: Endogenous Cushing's syndrome (CS) is a rare endocrine condition caused by chronic oversecretion of cortisol, resulting in a diverse constellation of symptoms. This study examined the ongoing burden of illness (BOI), from the first appearance of symptoms through treatment, which is currently not well evaluated. METHODS: A quantitative, cross-sectional, web-enabled survey including 5 validated patient reported outcomes (PRO) measures was conducted in patients with CS who had been diagnosed ≥ 6 months prior and who had received ≥ 1 treatment for their endogenous CS at the time of the survey. RESULTS: Fifty-five patients participated in this study; 85% were women. The mean age was 43.4 ± 12.3 years (± standard deviation, SD). On average, respondents reported a 10-year gap between the first occurrence of symptoms and diagnosis; 80% underwent surgical treatment for CS. Respondents experienced symptoms on 16 days in a typical month, and their health-related quality of life was moderately impacted based on the CushingQoL score. Weight gain, muscle fatigue, and weakness were the most common symptoms and 69% percent of patients reported moderate or severe fatigue using the Brief Fatigue Inventory. Following treatment, the occurrence of most symptoms declined over time, although anxiety and pain did not significantly decrease. Overall, 38% of participants reported an annual average of 25 missed workdays due to CS symptoms. CONCLUSIONS: These results demonstrate a BOI in CS despite ongoing treatment and illustrate the need for interventions to address persistent symptoms, particularly weight gain, pain, and anxiety.