gms | German Medical Science

Objective: Cushing’s disease has a considerable impact on HRQoL. Therefore, we developed a disease specific inventory for Cushing's disease (CD) that consists of 25 items. Normative data from healthy controls (HC) with which the individual patients' scores can be compared were assessed.

Method: Sources for item generation consisted of technical literature, interviews with patients and the rating of neurosurgeons, endocrinologists and a neuropsychologist. A preliminary inventory with 64 items was handed out to 63 CD patients. Item reduction and scale generation followed the principles of Classical Test Theory. Validation was performed with the WHOQoL-BREF. For assessing normative data, the inventory was filled out by 1784 HC omitting the introductory sentence “Because of my Cushing's disease” that was included in the CD group.

Results: The final version of the inventory contained 25 items, showed high reliability (Cronbach's alpha = 0.93) and validity (r= –0.65) and includes the subdomains Depression, Sexual Activity, Environment, Eating Behavior, Bodily Restrictions and Cognition. We found a non-linear correlation between the inventory scores and patients' age, younger and middle-aged patients having inferior HRQoL than patients between 31 and 50 years and older than 61 years. Preoperative 24 h UFC levels correlated significantly with the subscale Cognition and only marginally failed significance level for the subscale Eating Behavior, while preoperative cortisol and ACTH levels did not correlate with any scale. In 28.6% of our CD patients we found slight and in 41.3% severe impairment in the Total Score of the questionnaire compared to HC. Less than one-third of our patient sample presented with unimpaired HRQoL.

Conclusions: The new questionnaire is a feasible instrument to assess HRQoL in CD in a clinical and investigative setting and provides normative data for all age groups and genders.