Psychometric performance of the CushingQoL questionnaire in conditions of real clinical practice.
OBJECTIVE
To evaluate health-related quality of life (HRQoL) in Cushing's syndrome (CS) with the disease-generated CushingQoL questionnaire and to confirm its psychometric properties of test-retest reliability and sensitivity to change.


METHODS
Clinical practice conditions in a tertiary referral center.


METHODS
The CushingQoL and EuroQoL questionnaires were administered at baseline and during follow-up and correlated with clinical parameters in 59 patients with CS. To check test-retest reliability, stable patients (either biochemically cured or with active hypercortisolism) were evaluated twice. To investigate sensitivity to change, new patients were evaluated at diagnosis and twice more following improvement after successful surgery.


RESULTS
At baseline, patients with active disease scored lower (indicating worse HRQoL) than those cured on the CushingQoL (46 ± 14 vs 58 ± 20, P<0.05) but not on the EuroQoL-visual analog scale (VAS; 64 ± 20 vs 70 ± 16, P NS). Test-retest reliability of CushingQoL was confirmed in stable patients, both in the 'cured group' (intraclass correlation coefficient (ICC)=0.78, n=34) and in the 'active group' (ICC=0.66, n=14). Sensitivity to change was confirmed in the 'improvement group' (n=11), as the CushingQoL score increased 4 ± 1.5 and 9 ± 3 months after surgery (P<0.01 and <0.001 respectively); the EuroQoL-VAS only improved after 9 ± 3 months (P<0.01). Effect sizes were 1.02 and 1.86 for CushingQoL at 4 ± 1.5 and 9 ± 3 months respectively. Finally, scores of both questionnaires were correlated (r=0.504; P<0.001).


CONCLUSIONS
The CushingQoL questionnaire shows good test-retest reliability and sensitivity to change in clinical practice conditions.
Endocrinology/Medicine Department, Hospital de Sant Pau, IIB-Sant Pau, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER Unit 747), ISCIII, Universitat Autònoma de Barcelona (UAB), C/Sant Antoni Maria Claret 167, 08025 Barcelona, Spain.
Alicia
A
Santos
Eugenia
E
Resmini
Ma Antonia
MA
Martínez-Momblán
Iris
I
Crespo
Elena
E
Valassi
Montserrat
M
Roset
Xavier
X
Badia
Susan M
SM
Webb
D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D047748:Pituitary ACTH Hypersecretion / Q000453:epidemiology* / Q000523:psychology* / Q000628:therapy; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D011795:Surveys and Questionnaires / Q000592:standards*