Comparison of the WHOQOL-BREF and KDQOL-36 in CKD Patients

Monday, July 11, 2011

Tzu-Chia Lin, BS
Department of Nursing, College of Medicine, National Cheng Kung University, Tainan, Taiwan
Miaofen Yen, PhD, RN
Department of Nursing & Institute of Allied Health Sciences, National Cheng Kung University, Tainan city, Taiwan

Learning Objective 1: To understand the psychometric properties of the WHOQOL-BREF and KDQOL-36.

Learning Objective 2: To understand the strengths and the weakness of the WHOQOL-BREF and KDQOL-36 when administered to CKD patients.

Purpose: Quality of life (QOL) is considered to be an important outcome measure for patients with Chronic Kidney Disease (CKD). WHOQOL-BREF and KDQOL-36 are the most commonly used generic and disease-specific scales in CKD patients respectively. However, there are limited data with respect to the comparison and the discriminative abilities of these scales. In addition, there are few symptoms in the early stage but more complications in the late stage which may influence the interpretation of QOL. The study purpose was to compare the psychometric properties of the two scales, and to examine the discriminative abilities of these questionnaires in CKD patients.

Methods:  Patients over 20 years of age and diagnosed of CKD were recruited. CKD was then staged according to the eGFR and we subdivided patients into two groups with the early stage for those with eGFR of 30-90 ml/min/1.73m2 and the late stage for those with eGFR less than 30 ml/min/1.73m2. QOL was assessed by the WHOQOL-BREF and the KDQOL-36. Demographic characteristics and medical data were also obtained.

Results: The study is in progress. Descriptive statistics will express as frequencies and percentage or as mean± SD. Analysis of variance will be investigated. Simple regression will be used to examine whether there is a linear trend between CKD stages and the domain scores. The psychometric properties of the two scales will also be evaluated. A multitrait-multimethod correlation matrix (MTMM) will be used to evaluate the relationship between the domains of the two scales and to test for the correlation among CKD stage.

Conclusion: The WHOQOL-BREF may be more applicable to CKD patients with early stage while the KDQOL-36 may be more sensitive in predicting renal function impairment and thus suitable for measuring QOL of CKD patients in the late stage.