Objective: Evaluate the reliability and validity of the Kidney Disease Quality of Life Short Form 36 (KDQOL-36) in Hispanics with mild-to-moderate chronic kidney disease (CKD).
Setting: Chronic Renal Insufficiency Cohort Study
Participants: 420 Hispanic (150 English- and 270 Spanish-speakers), and 409 non-Hispanic White individuals, matched by age (mean 57 years), sex (60% male), kidney function (mean estimated glomerular filtration rate 36ml/min/1.73m2), and diabetes (70%).
Methods: To measure construct validity, we selected instruments, comorbidities, and laboratory tests related to at least one KDQOL-36 subscale. Reliability was determined by calculating Cronbach's alpha.
Results: Reliability of each KDQOL-36 subscale [SF-12 Physical Component Summary (PCS) and Mental Component Summary (MCS), Symptoms/Problems, Burden of Kidney Disease and Effects of Kidney Disease] was very good (Cronbach's alpha >0.8). Construct validity was supported by expected negative correlation between MCS scores and the Beck Depression Inventory in all three subgroups (r=-0.56 to -0.61, P<.0001). There was inverse correlation between the Symptoms/ Problems subscale and the Patient Symptom Form (r= -0.70 to -0.77, P<.0001). We also found significant, positive correlation between the PCS score and a physical activity survey (r=+0.29 to +0.38, P< or =.003); and between the PCS and MCS scores and the Kansas City Questionnaire (r= +0.31 to +0.64, P<.0001). Reliability and validity were similar across all racial/ethnic groups analyzed separately.
Conclusion: Our findings support the use of the KDQOL-36 as a measure of HRQOL in this cohort of US Hispanics with CKD.