Identification of high-risk population and prevalence of kidney damage among asymptomatic central government employees in Delhi, India.

Chronic kidney disease (CKD) has attained epidemic proportions in India due to increased incidence of diabetes and hypertension (HTN). It was surmised that identification of only high-risk groups (HRGs) through a questionnaire would be sufficient to identify cases of kidney damage (KD). The study attempted to device a questionnaire to classify the subjects in to HRG and low-risk group (LRG) and assess the extent of early KD. The central government employees were classified into HRG and LRG based on "SCreening for Occult REnal Disease (SCORED)" and "EXTENDED" questionnaire formulated after addition of 10 more parameters apart from diabetes and HTN. Urine examination by dipstick, quantitative microalbumin, serum creatinine, and estimated glomerular filtration rate were assessed to determine KD. The data were analyzed for risk-group classification. Sensitivity was calculated based on the number of KD cases in the HRG. Of the 1104 employees screened, 58% and 42% were classified in HRG and LRG, respectively. There were 306 KD cases of whom, 65% were in the HRG. The sensitivity of the EXTENDED questionnaire to detect CKD was much higher (60%) compared to the SCORED questionnaire (25%). The prevalence of KD according to stage was: stage-1, 13.4%; stage-2, 9.9%; and late stages (3, 4, and 5), 4.5%. Microalbuminuria and dipstick-positive proteinuria showed statistically higher proportion in the HRG (25% and 4.1%) than in the LRG (19% and 1%, respectively) (P <0.05). Although the EXTENDED questionnaire was more sensitive in detecting KD, only screening the high-risk population will leave behind 35% of KD cases. There is, therefore, a need for mass screening at regular intervals.