Areef Ishani

There are no national level data on types of dialysis in use for acute kidney injury (AKI). We aimed to assess trends in dialysis modality for AKI and mortality associated with each modality from 1998 to 2005. Using data from the 5% Medicare cohort, we identified individuals with AKI requiring dialysis. Individuals with preexisting end-stage renal disease were excluded. Intermittent hemodialysis (IHD), daily intermittent hemodialysis, and continuous renal replacement therapy (CRRT) were defined using Current Procedure Terminology codes. Mortality was defined as death during 30 days after the first dialysis session. Between 1998 and 2005, there were a total of 18,249 patients identified with AKI requiring renal replacement therapy. CRRT was increasingly used for AKI, with 9.9% of patients in 1998 to 18.3% by 2005. Proportion of daily dialysis decreased during this period, while use of IHD remained stable at approximately 68%. Overall 30-day mortality declined from 44.4% in 1998 to 40.2% in 2005. Crude mortality for CRRT was highest in all years (51.0-61.8%), followed by daily (38.2-49.9%) and IHD groups (35.8-43.4%). Multinomial logistic regression analysis showed that white race, presence of sepsis, atherosclerotic heart diseases, peripheral vascular diseases, dysrhythmia, gastrointestinal and liver diseases, and any year after 2000 were independently associated with higher odds of using CRRT after adjusting for other variables. The proportion of patients using CRRT has increased over time. Mortality associated with IHD has decreased from 1998 to 2005. Mortality associated with different dialysis modalities is likely the result of severity of illness.

The incidence of ESRD is increasing rapidly. Limited information exists regarding early markers for the development of ESRD. This study aimed to determine over 25 yr the risk for ESRD associated with proteinuria, estimated GFR (eGFR), and hematocrit in men who did not have identified kidney disease and were randomly assigned into the Multiple Risk Factor Intervention Study (MRFIT). A total of 12,866 men who were at high risk for heart disease were enrolled (1973 to 1975) and followed through 1999. Renal replacement therapy was ascertained by matching identifiers with the United States Renal Data System’s data; vital status was from the National Death Index. Men who initiated renal replacement therapy or died as a result of kidney disease were deemed to have developed ESRD. Dipstick urine for proteinuria, eGFR, and hematocrit were related to development of ESRD. During 25 yr, 213 (1.7%) men developed ESRD. Predictors of ESRD were dipstick proteinuria of 1+ or ≥2+ (hazard ratio [HR] 3.1 [95% confidence interval (CI) 1.8 to 5.4] and 15.7 [95% CI 10.3 to 23.9] respectively) and an eGFR of 2 (HR 2.4; 95% CI 1.5 to 3.8). Correlation between eGFR and serum creatinine was 0.9; the risk for ESRD with a 1-SD difference of each was identical (HR 1.21). Bivariate analysis demonstrated a 41-fold increase in ESRD risk in those with an eGFR 2 and ≥2+ proteinuria (95% CI 15.2 to 71.1). There was no association between hematocrit and ESRD. Other baseline measures that independently predicted ESRD included age, cigarette smoking, BP, low HDL cholesterol, and fasting glucose. Among middle-aged men who were at high risk for cardiovascular disease but had no clinical evidence of cardiovascular disease or significant kidney disease, dipstick proteinuria and an eGFR value 2 were strong predictors of long-term development of ESRD. It remains unknown whether intervention for proteinuria or early identification of those with chronic kidney disease reduces the risk for ESRD.