BACKGROUND/RATIONALE:
A substantial body of literature indicates that the progression of CKD to End Stage Renal Disease can be delayed and mortality decreased, through the use of angiotensin converting enzyme inhibitors (ACEIs) and/or angiotension receptor blockers (ARBs), lipid and blood pressure control, and management by nephrology specialists. However, there are no systematically collected data regarding guideline concordant care provided to the veteran population with CKD.
OBJECTIVE(S):
Aim 1: To study K-DOQI/VA-DOD Chronic Kidney Disease Guideline care in VA patients with CKD and to evaluate predictors of the provision of guideline concordant care. Objective 1.1: To estimate the proportions of VA patients with CKD who receive recommended guideline concordant care. Objective 1.2: To evaluate potential predictors of the provision of guideline concordant care, including patient sociodemographic factors, comorbidities, and specialty care.
Objective 1.3: To evaluate potential predictors of nephrologist subspecialist care in VA patients with CKD taking into account CKD stage, medical comorbidities, and acuity of recognized renal disease.
Aim 2: To estimate incidence of first (incident) dialysis in VA patients with CKD and to evaluate potential predictors of incident dialysis. Objective 2.1: To estimate incidence of first (incident) dialysis, with separate estimates for planned (i.e. preceded by placement or attempted placement of permanent access) and emergency dialysis. Objective 2.2: To evaluate potential predictors of planned and emergency dialysis, , including the provision of guideline concordant care.
Aim 3: To estimate mortality prior to dialysis in VA patients with CKD and to evaluate potential predictors of pre-dialysis mortality
Objective 3.1 To estimate mortality rates prior to dialysis in VA patients with CKD.
Objective 3.2: To evaluate potential predictors of pre-dialysis mortality, including the provision of guideline concordant care.
METHODS:
We will develop a dynamic inception cohort of all veterans (both with and without diabetes) first identified as having CKD in FY99-02 based upon calculation of estimated GFR (eGFR) without prior dialysis. This cohort will be followed through FY04, measuring processes and intermediate outcomes of ambulatory care and the occurrence of cardiovascular events, dialysis, and mortality, using merged VA and CMS datasets.
FINDINGS/RESULTS:
Prevalence of CKD by GFR criterion was 31.6%. Only 20.2% to 42.4% of individuals with CKD received a renal-related diagnosis code in either VA or Medicare records over one year. Specificity of renal codes ranged from 93.2% to 99.4%. CKD is a common co-morbidity for patients with diabetes in the VA system, but diagnosis codes in administrative records are insensitive markers for patients with CKD. (Aim 1, Kern et al, HSR 2006)
Of 182,162 patients with Stage 3 or 4 CKD, 66% were dispensed ACE-I/ARB agents within a twelve month period from 1999-2000. The odds of receiving ACE-I/ARB agents were increased six-fold (OR 5.81; 95% CI 5.62-6.02; p < .0001) if potassium-wasting diuretics were dispensed, and increased 30% (OR 1.31; 95% CI 1.24 - 1.37; p < .0001) with nephrology care. The association of nephrology care with ACE-I/ARB agents disappeared when adjusted for
diuretic use. (Aim 1, Obj 1.1 and 1.2)(Tiwari et al, AmJManCare 2007)
Of 39,044 patients, 70.0 %, 22.5 %, and 7.6 % had early stage 3, late stage 3, and stage 4 CKD, respectively; 3.1%, 9.5%, and 28.1% visited a nephrologist, respectively. The association of higher consistency of nephrologist visits and reduced mortality were consistent across CKD stages. Overall, higher consistency of nephrologist visits was associated with greater reduction of mortality: the adjusted hazard ratios (AHRs) were 0.80 (95% CI=0.66, 0.97), 0.67 (0.54, 0.84), and 0.44 (0.31. 0.61), respectively, when the groups of two, three, and four visits were compared to those had no visits. One visit made no difference from no visits (AHR=1.02; 95% CI=0.89, 1.16). The consistency of outpatient nephrology care was independently associated in a graded fashion with lower pre-dialysis mortality for diabetic patients with moderately severe to severe CKD. However, only a minority of patients received care from a nephrologist. (Obj 1.3 and 3.1)
[Tseng C-L. Kern, EFO, Miller, DR, Tiwari A, Maney, M Rajan, M, Pogach L. Survival Benefit of Nephrology Care for Patients with Diabetes and Chronic Kidney Disease. Archives Internal Medicine 2008; 148-157].
We conducted a retrospective cohort study of 39,629 patients with diabetes and stage 3 to stage 5 chronic kidney disease. with a median follow up period was 19.3 months during 1997 to 2000. The cohort consisted of 81.4% whites, 14.4% blacks, 2.2% Hispanics and 2% others.
The overall dialysis-free mortality was 11.2 per 100 person-years. Dialysis-free mortality was 11.1 for whites, 11.6 for blacks, 10.7 for Hispanics and 11.0 for others. When adjusted for age, sex, and comorbid conditions, blacks had a hazard ratio of 1.13 (95% CI, 1.05-1.21), Hispanics had a hazard ratio of 1.07 (95% CI, 0.90-1.27) and others had a hazard ratio of 1.11 (95% CI, 0.93-1.33) compared with whites. The findings were not explained by access to nephrologist care. Identifying possible mediating factors for the race/ethnicity differences in chronic kidney disease outcomes that can be improved by the health care system is critical to developing action plans to eliminate differences, according to the researchers. (Tseng et al, CDC Diabetes Translation Conference, Oral Abstract 5/08]
IMPACT:
1. Kern et al (2006) support the current Patient Care Services initiative to implement eGFR in CPRS.
2. Tseng et al [Archives Internal Medicie 2008]that continuity of nephrology care reduces pre-dialysis mortality in a dose dependent manner was noted by Reuter's news Agency in the context of a possible shortage of nephrologists.
3. Tseng et al (CDC 2008) of pre-dialysis disparities in mortality was reported by Endocrinology Today.
PUBLICATIONS:
Journal Articles
- Tseng CL, Kern EF, Miller DR, Tiwari A, Maney M, Rajan M, Pogach L. Survival benefit of nephrologic care in patients with diabetes mellitus and chronic kidney disease. Archives of Internal Medicine. 2008; 168(1): 55-62.
- Kern EF, Maney M, Miller DR, Tseng CL, Tiwari A, Rajan M, Aron D, Pogach L. Failure of ICD-9-CM codes to identify patients with comorbid chronic kidney disease in diabetes. Health Services Research. 2006; 41(2): 564-80.
