Clinician's use of automated reports of estimated glomerular filtration rate: a qualitative study.

BACKGROUND: There is a growing awareness in primary care of the importance of identifying patients with chronic kidney disease (CKD) so that they can receive appropriate clinical care; one method that has been widely embraced is the use of automated reporting of estimated glomerular filtration rate (eGFR) by clinical laboratories. We undertook a qualitative study to examine how clinicians use eGFR in clinical decision making, patient communication issues, barriers to use of eGFR, and suggestions to improve the clinical usefulness of eGFR reports. METHODS: Our study used qualitative methods with structured interviews among primary care clinicians including both physicians and allied health providers, recruited from Kaiser Permanente Northwest, a non-profit health maintenance organization. RESULTS: We found that clinicians generally held favorable views toward eGFR reporting but did not use eGFR to replace serum creatinine in their clinical decision-making. Clinicians used eGFR as a tool to help identify CKD, educate patients about their kidney function and make treatment decisions. Barriers noted by several clinicians included a desire for greater education regarding care for patients with CKD and tools to facilitate discussion of eGFR findings with patients. CONCLUSIONS: The manner in which clinicians use eGFRs appears to be more complex than previously understood, and our study illustrates some of the efforts that might be usefully undertaken (e.g. specific clinician education) when encouraging further promulgation of eGFR reporting and usage.

Proteinuria among patients with chronic kidney disease: a performance measure for improving patient outcomes.

BACKGROUND: In an effort to improve identification and treatment of patients with chronic kidney disease (CKD), the National Kidney Foundation (NKF) developed the Kidney Disease Quality Outcomes Initiative (KDQOI) clinical practice guidelines, which include measurement of proteinuria among all patients with CKD who are not receiving chronic dialysis therapy. Encouraging dissemination and utilization of these guidelines may be enhanced by the development of performance measures. The question of whether adequate evidence exists to advocate for the measurement of proteinuria in CKD as a performance measure was explored. METHODS: The US Preventive Services Task Force "chain of evidence" framework was used to guide evidence synthesis from the systematic review. Five questions were applied to specific links in the evidence chain: (1) Is there direct evidence that testing for proteinuria improves health outcomes? (2) What is the yield of testing, in terms of both accuracy and reliability of the test and the prevalence of undiagnosed proteinuria? (3) What adverse effects result from testing a person for proteinuria? (4) Does treatment of proteinuria as a result of testing provide an incremental benefit in health outcomes? and (5) What adverse effects result from treating a person for proteinuria? The systematic search specifically targeted meta-analyses and systematic reviews. FINDINGS: The systematic review revealed no direct evidence that testing for proteinuria among patients with CKD reduced incidence of end-stage renal disease (ESRD). However, the strong links between testing, treatment, and outcome suggest a correlation between proteinuria testing and ESRD. CONCLUSIONS: Current evidence suggests that proteinuria testing (using the albumin-to-creatinine ratio [ACR]) among patients with CKD would be an appropriate health care quality performance measure for improving patient outcomes.

Renin-angiotensin system blockade in older adults with chronic kidney disease: a review of the literature.

PURPOSE OF REVIEW: We have reviewed the literature examining the benefits and harms of renin-angiotensin system (RAS) blockade in older adults, using studies which included patients with chronic kidney disease (CKD) as well as those which included a broader patient population. RECENT FINDINGS: We review the results of key trials which evaluate the impact of RAS blockade on renal outcomes, and those which address the impact of RAS blockade on more global outcomes (cardiovascular events and mortality). Many trials examining renal outcomes of RAS blockade excluded older patients or did not present age-stratified results, whereas trials which examined global outcomes often excluded patients with CKD. Most older patients with CKD have nonproteinuric nondiabetic CKD, thus differing from participants in trials which examined renal outcomes, which often included only patients with diabetes or proteinuria. Most studies did not address alternate outcomes which may carry greatest import for older patients, such as worsening comorbid illness or changes in functional status. SUMMARY: The role of RAS inhibition for older patients with CKD remains unclear. Information on age-specific effects of RAS blockade on a range of different outcomes among older patients with CKD would improve our ability to assess the benefits and harms of RAS inhibition in this population.

Systolic blood pressure and mortality among older community-dwelling adults with CKD.

BACKGROUND: Chronic kidney disease (CKD) is an increasingly common condition, especially in older adults. CKD manifests differently in older versus younger patients, with a risk of death that far outweighs the risk of CKD progressing to the point that dialysis is required. Current CKD guidelines recommend a blood pressure target <130/80 mm Hg for all patients with CKD; however, it is unknown how lower versus higher baseline blood pressures may affect older adults with CKD. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Older patients (aged ≥ 75 years) with CKD (estimated glomerular filtration rate <60 mL/min/1.73 m(2)) in a community-based health maintenance organization. PREDICTOR: Baseline systolic blood pressure (SBP) < 130, 130-160 (reference group), and > 160 mm Hg. OUTCOMES: Participants were followed up for 5 years to examine rates of mortality (primary outcome) and cardiovascular disease hospitalizations (secondary outcome). RESULTS: At baseline, 3,099 participants (38.5%) had SBP < 130 mm Hg, 3,772 (46.9%) had SBP of 131-160 mm Hg, and 1,171 (14.6%) had SBP >160 mm Hg. A total of 3,734 (46.4%) died and 2,881 (35.8%) were hospitalized. Adjusted HRs for mortality in the groups with SBP < 130 and > 160 mm Hg were 1.22 (95% CI, 1.11-1.34) and 1.06 (95% CI, 0.93-1.22), respectively. Adjusted HRs for cardiovascular hospitalization in these groups were 1.10 (95% CI, 0.99-1.23) and 1.26 (95% CI, 1.09-1.45), respectively. LIMITATIONS: Although causality should not be inferred from this retrospective analysis, results from this study can generate hypotheses for future randomized controlled trials to investigate the relationship between blood pressure and outcomes in older patients with CKD. CONCLUSIONS: Our study suggests that lower baseline SBP (≤ 130 mm Hg) may predict poorer outcomes in terms of both mortality and cardiovascular hospitalizations in older adults with CKD. Conversely, higher baseline SBP (> 160 mm Hg) may predict increased risk of cardiovascular hospitalizations, but does not predict mortality. Clinical trials are required to test this hypothesis.

Serum Bicarbonate as a Surrogate for pH in Hemodialysis: A Pilot Study.

RATIONALE & OBJECTIVE: Excess morbidity and mortality are associated with both high and low serum bicarbonate levels in epidemiologic studies of patients with end-stage kidney disease (ESKD) receiving hemodialysis. The Kidney Disease Outcomes Quality Initiative (KDOQI) recommends modifying dialysate bicarbonate concentration to achieve a predialysis serum bicarbonate level ≥ 22 mmol/L, measured as total carbon dioxide (CO2). This practice assumes that total CO2 is an adequate surrogate for acid-base status, yet its surrogacy performance is unknown in ESKD. We determined acid-base status at the beginning and end of hemodialysis using total CO2 and pH and tested whether total CO2 is an appropriate surrogate for acid-base status. STUDY DESIGN: Pilot study. SETTING & PARTICIPANTS: 25 veterans with ESKD receiving outpatient hemodialysis. TESTS COMPARED: pH, calculated bicarbonate level, and total CO2. OUTCOMES: The proportion of paired samples for which total CO2 misclassified acid-base status according to pH was determined. Bias of total CO2 was evaluated using Bland-Altman plots, comparing it to calculated bicarbonate. RESULTS: Among 71 samples, mean pH was 7.41 ± 0.03 predialysis and 7.48 ± 0.05 postdialysis. Compared with interpretation of full blood gas profiles, 9 of 25 (36%) participants were misclassified as acidemic using predialysis total CO2 measures alone (total CO2 < 22 mmol/L but pH ≥ 7.38); 1 (4%) participant was misclassified as alkalemic (total CO2 > 26 mmol/L but pH ≤ 7.42). Among paired samples in which predialysis total CO2 was < 22 mmol/L, the corresponding pH was acidemic (< 7.38) in just 3 of 13 (23%) instances. LIMITATIONS: Small, single-center, entirely male cohort. CONCLUSIONS: A majority of participants became alkalemic during routine hemodialysis despite arriving with normal pH. 10 of 25 (40%) participants' acid-base status was misclassified using total CO2 measurements alone; the majority of predialysis total CO2 values that would trigger therapeutic modification according to practice guidelines did not have acidemia when assessed using pH. Efforts to improve dialysis prescription require recognition that total CO2 may not be reliable for interpreting acid-base status in hemodialysis patients.

Systolic BP and Mortality in Older Adults with CKD.

BACKGROUND AND OBJECTIVES: Optimal BP targets for older adults with CKD are unclear. This study sought to determine whether a nonlinear relationship between BP and mortality-as described for the broader CKD population and for older adults in the general population-is present for older adults with CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A cohort of 21,015 adults age 65-105 years with a moderate or severe reduction in eGFR (<60 ml/min per 1.73 m(2)) were identified within the Kaiser Permanente Northwest Health Maintenance Organization population. The relationship between baseline systolic BP (SBP; ≤120, 121-130, 131-140, 141-150, >150 mmHg; referent, 131-140 mmHg) and all-cause mortality across age groups (65-70, 71-80, and >80 years) was examined; patients were followed for up to 11 years after cohort entry. RESULTS: The median times at risk were 3.15 years, 3.53 years, and 2.76 years for adults age 65-70, 71-80, and >80 years, respectively. Mortality during follow-up was 19.6% for those age 65-70 years, 33.4% for those age 71-80 years, and 55.7% for those age >80 years. The relationship between SBP and mortality varied as a function of age. The risk of death was highest for patients with the lowest SBP in all age groups. Only among adults age 65-70 years was an SBP>140 mmHg associated with a higher risk of death compared with the referent category. Patterns of age modification of the relationship between SBP and mortality were consistent in all sensitivity analyses. CONCLUSIONS: In a cohort of older adults, the relationship between SBP and mortality varied systematically with age. A relationship between higher SBP and mortality was present only for younger members of this cohort and not for those older than 70. These results raise the question of whether the relative benefits and harms of lowering BP to recommended targets for older adults with CKD may vary as a function of age.

Predicting mortality in older adults with kidney disease: a pragmatic prediction model.

OBJECTIVES: To develop mortality risk prediction models for older adults with chronic kidney disease (CKD) that include comorbidities and measures of health status and use not associated with particular comorbid conditions (nondisease-specific measures). DESIGN: Retrospective cohort study. SETTING: Kaiser Permanente Northwest (KPNW) Health Maintenance Organization. PARTICIPANTS: Individuals with severe CKD (estimated glomerular filtration rate<30 mL/min per 1.73 m2; N=4,054; n=1,915 aged 65-79, n=2,139 aged ≥80) who received care at KPNW between 2000 and 2008. MEASUREMENTS: Cox proportional hazards analysis was used to examine the association between selected participant characteristics and all-cause mortality and to generate age group-specific risk prediction models. Predicted and observed risks were evaluated according to quintile. Predictors from the Cox models were translated into a points-based system. Internal validation was used to provide best estimates of how these models might perform in an external population. RESULTS: The risk prediction models used 16 characteristics to identify participants with the highest risk of mortality at 2 years for adults aged 65 to 79 and 80 and older. Predicted and observed risks agreed within 5% for each quintile; a 4 to 5 times difference in 2-year predicted mortality risk was observed between the highest and lowest quintiles. The c-statistics for each model (0.68-0.69) indicated effective discrimination without evidence of significant overfit (slope shrinkage 0.06-0.09). Models for each age group performed similarly for mortality prediction at 6 months and 2 years in terms of discrimination and calibration. CONCLUSION: When validated, these risk prediction models may be helpful in supporting discussions about prognosis and treatment decisions sensitive to prognosis in older adults with CKD in real-world clinical settings.

Should measuring haemoglobin among chronic kidney disease patients be a performance measure?

OBJECTIVE: We attempted to: (1) to assess whether or not adequate evidence exists to advocate the measurement of anaemia in chronic kidney disease as a performance measure; and (2) to determine what the appropriate benchmarks might be for health systems seeking to implement this performance measure. DESIGN: Our study was conducted in two phases: (1) we used the United States Preventive Service Task Force chain of evidence methodology to determine six key questions that were subsequently reviewed to determine if adequate evidence existed to recommend haemoglobin testing among patients with chronic kidney disease; and (2) in order to establish a benchmark for a potential performance measure we measured the number of patients who had a test for anaemia during the preceding year and during the preceding three years. We established these benchmarks using chronic kidney disease defined both by estimated glomerular filtration rate and ICD-9 codes. SETTING: Benchmarking was undertaken at Kaiser Permanente Northwest, which serves the Portland, Oregon and Vancouver, Washington metropolitan area, and Kaiser Permanente Georgia, which serves the Atlanta metropolitan area. PARTICIPANTS: Patients with chronic kidney disease identified by either estimated glomerular filtration rate or ICD-9 code. MAIN OUTCOMES MEASUREMENT: Serum haemoglobin INTERVENTION: This was an observational study. RESULTS: Our review of the evidence found no direct evidence that testing for anaemia among patients with chronic kidney disease improved patient morbidity or mortality. The ideal test for anaemia was serum haemoglobin. We found that available treatments of anaemia improve fatigue, but may increase mortality and stoke. We also found that an overwhelming majority of patients with chronic kidney disease defined by either estimated glomerular filtration rate or ICD-9 codes, over one or three years had had a haemoglobin measurement. CONCLUSION: There is currently inadequate evidence to recommend haemoglobin measurement among patients with chronic kidney disease as a performance measure. In addition, most patients with chronic kidney disease have already had haemoglobin measurement, minimizing the potential benefit of a performance measure.