Physician adjudication of angioedema diagnosis codes in a population of patients with heart failure prescribed angiotensin-converting enzyme inhibitor therapy.

PURPOSE: Our objective was to calculate the positive predictive value (PPV) of the ICD-9 diagnosis code for angioedema when physicians adjudicate the events by electronic health record review. Our secondary objective was to evaluate the inter-rater reliability of physician adjudication. METHODS: Patients from the Cardiovascular Research Network previously diagnosed with heart failure who were started on angiotensin-converting enzyme inhibitors (ACEI) during the study period (July 1, 2006 through September 30, 2015) were included. A team of two physicians per participating site adjudicated possible events using electronic health records for all patients coded for angioedema for a total of five sites. The PPV was calculated as the number of physician-adjudicated cases divided by all cases with the diagnosis code of angioedema (ICD-9-CM code 995.1) meeting the inclusion criteria. The inter-rater reliability of physician teams, or kappa statistic, was also calculated. RESULTS: There were 38 061 adults with heart failure initiating ACEI in the study (21 489 patient-years). Of 114 coded events that were adjudicated by physicians, 98 angioedema events were confirmed for a PPV of 86% (95% CI: 80%, 92%). The kappa statistic based on physician inter-rater reliability was 0.65 (95% CI: 0.47, 0.82). CONCLUSIONS: ICD-9 diagnosis code of 995.1 (angioneurotic edema, not elsewhere classified) is highly predictive of angioedema in adults with heart failure exposed to ACEI.

Comparison of a Kidney Replacement Therapy Risk Score Developed in Kaiser Permanente Northwest vs Estimated Glomerular Filtration Rate in Advanced Chronic Kidney Disease Using Decision Curve Analysis.

INTRODUCTION: Use of kidney replacement therapy (KRT) prediction models for guiding arteriovenous fistula (AVF) referrals in advanced chronic kidney disease (CKD) is unknown. We aimed to compare a hypothetical approach using a KRT prediction model developed in Kaiser Permanente Northwest to estimated glomerular filtration rate (eGFR) for AVF referrals. METHODS: Our retrospective cohort consisted of patients with stage G4 CKD in Kaiser Permanente Northwest followed by nephrology. Two-year KRT risk was calculated at each nephrology visit up to 2 years from entrance into cohort based on a previously published model. We calculated sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) based on several 2-year KRT risk and eGFR cutoffs for outcome of hemodialysis at 18 months. We compared an approach of AVF referral using 2-year KRT risk and eGFR cutoffs using decision curve analysis. RESULTS: Two-year KRT risk better discriminated progression to hemodialysis compared to eGFR < 15 mL/min (AUC 0.60 vs 0.69 at 2-year KRT risk > 20% and 0.69 at 2-year KRT risk > 40%, p = 0.003 and 0.006, respectively) but not to eGFR of 20 mL/min (AUC 0.64, p = 0.16 and 0.19, respectively). Decision curve analysis showed that AVF referral guided by 2-year KRT risk score resulted in higher net benefit compared to eGFR at low thresholds for referral. CONCLUSION: In stage G4 CKD, a 2-year KRT risk model better predicted progression to KRT at 18 months compared to an eGFR of 15 mL/min but not to 20 mL/min and may improve timely referral for AVF placement in patients at lower thresholds for referral.

Predicted risk of renal replacement therapy at arteriovenous fistula referral in chronic kidney disease.

BACKGROUND AND OBJECTIVES: Optimal timing of arteriovenous fistula placement in chronic kidney disease remains difficult and contributes to high central venous catheter use at initial hemodialysis. We tested whether a prediction model for progression to renal replacement therapy developed at Kaiser Permanente Northwest may help guide decisions about timing of referral for arteriovenous fistula placement. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: A total of 205 chronic kidney disease stage 4 patients followed by nephrology referred for arteriovenous fistula placement were followed for up to 2 years. Patients were censored if they died or discontinued Kaiser Permanente Northwest coverage. Survival analyses were performed for overall progression to renal replacement therapy divided by quartiles based on 2-year risk for renal replacement therapy and estimated glomerular filtrate rate at time of referral. RESULTS: By 2 years, 60% progressed to renal replacement therapy and 11% had died. 80% in the highest risk versus 36% in the lowest risk quartile progressed to renal replacement therapy (predicted risk 84% vs 17%). 75% in the lowest estimated glomerular filtrate rate versus 56% in the highest estimated glomerular filtrate rate quartile progressed to renal replacement therapy (mean estimated glomerular filtrate rate 13 mL/min vs 21 mL/min). The hazard ratio was significantly higher for each consecutive higher renal replacement therapy quartile risk while for estimated glomerular filtrate rate, the hazard ratio was only significantly higher for the lowest compared to the highest quartile. The extreme quartile risk ratio was higher for 2-year risk for renal replacement therapy compared to estimated glomerular filtrate rate (4.0 vs 2.4). CONCLUSION: In patients with chronic kidney disease stage 4 referred for arteriovenous fistula placement, 2-year renal replacement therapy risk better discriminated progression to renal replacement therapy compared to estimated glomerular filtrate rate at time of referral.

A Quality Improvement Initiative Targeting Chronic Kidney Disease Metrics Through Increased Urinary Albumin Testing.

INTRODUCTION: Achievement of quality metrics in chronic kidney disease (CKD), specifically urinary albumin testing and angiotensin-converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB) use, remained lower in Kaiser Permanente Northwest compared with other Kaiser Permanente regions. We were interested if more frequent testing of urine albumin (ACR) improved CKD quality metrics. METHODS: We implemented a quality improvement project automating ACR testing using an informatics tool in patients with stage 3 CKD linked to an electronic health record (EHR) alert recommending ACEi or ARB initiation in patients with renal indication. RESULTS: At 1 and 2 years after implementation of ACR testing, ACR testing increased from 26.9% prior to implementation to 83% at 1 year and 77% at 2 year after implementation (p < 0.001). However, ACEi or ARB use did not increase significantly (65.8% vs 65.7% vs 66.4%, p = 0.54). There was also no significant change in other quality metrics, including diabetes control, hypertension control, and comanagement of higher-risk CKD patients. DISCUSSION AND CONCLUSION: In patients with stage 3 CKD, increased ACR testing via automated testing linked with EHR alert did not result in an improvement in CKD quality metrics.

Association of Proteinuria with Central Venous Catheter Use at Initial Hemodialysis.

CONTEXT: Central venous catheter (CVC) use is associated with increased mortality and complications in hemodialysis recipients. Although prevalent CVC use has decreased, incident use remains high. OBJECTIVE: To examine characteristics associated with CVC use at initial dialysis, specifically looking at proteinuria as a predictor of interest. DESIGN: Retrospective cohort of 918 hemodialysis recipients from Kaiser Permanente Northwest who started hemodialysis from January 1, 2004, to January 1, 2014. MAIN OUTCOME MEASURES: Multivariable logistic regression was used to examine an association of proteinuria with the primary outcome of CVC use. RESULTS: More than one-third (36%) of patients in our cohort started hemodialysis with an arteriovenous fistula, and 64% started with a CVC. Proteinuria was associated with starting hemodialysis with a CVC (likelihood ratio test, p < 0.001) after adjustment for age, peripheral vascular disease, congestive heart failure, diabetes, sex, race, and length of predialysis care. However, on pairwise comparison, only patients with midgrade proteinuria (0.5-3.5 g) had lower odds of starting hemodialysis with a CVC (odds ratio = 0.39, 95% confidence interval = 0.24-0.65). CONCLUSION: Proteinuria was associated with use of CVC at initial hemodialysis. However, a graded association did not exist, and only patients with midgrade proteinuria had significantly lower odds of CVC use. Our findings suggest that proteinuria is an explanatory finding for CVC use but may not have pragmatic value for decision making. Patients with lower levels of proteinuria may have a higher risk of starting dialysis with a CVC.

Predicting 5-Year Risk of RRT in Stage 3 or 4 CKD: Development and External Validation.

BACKGROUND AND OBJECTIVES: Only a minority of patients with CKD progress to renal failure. Despite the potential benefits of risk stratification in the CKD population, risk prediction models are not routinely used. Our objective was to develop and externally validate a clinically useful and pragmatic prediction model for the 5-year risk of progression to RRT in stage 3 or 4 CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We used a retrospective cohort design. The development cohort consisted of 22,460 Kaiser Permanente Northwest members with stage 3 or 4 CKD (baseline 2002-2008). The validation cohort consisted of 16,553 Kaiser Permanente Colorado members with stage 3-4 CKD (baseline 2006-2008). The final model included eight predictors: age, sex, eGFR, hemoglobin, proteinuria/albuminuria, systolic BP, antihypertensive medication use, and diabetes and its complications. RESULTS: In the Northwest and Colorado cohorts, there were 737 and 360 events, and observed 5-year Kaplan-Meier risks of 4.72% (95% confidence interval [95% CI], 4.38 to 5.06) and 2.57% (95% CI, 2.30 to 2.83), respectively. Our prediction model performed extremely well in the development cohort, with a c-statistic of 0.96, an R2 of 79.7%, and good calibration. We had similarly good performance in the external validation cohort, with a c-statistic of 0.95, R2 of 81.2%, and good calibration. In the external validation cohort, the observed risk was slightly lower than the predicted risk in the highest-risk quintile. Using the top quintile of predicted risk as a cutpoint gave a sensitivity of 92.2%. CONCLUSIONS: We developed a pragmatic prediction model and risk score for predicting the 5-year RRT risk in stage 3 and 4 CKD. This model uses variables that are typically available in routine primary care settings, and can be used to help guide important decisions such as timing of referral to nephrology and fistula placement.

Predicting the Risk of Clostridium difficile Infection upon Admission: A Score to Identify Patients for Antimicrobial Stewardship Efforts.

INTRODUCTION: Increasing morbidity and health care costs related to Clostridium difficile infection (CDI) have heightened interest in methods to identify patients who would most benefit from interventions to mitigate the likelihood of CDI. OBJECTIVE: To develop a risk score that can be calculated upon hospital admission and used by antimicrobial stewards, including pharmacists and clinicians, to identify patients at risk for CDI who would benefit from enhanced antibiotic review and patient education. METHODS: We assembled a cohort of Kaiser Permanente Northwest patients with a hospital admission from July 1, 2005, through December 30, 2012, and identified CDI in the six months following hospital admission. Using Cox regression, we constructed a score to identify patients at high risk for CDI on the basis of preadmission characteristics. We calculated and plotted the observed six-month CDI risk for each decile of predicted risk. RESULTS: We identified 721 CDIs following 54,186 hospital admissions-a 6-month incidence of 13.3 CDIs/1000 patient admissions. Patients with the highest predicted risk of CDI had an observed incidence of 53 CDIs/1000 patient admissions. The score differentiated between patients who do and do not develop CDI, with values for the extended C-statistic of 0.75. Predicted risk for CDI agreed closely with observed risk. CONCLUSION: Our risk score accurately predicted six-month risk for CDI using preadmission characteristics. Accurate predictions among the highest-risk patient subgroups allow for the identification of patients who could be targeted for and who would likely benefit from review of inpatient antibiotic use or enhanced educational efforts at the time of discharge planning.

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.

Individuality of the plasma sodium concentration.

Older literature has suggested that the plasma sodium concentration is not individual, that it is neither intrinsic to an individual nor reproducible, longitudinally. We recently observed that the plasma sodium concentration is heritable. Because demonstrable heritability requires individuality of the relevant phenotype, we hypothesized that the plasma sodium concentration was substantially individual. In two large health plan-based cohorts, we demonstrated individuality of the plasma sodium concentration over a 10-yr interval; the intraclass correlation coefficient (ICC) averaged 0.4-0.5. The individuality of plasma sodium increased significantly with age. Plasma sodium individuality was equal to or only slightly less than that for plasma glucose but was less than the individuality for creatinine. The individuality of plasma sodium was further confirmed by comparing the Pearson correlation coefficient for within-individual versus between-individual pairs of sodium determinations and via application of the agreement index. Furthermore, the distribution of all sodium determinations for all participants within a population was similar to the distribution for the mean sodium concentration for individuals within that population. Therefore, the near-normal distribution of plasma sodium measurements within a population is likely not attributable to assay-specific factors but rather to genuine and durable biological variability in the osmotic set point. In aggregate, these data strongly support the individuality of the plasma sodium concentration. They further indicate that serial plasma sodium values for any given individual tend to cluster around a patient-specific set point and that these set points vary among individuals.

Chronic kidney disease and outcomes in heart failure with preserved versus reduced ejection fraction: the Cardiovascular Research Network PRESERVE Study.

BACKGROUND: There is scant evidence on the effect that chronic kidney disease (CKD) confers on clinically meaningful outcomes among patients with heart failure with preserved left ventricular ejection fraction (HF-PEF). METHODS AND RESULTS: We identified a community-based cohort of patients with HF. Electronic medical record data were used to divide into HF-PEF and reduced left ventricular EF on the basis of quantitative and qualitative estimates. Level of CKD was assessed by estimated glomerular filtration rate (eGFR) and by dipstick proteinuria. We followed patients for a median of 22.1 months for outcomes of death and hospitalization (HF-specific and all-cause). Multivariable Cox regression estimated the adjusted relative-risk of outcomes by level of CKD, separately for HF-PEF and HF with reduced left ventricular EF. We identified 14 579 patients with HF-PEF and 9762 with HF with reduced left ventricular EF. When compared with patients with eGFR between 60 and 89 mL/min per 1.73 m(2), lower eGFR was associated with an independent graded increased risk of death and hospitalization. For example, among patients with HF-PEF, the risk of death was nearly double for eGFR 15 to 29 mL/min per 1.73 m(2) and 7× higher for eGFR<15 mL/min per 1.73 m(2), with similar findings in those with HF with reduced left ventricular EF. CONCLUSIONS: CKD is common and an important independent predictor of death and hospitalization in adults with HF across the spectrum of left ventricular systolic function. Our study highlights the need to develop new and effective interventions for the growing number of patients with HF complicated by CKD.

Risk factors for adverse outcomes by left ventricular ejection fraction in a contemporary heart failure population.

BACKGROUND: Although heart failure (HF) is a syndrome with important differences in response to therapy by left ventricular ejection fraction (LVEF), existing risk stratification models typically group all HF patients together. The relative importance of common predictor variables for important clinical outcomes across strata of LVEF is relatively unknown. METHODS AND RESULTS: We identified all members with HF between 2005 and 2008 from 4 integrated healthcare systems in the Cardiovascular Research Network. LVEF was categorized as preserved (LVEF ≥ 50% or normal), borderline (41%-49% or mildly reduced), and reduced (≤ 40% or moderately to severely reduced). We used Cox regression models to identify independent predictors of death and hospitalization by LVEF category. Among 30094 ambulatory adults with HF, mean age was 74 years and 46% were women. LVEF was preserved in 49.5%, borderline in 16.2%, and reduced in 34.3% of patients. During a median follow-up of 1.8 years (interquartile range, 0.8-3.1), 8060 (26.8%) patients died, 8108 (26.9%) were hospitalized for HF, and 20272 (67.4%) were hospitalized for any reason. In multivariable models, nearly all tested covariates performed similarly across LVEF strata for the outcome of death from any cause, as well as for HF-related and all-cause hospitalizations. CONCLUSIONS: We found that in a large, diverse contemporary HF population, risk assessment was strikingly similar across all LVEF categories. These data suggest that, although many HF therapies are uniquely applied to patients with reduced LVEF, individual prognostic factor performance does not seem to be significantly related to level of left ventricular systolic function.

Contemporary prevalence and correlates of incident heart failure with preserved ejection fraction.

BACKGROUND: We assessed the prevalence of preserved left ventricular ejection fraction in patients with incident heart failure and differences in the demographic and clinical characteristics that may differentiate patients presenting with heart failure with preserved versus reduced left ventricular ejection fraction. METHODS: We identified all patients with newly diagnosed heart failure between 2005 and 2008 from 4 sites in the Cardiovascular Research Network on the basis of hospital discharge and ambulatory visit diagnoses, and assigned a category of preserved, borderline, or reduced left ventricular ejection fraction using data from electronic databases and chart review. RESULTS: We identified 11,994 patients with incident heart failure; of these, 6210 (51.8%) had preserved left ventricular ejection fraction, 1870 (15.6%) had borderline systolic dysfunction, and 3914 (32.6%) had reduced left ventricular ejection fraction. For those with heart failure with preserved left ventricular ejection fraction, the mean age was 74.7 years and 57.1% were women; for those with borderline systolic dysfunction, the mean age was 71.6 years and 38.4% were women; and for those with reduced left ventricular ejection fraction, the mean age was 69.1 years and 32.6% were women. Compared with white patients, black patients were less likely to have heart failure with preserved systolic function. Those with a history of coronary artery bypass surgery, mitral or aortic valvular disease, atrial fibrillation or flutter, or a diagnosis of hypertension were more likely to have heart failure with preserved systolic function, as were those with a diverse range of noncardiac comorbid conditions, including chronic lung disease, chronic liver disease, a history of a hospitalized bleed, a history of a mechanical fall, a diagnosis of depression, and a diagnosis of dementia. Patients with a history of acute myocardial infarction and a history of ventricular fibrillation or ventricular tachycardia were less likely to have heart failure with preserved left ventricular ejection fraction. Patients with higher systolic blood pressures at baseline and lower low-density lipoprotein levels were more likely to have heart failure with preserved left ventricular ejection fraction, as were those with lower hemoglobin levels and the lowest glomerular filtration rates. CONCLUSIONS: Heart failure with preserved left ventricular ejection fraction is the most common form of the heart failure syndrome among patients newly presenting with this condition, and women and older adults are especially affected. Evidence-based treatment strategies apply to less than one third of patients with newly diagnosed heart failure.

Predicting costs of care in heart failure patients.

BACKGROUND: Identifying heart failure patients most likely to suffer poor outcomes is an essential part of delivering interventions to those most likely to benefit. We sought a comprehensive account of heart failure events and their cumulative economic burden by examining patient characteristics that predict increased cost or poor outcomes. METHODS: We collected electronic medical data from members of a large HMO who had a heart failure diagnosis and an echocardiogram from 1999-2004, and followed them for one year. We examined the role of demographics, clinical and laboratory findings, comorbid disease and whether the heart failure was incident, as well as mortality. We used regression methods appropriate for censored cost data. RESULTS: Of the 4,696 patients, 8% were incident. Several diseases were associated with significantly higher and economically relevant cost changes, including atrial fibrillation (15% higher), coronary artery disease (14% higher), chronic lung disease (29% higher), depression (36% higher), diabetes (38% higher) and hyperlipidemia (21% higher). Some factors were associated with costs in a counterintuitive fashion (i.e. lower costs in the presence of the factor) including age, ejection fraction and anemia. But anemia and ejection fraction were also associated with a higher death rate. CONCLUSIONS: Close control of factors that are independently associated with higher cost or poor outcomes may be important for disease management. Analysis of costs in a disease like heart failure that has a high death rate underscores the need for economic methods to consider how mortality should best be considered in costing studies.

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.

Epidemiology and healthcare costs of incident Clostridium difficile infections identified in the outpatient healthcare setting.

OBJECTIVE: To describe the epidemiology and healthcare costs of Clostridium difficile infection (CDI) identified in the outpatient setting. DESIGN: Population-based, retrospective cohort study. PATIENTS: Kaiser Permanente Colorado and Kaiser Permanente Northwest members between June 1, 2005, and September 30, 2008. METHODS: We identified persons with incident CDI and classified CDI by whether it was identified in the outpatient or inpatient healthcare setting. We collected information about baseline variables and follow-up healthcare utilization, costs, and outcomes among patients with CDI. We compared characteristics of patients with CDI identified in the outpatient versus inpatient setting. RESULTS: We identified 3,067 incident CDIs; 56% were identified in the outpatient setting. Few strong, independent predictors of diagnostic setting were identified, although a previous stay in a nonacute healthcare institution (odds ratio [OR], 1.45 [95% confidence interval (CI), 1.13-1.86]) was statistically associated with outpatient-identified CDI, as was age from 50 to 59 years (OR, 1.64 [95% CI, 1.18-2.29]), 60 to 69 years (OR, 1.37 [95% CI, 1.03-1.82]), and 70 to 79 years (OR, 1.36 [95% CI, 1.06-1.74]), when compared with persons aged 80-89 years. CONCLUSIONS: We found that more than one-half of incident CDIs in this population were identified in the outpatient setting. Patients with outpatient-identified CDI were younger with fewer comorbidities, although they frequently had previous exposure to healthcare. These data suggest that practitioners should be aware of CDI and obtain appropriate diagnostic testing on outpatients with CDI symptoms.

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.

Clostridium difficile infection, Colorado and the northwestern United States, 2007.

To determine the incidence of Clostridium difficile infection during 2007, we examined infection in adult inpatient and outpatient members of a managed-care organization. Incidence was 14.9 C. difficile infections per 10,000 patient-years. Extrapolating this rate to US adults, we estimate that 284,875 C. difficile infections occurred during 2007.

Predicting chronic kidney disease outcomes: are two estimated glomerular filtration rates better than one?

The National Kidney Foundation's (NKF) Kidney Disease Outcomes Quality Initiative (KDOQI) definition of chronic kidney disease (CKD), stages 3-5, requires 2 estimated glomerular filtration rates (eGFRs) <60 ml/min/1.73 m(2) more than 3 months apart. By requiring 2 eGFRs, the NKF definition reduced identification of people without chronic disease, which may have decreased identification of individuals with early CKD, but increased identification of those who ultimately have progression of CKD or require renal replacement therapy (RRT). Our objective was to determine whether 2 eGFR tests were better than 1 eGFR as a predictor of RRT, CKD progression, or death. This retrospective incident cohort study evaluates outcomes in adults with an initial eGFR <60 ml/min/1.73 m(2) and a second eGFR after 90 days by examining a third follow-up eGFR. For the 2086 patients in this study, the mean initial eGFR was 50.7 ml/min/1.73 m(2) and the mean second eGFR was 59.3 ml/min/1.73 m(2). More than 40% of the population (925) did not have CKD based upon their second eGFR. The initial eGFR was the best predictor of the third eGFR. There was no material difference in the ability to predict outcome measures between 1 versus 2 eGFR tests, regardless of eGFR value or associated comorbidities. Identifying patients with CKD is a critical step when beginning to implement population management strategies for those patients. Our findings illustrate some of the trade-offs in strategies inherent in methods that might be used to identify patients with CKD; 1 eGFR will identify patients about 5 months sooner, allowing additional time for nephrologist and other therapeutic intervention, but approximately doubles the population to be managed.

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.