Long-term follow-up of a racially and ethnically diverse population of men with localized prostate cancer who did not undergo initial active treatment.

BACKGROUND: There is limited research on the racial/ethnic differences in long-term outcomes for men with untreated, localized prostate cancer. METHODS: Men diagnosed with localized, Gleason ≤7 prostate cancer who were not treated within 1 year of diagnosis from 1997-2007 were identified. Cumulative incidence rates of the following events were calculated; treatment initiation, metastasis, death due to prostate cancer and all-cause mortality, accounting for competing risks. The Cox model of all-cause mortality and Fine-Gray sub distribution model to account for competing risks were used to test for racial/ethnic differences in outcomes adjusted for clinical factors. RESULTS: There were 3925 men in the study, 749 Hispanic, 2415 non-Hispanic white, 559 non-Hispanic African American, and 202 non-Hispanic Asian/Pacific Islander (API). Median follow-up was 9.3 years. At 19 years, overall cumulative incidence of treatment, metastasis, death due to prostate cancer, and all-cause mortality was 25.0%, 14.7%, 11.7%, and 67.8%, respectively. In adjusted models compared to non-Hispanic whites, African Americans had higher rates of treatment (HR = 1.39, 95% CI = 1.15-1.68); they had an increased risk of metastasis beyond 10 years after diagnosis (HR = 4.70, 95% CI = 2.30-9.61); API and Hispanic had lower rates of all-cause mortality (HR = 0.66, 95% CI = 0.52-0.84, and HR = 0.72, 95% CI = 0.62-0.85, respectively), and API had lower rates of prostate cancer mortality in the first 10 years after diagnosis (HR = 0.29, 95% CI = 0.09-0.90) and elevated risks beyond 10 years (HR = 5.41, 95% CI = 1.39-21.11). CONCLUSIONS: Significant risks of metastasis and prostate cancer mortality exist in untreated men beyond 10 years after diagnosis, but are not equally distributed among racial/ethnic groups.

Disparities in early mortality among chronic kidney disease patients who transition to peritoneal dialysis and hemodialysis with and without catheters.

PURPOSE: The early period after chronic kidney disease (CKD) patients transition to end-stage renal disease (ESRD) represents the highest mortality risk but is variable among different patient populations and clinical circumstances. We compared early mortality outcomes among a diverse CKD population that transitioned to ESRD. METHODS: A retrospective cohort study (1/1/2002 through 12/31/2013) of CKD patients (age ≥ 18 years) who transitioned to peritoneal dialysis (PD), hemodialysis (HD) with arteriovenous fistula/grafts, and HD with catheters was performed. Multivariable Cox regression modeling was used to estimate 6-month all-cause mortality hazard ratios (HR) among the three treatment groups after adjustment for patient and clinical characteristics. RESULTS: Among 5373 ESRD patients (62.7 years, 41.3% females, 37.5% Hispanics, 13.3% PD, 34.9% HD with fistula/graft, 51.8% HD with catheter), 551 (10.3%) died at 6 months. Mortality rates were highest immediately after transition (299 deaths per 1000 person-years in first month). Compared to PD patients, the 6-month mortality HR (95% CI) was 1.87 (1.06-3.30) in HD with fistula/graft patients and 3.77 (2.17-6.57) in HD with catheter patients. Inpatient transition (HR 1.32), acute kidney injury (HR 2.06), and an eGFR ≥ 15 vs 5-9 (HR 1.68) at transition were also associated with higher early mortality risk. CONCLUSION: Among a diverse CKD population who transitioned to ESRD, we observed considerable differences in early mortality risk among PD, HD with fistula/graft, and HD with catheter patients. The identification of patient-specific and clinical environmental factors related to high early mortality may provide insights for managing advanced stages of CKD and shared decision making.

The impact of improving access to primary care.

OBJECTIVES: To measure the size and timing of changes in utilization and costs for employees and dependents who had major access barriers to primary care removed, across an 8-year period (2007 to 2014). STUDY DESIGN AND METHODS: Retrospective observational study examining patterns of utilization and costs before and after the implementation of a worksite medical office in 2010. The worksite office offered convenient primary care services with no travel from work, essentially guaranteed same day access, and no co-pay. Trends in visit rates and costs were compared for an intervention fixed cohort group (employees and dependents) at the employer (n = 1211) with a control fixed cohort group (n = 542 162) for 6 types of visits (primary, urgent, emergency, inpatient, specialty, and other outpatient). Difference-in-differences methods assessed the significance of between-group changes in utilization and costs. RESULTS: The worksite medical office intervention group had an increase in primary care visits relative to the control group (+43% vs +4%, P < 0.001). This was accompanied by a reduction in urgent care visits by the intervention group compared with the control group (-43% vs -5%, P < 0.001). There were no differences in the other types of visits, and the total visit costs for the intervention group increased 5.7% versus 2.7% for the control group (P = 0.008). A sub-group analysis of the intervention group (comparing dependents to employees) found that that the dependents achieved a reduction in costs of 2.7% (P < 0.001) across the study period. CONCLUSIONS: The potential for long-term reduction in utilization and costs with better access to primary care is significant, but not easily nor automatically achieved.

Patient-Reported Factors Associated With Poor Phosphorus Control in a Maintenance Hemodialysis Population.

OBJECTIVE: The purpose of this study was to determine the influence of patient-reported medication adherence and phosphorus-related knowledge on phosphorus control and pharmacy-reported adherence to phosphorus binding medication among patients on maintenance hemodialysis. DESIGN: Retrospective, cross-sectional cohort study. SUBJECTS: Seventy-nine hemodialysis patients (mean age 64.2 years, SD = 14 years; 46.8% female) in a stand-alone hemodialysis unit within an integrated learning healthcare system. Ten percent (10%) of subjects were Caucasian, 42% Latino, 19% African American, and 29% Asian. Forty-eight percent had diabetes; 72% had BMI ≥ 30. Inclusion criteria included the provision of survey data and having medication refill data available in the pharmacy system. 77.2% had mean phosphorus levels ≤ 5.5 mg/dL; 22.8% had mean phosphorus levels > 5.5 mg/dL. INTERVENTION: Subjects were administered the 8-item Morisky Medication Adherence Scale (MMAS-8) and also reported on their phosphorus-related knowledge. MAIN OUTCOME MEASURE: Phosphorus levels within an adequate range. RESULTS: The mean serum phosphorus level was 4.96 mg/dL (SD = 1.21). In the well-controlled group, mean phosphorus was 4.44 mg/dL (SD = 0.76). In the poorly controlled group, mean phosphorus was 6.69 mg/dL (SD = 0.74). A total of 61% of patients reported at least some unintentional medication nonadherence, and 48% reported intentional medication nonadherence. Phosphorus-specific knowledge was low, with just under half of patients reporting that they could not name two high-phosphorus foods or identify a phosphorus-related health risk. Phosphorus binder-related nonadherence was substantially higher in the uncontrolled than the controlled group. Adjusting for age, individuals with poorer self-reported binder adherence were less likely to have controlled phosphorus levels (odds ratio = 0.71, P = .06). CONCLUSION: Phosphorus-related non-adherence, but not low phosphorus-specific knowledge, was associated with poorer phosphorus control. Such findings provide important information for the development of evidence-based strategies for improving phosphorus control among patients on dialysis.

A Comprehensive Assessment Across the Healthcare Continuum: Risk of Hospital-Associated Clostridium difficile Infection Due to Outpatient and Inpatient Antibiotic Exposure.

BACKGROUND: Limitations in sample size, overly inclusive antibiotic classes, lack of adjustment of key risk variables, and inadequate assessment of cases contribute to widely ranging estimates of risk factors for Clostridium difficile infection (CDI). OBJECTIVE: To incorporate all key CDI risk factors in addition to 27 antibiotic classes into a single comprehensive model. DESIGN: Retrospective cohort study. SETTING: Kaiser Permanente Southern California. PATIENTS: Members of Kaiser Permanente Southern California at least 18 years old admitted to any of its 14 hospitals from January 1, 2011, through December 31, 2012. METHODS: Hospital-acquired CDI cases were identified by polymerase chain reaction assay. Exposure to major outpatient antibiotics (10 classes) and those administered during inpatient stays (27 classes) was assessed. Age, sex, self-identified race/ethnicity, Charlson Comorbidity Score, previous hospitalization, transfer from a skilled nursing facility, number of different antibiotic classes, statin use, and proton pump inhibitor use were also assessed. Poisson regression estimated adjusted risk of CDI. RESULTS: A total of 401,234 patients with 2,638 cases of incident CDI (0.7%) were detected. The final model demonstrated highest CDI risk associated with increasing age, exposure to multiple antibiotic classes, and skilled nursing facility transfer. Factors conferring the most reduced CDI risk were inpatient exposure to tetracyclines and first-generation cephalosporins, and outpatient macrolides. CONCLUSIONS Although type and aggregate antibiotic exposure are important, the factors that increase the likelihood of environmental spore acquisition should not be underestimated. Operationally, our findings have implications for antibiotic stewardship efforts and can inform empirical and culture-driven treatment approaches.

Trends in Prostate-specific Antigen Screening, Prostate Biopsies, Urology Visits, and Prostate Cancer Treatments From 2000 to 2012.

OBJECTIVE: To determine whether the rates of prostate-specific antigen (PSA) screening, related biopsies and subsequent prostate cancer utilization decreased between 2000 and 2012 in a large, managed care organization. METHODS: Male members of Kaiser Permanente Southern California who were aged ≥40 years and had no history of prostate cancer (N = 15,326) were passively followed through electronic health plan files from January 1, 2000, through December 31, 2012 (N = 1,539,469). The rates of PSA testing, elevated PSA tests, prostate biopsies, prostate cancer treatment (surgery and radiation), and urology visits were calculated per year among eligible men and stratified by age group. RESULTS: A 59% decrease in PSA screening occurred among men aged ≥75 years beginning in 2008, followed by 49% in ages 65-74, 20% in ages 50-64, and 33% in ages 40-49 years in 2009. However, the number of elevated PSA tests remained largely unchanged in all groups except in men aged ≥75 years (45% decrease). Prostate biopsy rates and urology visits remained consistent among elderly men. CONCLUSION: Among men in this managed care setting, although there was a sharp decline in PSA testing among men aged ≥75 years after 2008, prostate biopsy rates remained constant, and subsequent prostate cancer treatment remained highest among men in this age group. These results suggest that the guidelines recommending against PSA and the subsequent provider-targeted interventions implemented in this system resulted in decreased screening across age groups and potentially led to more discriminant screening among those aged ≥75 years.

Racial and ethnic disparities in extremes of fetal growth after gestational diabetes mellitus.

AIMS/HYPOTHESIS: The aim of this study was to assess and compare risks of having large- or small-for gestational age (LGA and SGA, respectively) infants born to women with gestational diabetes mellitus (GDM) from ten racial/ethnic groups. METHODS: LGA and SGA were defined as birthweight >90th and <10th percentile, respectively, specific to each racial/ethnic population and infant sex. Risks of LGA and SGA were compared among a retrospective cohort of 29,544 GDM deliveries from Hispanic, non-Hispanic white (NHW), non-Hispanic black (NHB), Filipino, Chinese, Asian Indian, Vietnamese, Korean, Japanese and Pacific Islander (PI) groups of women. RESULTS: Unadjusted LGA and SGA risks varied among the ten groups. For LGA, the highest risk was in infants born to NHB women (17.2%), followed by those born to PI (16.2%), Hispanic (14.5%), NHW (13.1%), Asian Indian (12.8%), Filipino (11.6%) and other Asian (9.6-11.1%) women (p < 0.0001). Compared with NHW, the LGA risk was significantly greater for NHB women with GDM (RR 1.25 [95% CI 1.11-1.40]; p = 0.0001 after adjustment for maternal characteristics). Further adjustment for maternal pre-pregnancy BMI and gestational weight gain in the sub-cohort with available data (n = 8,553) greatly attenuated the elevated LGA risk for NHB women. For SGA, the risks ranged from 5.6% to 11.3% (p = 0.003) where most groups (8/10) had risks that were lower than the population-expected 10% and risks were not significantly different from those in NHW women. CONCLUSIONS/INTERPRETATION: These data suggest that variation in extremes of fetal growth associated with GDM deliveries across race/ethnicity can be explained by maternal characteristics, maternal obesity and gestational weight gain. Women should be advised to target a normal weight and appropriate weight gain for pregnancies; this is particularly important for NHB women.

Systemic implementation strategies to improve hypertension: the Kaiser Permanente Southern California experience.

The past decade has seen hypertension improving in the United States where control is approximately 50%. Kaiser Permanente has mirrored and exceeded these national advances in control. Integrated models of care such as Kaiser Permanente and the Veterans Administration health systems have demonstrated the greatest hypertension outcomes. We detail the story of Kaiser Permanente Southern California (KPSC) to illustrate the success that can be achieved with an integrated health system model that uses implementation, dissemination, and performance feedback approaches to chronic disease care. KPSC, with a large ethnically diverse population of more than 3.6 million, has used a stepwise approach to achieve control rates greater than 85% in those recognized with hypertension. This was accomplished through systemic implementations of specific strategies: (1) capturing hypertensive members into a hypertension registry; (2) standardization of blood pressure measurements; (3) drafting and disseminating an internal treatment algorithm that is evidence-based and is advocating of combination therapy; and (4) a multidisciplinary approach using medical assistants, nurses, and pharmacists as key stakeholders. The infrastructure, support, and involvement across all levels of the health system with rapid and continuous performance feedback have been pivotal in ensuring the follow-through and maintenance of these strategies. The KPSC hypertension program is continually evolving in these areas. With these high control rates and established infrastructure, they are positioned to take on different innovations and study models. Such potential projects are drafting strategies on resistant hypertension or addressing the concerns about overtreatment of hypertension.

Hepatitis B testing and vaccination among adults with sexually transmitted infections in a large managed care organization.

Data on viral hepatitis B (HBV) testing and vaccination in primary care settings among persons at sexual risk for HBV infection have been sparse. We examined rates and factors associated with HBV serologic testing and vaccination rates in adults infected with sexually transmitted infections. We conducted a retrospective cohort study of adults diagnosed with chlamydia, gonorrhea, or syphilis in Kaiser Permanente Southern California in 2008-2011. The vaccine series initiation was examined in subjects who were tested susceptible. The 90-day hepatitis B surface antigen (HBsAg) testing rate was 28.1% in 15 357 adults. Testing rates increased through the study period. Only 8.8% of patients received both HBsAg and hepatitis B surface antibody tests to determine prior exposure and susceptibility to HBV. Among those who were tested susceptible, 116 (10.6%) subjects initiated the vaccine series. In multivariable logistic regression analysis, the odds of receiving testing was inversely associated with female sex, black race, other/unknown race, or having prespecified chronic comorbidities. In survival analysis, adults aged 25-34 years and ≥55 years were more likely to initiate hepatitis B vaccine series compared with those aged 18-24 years. There are missed opportunities in HBV testing and vaccination in primary care. Implementation of provider decision-making support tools in the electronic medical record system may potentially improve hepatitis B testing and vaccination rates.

The prevalence of primary pediatric prehypertension and hypertension in a real-world managed care system.

To assess the burden associated with hypertension, reliable estimates for the prevalence of pediatric hypertension are vital. For this cross-sectional study of 237,248 youths aged 6 to 17 years without indication of secondary hypertension, blood pressure (BP) was classified according to age, sex, and height using standards from the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents as prehypertension with at least 1 BP ≥90th percentile and as hypertension with 3 BPs ≥95th percentile. The prevalence of prehypertension and hypertension were 31.4% and 2.1%, respectively. An additional 21.4% had either 1 (16.6%) or 2 (4.8%) BPs ≥95th percentile. Based on this large population-based study using routinely measured BP from clinical care, a remarkable proportion of youth (6.9%) has hypertension or nearly meets the definition of hypertension with 2 documented BPs in the hypertensive range.

Trends and disparity in zoster vaccine uptake in a managed care population.

OBJECTIVES: Zoster vaccine is recommended for prevention of herpes zoster among adults aged 60 years and older. We examined the zoster vaccination rates during 2007-2011 and assessed association with age, sex, race/ethnicity, neighborhood income and education attainment in eligible adults at Kaiser Permanente Southern California, a managed care organization in the US. METHODS: We calculated annual zoster vaccination rate among members ≥60 years without documented contraindications. Multivariable logistic regression was performed to examine factors associated with zoster vaccine uptake in an open cohort of 819,466 adults. RESULTS: The zoster vaccination rates increased annually in all groups and the overall rate reached 21.7% in 2011 (P-trend<0.001). Coverage was highest among individuals aged 65-74 years, who were female and non-Hispanic White. In the adjusted analysis, odds of vaccination decreased by age. Females (odds ratio [OR]=1.19, 95% confidence interval [CI]=1.17-1.20) and those who lived in neighborhoods with higher education attainment were more likely to be vaccinated (>75% vs. <50% adults with some college education: OR=1.76, 95% CI=1.73-1.80). Compared to Whites, non-Hispanic Blacks and Hispanics were less likely to receive the vaccine (non-Hispanic Blacks: OR=0.56, 95% CI=0.55-0.58; Hispanics: OR=0.59, 95% CI=0.58-0.60). CONCLUSION: The zoster vaccine coverage is higher in this insured population than previously reported in the US general population, but it remains low. Significant racial/ethnic disparity was observed and worsened even among individuals with relatively equal access to zoster vaccination.

Increased asthma risk and asthma-related health care complications associated with childhood obesity.

Asthma is the most common chronic condition of childhood, yet the relationship between obesity and asthma risk and the impact of obesity on clinical asthma outcomes are not well understood. For this population-based, longitudinal study, demographic and clinical data were extracted from administrative and electronic health records of 623,358 patients aged 6-19 years who were enrolled in the Kaiser Permanente Southern California health plan in 2007-2011. Crude asthma incidence ranged from 16.9 per 1,000 person-years among normal-weight youth to 22.3 per 1,000 person-years among extremely obese youth. The adjusted risks of asthma for overweight, moderately obese, and extremely obese youth relative to those of normal weight youth were 1.16 (95% confidence interval: 1.13, 1.20), 1.23 (95% confidence interval: 1.19, 1.28), and 1.37 (95% confidence interval: 1.32, 1.42), respectively (Ptrend < 0.0001). The relationship between obesity and asthma risk was strongest in Asian/Pacific Islanders and in the youngest girls (aged 6-10 years), compared with other groups. Among youth who developed asthma, those who were moderately or extremely obese had more frequent asthma exacerbations requiring emergency department services and/or treatment with oral corticosteroids. In conclusion, obese youth are not only more likely to develop asthma, but they may be more likely to have severe asthma, resulting in a greater need for health care utilization and aggressive asthma treatment.

The accuracy and trends of smoking history documentation in electronic medical records in a large managed care organization.

The accuracy of smoking history documentation in the electronic medical records was examined at a large managed care organization among 36,494 male members who self-reported smoking history in mailed surveys. The sensitivity of electronic smoking history documentation for ever-smoking status was 0.19 in years 2003-2005 (using ICD-9/CPT code only), 0.80 in 2006-2008 and 0.84 in 2009-2010 (combination of ICD-9/CPT codes and risk factor module used after 2006). The positive predictive value was 0.96, 0.90, and 0.95 in these periods, respectively. Among self-reported ever-smokers, increased healthcare utilization and smoking intensity/duration were associated with higher likelihood of having electronic smoking history documentation, while Asian race and Spanish language preference were associated with lower likelihood. These data suggest that enhanced efforts may be needed to screen for and document smoking among racial/ethnic minorities.

Osteoporosis management program decreases incidence of hip fracture in patients with prostate cancer receiving androgen deprivation therapy.

OBJECTIVE: To evaluate the incidence of hip fracture in men with prostate cancer receiving androgen deprivation therapy (ADT). MATERIALS AND METHODS: One of the detrimental side effects of ADT for prostate cancer is osteoporosis. Through an osteoporosis prevention program implemented in our healthcare system, the patients at risk undergo dual x-ray absorptiometry scans and receive treatment if the T-score indicates bone loss. We evaluated the incidence of hip fracture in men with prostate cancer who were receiving ADT through a retrospective, cohort study conducted within a managed care organization. The participants were all men newly diagnosed with prostate cancer from January 2003 to December 2007 receiving leuprolide injections. Patients who had had a dual x-ray absorptiometry scan beginning 3 months before the index date through the end of study were included in the intervention group; all others were included in the comparison group. The main outcome of interest was a hip fracture occurring after the index date, excluding cancer pathologic fractures, traumatic fractures, and fractures associated with epilepsy. RESULTS: A total of 1071 patients were in the intervention group, and 411 were in the comparison group. In the intervention group, 18 hip fractures occurred compared with 17 in the comparison group. The incidence rate of hip fractures per 1000 person-years was 5.1 (95% confidence interval 3.0-8.0) in the intervention group and 18.1 (95% confidence interval 10.5-29.0) in the comparison group. CONCLUSION: The incidence rate of hip fracture in this population was reduced >70% with enrollment in an osteoporosis management system, avoiding this morbid complication of ADT.

Changes in serum prostate-specific antigen levels and the identification of prostate cancer in a large managed care population.

OBJECTIVE: To determine whether the rate of change in total serum prostate-specific antigen (PSA) levels accurately detects prostate cancer and to evaluate whether it adds any predictive value to a single measurement of serum PSA alone, in general practice settings. MATERIALS AND METHODS: A retrospective cohort of 219,388 community-dwelling men, aged ≥45 years, enrolled in the Kaiser Permanente Southern California health plan, with no history of prostate cancer and at least three PSA measurements, were followed from 1 January 1998 to 31 December 2007, for the development of biopsy-confirmed prostate cancer. Annual percent changes in total serum PSA levels were estimated using linear mixed models. The accuracy of prostate cancer prediction was assessed for prostate cancer overall and for aggressive disease (Gleason score ≥7) and compared with that of a single measure of PSA level using area under the receiver-operating characteristic curves (AUCs). RESULTS: The men in this cohort experienced a mean change of 2.9% in PSA levels per year and the rate of change in PSA increased modestly with age (P ≤ 0.001). Annual percent changes in PSA accurately predicted the presence of prostate cancer (AUC = 0.963) and aggressive disease (AUC = 0.955) and had more predictive accuracy for aggressive disease than did a single measurement of PSA alone (AUC = 0.727). CONCLUSIONS: Longitudinal measures of PSA improve the accuracy of aggressive prostate cancer detection when compared with a single measurement of PSA alone. Findings from this study provide insight into the usefulness of PSA velocity as a detection marker for aggressive prostate cancer.

Adapting group sequential methods to observational postlicensure vaccine safety surveillance: results of a pentavalent combination DTaP-IPV-Hib vaccine safety study.

To address gaps in traditional postlicensure vaccine safety surveillance and to promote rapid signal identification, new prospective monitoring systems using large health-care database cohorts have been developed. We newly adapted clinical trial group sequential methods to this observational setting in an original safety study of a combination diphtheria and tetanus toxoids and acellular pertussis adsorbed (DTaP), inactivated poliovirus (IPV), and Haemophilus influenzae type b (Hib) conjugate vaccine (DTaP-IPV-Hib) among children within the Vaccine Safety Datalink population. For each prespecified outcome, we conducted 11 sequential Poisson-based likelihood ratio tests during September 2008-January 2011 to compare DTaP-IPV-Hib vaccinees with historical recipients of other DTaP-containing vaccines. No increased risk was detected among 149,337 DTaP-IPV-Hib vaccinees versus historical comparators for any outcome, including medically attended fever, seizure, meningitis/encephalitis/myelitis, nonanaphylactic serious allergic reaction, anaphylaxis, Guillain-Barré syndrome, or invasive Hib disease. In end-of-study prespecified subgroup analyses, risk of medically attended fever was elevated among 1- to 2-year-olds who received DTaP-IPV-Hib vaccine versus historical comparators (relative risk = 1.83, 95% confidence interval: 1.34, 2.50) but not among infants under 1 year old (relative risk = 0.83, 95% confidence interval: 0.73, 0.94). Findings were similar in analyses with concurrent comparators who received other DTaP-containing vaccines during the study period. Although lack of a controlled experiment presents numerous challenges, implementation of group sequential monitoring methods in observational safety surveillance studies is promising and warrants further investigation.

Race and ethnicity data quality and imputation using U.S. Census data in an integrated health system: the Kaiser Permanente Southern California experience.

Research on racial and ethnic disparities using health system databases can shed light on the usual health care and outcomes of large numbers of individuals so that health inequities can be better understood and addressed. Such research often suffers from limitations in race/ethnicity data quality. We examined the quality of race/ethnicity data in a large, diverse, integrated health system that repeatedly collects these data on utilization of services. We tested the accuracy of Bayesian Improved Surname Geocoding for imputation of race/ethnicity data. Administrative race/ethnicity data were accurate as judged by comparison with self-report in adults. The Bayesian Improved Surname Geocoding method produced imputation results far better than chance assignment for the four most common race/ethnicity groups in the health system: Whites, Hispanics, Blacks, and Asians. These results support renewed efforts to conduct studies of racial and ethnic disparities in large health systems.