Longitudinal Changes in Sex Hormone Binding Globulin (SHBG) and Risk of Incident Diabetes: The Study of Women's Health Across the Nation (SWAN).

OBJECTIVE: To investigate the associations of longitudinal changes in sex hormone binding globulin (SHBG) and testosterone (T) over the menopause transition with the risk of diabetes. RESEARCH DESIGN AND METHODS: We followed 2,952 participants in the Study of Women's Health Across the Nation (SWAN) who were premenopausal or early perimenopausal and diabetes-free at baseline. SHBG,T, and estradiol (E2) levels were measured at up to 13 follow-up visits (over up to 17 years). We used complementary log-log-based discrete-time survival models anchored at baseline. RESULTS: Diabetes developed in 376 women. A 5-unit increase in time-varying SHBG was associated with a 10% reduced risk of diabetes (hazard ratio [HR] 0.91, 95% CI 0.87-0.95), adjusting for covariates, and baseline SHBG,T, and E2 levels. Time-varying T was not associated with diabetes risk. Compared with the lowest quartile for annual rate of change of SHBG since baseline (quartile 1 [Q1] -92.3 to -1.5 nmol/L), all other quartiles were associated with a decreased risk of diabetes adjusting for covariates and baseline SHBG; associations persisted after adjusting for rate of change of T and E2 (Q2 [> -1.5 to -0.2 nmol/L] HR 0.33, 95% CI 0.23-0.48; Q3 [> -0.2 to 1.3 nmol/L] HR 0.37, 95% CI 0.25-0.55; Q4 [>1.3 to 82.0 nmol/L] HR 0.43, 95% CI 0.30-0.63). CONCLUSIONS: Increasing levels of SHBG over the menopause transition were associated with a decreased risk of incident diabetes. Stable to increasing rates of change in SHBG were also independently associated with a decreased risk of diabetes compared with decreasing rates of change, suggesting SHBG may affect glucose through a mechanism beyond androgenicity.

Treatment patterns for ductal carcinoma in situ from 2000-2010 across six integrated health plans.

Considerable debate exists about the optimal treatment of ductal carcinoma in situ (DCIS). Using electronic data sources, we examined first course treatment patterns among women aged 18 years and older diagnosed with DCIS between 2000-2010 from six Kaiser Permanente (KP) regions. We calculated the proportion of patients receiving breast conserving surgery (BCS), BCS plus radiation therapy, unilateral mastectomy, bilateral mastectomy, and hormone therapy. Multinomial logistic regression was used to assess the association between patient characteristics and treatment. We included 9,437 women: 1,086 (11.5%) African-American; 1,455 (15.4%) Asian; 918 (9.7%) Hispanic; and 5,978 (63.3%) non-Hispanic white. Most cases (42.2%) received BCS plus radiation as their initial treatment. Nearly equal numbers of women received BCS without radiation (28.5%) or unilateral mastectomy (24.6%). Use of bilateral mastectomy was uncommon (4.7%), and most women (72.2%) did not receive hormone therapy has part of their first course treatment. We observed statistically significant differences in treatment patterns for DCIS by KP region and patient age. Predictably, nuclear grade and the presence of comorbidities were associated with first course treatment for DCIS. We observed statistically significant increases in BCS plus radiation therapy and bilateral mastectomy over time. Although still uncommon, the frequency of bilateral mastectomy increased from 2.7% in 2000 to 7.0% in 2010. We also observed differences in treatment by race/ethnicity. Our findings help illustrate the complex nature of DCIS treatment in the United States, and highlight the need for evidence based guidelines for DCIS care.

Distant invasive breast cancer recurrence risk in human epidermal growth factor receptor 2-positive T1a and T1b node-negative localized breast cancer diagnosed from 2000 to 2006: a cohort from an integrated health care delivery system.

PURPOSE: To determine the invasive recurrence (IR) risk among patients with small, node-negative human epidermal growth factor receptor 2 (HER2) -positive breast cancer. PATIENTS AND METHODS: Among 16,975 consecutive patients with invasive breast cancer diagnosed from January 1, 2000, to December 31, 2006, in a large, integrated health care system, we identified a cohort of 234 patients with HER2-positive T1aN0M0 or T1bN0M0 (T1abN0M0) disease with a median follow-up of 5.8 years. Kaplan-Meier methods were used to estimate the percentage of patients who were free of invasive recurrence (recurrence-free interval [RFI]) at 5 years for both distant (DRFI) and local (LRFI) recurrences. RESULTS: Of 15 IRs, 47% were locoregional only. Among T1ab patients not treated with adjuvant trastuzumab or chemotherapy (n = 171), the 5-year invasive DRFI was 98.2% (95% CI, 94.5% to 99.4%); it was 99.0% (95% CI, 93.0% to 99.9%) for T1a patients, and 97.0% (95% CI, 88.6% to 99.2%) for T1b patients. Locoregional plus distant 5-year invasive RFI was 97.0% (95% CI, 90.9% to 99.0%) for T1a and 91.9% (95% CI, 81.5% to 96.6%) for T1b patients; it was 89.4% (95% CI, 70.6% to 96.5%) for T1b tumors reported at 1.0 cm. T1b tumors reported at 1.0 cm accounted for 24% of the T1ab cohort, 61% of the cohort total tumor volume, and 75% of distant recurrences. Invasive RFI for T1b 1.0 cm tumors was lower than that for T1a tumors: 84.5% versus 97.4% (P = .009). CONCLUSION: The distant IR risk of T1a HER2-positive breast cancer appears quite low. The distant IR risk in T1b patients, particularly those with 1.0-cm tumors, is higher. Potential risk differences for T1a and T1b, including the 1.0-cm tumors, should be considered when making treatment decisions.

Ovarian cancer rates after hysterectomy with and without salpingo-oophorectomy.

OBJECTIVE: To estimate ovarian and peritoneal cancer rates after hysterectomy with and without salpingo-oophorectomy for benign conditions. METHODS: All patients after hysterectomy for benign disease from 1988 to 2006 in Kaiser Permanente Northern California, an integrated health organization. Incidence rates per 100,000 person-years were calculated. RESULTS: Of 56,692 patients, the majority (54%) underwent hysterectomy with bilateral salpingo-oophorectomy; 7% had hysterectomy with unilateral salpingo-oophorectomy, and 39% had hysterectomy alone. There were 40 ovarian and eight peritoneal cancers diagnosed during follow-up. Median age at ovarian and peritoneal cancer diagnosis was 50 and 64 years, respectively. Age-standardized rates (per 100,000 person-years) of ovarian or peritoneal cancer were 26.7 (95% confidence interval [CI] 16-37.5) for those with hysterectomy alone, 22.8 (95% CI 0.0-46.8) for hysterectomy and unilateral salpingo-oophorectomy, and 3.9 (95% CI 1.5-6.4) for hysterectomy and bilateral salpingo-oophorectomy. Rates of ovarian cancer were 26.2 (95% CI 15.5-37) for those with hysterectomy alone, 17.5 (95% CI 0.0-39.1) for hysterectomy and unilateral salpingo-oophorectomy, and 1.7 (95% CI 0.4-3) for those with hysterectomy and bilateral salpingo-oophorectomy. Compared with women undergoing hysterectomy alone, those receiving an unilateral salpingo-oophorectomy had a hazard ratio (HR) for ovarian cancer of 0.58 (95% CI 0.18-1.9) and those undergoing bilateral salpingo-oophorectomy had an HR of 0.12 (95% CI 0.05-0.28). CONCLUSIONS: The removal of both ovaries decreases the incidence of ovarian and peritoneal cancers. Removal of one ovary might also decrease the incidence of ovarian cancer but warrants further investigation. LEVEL OF EVIDENCE: II.

Cohort study of insulin glargine and risk of breast, prostate, and colorectal cancer among patients with diabetes.

OBJECTIVE: To examine whether use of insulin glargine, compared with another long-acting insulin, is associated with risk of breast, prostate, colorectal cancer, or all cancers combined. RESEARCH DESIGN AND METHODS: Computerized health records from Kaiser Permanente Northern and Southern California regions starting in 2001 and ending in 2009 were used to conduct a population-based cohort study among patients with diabetes aged ≥18 years. With use of Cox regression modeling, cancer risk in users of insulin glargine (n = 27,418) was compared with cancer risk in users of NPH (n = 100,757). RESULTS: The cohort had a median follow-up of 3.3 years during which there was a median of 1.2 years of glargine use and 1.4 years of NPH use. Among users of NPH at baseline, there was no clear increase in risk of breast, prostate, colorectal, or all cancers combined associated with switching to glargine. Among those initiating insulin, ever use or ≥2 years of glargine was not associated with increased risk of prostate or colorectal cancer or all cancers combined. Among initiators, the hazard ratio (HR) for breast cancer associated with ever use of glargine was 1.3 (95% CI 1.0-1.8); the HR for breast cancer associated with use of glargine for ≥2 years was 1.6 or 1.7 depending on whether glargine users had also used NPH. CONCLUSIONS: Results of this study should be viewed cautiously, given the relatively short duration of glargine use to date and the large number of potential associations examined.

Serial glycosylated hemoglobin levels and risk of colorectal neoplasia among patients with type 2 diabetes mellitus.

BACKGROUND: Hyperglycemia may increase the risk of colorectal neoplasia by serving as an energy source for neoplastic growth. We sought to determine whether glycemic control measured by serial hemoglobin A1c (HbA1c) was associated with the risk of colorectal adenoma. METHODS: Among a cohort of patients with type 2 diabetes mellitus who received health care within the Kaiser Permanente Northern California from 1994 to 2005, we conducted 2 case-control analyses. Cases had at least 1 colorectal adenoma identified at either colonoscopy (analysis 1) or sigmoidoscopy (analysis 2). Controls had no colorectal neoplasia identified at the corresponding endoscopic examination. Serial HbA1c levels between the cases and the controls were compared using a longitudinal model. RESULTS: Case-control analysis 1 included 4,248 patients, of whom 1,296 (31%) had at least 1 adenoma. The adjusted mean HbA1c levels among those without any adenomas was 8.20% versus 8.26% among those with at least 1 adenoma, a difference of 0.06% (95% CI = -0.02 to 0.14, P = 0.16). Case-control analysis 2 included 9,813 patients, of whom 951 (10%) had at least 1 distal adenoma. The adjusted mean HbA1c levels among those without any distal adenomas was 8.32% versus 8.37% among those with at least 1 distal adenoma, a difference of 0.05% (95% CI = -00.04 to 0.14, P = 0.25). The results were similar for advanced adenomas. CONCLUSIONS: Glycemic control was not associated with the risk of colorectal adenoma among diabetic persons. IMPACT: These results would suggest that glycemic control is unlikely to confound the reported association between diabetes medications and the risk of colorectal cancer.

Mammographic density and risk of second breast cancer after ductal carcinoma in situ.

BACKGROUND: We examined whether mammographic density predicts risk of second breast cancers among patients with ductal carcinoma in situ (DCIS). METHODS: The study included DCIS patients diagnosed during 1990 to 1997 and treated with breast-conserving surgery at Kaiser Permanente Northern California. Medical records were reviewed for clinical factors and subsequent breast cancers (DCIS and invasive). Ipsilateral mammograms from the index DCIS were assessed for density without knowledge of subsequent cancer status. Cox regression modeling was used to examine the association between mammographic density and risk of breast cancer events. RESULTS: Of the 935 eligible DCIS patients, 164 (18%) had a subsequent ipsilateral breast cancer, and 59 (6%) had a new primary cancer in the contralateral breast during follow-up (median, 103 mo). Those with the greatest total area of density (upper 20% of values) were at increased risk for invasive disease in either breast [hazard ratio (HR), 2.1; 95% confidence interval (95% CI), 1.2-3.8] or any cancer (DCIS or invasive) in the ipsilateral (HR, 1.7; 95% CI, 1.0-2.9) or contralateral (HR, 3.0; 95% CI, 1.3-6.9) breast compared with those with the smallest area of density (bottom 20%). HRs for these same end points comparing those in the highest with those in the lowest American College of Radiology Breast Imaging Reporting and Data System category were 1.6 (95% CI, 0.7-3.6), 1.3 (95% CI, 0.7-2.6), and 5.0 (95% CI, 1.4-17.9), respectively. There was a suggestion of increasing risk of contralateral, but not ipsilateral, cancer with increasing percent density. CONCLUSIONS: Women with mammographically dense breasts may be at higher risk of subsequent breast cancer, especially in the contralateral breast. IMPACT: Information about mammographic density may help with DCIS treatment decisions.

Thiazolidinedione therapy is not associated with increased colonic neoplasia risk in patients with diabetes mellitus.

BACKGROUND & AIMS: Thiazolidinedione ligands for peroxisome proliferator-activated receptor gamma (PPARgamma), are used to treat diabetes. PPARgamma is highly expressed in the colon, and exposure to thiazolidinediones has been proposed to affect the risk for colorectal neoplasia. In vitro models suggest that thiazolidinediones have antineoplastic effects, whereas in vivo studies have produced mixed results: Some indicate an increased risk for intestinal tumors. This study examined the association between PPARgamma-targeted therapies and the risk of colonic neoplasia in patients with diabetes. METHODS: We conducted 3 retrospective case-control studies nested within the cohort of diabetic patients who were cared for within the Kaiser Permanente of Northern California system from 1994 to 2005. Case subjects were those with colonic neoplasia identified at the time of colonoscopy (study 1), sigmoidoscopy (study 2), or at follow-up lower endoscopy (study 3). Controls had no neoplasia identified at the endoscopic examination. A minimum of 1 year of therapy was used to define medication exposure. RESULTS: Fourteen thousand eighty-six patients were included. Among patients undergoing colonoscopy, there was an inverse association between thiazolidinedione exposure and prevalence of neoplasia (adjusted odd ratio [OR], 0.73; 95% confidence interval [CI], 0.57-0.92); however, this was not evident among patients without anemia (adjusted OR, 0.97; 95% CI, 0.64-1.49). Significant associations between any or long-term thiazolidinedione use and colonic neoplasia were not observed among patients undergoing sigmoidoscopy or serial lower endoscopies. CONCLUSIONS: These results indicate that thiazolidinedione therapy is not associated with an increased risk for colonic neoplasia.

Physical activity and mammographic density in a cohort of midlife women.

PURPOSE: Physical activity (PA) is one of few modifiable breast cancer risk factors. There have been few studies of the relation between PA and mammographic density, especially in multiethnic populations. METHODS: In a cohort of pre- and early perimenopausal women of non-Hispanic white (N = 373), African American (N = 55), Chinese (N = 178), and Japanese (N = 166) ethnicity, we used multivariable linear regression to examine the association between two measures of mammographic density (percent density and area of density) and mutually exclusive components of recent physical activity (sports, household/caregiving and work activity, active living). RESULTS: After adjusting for race/ethnicity, menopausal status, parity, past use of hormones, body mass index, waist circumference and education, we observed nonsignificant inverse associations for percent mammographic density and the highest versus the lowest category of each of our PA domains. For example, the adjusted beta for active living = -2.62, 95% confidence interval (CI) (-5.84, 0.60). Nonsignificant inverse associations also were observed for area of density and each PA domain except work activity. However, most associations were nonlinear. CONCLUSION: Our results are consistent with a modest inverse association between multiple domains of PA and mammographic density, although findings may have been attributable to chance alone.

Medical therapy for diabetes is associated with increased use of lower endoscopy.

BACKGROUND: Diabetes mellitus is associated with an increased risk of colorectal neoplasia and diabetes medications may further influence the risk. Observational studies of the effect of diabetes medications on colonic neoplasia may be biased if use of diabetes medications is associated with undergoing lower endoscopy. This study examined the association between diabetes therapies and use of lower endoscopy. METHODS: This retrospective cohort study included patients with diabetes in an integrated, prepaid health plan. The primary exposure variables were use of sulfonylureas, metformin, thiazolidinediones (TZDs), and insulin. The outcome measure was completion of a flexible sigmoidoscopy or colonoscopy. Cox proportional hazards modeling, accounting for the time-varying nature of the medication exposures, was used to generate estimates of the relative hazard (HR) of lower endoscopy with different medications. RESULTS: The study included 44 169 patients followed for a mean duration of 4.2 years (SD = 2.5 years); 34% underwent at least one lower endoscopy. Patients who filled a diabetes medication prescription were more likely to undergo lower endoscopy (HR = 1.13, 95%CI 1.06-1.21). Compared to those taking only sulfonylureas, patients receiving sulfonylureas and metformin (HR = 1.12, 95%CI 1.06-1.18) or metformin alone (HR = 1.17, 95%CI 1.07-1.26) were more likely to undergo lower endoscopy. For all medications, new use was associated with undergoing lower endoscopy (p < 0.05 for all comparisons). CONCLUSIONS: Diabetic patients receiving medications are more likely to undergo lower endoscopy than those on diet control alone, particularly in the first year after initiating a new medication class and if taking metformin.

Mammographic density in a multiethnic cohort.

OBJECTIVES: To compare mammographic density among premenopausal and early perimenopausal women from four racial/ethnic groups and to examine density and acculturation among Japanese and Chinese women. DESIGN: The study included 391 white, 60 African American, 171 Japanese, and 179 Chinese participants in the Study of Women's Health Across the Nation, a multisite study of US women transitioning through menopause. Mammograms done when women were premenopausal or early perimenopausal were assessed for area of dense breast tissue and the percent of the breast occupied by dense tissue (percent density). Information on race/ethnicity, acculturation, and other factors was obtained from standardized instruments. Multiple linear regression modeling was used to examine the association between race/ethnicity or acculturation and density measures. RESULTS: Age-adjusted mean percent density was highest for Chinese (52%) and lowest for African American (34%) women. After additional adjustment for body mass index, menopause status, age at first birth, breast-feeding duration, waist circumference, and smoking, African Americans had the highest mean percent density (51%) and Japanese women had the lowest (39%). In contrast, the area of dense tissue was highest for African Americans and similar for white, Japanese, and Chinese women. Less acculturated Chinese and Japanese women tended to have a larger area of density and a higher percent density. CONCLUSIONS: Neither the age-adjusted nor fully adjusted results for percent density or area of dense tissue reflected current differences in breast cancer incidence rates among similarly aged African American, Japanese, Chinese, and white women. In addition, mammographic density was higher in less acculturated Asian women.

A population-based study of tumor gene expression and risk of breast cancer death among lymph node-negative patients.

INTRODUCTION: The Oncotype DX assay was recently reported to predict risk for distant recurrence among a clinical trial population of tamoxifen-treated patients with lymph node-negative, estrogen receptor (ER)-positive breast cancer. To confirm and extend these findings, we evaluated the performance of this 21-gene assay among node-negative patients from a community hospital setting. METHODS: A case-control study was conducted among 4,964 Kaiser Permanente patients diagnosed with node-negative invasive breast cancer from 1985 to 1994 and not treated with adjuvant chemotherapy. Cases (n = 220) were patients who died from breast cancer. Controls (n = 570) were breast cancer patients who were individually matched to cases with respect to age, race, adjuvant tamoxifen, medical facility and diagnosis year, and were alive at the date of death of their matched case. Using an RT-PCR assay, archived tumor tissues were analyzed for expression levels of 16 cancer-related and five reference genes, and a summary risk score (the Recurrence Score) was calculated for each patient. Conditional logistic regression methods were used to estimate the association between risk of breast cancer death and Recurrence Score. RESULTS: After adjusting for tumor size and grade, the Recurrence Score was associated with risk of breast cancer death in ER-positive, tamoxifen-treated and -untreated patients (P = 0.003 and P = 0.03, respectively). At 10 years, the risks for breast cancer death in ER-positive, tamoxifen-treated patients were 2.8% (95% confidence interval [CI] 1.7-3.9%), 10.7% (95% CI 6.3-14.9%), and 15.5% (95% CI 7.6-22.8%) for those in the low, intermediate and high risk Recurrence Score groups, respectively. They were 6.2% (95% CI 4.5-7.9%), 17.8% (95% CI 11.8-23.3%), and 19.9% (95% CI 14.2-25.2%) for ER-positive patients not treated with tamoxifen. In both the tamoxifen-treated and -untreated groups, approximately 50% of patients had low risk Recurrence Score values. CONCLUSION: In this large, population-based study of lymph node-negative patients not treated with chemotherapy, the Recurrence Score was strongly associated with risk of breast cancer death among ER-positive, tamoxifen-treated and -untreated patients.

Gender and risk of adverse outcomes in heart failure.

Congestive heart failure (CHF) is the leading cause of hospitalization in the elderly, and these patients are at high risk for subsequent hospitalization. Whether gender affects the risk of rehospitalization in patients who have CHF is less well understood. We studied a random sample of 1,700 adults who had been hospitalized with CHF (from July 1, 1999 to June 30, 2000) and identified all readmissions through June 30, 2001. We used proportional hazards regression to evaluate whether gender affects the risk of all-cause and CHF-specific rehospitalization, after adjusting for differences in demographic characteristics, health-related behaviors, co-morbid conditions, left ventricular systolic function status, and use of CHF therapies. Among 1,591 adults who had confirmed CHF, 752 were women (47.3%). Women were older than men (73 vs 71 years, p <0.001) and more likely to have preserved systolic function (55.3% vs 40.9%, p <0.001), hypertension (83.1% vs 75.2%, p <0.001), and prior renal insufficiency (46.8% vs 34.6%, p <0.001). No significant differences existed between women and men with respect to crude rates of any readmission (144.7 vs 134.6 per 100 person-years, p = 0.36) or CHF-specific readmission (39.9 vs 37.4 per 100 person-years, p = 0.65). After adjusting for potential confounders, there was no significant difference between women and men with respect to risk of any readmission (adjusted hazard ratio 0.88, 95% confidence interval 0.76 to 1.02) or readmission for CHF (adjusted hazard ratio 0.89, 95% confidence interval 0.71 to 1.11). Among a contemporary, diverse population of patients who had CHF, rates of readmission overall and for CHF remained high, but gender was not independently associated with a differential risk of readmission.

Mammographic density and breast cancer after ductal carcinoma in situ.

Women with ductal carcinoma in situ (DCIS) are at substantially increased risk for a second breast cancer, but few strong predictors for these subsequent tumors have been identified. We used Cox regression modeling to examine the association between mammographic density at diagnosis of DCIS of 504 women from the National Surgical Adjuvant Breast and Bowel Project B-17 trial and risk of subsequent breast cancer events. In this group of patients, mostly 50 years old or older, approximately 6.6% had breasts categorized as highly dense (i.e., > or =75% of the breast occupied by dense tissue). After adjusting for treatment with radiotherapy, age, and body mass index, women with highly dense breasts had 2.8 (95% confidence interval [CI] = 1.3 to 6.1) times the risk of subsequent breast cancer (DCIS or invasive), 3.2 (95% CI = 1.2 to 8.5) times the risk of invasive breast cancer, and 3.0 (95% CI = 1.2 to 7.5) times the risk of any ipsilateral breast cancer, compared with women with less than 25% of the breast occupied by dense tissue. Our results provide initial evidence that the risk of second breast cancers may be increased among DCIS patients with highly dense breasts.

Cultural competence policies and other predictors of asthma care quality for Medicaid-insured children.

OBJECTIVE: More than half of Medicaid enrollees are now in managed care. Scant information exists about which policies of practice sites improve quality of care in managed Medicaid. Children with asthma are a sentinel group for Medicaid quality monitoring because they are at elevated risk for adverse outcomes. The objective of this study was to identify practice-site policies and features associated with quality of care for Medicaid-insured children with asthma. METHODS: A prospective cohort study with 1-year follow-up was conducted in 5 health plans in California, Washington, and Massachusetts. Data were collected via telephone interviews with parents at baseline and 1 year, surveys of practice sites and clinicians, and computerized databases. The practice site survey asked about policies to promote cultural competence, the use of several types of reports to clinicians, support for self-management of asthma, case management and care coordination, and access to and continuity of care. Quality of care was evaluated on the basis of 5 measures: 1) preventive medication underuse based on parent report; 2) the parent's rating of asthma care; 3) the 1-year change in the child's asthma physical status based on a standardized measure; 4) preventive medication underprescribing based on computerized data; and 5) the occurrence of a hospital-based episode. RESULTS: Of the 1663 children in the study population, 67% had persistent asthma at baseline based on parent report of symptoms and medications. At 1-year follow-up, 65% of the children with persistent asthma were underusing preventive medication based on parent report. In multivariate analyses, patients of practice sites with the highest cultural competence scores were less likely to be underusing preventive asthma medications based on parent report at follow-up (odds ratio [OR]: 0.15; 95% confidence interval [CI]: 0.06-0.41 for the highest vs lowest categories) and had better parent ratings of care. The use of asthma reports to clinicians was predictive of less preventive medication underprescribing based on computerized data (OR: 0.33; 95% CI: 0.16-0.69), better parent ratings of care, and better asthma physical status at follow-up. Patients of practice sites with policies to promote access and continuity had less underuse of preventive medications (OR: 0.56; 95% CI: 0.34-0.93). Among the 83 practice sites, the practice site's size, organizational type, percentage of patients insured by Medicaid, mechanism of payment for specialty care, and other primary care features were not consistently associated with quality measures. CONCLUSIONS: Practice-site policies to promote cultural competence, the use of reports to clinicians, and access and continuity predicted higher quality of care for children with asthma in managed Medicaid.

Racial variation in the prevalence of atrial fibrillation among patients with heart failure: the Epidemiology, Practice, Outcomes, and Costs of Heart Failure (EPOCH) study.

OBJECTIVES: This study was designed to determine the association between race and atrial fibrillation (AF) among patients with heart failure (HF). BACKGROUND: Atrial fibrillation is known to complicate HF, but whether its prevalence varies by race, and the reasons why, are not well understood. METHODS: We identified adults hospitalized with confirmed HF within a large integrated healthcare delivery system. We obtained information on demographics, comorbidity, vital signs, medications, and left ventricular systolic function status. "Atrial fibrillation" was defined as AF or atrial flutter documented by electrocardiogram or prior physician-assigned diagnoses. We evaluated the independent relationship between race and AF using multivariable logistic regression. RESULTS: Among 1,373 HF patients (223 African Americans, 1,150 Caucasians), the prevalence of AF was 36.9% (95% confidence interval [CI] 34.3% to 39.5%). Compared with Caucasians, African Americans were younger (mean age 67 vs. 74 years, p < 0.001) and more likely to have hypertension (86.6% vs. 77.7%, p < 0.01) and prior diagnosed HF (79.4% vs. 70.7%, p < 0.01). African Americans had less prior diagnosed coronary disease, revascularization, hypothyroidism, or valve replacement. Atrial fibrillation was much less prevalent in African Americans (19.7%) than Caucasians (38.3%, p < 0.001). After adjustment for risk factors for AF and other potential confounders, African Americans had 49% lower odds of AF (adjusted odds ratio 0.51, 95% CI 0.35 to 0.76). CONCLUSIONS: In a contemporary HF cohort, AF was significantly less common among African Americans than among Caucasians. This variation was not explained by differences in traditional risk factors for AF, HF etiology and severity, and treatment.

Use of asthma medication dispensing patterns to predict risk of adverse health outcomes: a study of Medicaid-insured children in managed care programs.

BACKGROUND: Regular use of inhaled anti-inflammatory (AI) medication improves outcomes for children with persistent asthma. OBJECTIVE: To relate 3 measures of asthma medication dispensing to physical health and hospital-based events among children with asthma who were enrolled in 1 of 5 managed care health plans. METHODS: Parents of Medicaid-insured children with asthma were interviewed at baseline and 1-year follow-up. Utilization data were collected from the health plans in which the children were enrolled. Subjects were stratified into 3 subgroups according to asthma severity: intermittent asthma; persistent asthma for which beta-agonist (BA) medication was dispensed infrequently (< or = 3 times per year); and persistent asthma for which BA medication was dispensed frequently (> or = 4 times per year). RESULTS: Baseline interviews were completed by 1,663 parents (63% response rate), 1,504 of whom were enrolled in their health plan for at least 11 months during the baseline year. Follow-up interviews were completed by 1,287 (86%) of the 1,504 parents. Among the subgroup of children with persistent asthma for whom BA was dispensed frequently, those who had 1 to 3 AI dispensings had a greater risk for hospital-based events than those with 6 or more AI dispensings. Baseline-year AI medication utilization patterns were not associated with follow-up-year outcomes. No clinically meaningful association was found in subgroups with less severe asthma; however, few AI medications were dispensed to these children. CONCLUSIONS: Policymakers and clinicians who wish to use medication-based measures to evaluate quality of asthma care should consider counting the number of times AI medication is dispensed among children with more severe asthma.

Anticoagulation therapy for stroke prevention in atrial fibrillation: how well do randomized trials translate into clinical practice?

CONTEXT: Warfarin has been shown to be highly efficacious for preventing thromboembolism in atrial fibrillation in randomized trials, but its effectiveness and safety in clinical practice is less clear. OBJECTIVE: To evaluate the effect of warfarin on risk of thromboembolism, hemorrhage, and death in atrial fibrillation within a usual care setting. DESIGN: Cohort study assembled between July 1, 1996, and December 31, 1997, and followed up through August 31, 1999. SETTING: Large integrated health care system in Northern California. PATIENTS: Of 13,559 adults with nonvalvular atrial fibrillation, 11,526 were studied, 43% of whom were women, mean age 71 years, with no known contraindications to anticoagulation at baseline. MAIN OUTCOMES: Ischemic stroke, peripheral embolism, hemorrhage, and death according to warfarin use and comorbidity status, as determined by automated databases, review of medical records, and state mortality files. RESULTS: Among 11,526 patients, 397 incident thromboembolic events (372 ischemic strokes, 25 peripheral embolism) occurred during 25,341 person-years of follow-up, and warfarin therapy was associated with a 51% (95% confidence interval [CI], 39%-60%) lower risk of thromboembolism compared with no warfarin therapy (either no antithrombotic therapy or aspirin) after adjusting for potential confounders and likelihood of receiving warfarin. Warfarin was effective in reducing thromboembolic risk in the presence or absence of risk factors for stroke. A nested case-control analysis estimated a 64% reduction in odds of thromboembolism with warfarin compared with no antithrombotic therapy. Warfarin was also associated with a reduced risk of all-cause mortality (adjusted hazard ratio, 0.69; 95% CI, 0.61-0.77). Intracranial hemorrhage was uncommon, but the rate was moderately higher among those taking vs those not taking warfarin (0.46 vs 0.23 per 100 person-years, respectively; P =.003, adjusted hazard ratio, 1.97; 95% CI, 1.24-3.13). However, warfarin therapy was not associated with an increased adjusted risk of nonintracranial major hemorrhage. The effects of warfarin were similar when patients with contraindications at baseline were analyzed separately or combined with those without contraindications (total cohort of 13,559). CONCLUSIONS: Warfarin is very effective for preventing ischemic stroke in patients with atrial fibrillation in clinical practice while the absolute increase in the risk of intracranial hemorrhage is small. Results of randomized trials of anticoagulation translate well into clinical care for patients with atrial fibrillation.

Clinician support and psychosocial risk factors associated with breastfeeding discontinuation.

OBJECTIVE: Breastfeeding rates fall short of goals set in Healthy People 2010 and other national recommendations. The current, national breastfeeding continuation rate of 29% at 6 months lags behind the Healthy People 2010 goal of 50%. The objective of this study was to evaluate associations between breastfeeding discontinuation at 2 and 12 weeks postpartum and clinician support, maternal physical and mental health status, workplace issues, and other factors amenable to intervention. METHODS: A prospective cohort study was conducted of low-risk mothers and infants who were in a health maintenance organization and enrolled in a randomized, controlled trial of home visits. Mothers were interviewed in person at 1 to 2 days postpartum and by telephone at 2 and 12 weeks. Logistic regression modeling was performed to assess the independent effects of the predictors of interest, adjusting for sociodemographic and other confounding variables. RESULTS: Of the 1163 mother-newborn pairs in the cohort, 1007 (87%) initiated breastfeeding, 872 (75%) were breastfeeding at the 2-week interview, and 646 (55%) were breastfeeding at the 12-week interview. In the final multivariate models, breastfeeding discontinuation at 2 weeks was associated with lack of confidence in ability to breastfeed at the 1- to 2-day interview (odds ratio [OR]: 2.8; 95% confidence interval [CI]: 1.02-7.6), early breastfeeding problems (OR: 1.5; 95% CI: 1.1-1.97), Asian race/ethnicity (OR: 2.6; 95% CI: 1.1-5.7), and lower maternal education (OR: 1.5; 95% CI: 1.2-1.9). Mothers were much less likely to discontinue breastfeeding at 12 weeks postpartum if they reported (during the 12-week interview) having received encouragement from their clinician to breastfeed (OR: 0.6; 95% CI: 0.4-0.8). Breastfeeding discontinuation at 12 weeks was also associated with demographic factors and maternal depressive symptoms (OR: 1.18; 95% CI: 1.01-1.37) and returning to work or school by 12 weeks postpartum (OR: 2.4; 95% CI: 1.8-3.3). CONCLUSIONS: Our results indicate that support from clinicians and maternal depressive symptoms are associated with breastfeeding duration. Attention to these issues may help to promote breastfeeding continuation among mothers who initiate. Policies to enhance scheduling flexibility and privacy for breastfeeding mothers at work or school may also be important, given the elevated risk of discontinuation associated with return to work or school.