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HYPERTENSION/2004/034256 R1 Methods Study Sample and Procedures To determine whether patient-centered characteristics are associated with processes of care for hypertension, we studied patients who had at least one hypertensionrelated outpatient visit to one of twelve general medicine clinics in community health centers and community practices affiliated with a large urban academic medical center from July 1, 2001 through June 30, 2002. To determine hypertension-related visits, we reviewed the electronic medical record (EMR) for all clinic visits with a primary or secondary diagnostic code of hypertension (HTN) (ICD-9 401- 401.9, 405- 405.99). The study protocol was approved by the Human Studies Committee at the Brigham and Women’s Hospital. Medical Record Trained abstracters reviewed the EMR of each hypertension-related visit, collecting: patient race/ethnicity, patient age at time of visit, sex, primary insurer at time of visit, presence of comorbid disease (diabetes, congestive heart failure (CHF), coronary artery disease (CAD), or renal failure) listed on the patient problem list, drug allergies, class of antihypertensive drug on medication list, and any changes made to antihypertensive drug therapy during visit (decrease or discontinuation of drug, change to another class of drug, or increase of drug dose or addition of new drug). Patient zip code was also obtained and linked to 2000 U.S. Census data to obtain the median annual household income in each patient’s zip code. JNC Adherence 1 HYPERTENSION/2004/034256 R1 To determine adherence to published JNC guidelines, we developed an algorithm (Figure I) to assess whether patients were receiving the JNC-recommended drug therapy at the time of each visit. Visits were classified as JNC adherent if the patient had been receiving a JNC-recommended medication. Visits at which the patient was taking more than one antihypertensive medication were considered adherent if at least one of the medications was from a recommended drug class. Visits were considered non-JNC adherent if a patient was receiving a non-recommended medication, or was not receiving drug therapy when a clear indication for treatment was found on EMR review. Visits at which a patient had a documented allergy or contraindication to the JNC recommended medication were considered adherent if the patient was receiving a different class of antihypertensive medications. Those visits in which no antihypertensive medications were listed and no comorbid disease indication for drug treatment was documented were excluded from analysis because of difficulty in determining whether the patient should be on pharmacologic therapy at their index visit (N=2,641) (however, these visits were eligible for inclusion for our examination of intensification of therapy). Each reviewer assessed JNC adherence in a subset of 65 records; we then tested for inter-rater reliability (kappa=0.98) and found excellent agreement among reviewers. Blood Pressure Control To determine BP at time of visit, we obtained BP readings from the encounter note for each visit. If more than one BP was recorded for the visit, we averaged them to obtain the mean systolic and diastolic BP at the visit. We also classified each mean BP as controlled (<130/85 for patients with diabetes or renal failure or <140/90 for other patients) or uncontrolled for each visit. 2 HYPERTENSION/2004/034256 R1 Intensity of Therapy To determine whether providers intensified drug therapy for hypertension differentially for racial and ethnic groups, we conducted an EMR review of a random subset of 1,205 patients who had a minimum of two hypertension-related visits during the one-year study period (totaling 3,257 visits). Each visit was classified into one of the following categories according to previously defined changes in medications.1 A “decrease” was considered a decrease or stop in the dosage of any antihypertensive medication and no increase in another medication; “no change” was defined as a change within class (e.g., nifedipine to diltiazem) or no change of BP medications; and an “increase” was considered an increase in the dosage of any anti-hypertensive medication or starting a new medication. We further classified each visit into two categories, intensified (an increase) versus non-intensified (a decrease or no change). We developed an algorithm to determine whether a patient received at least one increase in drug therapy in response to a repeatedly elevated BP during the study period (Figure II). Each patient with fewer than two visits with an elevated BP was excluded from the algorithm (N=355). Each patient with an uncontrolled BP at more than one visit was identified as either an intensified case (at least one drug increase) or a non-intensified case (no drug increases). Each reviewer examined a subset of 30 records; we then tested for inter-rater reliability and found excellent agreement among reviewers (kappa=0.90). Data Analysis To examine the demographic and clinical characteristics of our cohort, we used chi-square tests for categorical variables and Student's t-tests for continuous variables to compare patient characteristics by race/ethnicity and to compare demographic and 3 HYPERTENSION/2004/034256 R1 clinical characteristics by visit type (JNC adherent vs. non-adherent). We report twotailed P values with statistical significance set at P0.05. We also estimated the association of BP control at a visit with JNC adherence and with the demographic and clinical characteristics obtained from EMR review. Since the JNC VI cutoff for uncontrolled BP is different for patients with diabetes or renal failure than for the general population, we also compared mean systolic and diastolic BP levels in patients with diabetes and/or renal failure and those without, using Student's t-test. Using logistic regression and adjusting for all measured confounders, we assessed whether race/ethnicity was associated with JNC adherence or BP control. Data were available on every variable for 12,790 of the 13,127 visits (97.4%) for multivariate analyses. We report adjusted odds ratios with 95% confidence intervals for JNCadherent visits and for BP control by patient race/ethnicity. All analyses used SUDAAN statistical software (Research Triangle Institute, Research Triangle Park, North Carolina) to adjust for within-patient correlation of visits and within-provider correlation of visits.2 For each of the 1,205 patients with multiple hypertension-related visits, we estimated the association of intensifying therapy (intensified case versus non-intensified case) during the study period with race/ethnicity using chi-square tests. We also estimated the association between intensifying therapy at a visit and obtaining BP control at a subsequent visit, adjusting for race/ethnicity and baseline systolic and diastolic BP using repeated measures logistic regression. In a secondary analysis, we included interaction terms for race/ethnicity and intensity of therapy to determine whether the association of intensity of therapy with subsequent BP control differed by race. All non-significant interaction terms were removed from the final model. Data were available on every 4 HYPERTENSION/2004/034256 R1 variable for 1,926 of the 3,257 visits (59.1%) for multivariate analyses. Models were estimated with the SAS procedures Proc GenMod and Proc Mixed. 5 HYPERTENSION/2004/034256 R1 References: 1. Berlowitz DR, Ash AS, Hickey EC, Friedman RH, Glickman M, Kader B, Moskowitz MA. Inadequate management of blood pressure in a hypertensive population. N Engl J Med. 1998; 339:1957-1963. 2. Frane J. SUDAAN: Professional Software for Survey Data Analysis. Research Triangle Park, NC: Research Triangle Institute; 1989. 6 HYPERTENSION/2004/034256 R1 LEGEND FOR FIGURES Figure I: Flow diagram of algorithm for determining JNC adherence. Inter-rater reliability was high (kappa 0.98). We identified a total of 13,127 visits as either “guideline adherent” (N=10,653) or a “non-adherent” (N=2474). Figure II: Flow diagram of algorithm for determining an “intensified case.” Inter-rater reliability was high (kappa 0.90). We identified a total of 850 cases as either an “intensified case (N=671) or a “non-intensified case” (N=179). 7 HYPERTENSION/2004/034256 R1 Figure I: Algorithm for determining adherence to JNC VI guidelines History of hypertension or elevated blood pressure? No Yes Diabetes or Targetorgan damage? No Excluded from analysis Yes Yes Diabetes? Blood pressure medications listed? No Yes ACE inhibitor or A-II blocker Age 60 or Black? Yes Diuretic or Calcium channel blocker No Myocardial infarction, or coronary artery disease? Yes Beta blocker No No Renal insufficiency? Yes ACE inhibitor or A-II blocker Yes ACE inhibitor or A-II blocker No Congestive heart failure or left ventricular hypertrophy? No Age 60 or Black? Diuretic or Beta Blocker No Yes Diuretic or Calcium channel blocker 8 HYPERTENSION/2004/034256 R1 Figure II: Algorithm for determining intensified case BP uncontrolled at any visit? Yes No Patient excluded from Therapy intensified 1st uncontrolled visit analyses No Yes BP controlled at a second visit following an uncontrolled visit? BP controlled at all subsequent visits? Yes Yes No No Therapy intensified at an uncontrolled follow-up visit? Yes Intensified case No Non-intensified case 9