Simon Tang

Predictors of adherence to concomitant antihypertensive and lipid-lowering medications in older adults: a retrospective, cohort study.

AbstractBackground: Many older individuals have concomitant hypertension and dyslipidaemia — two conditions that, together with age, increase the risk of adverse cardiovascular events. Adherence to antihypertensive (AH) and lipid-lowering (LL) therapy is therefore particularly important in older patients with concomitant hypertension and dyslipidaemia. Objective: To determine patterns and predictors of adherence to concomitant AH and LL therapy among an older Medicare-eligible population. Methods: Enrolees (n = 4052) aged ≥65 years who initiated treatment with both AH and LL therapy within a 90-day period were studied in this retrospective cohort study conducted in a US managed care organization. Adherence to AH and LL medications was measured as the proportion of days covered by any AH and/or LL medication in each 3-month interval, from the start of concomitant therapy for up to 36 months (mean follow-up 19.5 months). In each interval, patients were considered ‘adherent’ to AH and LL therapy if they had filled prescriptions sufficient to cover ≥80% of days with both medication classes. A multivariable regression model evaluated potential predictors of adherence to concomitant therapy, including patient demographics, clinical characteristics and health services use patterns at baseline. Results: The percentage of patients adherent to both AH and LL therapy declined rapidly, before stabilizing, with 40.5%, 32.7% and 32.9% adherent at 3, 6 and 12 months, respectively. At each timepoint, an additional 27.8–35.0% of patients were adherent to either AH or LL therapy, but not both. Adherence was on average greater to AH than LL therapy. After adjusting for age, sex and other potential predictors, patients were more likely to be adherent if AH/LL therapies were initiated closer together in time (adjusted odds ratio [AOR] 1.13 for 0–30 days vs 61–90 days, p = 0.0563), had a history of cardiovascular disease (AOR 1.27, p = 0.0004), took fewer additional medications (AOR 0.43 for six or more medications vs zero or one medication, p < 0.0001) or had more outpatient physician visits in the prior year (AOR 1.26 for four to six visits vs zero to one visit, p < 0.0027). Conclusion: Adherence to concomitant AH and LL therapy among older adults is poor. Modifiable factors that may improve adherence in Medicare-eligible patients include initiating therapy concurrently and reducing patients’ overall pill burden.

Association between prescription burden and medication adherence in patients initiating antihypertensive and lipid-lowering therapy.

PURPOSE The association between prescription burden and medication adherence in patients initiating antihypertensive and lipid-lowering therapy was studied. METHODS Patients enrolled in managed care organizations who initiated antihypertensive therapy coincident with lipid-lowering therapy (no more than 90 days apart) between January 1, 1997, and April 30, 2000, were eligible for inclusion. Analysis was limited to new users of antihypertensive and lipid-lowering therapy. The proportion of days covered (PDC) by antihypertensive and lipid-lowering therapy was calculated for the first year after therapy initiation; patients with a PDC of > or =80% for both drug classes were considered adherent. Prescription burden was defined as the number of prescription medications taken in the year prior to starting antihypertensive and lipid-lowering therapy. Demographic, clinical, and health-service-use variables associated with both prescription burden and medication adherence were measured using medical and pharmacy claims data from the year before initiation of antihypertensive and lipid-lowering therapy. RESULTS Among 5759 patients, the mean +/- S.D. prescription burden was 3.6 +/- 3.7 (median, 3) medications, and the mean +/- S.D. PDC with antihypertensive and lipid-lowering therapy was 53.9% +/- 31.9% (median, 58.5%). Among patients with 0, 1, and 2 prior medications, 41%, 35%, and 30% of patients were adherent, respectively, to antihypertensive and lipid-lowering therapy. Among patients with 10 or more prior medications, 20% were adherent. CONCLUSION Among patients in a managed care database taking antihypertensive and lipid-lowering medications, adherence to those regimens became less likely as the number of prescription medications increased. The reduction in adherence with additional prescription medications was greatest in patients with the fewest preexisting prescriptions.

Impact of Systemic Hypertension on the Cardiovascular Benefits of Statin Therapy—A Meta-Analysis

The ASCOT-LLA and ALLHAT-LLT trials provide conflicting evidence of the efficacy of statins in decreasing cardiovascular (CV) morbidity and mortality in hypertensive patients. We performed a meta-analysis to compare the overall efficacy of statins in hypertensive and nonhypertensive patients enrolled in major randomized clinical trials. We systematically reviewed PubMed publications from 1985 onward for placebo-controlled randomized trials that examined the effect of statins on cardiac morbidity and mortality. Only trials that followed >or=1,000 patients for >or=2 years were included in the meta-analysis. Outcomes included cardiac or CV death, major coronary events, or major CV events. Pooled estimates of relative risk (RR) were calculated separately for hypertensive and nonhypertensive patients. The moderating effect of the percentage of hypertensive patients at baseline was tested using meta-regression. Besides the ASCOT-LLA and ALLHAT-LLT, 12 trials enrolling 69,984 patients met inclusion criteria. Overall, in these 12 trials, statin therapy decreased cardiac death by 24% (RR 0.76, 95% confidence interval [CI] 0.71 to 0.82). There was no evidence of difference in RR estimates for hypertensive (RR 0.78, 95% CI 0.72 to 0.84) and nonhypertensive (RR 0.76, 95% CI 0.72 to 0.80) patients. Similarly, meta-regression showed that the efficacy of statins was not moderated by the percentage of hypertensive patients at baseline (Q estimate 1.51, p=0.22). In conclusion, statin therapy effectively decreases CV morbidity and mortality to the same extent in hypertensive and nonhypertensive patients.

Does a single-pill antihypertensive/lipid-lowering regimen improve adherence in US managed care enrolees? A non-randomized, observational, retrospective study.

BackgroundA previous study in 4703 patients suggested that a single-pill combination of amlodipine and atorvastatin is associated with greater adherence to therapy than a two-pill calcium channel antagonist (calcium channel blocker [CCB]) and HMG-CoA reductase inhibitor (statin) regimen. However, the impact of prior medication use on the potential adherence benefits of single-pill amlodipine/atorvastatin has not been studied.ObjectiveTo compare adherence to single-pill amlodipine/atorvastatin versus two-pill CCB + statin regimens in a large managed care population, stratified according to prior CCB and statin use.MethodsThis retrospective study was conducted among managed care enrollees in the US. Patients included in the analysis had to have a pharmacy claim for single-pill amlodipine/atorvastatin or claims for both a CCB and a statin within any 30-day window between April 2004 and April 2005. Adherence was measured over 6 months following the index date (the date of the first single-pill amlodipine/atorvastatin claim or of the claim for the second medication class for any two-pill CCB + statin regimen) as the proportion of days covered (PDC) by both CCB and statin therapy; patients were considered ‘adherent’ if PDC was ≥80%. Patients were divided into four cohorts based on pre-index CCB and statin use: (i) naive (CCB)/naive (statin); (ii) experienced (CCB)/naive (statin); (iii) naive (CCB)/experienced (statin); and (iv) experienced (CCB)/experienced (statin). Within each cohort, adherence was compared for patients receiving single-pill amlodipine/atorvastatin versus two-pill amlodipine + atorvastatin or other two-pill CCB + statin regimens (including amlodipine or atorvastatin but not both) at index. Multivariable logistic regression with propensity score weighting was used to adjust for covariates, including age, sex and co-morbidities.ResultsIn total, 35 430 patients were included in the analysis. At month 6 (after adjusting for covariates), patients in the experienced (CCB)/naive (statin) cohort receiving single-pill amlodipine/atorvastatin were more than twice as likely to be adherent as those receiving two-pill amlodipine + atorvastatin (odds ratio [OR] 2.20; p < 0.0001) or other two-pill CCB + statin regimens (OR 2.75; p < 0.0001). Similarly, patients in the naive (CCB)/experienced (statin) cohort receiving single-pill amlodipine/atorvastatin were more likely to be adherent than those receiving two-pill amlodipine + atorvastatin (OR 1.72; p < 0.0001) or other two-pill CCB + statin regimens (OR 2.81; p < 0.0001). In contrast, in the naive (CCB)/naive (statin) cohort there was no significant difference in adherence between patients receiving single-pill amlodipine/atorvastatin versus two-pill amlodipine + atorvastatin (OR 1.00), although patients receiving single-pill amlodipine/atorvastatin were slightly more likely to be adherent than those receiving other two-pill CCB + statin regimens (OR 1.29; p < 0.01). In the experienced (CCB)/experienced (statin) cohort there was also no significant difference between patients receiving single-pill amlodipine/atorvastatin versus two-pill amlodipine + atorvastatin (OR 1.08), and only a slightly greater likelihood of achieving adherence to single-pill amlodipine/ atorvastatin versus other two-pill CCB + statin regimens (OR 1.19; p < 0.01).ConclusionsThis large retrospective study confirms previous observations that single-pill amlodipine/ atorvastatin can help improve adherence versus two-pill CCB + statin regimens. However, greater improvements in adherence are likely to be observed in patients with prior experience of either CCB or statin therapy than in those either naive to, or experienced with, both therapies.

Does synchronizing initiation of therapy affect adherence to concomitant use of antihypertensive and lipid-lowering therapy?

Although efficacious medications are available to treat hypertension and dyslipidemia, treatment adherence is often poor. This retrospective study evaluated adherence in patients newly initiating antihypertensive (AH) and lipid-lowering (LL) therapies simultaneously versus within 180 days of one another. Data were analyzed for US managed care plan enrollees initiating AH before LL (cohort 1; n = 7099), LL before AH (cohort 2; n = 3229), or AH/LL simultaneously (cohort 3; n = 5072). A multivariate model evaluated potential predictors of adherence (medication possession ratio ≥ 0.80 over a bimonthly period). Percentages of patients adherent to AH/LL at 2, 6, and 12 months were as follows: 59.4%, 32.7%, and 31.3% in cohort 1; 45.0%, 30.8%, and 31.0% in cohort 2; and 75.2%, 34.4%, and 34.0% in cohort 3, respectively. After adjustment for potential confounders, patients initiating AH before LL therapy, or LL before AH therapy, were less likely to be adherent than patients prescribed both agents simultaneously (odds ratios = 0.838 and 0.691, respectively; P < 0.0001). Synchronous initiation of AH and LL therapies is an important predictor of adherence.

Treatment and Control of BP and Lipids in Patients with Hypertension and Additional Risk Factors

BackgroundNCEP ATP III (National Cholesterol Education Program Adult Treatment Panel III) guidelines recommend that for patients at high risk for cardiovascular disease (CVD), lipid-lowering therapy should be considered even at relatively low cholesterol levels (low-density lipoprotein-cholesterol ↓100 mg/dL). Furthermore, the ASCOT-LLA (Anglo-Scandinavian Cardiac Outcomes Trial-Lipid-Lowering Arm) has demonstrated the importance of statin therapy in the primary prevention of major cardiovascular events in people with hypertension and ↓3 cardiovascular risk factors with total cholesterol levels of ↑250 mg/dL (↑6.5 mmol/L).ObjectiveTo analyze the utilization of antihypertensive and lipid-lowering medications, and associated rates of BP and cholesterol goal attainment, in the primary prevention of CVD among patients with hypertension.Study designRetrospective cross-sectional analysis of data from outpatient medical records (including BP, co-morbidities, and medications) abstracted for visits between 1 October 2001 and 30 September 2003 to the Atlanta Veterans Affairs Medical Center (VAMC). Patients were tracked for at least 1 year.PatientsVeterans newly diagnosed with hypertension, with lipid levels ↑240 mg/dL (↑6.2 mmol/L) and no prior coronary heart disease, and who were seeking care at the VAMC were included in the analysis. Patients were grouped by the presence of <3 or ↓3 cardiovascular risk factors in addition to hypertension.Main outcome measuresThe frequency of utilizing antihypertensive and lipid-lowering medications, and attainment of BP targets were assessed based on the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) guidelines (<140/90mm Hg, or <130/80mm Hg for patients with diabetes mellitus or chronic kidney disease) and a ratio of total cholesterol/ high-density lipoprotein-cholesterol (HDL-C) <6.ResultsA total of 7839 veterans were included. Mean age was 58.7 ±13.2 years, and 93.8% were men. Among patients with ↓3 cardiovascular risk factors, 81.9% received any antihypertensive medication and 60.4% were prescribed multiple antihypertensive agents compared with 69.7% and 44.3% of patients, respectively, in the group with <3 cardiovascular risk factors. Lipid-lowering medications were prescribed to 55.3% of patients with ↓3 cardiovascular risk factors, and to 33.8% of those with <3 cardiovascular risk factors. Overall, 14.3% of patients met both BP and lipid targets (8.1% and 17.4% of patients with ↓3 and <3 cardiovascular risk factors, respectively [p <0.0001]). JNC 7 goals were attained in 27.9% of patients with ↓3 cardiovascular risk factors and 41.7% of those with <3 cardiovascular risk factors (p <0.001). Total cholesterol/HDL-C ratio <6 was achieved by 32.3% of patients with ↓3 cardiovascular risk factors and 52.1% of those with <3 cardiovascular risk factors (p <0.001).ConclusionVeterans with ↓3 risk factors for CVD were treated more intensively, but levels of goal attainment were lower compared with patients with <3 cardiovascular risk factors. Our results suggest that the therapeutic strategies used by physicians in the Atlanta VAMC need to be adapted in order to improve lipid goal attainment among patients with hypertension, and thereby further reduce the risk of cardiovascular events.

Transition Probabilities and Predictors of Adherence in a California Medicaid Population Using Antihypertensive and Lipid-Lowering Medications

OBJECTIVES To determine adherence rates, transition probabilities, and factors associated with transition from higher to lower adherence in antihypertensive (AH) and lipid-lowering (LL) medications. METHODS California Medicaid data (1995-2003) were used to identify hypertensive patients with prescriptions for both AH and LL medications. Proportion of days covered (PDC) was used to define three adherence classifications: fully adherent (FA, PDC >or= 0.8), partially adherent (PA, 0.2 <or= PDC < 0.8), and nonadherent (NA, PDC < 0.2). Annual transition matrices documented the probability of adherence status changes. RESULTS Only 13% of the 5943 patients were FA to both drugs at baseline. Patients who were FA (60%) or NA (84%) to both drugs had high probability of maintaining status at year two (Y2). Significant variables associated with a transition from adherent to NA at Y2 included African American race (odds ratio [OR] 1.5), other race groups (OR 1.2), lack of Medicare eligibility (OR 1.3), and initiating LL therapy of fibric acid derivatives (OR 1.3) or niacin (OR 1.8). CONCLUSIONS Patients FA or NA with both drugs at baseline were more likely to maintain their adherence status. Race, insurance coverage, and type of LL medication were significantly associated with transitioning from any adherence status to nonadherence. These findings may be useful in guiding cost-effectiveness analyses incorporating adherence estimates.

A Retrospective Cohort Study of the Potency of lipid-lowering therapy and Race-gender Differences in LDL cholesterol control

BackgroundReasons for race and gender differences in controlling elevated low density lipoprotein (LDL) cholesterol may be related to variations in prescribed lipid-lowering therapy. We examined the effect of lipid-lowering drug treatment and potency on time until LDL control for black and white women and men with a baseline elevated LDL.MethodsWe studied 3,484 older hypertensive patients with dyslipidemia in 6 primary care practices over a 4-year timeframe. Potency of lipid-lowering drugs calculated for each treated day and summed to assess total potency for at least 6 and up to 24 months. Cox models of time to LDL control within two years and logistic regression models of control within 6 months by race-gender adjust for: demographics, clinical, health care delivery, primary/specialty care, LDL measurement, and drug potency.ResultsTime to LDL control decreased as lipid-lowering drug potency increased (P < 0.001). Black women (N = 1,440) received the highest potency therapy (P < 0.001) yet were less likely to achieve LDL control than white men (N = 717) (fully adjusted hazard ratio [HR] 0.66 [95% CI 0.56-0.78]). Black men (N = 666) and white women (N = 661) also had lower adjusted HRs of LDL control (0.82 [95% CI 0.69, 0.98] and 0.75 [95% CI 0.64-0.88], respectively) than white men. Logistic regression models of LDL control by 6 months and other sensitivity models affirmed these results.ConclusionsBlack women and, to a lesser extent, black men and white women were less likely to achieve LDL control than white men after accounting for lipid-lowering drug potency as well as diverse patient and provider factors. Future work should focus on the contributions of medication adherence and response to treatment to these clinically important differences.

Treatment of Hypertension and Dyslipidemia or Their Combination Among US Managed-Care Patients

The authors examined treatment rates in managed‐care patients with hypertension (HTN) only or dyslipidemia (DYS) only compared with patients who had both (HTN+DYS). A retrospective, cross‐sectional claims analysis was performed in a 2002 US national managed‐care database of 1.23 million continuously eligible members aged 18 years or older. Median age was 44.0 years, 8.8% were aged 65 years or older, and 53.2% were women. Study criteria identified 354,324 patients, 32.9% with HTN only, 34.7% with DYS only, and 32.4% with HTN+DYS. Overall, 49.7% of HTN patients had DYS and 48.3% of DYS patients had HTN. Patients with HTN+DYS were significantly older, more likely to have cardiovascular comorbidities, and more likely to use medications and hospital facilities than were patients with HTN only or DYS only (P<.01). About two‐thirds of patients with HTN only received 1 or more prescription for an antihypertensive medication, compared with three‐quarters of those with HTN+DYS. Fewer than half of patients with DYS only and approximately two‐thirds with HTN+DYS received a cholesterol‐lowering agent.

Are high-risk hypertensive patients being prescribed concomitant statin therapy?: a retrospective cohort study.

BackgroundTreatment guidelines for dyslipidemic patients have focused on lipid levels and risk assessments. However, normolipidemic patients who have multiple risk factors for cardiovascular disease may also benefit from HMG-CoA reductase inhibitor (statin) therapy.ObjectiveWe examined the frequency of statin prescriptions in patients initiating antihypertensive drug treatment in a US managed-care setting.Study Design and PatientsThis retrospective cohort study used the PharMetrics’ Patient-Centric Database to identify enrollees initiating antihypertensive treatment (September 2001 to February 2004). Patients newly treated with antihypertensives and with various levels of coronary heart disease (CHD) risk (including dyslipidemia, established CHD, type 2 diabetes mellitus, and no CHD but three or more cardiovascular risk factors) were included in the study.Main Outcome MeasureCumulative probability of receiving statin therapy each month after antihypertensive initiation. Multivariable logistic regression was used to identify factors associated with receiving concomitant statin therapy.ResultsOf 142 389 patients (mean age 51.7 years) newly treated with antihypertensives, 32 056 (22.5%) were prescribed statins within 1 year. The cumulative probability of being prescribed a statin increased with increasing numbers of CHD risk factors, irrespective of dyslipidemia status. After adjusting for age, sex, and other potential predictors, patients were more likely to receive statin therapy if they had a history of dyslipidemia (adjusted odds ratio [AOR] 5.68 [95% CI 5.52, 5.85]), established CHD/congestive heart failure (AOR 3.39 [95% CI 3.16, 3.63]), or three or more additional cardiovascular risk factors but no CHD (AOR 3.01 [95% CI 2.74, 3.30]).ConclusionAmong patients beginning antihypertensive treatment, those with established CHD or CHD risk factors were more likely to receive statins, but a substantial fraction did not fill any statin prescription. The increased use of statin therapy could benefit many hypertensive patients with additional CHD risk factors.