Differences in cardiovascular event rates between atorvastatin and simvastatin among new users: managed-care experience

Associated factors for discontinuation of statin use one year after discharge in patients with acute coronary syndrome in China

OBJECTIVES

To determine the associated factors for discontinuation of statin use 1 year after discharge in patients who survived from acute coronary syndrome (ACS) in China.

SETTINGS

75 hospitals across China.

DESIGN

A cohort follow-up study.

PARTICIPANTS

The study included 10 337 patients with ACS hospitalised in 2007-2010 and discharged with statins from 75 hospitals in China in the Clinical Pathways for Acute Coronary Syndromes in China Study-Phase 2 (CPACS-2), who were followed-up at 6 and 12 months postdischarge.

PRIMARY OUTCOME MEASURES

The primary outcome was the discontinuation of statin use defined as not in current use of statin at either 6-month or 12-month follow-up.

RESULTS

Multivariable logistic regression model showed that patients who did not have cholesterol measurement (adjusted OR=1.29; 95% CI: 1.10 to 1.50) and patients with either higher (1.27; 1.13 to 1.43) or lower dose of statin (1.22; 1.07 to 1.40), compared with those with standard dose, were more likely to discontinue the use of statin. In addition, patients on the CPACS-2 intervention pathway (adjusted OR=0.83; 95% CI: 0.74 to 0.94), patients with medical insurance (0.75; 0.67 to 0.85), history of hypertension (0.83; 0.75 to 0.92), high low-density lipoprotein cholesterol (0.70; 0.57 to 0.87) at the baseline, prior statin use (0.73; 0.63 to 0.84), use of atorvastatin (0.78; 0.70 to 0.88) and those who underwent percutaneous coronary intervention or coronary artery bypass grafting during hospitalisation (0.47; 0.43 to 0.53) were less likely to discontinue statin use. The 1-year statin discontinuation rate decreased from 29.5% in 2007-2008 to 17.8% in 2010 (adjusted OR=0.60; 95% CI: 0.51 to 0.70).

CONCLUSION

Implementing clinical pathway, enhancing medical insurance coverage, strengthening health education in both physicians and patients, using statin at standard dosage may help improve the adherence to statin use after discharge in Chinese patients with ACS.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12609000491268).

Comparative effectiveness of rosuvastatin versus simvastatin in primary prevention among new users: a cohort study in the French national health insurance database

Purpose

Using the French claims database (Système National d'Information Inter-Régimes de l'Assurance Maladie) linked to the hospital discharge database (Programme de Médicalisation des Systèmes d'Information), this observational study compared the effectiveness of rosuvastatin and simvastatin prescribed at doses with close LDL-cholesterol-lowering potency on all-cause mortality and cardiovascular and cerebrovascular diseases (CCDs) in primary prevention.

Methods

This historical cohort included patients with no prior CCD, aged 40–79 years, who initiated statin therapy with rosuvastatin 5 mg or simvastatin 20 mg in 2008–2009 in general practice. Follow-up started after a 1-year period used to select patients who regularly received the initial treatment.

In an intention-to-treat analysis, patients were followed up to December 2011. In a per-protocol analysis, they were censored prematurely when they discontinued their initial treatment. Adjustment for baseline covariates (age, deprivation index, comedications, comorbidities, prior hospital admissions) was carried out by a Cox proportional hazards model. In the per-protocol analysis, estimation was done by “inverse probability of censoring weighting” using additional time-dependent covariates. Analyses were gender-specific.

Results

A total of 106 941 patients initiated statin therapy with rosuvastatin 5 mg and 56 860 with simvastatin 20 mg. Mean follow-up was 35.8 months. For both genders and both types of analyses, the difference in incidence rates of mortality and/or CCD between rosuvastatin 5 mg and simvastatin 20 mg users was not statistically significant after adjustment (e.g., for CCD and/or mortality in men, in intention-to-treat analysis HR = 0.94 [95% CI = 0.85–1.04], in per-protocol analysis HR = 0.98 [0.87–1.10]).

Conclusions

The results of this real-life study based on medico-administrative databases do not support preferential prescription of rosuvastatin compared to simvastatin for primary prevention of CCD.

Therapeutic practice patterns related to statin potency and ezetimibe/simvastatin combination therapies in lowering LDL-C in patients with high-risk cardiovascular disease

BACKGROUND

Statin combination therapy and statin uptitration have been shown to be efficacious in low-density lipoprotein cholesterol (LDL-C) lowering and are recommended for patients with high-risk coronary heart disease (CHD) who do not reach guideline-endorsed LDL-C goals on statin monotherapy.

OBJECTIVE

This analysis evaluated treatment practice patterns and LDL-C lowering for patients with CHD/CHD risk equivalent on statin monotherapy in a real-world practice setting in the United States.

METHODS

In this retrospective, observational study, patients with CHD/CHD risk equivalent on statin therapy were identified during 2004 to 2008 in a US managed care database. Prescribing patterns and effect of switching from statin monotherapy to combination ezetimibe/simvastatin therapy vs uptitration to higher statin dose/potency level and no change from initial statin potency on LDL-C lowering were assessed. Percentage of change from baseline in LDL-C levels and odds ratios for LDL-C goal attainment were estimated with analyses of covariance and logistic regression.

RESULTS

Of 27,919 eligible patients on statin therapy, 2671 (9.6%) switched to ezetimibe/simvastatin therapy, 11,035 (39.5%) uptitrated statins, and 14,213 (50.9%) remained on the same statin monotherapy. LDL-C reduction from baseline and attainment of LDL-C <100 and <70 mg/dL were substantially greater for patients who switched to ezetimibe/simvastatin therapy (-24.0%, 81.2%, and 35.2%, respectively) than for patients who titrated (-9.6%, 68.0%, and 18.4%, respectively) or remained on initial statin therapy (4.9%, 72.2%, and 23.7%, respectively). The odds ratios for attainment of LDL-C <100 and <70 mg/dL were also higher for patients who switched than for patients who uptitrated and had no therapy change than for patients who titrated vs no therapy change. Similarly, among a subgroup of patients not at LDL-C <100 mg/dL on baseline therapy, attainment of LDL-C <100 and <70 mg/dL was greater for patients who switched than for statin uptitration vs no change, as well as for patients who uptritrated statins vs no therapy change.

CONCLUSION

In this study, LDL-C lowering and goal attainment rates improved substantially for patients with high-risk CHD on statin monotherapy who switched to combination ezetimibe/statin or uptitrated their statin therapies; however, approximately one-third of these patients still did not attain the optional recommended LDL-C goal of <70 mg/dL. Moreover, these higher efficacy lipid-lowering therapies were infrequently prescribed, indicating the need for further assessment of barriers to LDL-C goal attainment in actual practice settings.

Cardiovascular and economic outcomes after initiation of atorvastatin versus simvastatin in an employed population stratified by cardiovascular risk

The relative effects of atorvastatin and simvastatin among higher- and lower-risk patients are not well characterized. This study compared cardiovascular (CV) risk and direct and indirect costs among higher- and lower-risk employees initiating atorvastatin vs. simvastatin. Using a large employer claims database (1999-2006), employees were stratified as 1) high-risk employees with prior CV events, diabetes, or renal disorders; and 2) low- to intermediate-risk employees without these conditions. Propensity score matching was used, and 2-year outcomes were compared between matched cohorts. Indirect costs included disability payments and medically related absenteeism. Drug costs were imputed with recent prices to account for availability of generic simvastatin. Among 4167 matched pairs of high-risk employees, atorvastatin use was associated with a numerically lower risk of CV events (17.6 versus 18.4%, P = 0.37), higher direct medical costs ($17,590 versus $17,377, P = 0.002), numerically lower indirect costs ($4830 versus $4989, P = 0.29), and higher total costs by $54 ($22,420 versus $22,366, P = 0.034). The majority of high-risk employees (62%) received low initial statin doses (atorvastatin = 10 mg or simvastatin = 20 mg). Among 9326 matched pairs of low- to intermediate-risk employees, atorvastatin use was associated with a lower risk of CV events (3.1% versus 3.7%, P = 0.030), lower direct medical costs ($8400 versus $8436, P < 0.001), numerically lower indirect costs ($2781 versus $2807; P = 0.12), and lower total costs by $61 ($11,181 versus $11,243, P < 0.001). These results suggest that formulary policies reserving atorvastatin for higher-risk patients may not be cost-saving from the employer perspective.

Dynamics of long-term statin therapy

PURPOSE

Knowledge of the different usage patterns that emerge during a long-term statin therapy is limited. The aim of this study was to characterize statin use, including the rates of reinitiation after extended periods of non-use, transitions between good and poor adherence, and the effect of the length of a drug-free period on the identification of new users.

METHODS

The study cohort comprised individuals aged 45-84 years who were identified in the Finnish prescription register as having purchased statins between 1997 and 2007. New users in 1997, including those with no statin purchases during the preceding 3 years, were followed-up until institutionalization, death, or 31 December 2007. Reinitiation rates after ≥180 days with no refill for statins were analyzed using survival analysis. Annual adherence levels and the prevalences of good (proportion of days covered ≥0.80) and poor (<0.80) adherence were calculated for ten 1-year periods following initiation. For statin users in 2007, purchases were captured over the previous 10 years.

RESULTS

Based on the data extracted from the Finnish prescription register, 32,760 persons initiated statin treatment in 1997, of whom 48.1% had discontinued it for at least 180 days by the end of the follow-up period. Of the discontinuers, 46.7% restarted the treatment within 1 year and 88.7% by the end of the follow-up. Of those followed up for ≥10 years, 51.8% had ≥6 years of treatment with good adherence. In 2007, 27.7% of the initiators having no statin purchases within the previous year had refills during the preceding 10 years.

CONCLUSION

Statin use is dynamic. This should be taken into consideration in clinical practice and when studying the incidence, patterns, and health outcomes of statin use.

Cardiovascular and economic outcomes after initiation of lipid-lowering therapy with atorvastatin vs simvastatin in an employed population

OBJECTIVE

To compare the risk of cardiovascular-related hospitalization, statin adherence, and direct (medical and drug) and indirect (disability and medically related absenteeism) costs in US employees in whom atorvastatin or simvastatin was newly prescribed.

PATIENTS AND METHODS

Active employees aged 18 to 64 years with a new atorvastatin or simvastatin prescription were identified from a deidentified claims database for 23 privately insured US companies from January 1, 1999, through December 31, 2006. Employees given atorvastatin were matched to those given simvastatin according to propensity scores based on patient characteristics, index statin dose, preindex cardiovascular events, and wage. Outcomes were compared between matched cohorts during the 2-year postindex period, including the risk of cardiovascular-related hospitalization, adherence to the index statin, use of other lipid-lowering drugs, direct medical costs for third-party payers, and indirect costs to employers. Indirect costs were computed as follows: Disability Payments + Daily Wage x Days of Medically Related Absenteeism. Atorvastatin and simvastatin drug costs were imputed using recent pricing to account for the availability of lower-cost generic simvastatin after the study period.

RESULTS

Among 13,584 matched pairs, treatment with atorvastatin vs simvastatin was associated with a reduced risk of cardiovascular-related hospitalization, higher adherence, and less use of other lipid-lowering drugs. The increase in statin costs associated with atorvastatin vs simvastatin therapy was almost completely offset by reductions in medical service and indirect costs.

CONCLUSION

In this study, treatment with atorvastatin compared with simvastatin was associated with a reduced risk of cardiovascular events, reduced indirect costs, and a minimal difference in total costs to employers.