Statin use after first myocardial infarction in UK men and women from 1997 to 2006: Who started and who continued treatment?
Introduction
Statins are widely prescribed for primary and secondary prevention of cardiovascular disease, and their utilisation has steadily increased [1], [2], [3], [4], [5], [6]. In particular, their use has been shown to substantially reduce cardiovascular events after myocardial infarction (MI) [7]. However, the benefits increase with increasing duration of treatment [8], and concerns exist that long-term continuation with statin therapy is poor [5], [9], [10], [11]. Relatively few data exist on how continuation with therapy may have altered during periods when initiation rates have risen markedly. A US study of an elderly population suggested a weak trend towards improved sustained compliance during the 1990’s and early 2000’s [4], while a Finnish study of all new statin users reported improvement in 1 year persistence between 1995 and 2003 [3].
There is also interest in those factors related to initiation and continued therapy and whether these have remained constant over time. Thus while it is known that socio-economic differences in initial uptake of statins existed [12], it is not known whether these differences persist in populations where statin utilisation is generally high, as has been the case in secondary prevention in recent years. Marked age inequalities in statin prescribing also existed during the 1990’s [1], [13], whilst the evidence for higher use in men has been inconsistent, some studies suggesting that this is due to differences in age and disease severity [1].
The last 10 years have seen the introduction of numerous guidelines for clinicians, emphasising secondary prevention with statins. In the UK, in 2000, a National Service Framework for Coronary Heart Disease [14] was followed in 2004 by the introduction of a new Primary Care contract [15], which introduced incentives for achieving cholesterol lowering targets. The years 1997–2007 in the UK thus constitute a natural experiment which allows an examination of the impact of increasing levels of initiation of statin therapy for secondary prevention of cardiovascular disease on both inequities in access to therapy and on continuation in therapy. Specifically we examine trends over a 10 year period in patients having a first myocardial infarction (MI), using a large UK primary care database. We also investigate predictors of initiation and continuation in these patients and whether the role of social factors and age changed over this period.
Section snippets
Subjects
Data were from DIN-LINK, an anonymised, computerised UK primary care database. The completeness and accuracy of DIN-LINK has been demonstrated, by comparisons with other national data sources and the practices and GPs in DIN-LINK are comparable to the practices and GPs in other GP research databases [16]. The database contains a small area socio-demographic indicator, the Index of Multiple Deprivation (IMD) [17], for most patients in England. Morbidity and drug data are coded using Read codes.
Results
Of the 10,138 patients identified with a first time MI, 9367 (92.4%) were followed for at least 6 months, of whom 6988 (74.6%) were prescribed a statin during this time. Of the 9367 patients the average age was 66 years and 66% were male.
Main findings
Statin use for secondary prevention after first MI in the UK has increased markedly since 1997, but importantly, this has not influenced long-term compliance. Despite assertions in the literature that persistence and adherence with statins for secondary prevention after first MI are poor [9], [10], [11], our data show that of those initiated on a statin, 80% are still covered by a prescription at 1 year, while 78% had been covered by a prescription for ≥80% of the time, with no clear trends
Ethical approval
Ethics Approval was by the Wandsworth Research Ethics Committee.
Conflict of interest
None declared.
Acknowledgements
We thank Cegidem Strategic Data for providing the DIN-LINK data. The BUPA Foundation funded the work (Grant Number 668/G15).
References (32)
- et al.
Preventive drug use in patients with a history of nonfatal myocardial infarction during 12-year follow-up in The Netherlands: a retrospective analysis
Clin Ther
(2005) - et al.
Cardiovascular prevention guidelines in daily practice: a comparison of EUROASPIRE I, II, and III surveys in eight European countries
Lancet
(2009) - et al.
Long-term persistence with statin treatment in a not-for-profit health maintenance organization: a population-based retrospective cohort study in Israel
Clin Ther
(2008) - et al.
Developing a large electronic primary care database (Doctors’ Independent Network) for research
Int J Med Inf
(2004) - et al.
Toward a standard definition and measurement of persistence with drug therapy: examples from research on statin and antihypertensive utilization
Clin Ther
(2006) - et al.
Comparison of measures of medication persistency using a prescription drug database
Am Heart J
(2007) - et al.
Association between copayment and adherence to statin treatment initiated after coronary heart disease hospitalization: a longitudinal, retrospective, cohort study
Clin Ther
(2007) - et al.
Evolution of statin prescribing 1994–2001: a case of agism but not of sexism?
Heart
(2003) - et al.
Trends in secondary prevention of ischaemic heart disease in the UK 1994–2005: use of individual and combination treatment
Heart
(2008) - et al.
Pattern of statin use among 10 cohorts of new users from 1995 to 2004: a register-based nationwide study
Am J Manag Care
(2010)
Trends in adherence to secondary prevention medications in elderly post-myocardial infarction patients
Pharmacoepidemiol Drug Saf
Randomised trial of cholesterol lowering in 4444 patients with coronary heart disease: the Scandinavian Simvastatin Survival Study (4S)
Lancet
Quantifying effect of statins on low density lipoprotein cholesterol, ischaemic heart disease, and stroke: systematic review and meta-analysis
Br Med J
Five-year follow-up of drug utilization for secondary prevention in coronary artery disease
Pharm World Sci
Medication adherence trends with statins
Adv Ther
Use of statins and beta-blockers after acute myocardial infarction according to income and education
J Epidemiol Commun Heal
Cited by (24)
Socioeconomic deprivation and prognostic outcomes in acute coronary syndrome: A meta-analysis using multidimensional socioeconomic status indices
2023, International Journal of CardiologySocioeconomic inequity in incidence, outcomes and care for acute coronary syndrome: A systematic review
2022, International Journal of CardiologyCitation Excerpt :Overall, a similar, even stronger, tendency was found when we stratified the medical care outcomes into reperfusion therapy or CAG, Cardiovascular pharmacotherapy, and CR (Appendix E fig. E.1). This tendency was opposite or unclear in the two studies focusing on composite medical care. [3,29,32,75,89–165] The 78 included studies on inequity in mortality included more than 13 million ACS patients (up to 6.6 million per study).
Effect of Socioeconomic Status on Propensity to Change Risk Behaviors Following Myocardial Infarction: Implications for Healthy Lifestyle Medicine
2017, Progress in Cardiovascular DiseasesSocioeconomic inequalities in access to treatment for coronary heart disease: A systematic review
2016, International Journal of CardiologyCitation Excerpt :Socioeconomic differences in access to secondary prevention for CHD were analyzed with respect to drug treatment (e.g., lipid-lowering drugs, beta-blockers, angiotensin-converting-enzyme inhibitors (ACEI), and antiplatelets) and CR (e.g., referral, participation, and regular attendance). About half of the studies (10 of 18) focusing on access to drug treatment found lower treatment rates for patients with low SES compared to patients with high SES [41–50], but two studies found inconsistencies in this relationship when considering all medications [48,49]. A comparable number of studies (8 of 18) found no association between SES and access to drug treatment [11,51–57].
Use of health care system-supplied aspirin by veterans with postoperative heart attack or unstable angina
2015, American Journal of the Medical SciencesCitation Excerpt :This finding was unexpected as one would hope that patients taking a more active role in preventive health habits (nonsmokers) would be more likely to use aspirin according to guidelines, also known as the healthy user effect.30 A study examining statin use in the United Kingdom after a MI found a history of smoking to be associated with poor adherence to statin therapy.24 It cannot be said with certainty the reason for these findings but one could speculate that patients with a history of smoking are either more interested in preventive care now, more likely to be identified as smokers due to the current/recent treatment for smoking cessation, or seen as higher-risk patients, resulting in more prevention counseling by their health care providers and, therefore, already taking aspirin.