Use of statins in general practices, 1996-8: cross sectional study

Socioeconomic inequality in medication persistence in primary and secondary prevention of coronary heart disease - A population-wide electronic cohort study

Background

Coronary heart disease (CHD) mortality in England fell by 36% between 2000 and 2007 and it is estimated that approximately 50% of the fall was due to improved treatment uptake. Marked socio-economic inequalities in CHD mortality in the United Kingdom (UK) remain, with higher age-adjusted rates in more deprived groups. Inequalities in the persistence of medication for primary and secondary prevention of CHD may contribute to the observed social gradient and we investigated this possibility in the population of Wales (UK).

Methods and findings

An electronic cohort of individuals aged over 20 (n = 1,199,342) in Wales (UK) was formed using linked data from primary and secondary care and followed for six years (2004–2010). We identified indications for medication (statins, aspirin, ACE inhibitors, clopidogrel) recommended in UK National Institute for Clinical Excellence (NICE) guidance for CHD (high risk, stable angina, stable angina plus diabetes, unstable angina, and myocardial infarction) and measured the persistence of indicated medication (time from initiation to discontinuation) across quintiles of the Welsh Index of Multiple Deprivation, an area-based measure of socio-economic inequality, using Cox regression frailty models. In models adjusted for demographic factors, CHD risk and comorbidities across 15 comparisons for persistence of the medications, none favoured the least deprived quintile, two favoured the most deprived quintile and 13 showed no significant differences.

Conclusions

During our study period (2004–2010) we found no significant evidence of socio-economic inequality in the persistence of recommended medication for primary and secondary prevention of CHD.

Equity in healthcare for coronary heart disease, Wales (UK) 2004-2010: A population-based electronic cohort study

BACKGROUND

Despite substantial falls in coronary heart disease (CHD) mortality in the United Kingdom (UK), marked socioeconomic inequalities in CHD risk factors and CHD mortality persist. We investigated whether inequity in CHD healthcare in Wales (UK) could contribute to the observed social gradient in CHD mortality.

METHODS AND FINDINGS

Linking data from primary and secondary care we constructed an electronic cohort of individuals (n = 1199342) with six year follow-up, 2004-2010. We identified indications for recommended CHD interventions, measured time to their delivery, and estimated risk of receiving the interventions for each of five ordered deprivation groups using a time-to-event approach with Cox regression frailty models. Interventions in primary and secondary prevention included risk-factor measurement, smoking management, statins and antihypertensive therapy, and in established CHD included medication and revascularization. For primary prevention, five of the 11 models favoured the more deprived and one favoured the less deprived. For medication in secondary prevention and established CHD, one of the 15 models favoured the more deprived and one the less deprived. In relation to revascularization, six of the 12 models favoured the less deprived and none favoured the more deprived-this evidence of inequity exemplified by a hazard ratio for revascularization in stable angina of 0.79 (95% confidence interval 0.68, 0.92). The main study limitation is the possibility of under-ascertainment or misclassification of clinical indications and treatment from variability in coding.

CONCLUSIONS

Primary care components of CHD healthcare were equitably delivered. Evidence of inequity was found for revascularization procedures, although this inequity is likely to have only a modest effect on social gradients in CHD mortality. Policymakers should focus on reducing inequalities in CHD risk factors, particularly smoking, as these, rather than inequity in healthcare, are likely to be key drivers of inequalities in CHD mortality.

Initiation rates of statin therapy for the primary prevention of cardiovascular disease: an assessment of differences between countries of the UK and between regions within England

OBJECTIVES

To investigate the extent to which variation exists in the initiation rate of statin therapy for the primary prevention of cardiovascular disease between countries of the UK and between different regions within England.

DESIGN

Cohort study using data from a large UK primary care database.

SETTING UK PARTICIPANTS

4,820,885 individuals from 554 general practices during the period 2004-2012.

MAIN OUTCOME MEASURES

Rate of statin therapy initiation per 1000 person-years.

RESULTS

Relative to a fixed English rate of 1 initiation per 1000 person-years and accounting for gender, age and social deprivation level, the rate was similar for Scotland at 0.92 (95% CI 0.84 to 1.00) and rates for Northern Ireland and Wales were higher at 1.40 (95% CI 1.20 to 1.62) and 1.18 (95% CI 1.05 to 1.32), respectively. Within England, the regions could be classified into three groups with respect to statin therapy initiation rates (relative to a rate of 1 initiation per 1000 person-years for London): the South Central 0.73 (95% CI 0.64 to 0.83), South West 0.80 (95% CI 0.71 to 0.91), East of England 0.81 (95% CI 0.71 to 0.94) and South East Coast 0.83 (95% CI 0.73 to 0.95); strategic health authorities had similar low rates followed by the East Midlands 0.88 (95% CI 0.73 to 1.05), West Midlands 0.96 (95% CI 0.84 to 1.09), North East 0.96 (95% CI 0.79 to 1.16), Yorkshire and Humber 0.97 (95% CI 0.81 to 1.17) and London strategic health authorities. North West England exhibited the highest rate of statin therapy initiation of 1.16 (95% CI 1.02 to 1.31).

CONCLUSIONS

Considerable variation in the rate of statin therapy initiation was observed between the four countries of the UK and between different geographical regions within England.

Differential associations between actual and expected GP practice prescribing rates for statins, ACE inhibitors, and beta-blockers: a cross-sectional study in England

Aim

To explore the relationship between actual and expected general medical practitioner (GP) practice prescribing rates for statins, angiotensin converting enzyme (ACE) inhibitors, and beta-blockers.

Background

There is a growing body of literature highlighting inequities in GP practice prescribing rates for many drug therapies. The equity of prescribing is of central importance in the area of therapeutics since it explores the interface between those patients who should and those who actually do receive a drug therapy.

Setting

Four primary care trusts (PCTs 1–4) in the North West of England, including 132 GP practices.

Methods

Actual and expected prescribing rates for statins, beta-blockers, and ACE inhibitors were specifically developed for each GP practice.

Results

There were no statistically significant correlations between actual and expected prescribing rates in PCT2 and PCT3, although in PCT1 there were statistically significant correlations for statins (0.286, p < 0.05) and ACE inhibitors (0.381, p < 0.01). In PCT4, correlations were moderate to high for beta-blockers (0.693, p < 0.01), and moderate for statins (0.541, p < 0.05) and ACE inhibitors (0.585, p < 0.01). Scatterplots highlighted large variations between individual GP practices (both within and between PCTs) in terms of the relationship between actual and expected prescribing rates.

Conclusion

This paper highlights variability between PCTs and GP practices in terms of the relationship between actual and expected prescribing rates. The findings from this paper may further advance the suggestion of inequities in prescribing rates for coronary heart disease (CHD) drugs, and studies such as this may be repeated in different therapeutic areas, healthcare settings, and countries.

Statin-associated weakness in myasthenia gravis: a case report

Introduction

Myasthenia gravis is a commonly undiagnosed condition in the elderly. Statin medications can cause weakness and are linked to the development and deterioration of several autoimmune conditions, including myasthenia gravis.

Case presentation

We report the case of a 60-year-old Caucasian man who presented with acute onset of dysarthria and dysphagia initially attributed to a brain stem stroke. Oculobulbar and limb weakness progressed until myasthenia gravis was diagnosed and treated, and until statin therapy was finally withdrawn.

Conclusion

Myasthenia gravis may be underappreciated as a cause of acute bulbar weakness among the elderly. Statin therapy appeared to have contributed to the weakness in our patient who was diagnosed with myasthenia gravis.

How equitable are GP practice prescribing rates for statins?: an ecological study in four primary care trusts in North West England

Background

There is a growing body of literature highlighting inequities in GP practice prescribing rates for a number of drug therapies. The small amount of research on statin prescribing has either focussed on variations rather than equity per se, been based on populations other than GP practices or has used cost-based prescribing rates.

Aim

To explore the equity of GP practice prescribing rates for statins, using the theoretical framework of equity of treatment (also known as horizontal equity or comparative need).

Methods

The study involved a cross-sectional secondary analysis in four primary care trusts (PCTs 1–4) in the North West of England, including 132 GP practices. Prescribing rates and health care needs indicators (HCNIs) were developed for all GP practices.

Results

Scatter-plots revealed large differences between individual GP practices, both within and between PCTs, in terms of the relationship between statin prescribing and healthcare need. In addition, there were large differences between GP practices in terms of the relationship between actual and expected prescribing rates for statins. Multiple regression analyses explained almost 30% of the variation in prescribing rates in the combined dataset, 25% in PCT1, 31% in PCT3, 51% in PC4 and 58% in PCT2. There were positive associations with variables relating to CHD hospital diagnoses and procedures and negative associations with variables relating to ethnicity, material deprivation, the proportion of patients aged over 75 years and single-handed GP practices.

Conclusion

Overall, this study found inequitable relationships between actual and expected prescribing rates, and possible inequities in statin prescribing rates on the basis of ethnicity, deprivation, single-handed practices and the proportion of patients aged over 75 years.

Disparities in stroke preventive care in general practice did not explain socioeconomic disparities in stroke

OBJECTIVE

To assess socioeconomic disparities in stroke incidence and in the quality of preventive care for stroke in the Netherlands.

STUDY DESIGN AND SETTINGS

A total of 190,664 patients who registered in 96 general practices were followed up for 12 months. Data were collected on diagnoses, referrals, prescriptions, and diagnostic procedures. Hazard ratios (HR) were calculated to assess the association between educational level and stroke incidence. Multilevel logistic regression was used to assess socioeconomic disparities in the quality of preventive care for stroke precursors.

RESULTS

Lower educational level was associated with higher incidence of stroke in men (HR=1.36, 95% CI=1.06-1.74) but not in women. Among both men and women, there were socioeconomic disparities in the prevalence of hypertension, hypercholesterolemia, diabetes, angina pectoris, heart failure, and peripheral artery disease. Lower educated hypercholesterolemia patients under medication were less likely to be prescribed statins (odds ratio=0.62, 95% CI=0.42-0.91). However, for other precursors of stroke, there were no major disparities in the quality of preventive care.

CONCLUSION

There are socioeconomic disparities in stroke incidence among men but not among women. Socioeconomic differences in factors such as hypertension and diabetes are likely to contribute to stroke disparities. However, general practitioners (GPs) provide care of a similar quality to patients from different socioeconomic groups.

Non-attendance at secondary prevention clinics: the effect on lipid management

BACKGROUND

Secondary prevention of coronary artery disease is effective in reducing morbitiy and mortality. Our aim was to assess lipid management following non-attendance to a hospital based secondary prevention clinic.

METHODS

Data were collected over 5 years on statin usage and total cholesterol levels for patients with coronary artery disease following attendance at a cardiac nurse led outpatient clinic. Lipid levels were taken from a central laboratory database, for both patients discharged from clinic and non-attenders.

RESULTS

From 935 inpatients discharged from hospital, 248 (29%) defaulted from outpatient follow up. Lipid lowering drug usage was similar (72% vs. 74% for non-attenders, p=NS). Attenders at the nurse led outpatient clinic were more likely to achieve a total cholesterol <5 mmol/L at discharge than non-attenders (70% vs. 43%; p < 0.001), with a lower mean total cholesterol (4.75 +/- 0.06 mmol/L vs. 5.33 +/- 0.08 mmol/L; p < 0.001). Non-attenders subsequently had a greater number of cholesterol measurements than those who were discharged from the hospital based clinic (range 0-12, c2 23.8 on 12 df p < 0.005). Lipid profiles in hospital non-attenders remained inferior with fewer achieving a total cholesterol <5 mmol/L (61% vs. 78%; p < 0.001), and having greater mean total cholesterol levels (4.85 +/- 0.06 mmol/L vs. 4.52 +/- 0.05 mmol/L; p < 0.001).

CONCLUSIONS

Patients defaulting from hospital follow up have higher total cholesterols with fewer at target level compared to attenders. Though non-attenders receive subsequent lipid measurement, inferior lipid profiles persist compared to patients who completed hospital follow up to be discharged. Further implementation strategies are needed with regard to lipid management in this patient group.

Factors influencing clinicians' decisions to prescribe medication to prevent coronary heart disease

BACKGROUND AND OBJECTIVE

There are variations between individual clinicians as to the thresholds at which preventive treatment for coronary heart disease (CHD) should commence. Patients' decisions may be influenced by clinicians' recommendations. Free text comments added by respondents to closed questionnaires may identify areas which are of real concern to them about the topic being studied. The study aimed to identify issues voluntarily raised by clinicians surrounding the decision to prescribe preventive treatment for CHD.

METHODS

An analysis was undertaken of the free text comments made by cardiologists, general practitioners and practice nurses who responded to a closed question postal questionnaire in which they were asked to identify at which level of pretreatment risk they would offer treatment.

RESULTS AND DISCUSSION

A similar percentage of respondents in each professional group provided free text comments. Clinicians' concerns centred on five main themes around prescribing decisions: the risks and benefits of treatment, the patient's role in treatment decisions, patient characteristics, costs to patients, and costs to the health services. Different issues may be of more concern to some professional groups than others.

CONCLUSION

In addition to the use of risk assessment tools and guidelines, clinicians' actual prescribing behaviour may be influenced by more subjective factors. Patients at similar risk may receive different advice depending on the individual clinician they consult.

Evidence for inequalities in the management of coronary heart disease in Scotland

OBJECTIVES

To investigate whether sex, age, and deprivation inequalities existed in the prescription of secondary preventive treatment for coronary heart disease (CHD) in Scottish general practice and whether these differences altered over time.

DESIGN

6 year cross sectional study based on general practice morbidity and prescribing data.

SETTING

55 primary care practices in Scotland.

SUBJECTS

14,435 patients with diagnosed CHD.

MAIN OUTCOME MEASURE

Prescription of various groups of secondary preventive treatment in six study years.

RESULTS

The use of all secondary prevention treatments increased over time (63.6% of patients with CHD in 1997 to 87.6% in 2002). After adjustments for age, sex, deprivation, co-morbidities, and practice where appropriate, women received fewer secondary prevention treatments than men, a difference that increased over time (March 1997: adjusted odds ratio (OR) 0.9, 95% confidence interval (CI) 0.8 to 1.0; March 2002: OR 0.6, 95% CI 0.6 to 0.7). Sex differences were observed within each group of treatments studied. The oldest group of patients was less likely than the youngest group to receive any secondary preventive treatment in the year up to March 1997 (OR 0.6, 95% CI 0.5 to 0.7) but were more likely by 2002 (OR 1.3, 95% CI 1.1 to 1.5) to receive secondary prevention. The most affluent patients with CHD were significantly less likely to receive a statin between March 1998 and 2001 (March 1998 OR 0.6, 95% CI 0.5 to 0.9), a finding that disappeared by 2002 (OR 0.9, 95% CI 0.7 to 1.1).

CONCLUSION

The results suggest that inequalities exist in the secondary prevention of CHD in Scotland.

Exploring the equity of GP practice prescribing rates for selected coronary heart disease drugs: a multiple regression analysis with proxies of healthcare need

BACKGROUND: There is a small, but growing body of literature highlighting inequities in GP practice prescribing rates for many drug therapies. The aim of this paper is to further explore the equity of prescribing for five major CHD drug groups and to explain the amount of variation in GP practice prescribing rates that can be explained by a range of healthcare needs indicators (HCNIs). METHODS: The study involved a cross-sectional secondary analysis in four primary care trusts (PCTs 1-4) in the North West of England, including 132 GP practices. Prescribing rates (average daily quantities per registered patient aged over 35 years) and HCNIs were developed for all GP practices. Analysis was undertaken using multiple linear regression. RESULTS: Between 22-25% of the variation in prescribing rates for statins, beta-blockers and bendrofluazide was explained in the multiple regression models. Slightly more variation was explained for ACE inhibitors (31.6%) and considerably more for aspirin (51.2%). Prescribing rates were positively associated with CHD hospital diagnoses and procedures for all drug groups other than ACE inhibitors. The proportion of patients aged 55-74 years was positively related to all prescribing rates other than aspirin, where they were positively related to the proportion of patients aged >75 years. However, prescribing rates for statins and ACE inhibitors were negatively associated with the proportion of patients aged >75 years in addition to the proportion of patients from minority ethnic groups. Prescribing rates for aspirin, bendrofluazide and all CHD drugs combined were negatively associated with deprivation. CONCLUSION: Although around 25-50% of the variation in prescribing rates was explained by HCNIs, this varied markedly between PCTs and drug groups. Prescribing rates were generally characterised by both positive and negative associations with HCNIs, suggesting possible inequities in prescribing rates on the basis of ethnicity, deprivation and the proportion of patients aged over 75 years (for statins and ACE inhibitors, but not for aspirin).

Are GP practice prescribing rates for coronary heart disease drugs equitable? A cross sectional analysis in four primary care trusts in England

STUDY OBJECTIVE

To analyse the associations between proxies of healthcare need and GP practice prescribing rates for five major coronary heart disease (CHD) drug groups.

DESIGN

Cross sectional secondary analysis.

SETTING

Four primary care trusts (PCTs 1-4) in the north west of England, encompassing 132 GP practices.

RESULTS

Prescribing rates were generally positively associated with the percentage of patients aged 55-74 years and PASS-PUs (regionally specific prevalence, age, and sex standardised prescribing units). However, the percentage of patients aged over 75 years showed a lack of association with prescribing rates in all PCTs other than PCT2. Correlations with the proportion of South Asian patients were generally negative, particularly in PCT2, PCT4, and the combined dataset. There was a general lack of association with deprivation proxies and SMRs for CHD, although there were negative associations with both variables in PCT4 and the combined dataset. Scatter plots showed that GP practices with similar prescribing rates had widely differing levels of comparative healthcare need, and GP practices with similar levels of healthcare need had widely differing prescribing rates.

CONCLUSION

GP prescribing rates in some PCTs were negatively associated with proxies of healthcare need based on patient age (patients aged over 75 years), ethnicity, levels of deprivation, and SMRs for CHD. As such, this study suggests that prescribing rates in these PCTs may be inequitable as they are not positively associated with healthcare need. This study may form the baseline for further studies to assess the effectiveness of the NSF for CHD in reducing the inequities in prescribing rates.

Systematic review of published multi-practice audits from British general practice

BACKGROUND

Audit has been a major part of attempts to improve patient care in Britain, with substantial resources devoted to it since the 1990 National Health Service reforms. Systematic reviews have considered audit to be of variable, but often moderate, effectiveness. However, these have included few studies from British primary care, and as quality improvement activities may be context specific, it is hard to judge how effective audit has been here.

RESULTS

A search for audits published in peer-reviewed journals revealed 48 two-stage projects carried out in British general practice, of which 27 principally concerned chronic disease management and nine prescribing. Most audits showed some improvements in performance, and those using controls showed 27/56 (48%) parameters had changed significantly (P < 0.05).

CONCLUSIONS

This review adds further evidence that audit can often be moderately effective. However, it is frequently used as one of a complex set of interventions making precise evaluation difficult. Those responsible for clinical governance will need to choose carefully the subjects they audit in order to use their limited resources to maximum effect. These projects are illustrative examples but once again do not identify any 'magic bullets' that would be highly likely to improve professional performance.

Cost effectiveness of HMG-CoA reductase inhibitors in the management of coronary artery disease: the problem of under-treatment

HMG-CoA reductase inhibitors significantly reduce the risk of coronary artery disease (CAD) events and CAD-related mortality in patients with and without established CAD. Consequently, HMG-CoA reductase inhibitors have a central role within recommendations for lipid-modifying therapy. However, despite these guidelines, only one-third to one-half of eligible patients receive lipid-lowering therapy and as few as one-third of these patients achieve recommended target serum levels of low density lipoprotein-cholesterol. The underuse of HMG-CoA reductase inhibitors in eligible patients has important implications for mortality, morbidity and cost, given the enormous economic burden associated with CAD; direct healthcare costs, estimated at US $16-53 billion (2000 values) in the US and 1.6 billion pound (1996 values) in the UK alone, are largely driven by inpatient care. Hospitalization costs are reduced by treatment with HMG-CoA reductase inhibitors, particularly in high-risk groups such as patients with CAD and diabetes mellitus in whom net cost savings may be achieved. HMG-CoA reductase inhibitors are underused because of institutional factors and clinician and patient factors. Also, the vast number of patients eligible for treatment means that the use of HMG-CoA reductase inhibitors is undoubtedly limited by budgetary considerations. Secondary prevention in CAD using HMG-CoA reductase inhibitors is certainly cost effective. Primary prevention with HMG-CoA reductase inhibitors is also cost effective in many patients, depending upon CAD risk and drug dosage. As new, more powerful, HMG-CoA reductase inhibitors come to market, and the established HMG-CoA reductase inhibitors come off patent, the identification of the most cost-effective therapy becomes increasingly complex. Research in to the relative cost effectiveness of alternative HMG-CoA reductase inhibitors, taking full account of the institutional, clinician and patient barriers to uptake should be undertaken to identify the most appropriate role for the new therapies.

Evolution of statin prescribing 1994-2001: a case of agism but not of sexism?

OBJECTIVE

To study trends in the use of lipid lowering drugs in the UK, and to assess which patient factors influence prescribing.

METHODS

Routinely collected computerised medical data were analysed from 142 general practices across England and Wales that provide data for the Doctors' Independent Network database. Subjects included were people aged 35 years or more with treated ischaemic heart disease, averaging annually over 30,000. The temporal trend from 1994 to 2001 in prescription of lipid lowering drugs and daily statin dose and the odds ratios (ORs) for receiving a statin prescription in 1998 were examined.

RESULTS

Lipid lowering drug prescribing increased greatly over time, entirely because of statins, so that in 2001 56.3% of men and 41.1% of women with ischaemic heart disease received lipid lowering drugs. However, 33% of these patients were on a < 20 mg simvastatin daily equivalent. In 1998 the OR for receiving a statin fell from 1 at age 55-64 to 0.64 at 65-74 and 0.16 at 75-84 years. The age effect was similar in those without major comorbidity. Revascularised patients were much more likely to receive a statin than those with angina (OR 3.92, 95% confidence interval (CI) 3.57 to 4.31). Men were more likely to receive a statin than women (OR 1.62, 95% CI 1.54 to 1.71) but this difference disappeared after adjustment for age and severity of disease (OR 1.06). Geographical region had little effect but there was a very weak socioeconomic gradient.

CONCLUSIONS

Although prescribing has increased, many patients who may benefit from lipid lowering drugs either do not receive it or are undertreated, possibly because of lack of awareness of the relative potency of the different statins. Patients with angina and the elderly are less likely to receive treatment that may prevent a coronary event.

Who receives lipid-lowering drugs: the effects of comorbidities and patient characteristics on treatment initiation

AIMS

Little is known about the effects of comorbidities and patient characteristics on treatment initiation of lipid-lowering drugs (LLDs), which can be helpful in the evaluation of the risks and benefits of LLDs.

METHODS

Baseline characteristics among subjects who received their first ever-recorded LLD prescription in general practice between 1 January 1990 and 31 December 1997, and hyperlipidaemic patients without LLD therapy during the same period were obtained from the UK General Practice Research Database. Differences between patients who received and patients who did not receive LLDs, as well as patients who received different classes of LLDs were compared by fitting multivariate logistic regression models that adjusted for age, sex, body mass index, smoking status, and year of treatment initiation or hyperlipidaemia diagnosis.

RESULTS

We found that there were many differences in the baseline characteristics, such as number of general practitioner visits, diagnosis and severity of cardiovascular diseases, and concurrent medications, between the 25 331 patients who received and the 16 287 patients who did not receive LLDs. We also noted that patients with statin therapy had more prior hospitalization, more recent myocardial infarction/stroke, and more concurrent cardiovascular medications, than those patients who received other LLDs.

CONCLUSIONS

Patients who received LLDs in primary care, especially patients with statin therapy, were more likely to be elderly and to have more concomitant severe cardiovascular comorbidities than those hyperlipidaemic patients who did not receive LLDs. Examining the medical records of individuals eligible for LLD therapy is an important first step in selectively targeting who will experience the greatest benefit to risk ratio for the treatment of hyperlipidaemia, and is an important step in avoiding confounding by indication when designing epidemiological studies comparing the risks and benefits of treatments for hyperlipidaemia.

Developing prevalence-based prescribing units for analysing variations in general practitioner prescribing: a case study using statins

OBJECTIVE

To develop regionally specific prevalence-, age- and sex-standardized prescribing units (PASS-PUs) and to relate these to statin prescribing.

DESIGN

Cross-sectional.

SETTING

Ninety-four general practitioner (GP) practices within one health authority in the north-west of England.

MAIN OUTCOME MEASURES

Comparisons between specific therapeutic group age-sex-related prescribing units (STAR-PUs) and PASS-PUs for statin prescribing.

RESULTS

STAR-PUs and PASS-PUs were calculated for all GP practices and there was a high degree of correlation (Spearman's rank coefficient 0.88; P < 0.001). Using actual prescribing data for statins for a 12-month period, a statistically significant correlation was found between net ingredient cost per patient and STAR-PUs per patient (Spearman's rank coefficient 0.36; P < 0.01). However, the correlation between average daily quantities per patient and PASS-PUs per patient was not statistically significant. A scatter plot revealed a pattern whereby GP practices with high proportions of patients aged over 75 years exhibited low statin prescribing in relation to the expected prevalence of treated coronary heart disease (CHD) in their patient population.

CONCLUSIONS

Low weightings for patients aged over 75 years in calculating STAR-PUs lead to a much lower number of prescribing units within GP practice populations when compared with PASS-PUs. Current statin prescribing across GP practices in this study correlates with national prescribing cost patterns (as measured by STAR-PUs) although not with expected prevalence of treated CHD (as measured by PASS-PUs). PASS-PUs reflect prevalence of treated CHD and may therefore be used to monitor and predict GP prescribing arising from the implementation of the National Service Framework targets for CHD. In addition, PASS-PUs maybe derived for a wide range of therapeutic areas.

Adherence to statin treatment and readmission of patients after myocardial infarction: a six year follow up study

OBJECTIVE

To investigate patients' adherence to statin treatment prescribed following their first myocardial infarction (MI) and to estimate the effect of adherence to statins on recurrence of MI and all cause mortality.

DESIGN

Cohort study using a record linkage database.

SETTING

Tayside, Scotland, UK.

PATIENTS

Patients who experienced their first MI between January 1990 and November 1995.

MAIN OUTCOME MEASURES

Percentage of statin use and adherence to statins by patients after an MI and the relative risk of hospitalisation for recurrent MI. The effect of adherence on all cause mortality was also examined. The covariates used were age, sex, socioeconomic deprivation, serum cholesterol concentration, diabetes mellitus, cardiovascular drug use, and other hospitalisations.

RESULTS

Of 5590 patients who experienced an incident MI, 717 (12.8%) experienced at least one further MI. Only 7.7% of patients used statins after an MI during the study period. Compared with those not taking statins, those who had 80% or better adherence to statin treatment had an adjusted relative risk of recurrent MI of 0.19 (95% confidence interval (CI) 0.08 to 0.47) and all cause mortality of 0.47 (95% CI 0.22 to 0.99). There was no significant reduction in either end point for those who were less than 80% adherent to statins.

CONCLUSIONS

Despite the infrequent use of statin during the study period, good adherence to statin treatment was associated with lower risk of recurrent MI.

Low prevalence of lipid lowering drug use in older men with established coronary heart disease

OBJECTIVE

To determine the prevalence and correlates of lipid lowering drug use among older British men with established coronary heart disease (CHD).

DESIGN

Cross sectional survey within a cohort study (British regional heart study) carried out at 20 years of follow up in 1998-2000.

SETTING

General practices in 24 British towns.

PARTICIPANTS

3689 men aged 60-75 years (response rate 76%).

MAIN OUTCOME MEASURES

Diagnoses of myocardial infarction and angina based on detailed review of general practice records. Lipid lowering drug use and blood cholesterol concentrations ascertained at 20 year follow up examination.

RESULTS

Among 286 men with definite myocardial infarction, 102 (36%) were taking a lipid lowering drug (93 (33%) a statin); among 360 men with definite angina without myocardial infarction, 84 (23%) were taking a lipid lowering drug (78 (21%) a statin). Most men with documented CHD who were not receiving a lipid lowering drug had a total cholesterol concentration of 5.0 mmol/l or more (87% of those with myocardial infarction, 82% with angina). Fewer than half of men with CHD receiving a statin had a total cholesterol concentration below 5.0 mmol/l (45% of those with myocardial infarction and 47% of those with angina). Only one third of the men taking a statin were receiving trial validated dosages. Among men with CHD, a history of revascularisation, more recent diagnosis, and younger age at diagnosis were associated with a higher probability of receiving lipid lowering drug treatment.

CONCLUSION

Among patients with established CHD, the prevalence of lipid lowering drug use remains low and statin regimens suboptimal. Major improvements in secondary prevention are essential if the benefits of statins are to be realised.

Use of statins in the secondary prevention of coronary heart disease: is treatment equitable?

OBJECTIVE

To investigate possible inequities in the use of statins for people with coronary heart disease according to a wide range of social and clinical factors.

DESIGN AND SETTING

Cross sectional analysis of data from the Health Survey for England 1998, a population based survey.

SUBJECTS

760 adults with coronary heart disease.

RESULTS

Only 19.9% of subjects with coronary heart disease were receiving lipid lowering drugs (151 of 760; 95% confidence interval (CI) 17.0% to 22.7%). The likelihood of receiving statins was greatly reduced for older age groups: compared with those aged less than 65 years, the odds of receiving statin treatment were 0.53 (95% CI 0.35 to 0.80) for subjects aged 65-74 years, and 0.11 (95% CI 0.06 to 0.21) for subjects aged 75 years and over. Statins were given less often to current cigarette smokers than to non-smokers (odds ratio 0.55, 95% CI 0.32 to 0.96), and to subjects with angina compared with those with a previous myocardial infarct (odds ratio 0.63, 95% CI 0.43 to 0.93). Lower levels of statin use were also seen with increasing time since diagnosis (p = 0.12). No clear associations were observed with social measures.

CONCLUSIONS

Important inequalities were found in the use of statins among people with coronary heart disease, which could not be justified by evidence from the large statin trials. Proactive policies are required to ensure that the vast majority of (if not all) patients with coronary heart disease are receiving statins, regardless of age, sex, social class, smoking status, type of coronary heart disease, or time since diagnosis.

Time trends in lipid lowering drug use in The Netherlands. Has the backlog of candidates for treatment been eliminated?

AIMS

To assess time trends in lipid lowering drug use in The Netherlands.

METHODS

Data were obtained from the PHARMO-database, comprising pharmacy records of approximately 300 000 people in The Netherlands. In the period from 1991-98, we estimated prevalence of lipid lowering drug use on the first Wednesday of October. A patient was defined as incident user if (s)he filled a prescription for lipid lowering medication after a 360 days lipid lowering drug free interval. Both prevalence and incidence estimates were weighted for the sex and age distribution of the general Dutch population.

RESULTS

From 1991 to 1998, the prevalence of lipid lowering drug use increased from 0.5% (95% confidence interval (CI): 0.5, 0.6) to 2.3% (95% CI: 2.2, 2.4) in women and from 0.6% (95% CI: 0.6, 0.6) to 2.9% (95% CI: 2.8, 3.0) in men. Prevalence increased with increasing age and was highest in the age category 60-69 years (in 1998: 9.9% (95% CI: 9.4, 10.4) in women and 11.6% (95% CI: 11.0, 12.1) in men). In 1992, the estimated incidence of lipid lowering drug use was 251(95% CI: 226, 277)/100,000 person years in women and 251(95% CI: 225, 276)/100,000 person years in men. The largest incidence estimates were observed in 1996 (685(95% CI: 644, 726)/100,000 person years in women and 881(95% CI: 834, 928)/100,000 person years in men). After 1996, incidence stabilized in 1997 and decreased in 1998 to 599(561, 637)/100,000 person years in women and 731(688, 773)/100,000 person years in men. Most of the patients (approximately 95%) were treated with one lipid lowering agent. Statins were used by over 90% of patients from 1996 onwards. In 1998, 35% of the patients started with a statin that was not a first choice drug (mainly atorvastatin).

CONCLUSIONS

In the period from 1991-98, prevalence of lipid lowering drug use significantly increased in The Netherlands. However, incidence stabilized and decreased after 1996 which may be explained by the fact that the number of patients eligible for treatment was reached. The question remains whether lipid lowering medication was targeted to the appropriate patients.

Utilization of lipid-lowering drugs in men and women. a reflection of the research evidence?

This study analyzes the utilization of statin lipid-lowering drugs in a Canadian province using a population-wide drug prescription database. The utilization pattern is compared to the results of a systematic review of randomized controlled trials on their effectiveness. The study found that 74.7% of individuals prescribed a statin had no reported history of coronary heart disease (CHD). Women without CHD formed 23.1% of statins recipients; 32.9% of individuals filling a statin prescription were age 70 and over. Only 15.3% of men with CHD had been prescribed a statin. Based on the systematic review, 88.7% of the utilization of statins in this Canadian province was not supported by the results of the systematic review. Considering baseline lipid-levels does not substantially alter these findings. This study concludes that statins prescribing practices need to be realigned with research evidence. This implies refocusing utilization away from women and the elderly, towards men with CHD.

Comparison of different methods to estimate prevalence of drug use by using pharmacy records

Several methods to estimate prevalence of drug use are available, which may complicate a valid comparison of these estimates. Standardization may contribute to more valid comparisons. We compared different methods to estimate prevalence of drug use by using pharmacy records. Data were obtained from the Dutch population-based PHARMO-database comprising medication histories of 300,000 subjects. Five point prevalences and a 1-year prevalence of cholesterol-lowering drug use were estimated in 1995. Four point prevalences differed in data handling before estimating prevalence (e.g., correction for irregular drug use or construction of episodes of drug use). The numerator of the fifth point prevalence estimate represented the number of defined daily doses (DDDs) instead of the number of patients filling a prescription. The first four point prevalences ranged from 11.0-12.1 per thousand. Prevalence ratio (male:female) was 1.2 for these methods. The fifth method resulted in an estimate similar to the other point prevalences (11.9 DDDs/1000 inhabitants). However, the prevalence ratio was 1.4 due to larger average number of DDDs prescribed to men. One year-prevalence was 4-5 per thousand higher than point prevalences. The comparison of these methods indicated that the choice of prevalence measure (point versus period prevalence) substantially influenced the prevalence estimate, whereas the influence of data handling was negligible. For standardization purposes in drug utilization research, we recommend estimating point prevalence instead of period prevalence. The various methods of data handling before estimating point prevalence yielded similar results and therefore we cannot recommend one specific method. However, defined daily doses should not be used to estimate (point) prevalences of drug use because this measure is significantly influenced by prescribed dosage regimens.

Use of lipid-lowering drugs during 1991-98 in Northern Jutland, Denmark

AIMS

To examine a) the use of lipid-lowering drugs in North Jutland County in Denmark from 1991 to 1998 and b) the pattern of usage according to sex and age.

METHODS AND RESULTS

We used the Pharmaco-Epidemiological Prescription Database in the county to identify all reimbursed prescriptions for lipid-lowering therapy from 1991 to 1998. One-year incidence rates (IR) and prevalence (P) of the use of lipid-lowering drugs were calculated. Both IR and P of patients in lipid-lowering therapy were stable until 1994, with the IR below 100 per 100 000 for both sexes. The IR then increased from 59.9 to 236.5 per 100 000 person-years in 1998 for women, and from 88.6 to 322.8 per 100 000 person-years for men. The utilization patterns were identical between the sexes. Thus, in both women and men the highest prevalence and incidence rates of lipid-lowering drug therapy were seen in the 60-69-year-olds. Furthermore, the marked increase in both prevalence and incidence of persons on lipid-lowering drug therapy between 1994 and 1998 was the result of an increased number of prescriptions in the 50-59, 60-69 and 70 + years olds, in both women and men. There was a remarkable 4-5 fold increase in the numbers of new patients who received statins during the same period.

CONCLUSIONS

The overall use of lipid-lowering drugs has increased markedly over the last few years in Northern Jutland, Denmark. The increase began following publication of the first major trial documenting the benefit of therapy with statins.