Patient Factors Influencing the Prescribing of Lipid Lowering Drugs for Primary Prevention of Cardiovascular Disease in UK General Practice: A National Retrospective Cohort Study

Abstract

BackgroundGuidelines indicate eligibility for lipid lowering drugs, but it is not known to what extent GPs' follow guidelines in routine clinical practice or whether additional clinical factors systematically influence their prescribing decisions.MethodsA retrospective cohort analysis was undertaken using electronic primary care records from 421 UK general practices. At baseline (May 2008) patients were aged 30 to 74 years, free from cardiovascular disease and not taking lipid lowering drugs. The outcome was prescription of a lipid lowering drug within the next two years. The proportions of eligible and ineligible patients prescribed lipid lowering drugs were reported and multivariable logistic regression models were used to investigate associations between age, sex, cardiovascular risk factors and prescribing.ResultsOf 365,718 patients with complete data, 13.8% (50,558) were prescribed lipid lowering drugs: 28.5% (21,101/74,137) of those eligible and 10.1% (29,457/291,581) of those ineligible. Only 41.7% (21,101/50,558) of those prescribed lipid lowering drugs were eligible. In multivariable analysis prescribing was most strongly associated with increasing age (OR for age ≥65 years 4.21; 95% CI 4.05–4.39); diabetes (OR 4.49; 95% CI 4.35–4.64); total cholesterol level ≥7 mmol/L (OR 2.20; 95% CI 2.12–2.29); and ≥4 blood pressure measurements in the past year (OR 4.24; 95% CI 4.06–4.42). The predictors were similar in eligible and ineligible patients.ConclusionsMost lipid lowering drugs for primary prevention are prescribed to ineligible patients. There is underuse of lipid lowering drugs in eligible patients.

Statin prescribing for primary prevention of cardiovascular disease: a cross-sectional, observational study

“…Family history assumed missing values were negative. However, like the Wu et al 4 and van Staa et al 5 studies, the current study has limited data on CVD risk for those not on statins and 40% of the eligible population aged ≥30 years did not have CVD risk estimated. This means that it was not possible to provide a detailed analysis of those eligible patients who do not use statins because of the uncertainty of their risk profile and eligibility.…”

“…Current tools for CVD estimation are relatively crude at an individual level 10,11 and may underestimate risk associated with extreme obesity, prediabetic states, chronic kidney disease, or other aspects such as heavy alcohol consumption or very sedentary lifestyles, which were not included in these studies. 12 For primary prevention in individuals at highest risk of CVD (≥20%), 32 out of 33 will not gain from statin treatment 4,5 As in previous studies, statin prescription to patients at <20% risk in the current study was mainly directed towards those who were:…”

“…' … most statins are prescribed to patients who are not eligible for treatment … Overall we find more evidence to support the view that prescribing of statins is influenced more by single risk factors treated as categories (age ≥65 years; diabetes; total cholesterol ≥7 mmol/l) …' 4 Since the national NHS Health Check started in 2009, statins have been promoted in the east London Clinical Commissioning Groups (CCGs) of Newham, City and Hackney, and Tower Hamlets with a systematic programme incentivising uptake and statin prescription in patients with a CVD risk of ≥20%. 6 Of those aged 40-74 years who are eligible in any 1 year, 67% are currently attending an NHS Health Check.…”

“…2,3 Two studies examined statin treatment for primary prevention in the UK up until 2010-2011. 4,5 They concluded that statin prescribing for primary prevention was poorly targeted according to the guidance at the time. van Staa et al used a 2011 nationally representative sample of general practices with 300 914 patients prescribed statins, excluding those with diabetes and CVD.…”

“…5 Wu et al used a separate national general practice database for the earlier years 2008-2010. 4 The cohort of 365 718 patients excluded those with CVD and included those with diabetes. In total, 28.5% of those with diabetes or a 10-year CVD risk of ≥20%, and 10.1% of patients below this threshold, were prescribed lipid-lowering medication.…”