Pharmacist-led Statin Outreach Support (SOS): cluster randomised controlled trial in primary care

Abstract

Summary Background Elevated blood lipids (particularly cholesterol and sub-fractions) contribute to the risk of developing cerebral, peripheral and cardiovascular disease and associated complications which are leading causes of morbidity and death. Statins reduce the risk of suffering vascular events, with or without decreasing cholesterol levels. Statin prescribing continues to increase but there is scope to improve prescribing and dosing, particularly in primary care. However, there is insufficient empirical evidence to inform approaches to quality improvement. Methods Following pilot work, we designed a new model of primary care based pharmacist-led intervention for General Practitioners (GPs) and nurses. The aim of the intervention (called Statin Outreach Support, SOS) was to improve statin prescribing by GPs, in line with recent evidence, targeting patients at highest risk of suffering a vascular event. Eleven trained pharmacists worked in SOS allocated practices one day per week for a year. During this period, the pharmacist met three times with all GPs, all nurses and other practice staff. Between meetings, pharmacists used patient level clinical and prescribing data to identify eligible patients and help practices initiate, up-titrate the dose or switch to simvastatin 40mg where indicated. The effectiveness of SOS was tested in a prospective single blind cluster randomised controlled trial. Usual care (UC) practices received no pharmacist support during the study. With a mean of 1.7 years follow up, the study had over 90% power (at 5% significance) to detect a difference of 12% in the proportion of patients with controlled cholesterol after practices had received the SOS intervention. Results Thirty one practices were recruited from the UK’s largest Health Board area. At randomisation, 16 practices were allocated to the SOS intervention and 15 to UC with 4,040 patients included at baseline. Recruited practices showed few differences compared with invited, non participating practices. Practices and patients randomised to each arm of the study had similar distributions with respect to age, complications, cholesterol levels and statin prescribing. The mean age was 68 years; 53% male, 45% ischaemic aetiology. Fifty nine percent had no statin prescribed at baseline; only 51% had cholesterol controlled. Follow up included 7586 patients in 29 practices (one practice had disbanded between recruitment and randomisation and another practice dropped out). Compared with UC, the SOS intervention achieved the primary endpoint of increasing the proportion of patients prescribed Simvastatin 40mg with controlled cholesterol (SOS 44.9% vs. UC 27.9%; odds ratio 1.79 (95% CI: 1.61, 1.98), p< 0.001). Secondary endpoints were also improved in the SOS arm practices. The intervention effect was strong and consistent across most subgroups including a positive impact on patients from practices in areas of greater socioeconomic deprivation. Conclusion A pragmatic, new, complex intervention was developed, tested and shown to be effective in a cluster randomised controlled trial with good internal and external validity. If implemented on a wider scale, in practices with comparable characteristics and baseline prescribing, the SOS intervention has the potential to reduce the burden of vascular events for patients with vascular disease. This work provides a convincing evidence base for the role of pharmacists collaborating with primary care practices, to improve statin prescribing and drug based cholesterol management, for patients at highest risk of suffering vascular events.