Assessing long-term effectiveness and cost-effectiveness of statin therapy in the UK: a modelling study using individual participant data sets.

Abstract

Background: Cardiovascular disease has declined but remains a major disease burden across developed countries.

Objective: To assess the effectiveness and cost-effectiveness of statin therapy across United Kingdom population categories.

Design: The cardiovascular disease microsimulation model, developed using Cholesterol Treatment Trialists' Collaboration data and the United Kingdom Biobank cohort, projected cardiovascular events, mortality, quality of life and healthcare costs using participant characteristics.

Setting: United Kingdom primary health care.

Participants: A total of 117,896 participants in 16 statin trials in the Cholesterol Treatment Trialists' Collaboration; 501,854 United Kingdom Biobank participants by previous cardiovascular disease status, sex, age (40-49, 50-59 and 60-70 years), 10-year cardiovascular disease risk [QRISK^®3 (%): < 5, 5-10, 10-15, 15-20 and ≥ 20] and low-density lipoprotein cholesterol level (< 3.4, 3.4-4.1 and ≥ 4.1 mmol/l); 20,122 United Kingdom Biobank and Whitehall II participants aged ≥ 70 years by previous cardiovascular disease status, sex and low-density lipoprotein cholesterol (< 3.4, 3.4-4.1 and ≥ 4.1 mmol/l).

Interventions: Lifetime standard (35-45% low-density lipoprotein cholesterol reduction) or higher-intensity (≥ 45% reduction) statin.

Main outcome measures: Quality-adjusted life-years and incremental cost per quality-adjusted life-year gained from the United Kingdom healthcare perspective.

Data sources: Cholesterol Treatment Trialists' Collaboration and United Kingdom Biobank data informed risk equations. United Kingdom primary and hospital care data informed healthcare costs (2020-1 Great British pounds); £1.10 standard or £1.68 higher-intensity generic statin therapy per 28 tablets; and Health Survey for England data informed health-related quality of life. Meta-analyses of trials and cohort studies informed the effects of statin therapies on cardiovascular events, incident diabetes, myopathy and rhabdomyolysis.

Results: Across categories of participants 40-70 years old, lifetime use of standard statin therapy resulted in undiscounted 0.20-1.09 quality-adjusted life-years gained per person, and higher-intensity statin therapy added a further 0.03-0.20 quality-adjusted life-years per person. Among participants aged ≥ 70 years, lifetime standard statin was estimated to increase quality-adjusted life-years by 0.24-0.70 and higher-intensity statin by a further 0.04-0.13 quality-adjusted life-years per person. Benefits were larger among participants at higher cardiovascular disease risk or with higher low-density lipoprotein cholesterol. Standard statin therapy was cost-effective across all categories of people 40-70 years old, with incremental costs per quality-adjusted life-year gained from £280 to £8530. Higher-intensity statin therapy was cost-effective at higher cardiovascular disease risk or higher low-density lipoprotein cholesterol. Both standard and higher-intensity statin therapies appeared to be cost-effective for people aged ≥ 70 years, with an incremental cost per quality-adjusted life-year gained of under £3500 for standard and under £11,780 for higher-intensity statin. Standard or higher-intensity statin therapy was certain to be cost effective in the base-case analysis at a threshold of £20,000 per quality-adjusted life-year. Statins remained cost-effective in sensitivity analyses.

Limitations: The randomised evidence for effects of statin therapy is for about 5 years of treatment. There is limited randomised evidence of the effects of statin therapy in older people without previous cardiovascular disease.

Conclusions: Based on the current evidence of the effects of statin therapy and modelled contemporary disease risks, low-cost statin therapy is cost-effective across all categories of men and women aged ≥ 40 years in the United Kingdom, with higher-intensity statin therapy cost-effective at higher cardiovascular disease risk or higher low-density lipoprotein cholesterol.

Future work: Cholesterol Treatment Trialists' Collaboration has ongoing studies of effects of statin therapy using individual participant data from randomised statin trials. Ongoing large randomised controlled trials are studying the effects of statin therapy in people ≥ 70 years old. Future economic analyses should integrate the emerging new evidence.

Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 17/140/02) and is published in full in Health Technology Assessment; Vol. 28, No. 79. See the NIHR Funding and Awards website for further award information.