Health economic evaluation of primary prevention strategies against cardiovascular disease
Health technology assessment
|Updated
Key message
Background
Cardiovascular disease (CVD) has for decades been the most common cause of death in Norway and most other Western countries. Several groups of drugs have shown in clinical trials to prevent CVD. In this report, we have evaluated the cost-effectiveness of these drugs.
Methods
Based on a model of the progression of CVD from healthy to death, we explored which drugs that might be cost-effective. Analyses were conducted both compared to no treatment and between different drugs. Analyses were conducted on different risk levels and in different age groups for both men and women. We also performed probabilistic sensitivity analyses. Our analyses were accompanied by a systematic review of other economic evaluations of preventive strategies against CVD.
Results
Calcium channel blockers, thiazides, beta blockers, aspirin and statins were all cost-effective compared to no treatment for all groups of men and women in age groups between 40 and 69. The life year gains for each of the drugs varied between 3 and 17 months. Calcium channel blockers and thiazides were the most cost-effective combination of two antihypertensive drugs. In the base case analyses, the combination of calcium channel blockers, thiazides and ACE-inhibitors was the most cost-effective combination of three drugs. The sensitivity analyses indicate considerable uncertainty related to the question of which was the most cost-effective of the antihypertensive drugs. Whether treatment was cost-effective compared to no treatment was concerned with less uncertainty. Our systematic review of other economic evaluations showed considerable discrepancies between analyses of prevention strategies against CVD.
Discussion
The results of this study indicate that statins, several antihypertensives and aspirin are cost-effective in all analysed groups between 40 and 69 years old. It is worthwhile noting, however, that the model is built on numerous assumptions, and this introduces considerable uncertainty with respect to optimal choice of therapies.
Summary
Background
Cardiovascular disease (CVD) has for decades been the most common cause of death in Norway and most other Western countries. Cholesterol-lowering drugs ( e.g. statins), antihypertensives (calcium channel blockers (CCB’s), thiazides, beta blockers, ACE-inhibitors and angiotensin receptor blockers (ARBs)) and acetyl-salicylic acid (ASA, aspirin) may inhibit or slow the disease progression and postpone or even prevent clinical events and conditions that may result from CVD. Whether societies are willing to pay for these drugs depend, among other things, on how cost-effective they are. When drugs loose their patent, they become cheaper and hence also more cost-effective. The objective of this study was to analyse costs and life year gains from using the mentioned drugs for primary prevention of CVD.
Methods
We developed a decision analytic model (Markov model) based on Norwegian incidence data and treatment costs. Effectiveness of the drugs was based on a systematic review conducted by the Norwegian Knowledge Centre for the Health Services. The model calculates life year gains with different drugs and life time costs related to CVD.
We did separate analyses for men and women in age groups 40-49, 50-59 and 60-69. For the first group, we conducted analyses for those with 1% and 2% ten-year risk of CVD related death, while for the other two age groups, we analysed 5% and 10% risk. We also performed probabilistic sensitivity analyses on selected analyses to get an impression on the uncertainty surrounding our analyses.
Cost-effectiveness is in our analyses defined as incremental cost below NOK 500,000 per life year gained. Cost-saving is when incremental costs are negative and life year gained is positive.
We also conducted a systematic search for literature on cost-effectiveness of prevention strategies against CVD. Articles were chosen and evaluated based on a standard checklist developed by the Norwegian Knowledge Centre for the health services.
Results
Calcium channel blockers, thiazides, beta blockers, aspirin and statins were all cost-effective compared to no treatment for all groups of men and women in age groups between 40 and 69. The life year gains for each of the drugs varied between 3 and 17 months.
Calcium channel blockers and thiazides were the most cost-effective combination of two antihypertensive drugs. In the base case analyses, the combination of calcium channel blockers, thiazides and ACE-inhibitors was the most cost-effective combination of three drugs.
The sensitivity analyses indicate considerable uncertainty related to the question of which was the most cost-effective of the antihypertensive drugs. Whether treatment was cost-effective compared to no treatment was concerned with less uncertainty.
Our systematic review of other economic evaluations showed considerable discrepancies between analyses of prevention strategies against CVD. There seem to have been conducted several analyses on statins, compared to other groups of medications. None of the analyses on statins are however based on updated prices after loss of patent.
Discussion
The results of this study indicate that statins, several antihypertensives and aspirin are cost-effective in all analysed groups between 40 and 69 years old. It is worthwhile noting, however, that the model is built on numerous assumptions, and this introduces considerable uncertainty with respect to optimal choice of therapies. Also, there may be disagreement about whether large proportions of healthy individuals should take drugs for the primary prevention of CVD, even though the drugs are cost-effective.