- Oral presentation
- Open Access
O313 Relation between adverse effects of ARV treatment and underlying risk in number needed to treat to harm (NNTH) – myocardial infarction and abacavir use
© Kowalska et al; licensee BioMed Central Ltd. 2008
- Published: 10 November 2008
- Myocardial Infarction
- Total Cholesterol
- Guide Intervention
- Steep Decrease
With potentially life-long treatment of patients with HIV it is crucial to ensure antiretroviral treatment is used in such a way that adverse effects are reduced as much as possible.
We illustrate methodology of the number needed to treat to harm (NNTH) using the recent findings from the D:A:D study (90% increased relative risk, RR = 1.90, of myocardial infarction [MI] in patients on abacavir compared with patients not receiving abacavir) . We assume this RR remains constant across the range of underlying risk of MI. NNTH was calculated as 1/[(underlying risk of MI × 1.90) – underlying risk of MI], where the underlying risk of MI is calculated for the next 5 years using a parametric statistical model based on the Framingham score http://www.cphiv.dk/TOOLS/tabid/282/Default.aspx.
Change in factors contributing to underlying risk
Underlying risk of MI in 5 years (%)
Example low risk profile (described in text)
If total cholesterol 240 mg/dL (6.2 mmol/L)
If sBP 160 mmHg
If HDL 35 mg/dL (0.9 mmol/L)
If HDL and total cholesterol unfavourable
If smoking and diabetes
If smoking and total cholesterol unfavourable
If smoking and sBP 160 mmHg
If smoking and HDL unfavourable
If smoking and lipids unfavourable
If all unfavourable combined (excluding ECG-LVH)
If all unfavourable combined (including ECG-LVH)
It is possible to increase NNTH values for any group of patients on abacavir by decreasing the underlying risk of MI. Therefore, if underlying risk of MI can be reduced, the NNTH for a given therapy will increase, meaning that the therapy can be administered to more people without causing additional harm.
- Sabin C, et al: Use of nucleoside reverse transcriptase inhibitors and risk of myocardial infarction in HIV-infected patients enrolled in the D:A:D study: a multi-cohort collaboration. Lancet. 2008, 371 (9622): 1417-26. 10.1016/S0140-6736(08)60423-7.PubMedView ArticleGoogle Scholar
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This article is published under license to BioMed Central Ltd.