Freedberg K A, Hardy W D, Holzman R S, Tosteson A N, Craven D E
Department of Medicine and Thorndike Memorial Laboratory, Boston City Hospital, Massachusetts, USA.
Med Decis Making. 1996 Jan-Mar;16(1):29-35. doi: 10.1177/0272989X9601600110.
To compare literature-based estimates of the cost-effectiveness ratios of strategies for secondary prophylaxis of Pneumocystis carinii pneumonia (PCP) in AIDS patients with estimates obtained using data from a recent comparative clinical trial.
A decision-analytic Markov model with data on drug efficacy and toxicity from both the medical literature and a national randomized clinical trial. Drug costs were from average wholesale prices. Discounted life expectancy, total direct medical costs, and cost-effectiveness were projected in dollars per year of life saved (YLS).
Hypothetical for the literature-based model, then the clinical trial results from the multicenter AIDS Clinical Trials Group (ACTG Protocol 021).
Patients with AIDS and a prior episode of PCP.
Strategies included no prophylaxis, TMP-SMX (160/800 mg) daily, or aerosolized pentamidine (300 mg) monthly. Patients experiencing major toxic reactions to either medication would cross over to the other agent.
In the literature-based model no prophylaxis was associated with a projected life expectancy of 1.430 years, and total direct cost of $42,080. TMP-SMX increased life expectancy to 2.051 years and cost to $42,300; for aerosolized pentamidine life expectancy was 2.066 years and cost $43,960. TMP-SMX had an incremental cost-effectiveness ratio of $350 per YLS compared with no prophylaxis; the incremental ratio for aerosolized pentamidine was $2,950 per YLS when compared with no prophylaxis, but rose to $110,880 per YLS compared with TMP-SMX. When data from ACTG clinical trial 021 were utilized in the model, the incremental cost-effectiveness ratio for TMP-SMX compared with no prophylaxis was $720 per YLS; aerosolized pentamidine was not cost-effective, and was "dominated" by TMP-SMX because it was associated with higher costs and shorter life expectancy.
Literature-based cost-effectiveness models are useful in developing health policy before clinical trials are completed. Clinical trial results, when available, can be used to validate and revise these models. For secondary PCP prophylaxis in AIDS patients, TMP-SMX is substantially more cost-effective than aerosolized pentamidine.
比较基于文献估计的艾滋病患者卡氏肺孢子虫肺炎（PCP）二级预防策略的成本效益比与利用近期一项比较临床试验数据得出的估计值。
采用一个决策分析马尔可夫模型，数据来源于医学文献和一项全国随机临床试验中的药物疗效及毒性数据。药物成本取自平均批发价。按每挽救一年生命（YLS）的美元数预测贴现预期寿命、总直接医疗成本及成本效益。
基于文献的模型为假设情况，之后采用多中心艾滋病临床试验组（ACTG方案021）的临床试验结果。
患有艾滋病且曾患过一次PCP的患者。
策略包括不进行预防、每日服用复方新诺明（160/800毫克）或每月雾化吸入喷他脒（300毫克）。对任一药物出现严重毒性反应的患者将改用另一种药物。
在基于文献的模型中，不进行预防预计预期寿命为1.430年，总直接成本为42,080美元。复方新诺明使预期寿命增至2.051年，成本为42,300美元；雾化吸入喷他脒的预期寿命为2.066年，成本为43,960美元。与不进行预防相比，复方新诺明每YLS的增量成本效益比为350美元；与不进行预防相比，雾化吸入喷他脒每YLS的增量成本效益比为2,950美元，但与复方新诺明相比则增至每YLS 110,88万美元。当在模型中使用ACTG临床试验021的数据时，与不进行预防相比，复方新诺明每YLS的增量成本效益比为720美元；雾化吸入喷他脒不具有成本效益，且被复方新诺明“主导”，因为它成本更高且预期寿命更短。
在临床试验完成之前，基于文献的成本效益模型有助于制定卫生政策。如有临床试验结果，可用于验证和修订这些模型。对于艾滋病患者PCP的二级预防，复方新诺明比雾化吸入喷他脒更具成本效益。
