Lavender M, Craig N, Kerr R, Howel D
Newcastle and North Tyneside Health Authority, UK.
J Health Serv Res Policy. 1998 Jan;3(1):6-11. doi: 10.1177/135581969800300104.
To investigate the benefit of carotid endarterectomy relative to medical treatment, by comparing the outcome for different groups of patients following transient ischaemic attacks.
A Markov model was used to describe the survival and quality of life of patients treated for a transient ischaemic attack. The benefit is measured in terms of quality adjusted life months (QALMs). The outcome was estimated using a computer simulation with parameters based on published studies on the probability of events following treatment. The benefit of carotid endarterectomy was explored using a baseline set of parameters and a sensitivity analysis.
The baseline scenario of a 65-year-old male patient with the model factors set at an intermediate level showed a benefit for surgery of 3 QALMs compared with medical treatment alone. The sensitivity analysis showed that the most favourable combination of factors had a benefit of 13.4 QALMs and the least favourable a loss of 2 QALMs. Of all 128 factor combinations, 79.9% showed a benefit for surgery, 5.5% showed equal benefit, and 15.6% showed a benefit for medical treatment.
Computer simulations have the potential for deriving estimates of benefit for different patient groups from the results of clinical trials. Combined with reliable information on costs, the technique could also demonstrate variations in cost-effectiveness for these groups. For patients following a transient ischaemic attack, the results from this simulation and limited cost information suggest that carotid endarterectomy is unlikely to be a cost-effective intervention in the UK for many patient groups despite a reduction in the risk of stroke.
通过比较短暂性脑缺血发作后不同患者组的治疗结果，研究颈动脉内膜切除术相对于药物治疗的益处。
采用马尔可夫模型描述短暂性脑缺血发作患者的生存情况和生活质量。益处以质量调整生命月（QALMs）衡量。使用计算机模拟根据已发表的治疗后事件概率研究中的参数来估计结果。通过一组基线参数和敏感性分析来探究颈动脉内膜切除术的益处。
一名65岁男性患者的基线情况，模型因素设定为中等水平，结果显示与单纯药物治疗相比，手术的益处为3个质量调整生命月。敏感性分析表明，最有利的因素组合益处为13.4个质量调整生命月，最不利的组合损失2个质量调整生命月。在所有128种因素组合中，79.9%显示手术有益，5.5%显示益处相同，15.6%显示药物治疗有益。
计算机模拟有潜力根据临床试验结果得出不同患者组的益处估计值。结合可靠的成本信息，该技术还可展示这些组在成本效益方面的差异。对于短暂性脑缺血发作后的患者，该模拟结果和有限的成本信息表明，尽管颈动脉内膜切除术可降低中风风险，但在英国对许多患者组而言不太可能是具有成本效益的干预措施。
