Medical Statistics Unit, Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel St, London WC1E 7HT.
Health Econ. 2010 Jan;19(1):43-55. doi: 10.1002/hec.1444.
Health economic decision models are based on specific assumptions relating to model structure and parameter estimation. Validation of these models is recommended as an indicator of reliability, but is not commonly reported. Furthermore, models derived from different data and employing different assumptions may produce a variety of results.A Markov model for evaluating the long-term cost-effectiveness of screening for abdominal aortic aneurysm is described. Internal, prospective and external validations are carried out using individual participant data from two randomised trials. Validation is assessed in terms of total numbers and timings of key events, and total costs and life-years. Since the initial model validates well only internally, two further models are developed that better fit the prospective and external validation data. All three models are then extrapolated to a life-time horizon, producing cost-effectiveness estimates ranging from pound1600 to pound4200 per life-year gained.Parameter uncertainty is now commonly addressed in health economic decision modelling. However, the derivation of models from different data sources adds another level of uncertainty. This extra uncertainty should be recognised in practical decision-making and, where possible, specifically investigated through independent model validation.
健康经济决策模型基于与模型结构和参数估计相关的特定假设。建议对这些模型进行验证，以作为可靠性的指标，但通常未予报告。此外，源自不同数据并采用不同假设的模型可能会产生多种结果。本文描述了一种用于评估腹部主动脉瘤筛查的长期成本效益的马尔可夫模型。使用两项随机试验的个体参与者数据对内、前瞻性和外部进行验证。验证是根据关键事件的总数和时间以及总成本和生命年数来评估的。由于初始模型仅在内部验证良好，因此开发了另外两个更好地拟合前瞻性和外部验证数据的模型。然后将所有三个模型外推到终生范围，得出的成本效益估计值在每获得一个生命年的 1600 英镑至 4200 英镑之间。参数不确定性现在在健康经济决策模型中得到了广泛的解决。然而，从不同数据源推导出模型会增加另一层不确定性。在实际决策中应认识到这种额外的不确定性，并在可能的情况下通过独立的模型验证来专门研究。
