Department of Sociology and Center for Population Health and Aging, Duke University, Durham, North Carolina, USA.
Med Decis Making. 2010 Nov-Dec;30(6):625-38. doi: 10.1177/0272989X10363479.
To estimate and validate a multiattribute model of the clinical course of Alzheimer disease (AD) from mild AD to death in a high-quality prospective cohort study, and to estimate the impact of hypothetical modifications to AD progression rates on costs associated with Medicare and Medicaid services.
The authors estimated sex-specific longitudinal Grade of Membership (GoM) models for AD patients (103 men, 149 women) in the initial cohort of the Predictors Study (1989-2001) based on 80 individual measures obtained every 6 mo for 10 y. These models were replicated for AD patients (106 men, 148 women) in the 2nd Predictors Study cohort (1997-2007). Model validation required that the disease-specific transition parameters be identical for both Predictors Study cohorts. Medicare costs were estimated from the National Long Term Care Survey.
Sex-specific models were validated using the 2nd Predictors Study cohort with the GoM transition parameters constrained to the values estimated for the 1st Predictors Study cohort; 57 to 61 of the 80 individual measures contributed significantly to the GoM models. Simulated, cost-free interventions in the rate of progression of AD indicated that large potential cost offsets could occur for patients at the earliest stages of AD.
AD progression is characterized by a small number of parameters governing changes in large numbers of correlated indicators of AD severity. The analysis confirmed that the progression of AD represents a complex multidimensional physiological process that is similar across different study cohorts. The estimates suggested that there could be large cost offsets to Medicare and Medicaid from the slowing of AD progression among patients with mild AD. The methodology appears generally applicable in AD modeling.
在一项高质量的前瞻性队列研究中，从轻度 AD 到死亡，估计和验证阿尔茨海默病（AD）临床病程的多属性模型，并估计假设改变 AD 进展率对医疗保险和医疗补助服务相关成本的影响。
作者根据预测研究（1989-2001 年）初始队列中 AD 患者（103 名男性，149 名女性）的 80 项个体测量值，每 6 个月获得一次，为期 10 年，估计了这些患者的性别特异性纵向隶属度等级（GoM）模型。这些模型在第 2 个预测研究队列（1997-2007 年）中的 AD 患者（106 名男性，148 名女性）中进行了复制。模型验证要求两个预测研究队列的疾病特异性转换参数必须相同。医疗保险费用是从国家长期护理调查中估计的。
使用第 2 个预测研究队列对性别特异性模型进行了验证，GoM 转换参数被约束为第 1 个预测研究队列中估计的值；80 项个体测量值中的 57 至 61 项对 GoM 模型有显著贡献。模拟、无成本的 AD 进展率干预表明，AD 早期患者可能会产生较大的潜在成本节省。
AD 的进展特征是少数几个参数控制着大量与 AD 严重程度相关的指标的变化。该分析证实，AD 的进展代表了一个复杂的多维生理过程，在不同的研究队列中是相似的。这些估计表明，对于轻度 AD 患者 AD 进展的减缓，医疗保险和医疗补助可能会有较大的成本节省。该方法似乎在 AD 建模中具有普遍适用性。
