Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.
Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada.
Value Health. 2014 Jan-Feb;17(1):77-83. doi: 10.1016/j.jval.2013.10.009.
Health utility scores quantify health-related quality-of-life (HRQOL) in Alzheimer's disease (AD). These scores are calculated by using preference weights derived from general population samples. We recruited persons with AD and their primary informal caregivers and examined differences in health utility scores calculated by using two sets of published preference weights.
We recruited participants from nine clinics across Canada and administered the EuroQol five-dimensional (EQ-5D) questionnaire HRQOL instrument. We converted participants' EQ-5D questionnaire responses into two sets of health utility scores by using US and Canadian preference weights. We assessed agreement between sets by using the intraclass correlation coefficient. Bland-Altman plots depicted individual-level differences between sets.
For 216 persons with AD and their caregivers, mean health utility scores were higher when calculated with US instead of Canadian preference weights (P < 0.0001). The intraclass correlation coefficient (95% CI) was 0.79 (0.05-0.93) in the persons with AD group and 0.83 (0.30-0.94) in the caregiver group. Ninety-five percent of the individual differences in utility score fell between -0.16 and 0.03 for persons with AD and -0.15 and 0.05 for caregivers. Forty-three percent of these differences exceeded a minimum clinically important threshold of 0.074.
In AD studies, researchers should calculate health utility scores by using preference weights obtained in the general population of their country of interest. Using weights from other countries' populations could bias the utilities and adversely affect the results of economic evaluations of AD treatments.
健康效用评分量化了阿尔茨海默病（AD）患者的健康相关生活质量（HRQOL）。这些评分是通过使用来自一般人群样本的偏好权重计算得出的。我们招募了 AD 患者及其主要的非专业照护者，并检查了使用两组已发表的偏好权重计算得出的健康效用评分之间的差异。
我们从加拿大的 9 个诊所招募了参与者，并进行了 EuroQol 五维（EQ-5D）问卷 HRQOL 工具的测试。我们通过使用美国和加拿大的偏好权重将参与者的 EQ-5D 问卷回答转换为两组健康效用评分。我们使用组内相关系数评估两组之间的一致性。Bland-Altman 图描绘了两组之间的个体水平差异。
对于 216 名 AD 患者及其照顾者，使用美国偏好权重而不是加拿大偏好权重计算的健康效用评分更高（P<0.0001）。AD 患者组的组内相关系数（95%CI）为 0.79（0.05-0.93），照顾者组为 0.83（0.30-0.94）。AD 患者和照顾者的效用评分个体差异中有 95%落在 -0.16 到 0.03 之间和 -0.15 到 0.05 之间。这些差异中有 43%超过了 0.074 的最小临床重要阈值。
在 AD 研究中，研究人员应使用其感兴趣国家的一般人群中获得的偏好权重来计算健康效用评分。使用来自其他国家人群的权重可能会使效用产生偏差，并对 AD 治疗的经济评估结果产生不利影响。
