Institute of Health Economics and Technology Assessment, Vaclavska 316/12, 12000, Prague 2, Czech Republic.
Institute of Rheumatology, Prague, Czech Republic.
Patient. 2018 Jun;11(3):329-340. doi: 10.1007/s40271-017-0285-1.
Clinical trials and observational studies lacking measures of health-related quality of life (QoL) are often inapplicable when conducting cost-effectiveness analyses using quality-adjusted life-years (QALYs). The only solution is to map QoL ex post from additionally collected clinical outcomes and generic QoL instruments. Nonetheless, mapping studies are absent in psoriatic arthritis (PsA).
In this 2-year, prospective, multicentre, non-interventional study of PsA patients, EQ-5D and key clinical parameters such as Disease Activity in PsA (DAPsA), clinical DAPsA (cDAPsA; DAPsA without C-reactive protein [CRP]), and Health Assessment Questionnaire disability index (HAQ) were collected. We employed a linear mixed-effect regression model (ME) of the longitudinal dataset to explore the best predictors of QoL.
A total of 228 patients were followed over 873 appointments/observations. DAPsA, cDAPsA and HAQ were stable and highly significant predictors of EQ-5D utilities in both cross-sectional and longitudinal analyses. The best prediction was provided using a linear ME with HAQ and cDAPsA or DAPsA. A HAQ increase of 1 point represented a decrease in EQ-5D by -0.204 or -0.203 (p < 0.0001); a one-point increase in cDAPsA or DAPsA dropped EQ-5D equally by -0.005 (p < 0.0001). The ME revealed steeper and more accurate association compared with cross-sectional regressions or non-linear models/transformations.
This is the first mapping study conducted in PsA and we hope that our study will encourage further mapping studies in PsA. The results showed that in cases where CRP is absent, cDAPsA provides similar results to DAPsA in predicting QoL.
在进行成本效益分析时，使用质量调整生命年（QALY）时，缺乏健康相关生活质量（QoL）衡量标准的临床试验和观察性研究通常不适用。唯一的解决方案是根据额外收集的临床结果和通用 QoL 工具对 QoL 进行事后映射。然而，在银屑病关节炎（PsA）中，没有映射研究。
在这项为期 2 年的前瞻性、多中心、非干预性 PsA 患者研究中，收集了 EQ-5D 和关键临床参数，如关节炎活动度指数（DAPsA）、临床 DAPsA（无 C 反应蛋白 [CRP] 的 DAPsA）和健康评估问卷残疾指数（HAQ）。我们使用线性混合效应回归模型（ME）对纵向数据集进行分析，以探索 QoL 的最佳预测因素。
共对 228 例患者进行了 873 次就诊/观察随访。DAPsA、cDAPsA 和 HAQ 在横断面和纵向分析中均为 EQ-5D 效用的稳定且高度显著的预测因素。使用包含 HAQ 和 cDAPsA 或 DAPsA 的线性 ME 提供了最佳预测。HAQ 增加 1 分表示 EQ-5D 下降 0.204 或 0.203（p<0.0001）；cDAPsA 或 DAPsA 增加 1 分，EQ-5D 同样下降 0.005（p<0.0001）。与横断面回归或非线性模型/转换相比，ME 显示出更陡峭和更准确的关联。
这是在 PsA 中进行的第一项映射研究，我们希望我们的研究将鼓励在 PsA 中进行进一步的映射研究。结果表明，在 CRP 不存在的情况下，cDAPsA 在预测 QoL 方面与 DAPsA 提供相似的结果。
