Burcu Mehmet, Alexander G Caleb, Ng Xinyi, Harrington Donna
*Pharmaceutical Health Services Research Department, University of Maryland †Department of Epidemiology and Medicine, Center for Drug Safety and Effectiveness, Johns Hopkins University ‡School of Social Work, University of Maryland, Baltimore, MD.
Med Care. 2015 Feb;53(2):199-206. doi: 10.1097/MLR.0000000000000286.
Millions of Americans are burdened by out-of-pocket prescription costs. Although many survey measures have been developed to assess this burden, the construct validity and the factor structure of these instruments have not been rigorously assessed.
To characterize the factor structure and the construct validity of items assessing cost-related medication burden.
We applied exploratory factor and confirmatory factor analyses to the 2009 Medicare Current Beneficiary Survey, focusing on 10 items assessing cost-related mediation burden among a nationally representative sample of community-dwelling Medicare beneficiaries. The fit of competing models was compared using several indices.
The study population (N=8777) was predominantly aged over 65 years (83.3%), female (54.4%), and white (84.3%). Two distinct factors were present for the medication cost-reduction strategies: (1) cost-related medication nonadherence and (2) drug-shopping behaviors, not directly impacting medication compliance. The two factors were moderately correlated (r=0.55), highlighting the presence of a 2 distinct but related constructs for cost-related medication burden. An item assessing the use of mail or internet pharmacies did not load well on either factor and may not necessarily measure medication-related cost burden. An item assessing reduced spending on basic needs loaded strongly on the same factor with the cost-related medication nonadherence items, suggesting they together may represent extreme compensatory behaviors that may adversely affect health outcomes.
Two distinct constructs were derived from these items examining cost-related medication burden. Although cost-related medication burden is often associated with nonadherence, drug-shopping behaviors that do not directly impact adherence are also important measure of this burden.
数百万美国人面临着自付处方药费用的负担。尽管已经开发了许多调查措施来评估这种负担，但这些工具的结构效度和因子结构尚未得到严格评估。
描述评估与费用相关的药物负担项目的因子结构和结构效度。
我们对2009年医疗保险当前受益人调查应用了探索性因子分析和验证性因子分析，重点关注在全国具有代表性的社区居住医疗保险受益人群体中评估与费用相关的药物负担的10个项目。使用几个指标比较了竞争模型的拟合度。
研究人群（N = 8777）主要为65岁以上（83.3%）、女性（54.4%）和白人（84.3%）。药物费用降低策略存在两个不同的因子：（1）与费用相关的药物治疗不依从和（2）购药行为，这不会直接影响药物治疗依从性。这两个因子中度相关（r = 0.55），突出了与费用相关的药物负担存在两个不同但相关的结构。一个评估使用邮购或网络药店的项目在两个因子上的载荷都不好，可能不一定能衡量与药物相关的费用负担。一个评估基本需求支出减少的项目与与费用相关的药物治疗不依从项目在同一因子上有很强的载荷，表明它们可能共同代表了可能对健康结果产生不利影响的极端补偿行为。
从这些检查与费用相关的药物负担的项目中得出了两个不同的结构。尽管与费用相关的药物负担通常与不依从相关，但不直接影响依从性的购药行为也是这种负担的重要衡量指标。
