Vink N M, Klungel O H, Stolk R P, Denig P
Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Pharmacoepidemiol Drug Saf. 2009 Feb;18(2):159-65. doi: 10.1002/pds.1698.
Several measures using prescription data have been developed for estimating medication refill adherence. Few studies have made direct comparisons, and little is known about the accuracy of these measures in patients on a multiple-drug regimen.
To compare different calculation methods using prescription data for assessing refill adherence.
An observational cohort study among type 2 diabetes patients was conducted. Adherence to oral glucose-lowering, antihypertensive and lipid-lowering medication was assessed for 2004. We calculated medication possession ratios in a flexible period (MPRF), per calendar year (MPRY) and gaps between refills (GAP) at drug class and therapeutic level. Individual review of drug prescription profiles was conducted to validate identified cases of suboptimal refill adherence. Differences in Area Under the Curve (AUC) of ROC-curves were calculated to compare the methods.
Of the 3877 patients, 2969 (77%) patients received oral glucose-lowering medication, 2715 (70%) antihypertensives and 1797 (46%) lipid-lowering medication. Using cutoffs for MPR < 80% and GAP > 30 days, overall rates of suboptimal adherence for these drug classes were 32, 35 and 23% respectively. AUC for measures calculated at drug class level (range 0.85-0.90) were significantly larger than those calculated at therapeutic level (0.72-0.90). For oral glucose-regulating medication and antihypertensives, AUCs were largest for the MPRY and GAP measures (0.87-0.88). For lipid-lowering medication, the AUC was largest for the GAP measure (0.90).
Differences between adherence measures were small and favoured calculation on drug class level. For multiple drug use, both MPRY and GAP were good measures for identifying suboptimal refill adherence.
已开发出几种利用处方数据估算药物续方依从性的方法。很少有研究进行直接比较，对于接受多种药物治疗方案的患者而言，这些方法的准确性了解甚少。
比较使用处方数据评估续方依从性的不同计算方法。
对2型糖尿病患者进行了一项观察性队列研究。评估了2004年口服降糖药、抗高血压药和降脂药的依从性。我们在灵活时间段（MPRF）、按日历年（MPRY）以及按药物类别和治疗水平计算了续方间隔（GAP）的药物持有率。对药物处方资料进行逐个审核，以验证所确定的续方依从性欠佳的病例。计算ROC曲线的曲线下面积（AUC）差异以比较这些方法。
在3877例患者中，2969例（77%）患者接受口服降糖药治疗，2715例（70%）接受抗高血压药治疗，1797例（46%）接受降脂药治疗。使用MPR<80%和GAP>30天的临界值，这些药物类别的总体依从性欠佳率分别为32%、35%和23%。在药物类别水平计算的测量指标的AUC（范围为0.85 - 0.90）显著大于在治疗水平计算的测量指标的AUC（0.72 - 0.90）。对于口服降糖药和抗高血压药，MPRY和GAP测量指标的AUC最大（0.87 - 0.88）。对于降脂药，GAP测量指标的AUC最大（0.90）。
依从性测量指标之间的差异很小，且倾向于在药物类别水平进行计算。对于多种药物使用情况，MPRY和GAP都是识别续方依从性欠佳的良好指标。
