Department of Pediatrics, Duke University, Durham, NC 27710, USA.
Int J Endocrinol. 2010;2010:631971. doi: 10.1155/2010/631971. Epub 2010 Feb 4.
Objective. To determine if adherence as measured by pill count would show a significant association with serum-based measures of adherence. Methods. Data were obtained from a prenatal vitamin D supplementation trial where subjects were stratified by race and randomized into three dosing groups: 400 (control), 2000, or 4000 IU vitamin D(3)/day. One measurement of adherence was obtained via pill counts remaining compared to a novel definition for adherence using serum 25-hydroxy-vitamin D (25-OH-D) levels (absolute change in 25(OH)D over the study period and the subject's steady-state variation in their 25(OH)D levels). A multivariate logistic regression model examined whether mean percent adherence by pill count was significantly associated with the adherence measure by serum metabolite levels. Results. Subjects' mean percentage of adherence by pill count was not a significant predictor of adherence by serum metabolite levels. This finding was robust across a series of sensitivity analyses. Conclusions. Based on our novel definition of adherence, pill count was not a reliable predictor of adherence to protocol, and calls into question how adherence is measured in clinical research. Our findings have implications regarding the determination of efficacy of medications under study and offer an alternative approach to measuring adherence of long half-life supplements/medications.
目的。确定通过药物计数所测量的依从性是否与基于血清的依从性测量有显著关联。
方法。数据来自一项产前维生素 D 补充试验，其中受试者按种族分层并随机分为三组：400IU（对照组）、2000IU 或 4000IU 维生素 D（3）/天。通过与使用血清 25-羟维生素 D（25-OH-D）水平的新定义（研究期间 25(OH)D 的绝对变化和受试者 25(OH)D 水平的稳定态变异）进行比较，对药物计数残留的依从性进行了一次测量。使用多元逻辑回归模型检查了药物计数的平均百分比依从性是否与血清代谢物水平的依从性测量显著相关。
结果。药物计数的受试者平均百分比依从性并不是血清代谢物水平依从性的显著预测因子。这一发现经过一系列敏感性分析后仍然成立。
结论。根据我们新定义的依从性，药物计数并不是依从性方案的可靠预测因子，这对临床研究中如何测量依从性提出了质疑。我们的发现与正在研究的药物的疗效确定有关，并提供了一种测量长半衰期补充剂/药物依从性的替代方法。
