The study covered in- and out-of-hospital care in a region in north-western Spain. The intervention evaluated took the form of a change in the hospital drugs formulary. Before the intervention, the formulary contained four of the five low molecular weight heparins (LMWHs) marketed in Spain. The intervention consisted of withdrawing two LMWHs (bemiparin and dalteparin) from the formulary and restricting the use of another (tinzaparin), leaving only enoxaparin as an unrestricted prescription LMWH. Accordingly, the aim of this study was to evaluate the effect on in- and outpatient drug prescriptions of removing and restricting the use of several LMWHs in a hospital drugs formulary. We used a natural, before-after, quasi-experimental design with a control group and monthly data from January 2011 to December 2016. Based on data drawn from official Public Health Service sources, the following dependent variables were extracted: defined daily doses (DDD) per 1000 inhabitants per day (DDD/TID), DDD per 100 stays per day, and expenditure per DDD. The two compounds that were removed from the formulary registered an immediate decrease at both an intra- and out-of-hospital level (66.6% and 55.6% for bemiparin and 73.0% and 92.2% for dalteparin, respectively); similarly, the compound that was restricted also registered an immediate decrease (36.1% and 9.0% at the in- and outpatient levels, respectively); in contrast, the remaining LMWH (enoxaparin) registered an immediate, significant increase at both levels (44.9% and 32.6%, respectively). The intervention led to an immediate reduction of 6.8% and a change in trend in out-of-hospital cost/DDD; it also avoided an expenditure of €477,317.1 in the 21 months following the intervention. The results indicate that changes made in a hospital drugs formulary towards more efficient medications may lead to better use of pharmacotherapeutic resources in its health catchment area.

中文翻译：

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医院药品处方中仿制药品的删除和限制对住院和门诊药品处方的影响：带对照组的间断时间序列设计

该研究涵盖了西班牙西北部地区的院内和院外护理。评估的干预措施采取了改变医院药物处方的形式。在干预之前，处方集中包含在西班牙销售的五种低分子量肝素 (LMWH) 中的四种。干预措施包括从处方中撤回两种 LMWH（贝米肝素和达肝素），并限制另一种（亭扎肝素）的使用，仅留下依诺肝素作为非限制处方 LMWH。因此，本研究的目的是评估在医院药物处方中删除和限制使用几种 LMWH 对住院和门诊药物处方的影响。我们使用了自然、前后、准实验设计，其中包含对照组和 2011 年 1 月至 2016 年 12 月的每月数据。根据官方公共卫生服务来源的数据，提取了以下因变量：定义的每日剂量 (DDD) ）每 1000 名居民每天 (DDD/TID)、每 100 次每天住宿的 DDD 以及每 DDD 的支出。从处方中删除的两种化合物在院内和院外水平均立即下降（贝米肝素分别为 66.6% 和 55.6%，达肝素分别为 73.0% 和 92.2%）；同样，受到限制的化合物也立即下降（住院患者和门诊患者水平分别为 36.1% 和 9.0%）；相比之下，剩余的 LMWH（依诺肝素）在两个水平上均立即显着增加（分别为 44.9% 和 32.6%）。干预措施使院外费用/DDD 立即降低了 6.8%，并改变了趋势；干预后的 21 个月内还避免了 477,317.1 欧元的支出。结果表明，医院药物处方中朝着更有效的药物方向进行的改变可能会导致其健康区域更好地利用药物治疗资源。