National Heart and Lung Institute, Imperial College London, London, UK
Faculty of Epidemiology and Public Health, London School of Hygiene and Tropical Medicine, London, UK.
Thorax. 2019 Nov;74(11):1078-1086. doi: 10.1136/thoraxjnl-2018-212957. Epub 2019 Aug 5.
Switching inhalers to cheaper equivalent products is often advocated as a necessary cost saving measure, yet the impact on patient's health and healthcare utilisation has not been measured.
We identified asthma and chronic obstructive pulmonary disease (COPD) patients from UK primary care electronic healthcare records between 2000 and 2016. A self-controlled case series was used to estimate incidence rate ratios (IRR); comparing outcome rates during the risk period, 3 months after the exposure (financially motivated switch), and control periods (preswitch and postrisk period). Four outcomes were assessed: disease exacerbation, general practitioner consultation, non-specific respiratory events and adverse-medication events. Medication possession ratio (MPR) was calculated to assess adherence. 2017 National Health Service indicative prices were used to estimate cost differences per equivalent dose.
We identified a cohort of 569 901 asthma and 171 231 COPD regular inhaler users, 2% and 6% had been switched, respectively. Inhaler switches between a brand-to-generic inhaler, and all other switches (brand-to-brand, generic-to-generic, generic-to-brand), were associated with reduced exacerbations (brand-to-generic: IRR=0.75, 95% CI 0.64 to 0.88; all other: IRR=0.79, 95% CI 0.71 to 0.88). Gender, age, therapeutic class, inhaler device and inhaler-technique checks did not significantly modify this association (p<0.05). The rate of consultations, respiratory-events and adverse-medication events did not change significantly (consultations: IRR=1.00, 95% CI 0.99 to 1.01; respiratory-events: IRR=0.96, 95% CI 0.95 to 0.97; adverse-medication-events: IRR=1.05, 95% CI 0.96 to 1.15). Adherence significantly increased post-switch (median MPR: pre-switch=54%, post-switch=62%; p<0.001). Switching patients, in the cohort of regular inhaler users, to the cheapest equivalent inhaler, could have saved around £6 million annually.
Switching to an equivalent inhaler in patients with asthma or COPD appeared safe and did not negatively affect patient's health or healthcare utilisation.
将吸入器更换为更便宜的等效产品通常被认为是一种必要的节省成本措施，但对患者健康和医疗保健利用的影响尚未得到衡量。
我们从 2000 年至 2016 年的英国初级保健电子医疗记录中确定了哮喘和慢性阻塞性肺疾病（COPD）患者。使用自我对照病例系列来估计发病率比值（IRR）；比较风险期内、暴露后 3 个月（经济动机转换）和对照期（转换前和风险后）的结果发生率。评估了四种结果：疾病加重、全科医生就诊、非特异性呼吸道事件和药物不良事件。计算药物持有率（MPR）以评估依从性。使用 2017 年国民保健服务指示性价格来估计每种等效剂量的成本差异。
我们确定了一个由 569901 例哮喘和 171231 例 COPD 常规吸入器使用者组成的队列，分别有 2%和 6%的患者进行了转换。从品牌到仿制药的吸入器转换，以及所有其他转换（品牌到品牌、仿制药到仿制药、仿制药到品牌），与减少加重有关（品牌到仿制药：IRR=0.75，95%CI 0.64 至 0.88；所有其他：IRR=0.79，95%CI 0.71 至 0.88）。性别、年龄、治疗类别、吸入器装置和吸入器技术检查并未显著改变这种关联（p<0.05）。就诊率、呼吸道事件率和药物不良事件率没有显著变化（就诊：IRR=1.00，95%CI 0.99 至 1.01；呼吸道事件：IRR=0.96，95%CI 0.95 至 0.97；药物不良事件：IRR=1.05，95%CI 0.96 至 1.15）。转换后依从性显著增加（中位数 MPR：转换前=54%，转换后=62%；p<0.001）。在常规吸入器使用者的队列中，将患者转换为最便宜的等效吸入器，每年可节省约 600 万英镑。
在哮喘或 COPD 患者中转换为等效吸入器似乎是安全的，并且不会对患者的健康或医疗保健利用产生负面影响。
