Gray Andrew Lofts, Santa-Ana-Tellez Yared, J Wirtz Veronika
University of KwaZulu Natal, Durban, South Africa.
WHO Collaborating Centre for Pharmaceutical Policy and Regulation, Utrecht Institute for Pharmaceutical Sciences, Utrecht, The Netherlands.
Trop Med Int Health. 2016 Dec;21(12):1504-1512. doi: 10.1111/tmi.12785. Epub 2016 Oct 17.
To assess the impact of mandatory offer of generic substitution, introduced in South Africa in May 2003, on private sector sales of generic and originator medicines for chronic diseases.
Private sector sales data (June 2001 to May 2005) were obtained from IMS Health for proton pump inhibitors (PPIs; ATC code A02BC), HMG-CoA reductase inhibitors (statins; C10AA), dihydropyridine calcium antagonists (C08CA), angiotensin-converting enzyme inhibitors (ACE-I; C09AA) and selective serotonin reuptake inhibitors (SSRIs; N06AB). Monthly sales were expressed as defined daily doses per 1000 insured population per month (DDD/TIM). Interrupted time-series models were used to estimate the changes in slope and level of medicines use after the policy change. ARIMA models were used to correct for autocorrelation and stationarity.
Only the SSRIs saw a significant rise in level of generic utilisation (0.2 DDD/TIM; P < 0.001) and a fall in originator usage (-0.1 DDD/TIM; P < 0.001) after the policy change. Utilisation of generic PPIs fell (level 0.06 DDD/TIM, P = 0.048; slope 0.01 DDD/TIM, P = 0.043), but utilisation of originator products also grew (level 0.05 DDD/TIM, P < 0.001; slope 0.003, P = 0.001). Generic calcium antagonists and ACE-I showed an increase in slope (0.01 DDD/TIM, P = 0.016; 0.02 DDD/TIM, P < 0.001), while the originators showed a decrease in slope (-0.003 DDD/TIM, P = 0.046; -0.01 DDD/TIM, P < 0.001). There were insufficient data on generic statin use before the policy change to allow for analysis.
The mandatory offer of generic substitution appeared to have had a quantifiable effect on utilisation patterns in the 2 years after May 2003. Managed care interventions that were already in place before the intervention may have blunted the extent of the changes seen in this period. Generic policies are an important enabling provision for cost-containment efforts. However, decisions taken outside of official policy may anticipate or differ from that policy, with important consequences.
评估2003年5月在南非推行的强制提供仿制药替代政策对慢性病仿制药和原研药在私营部门销售额的影响。
从艾美仕市场研究公司获取2001年6月至2005年5月私营部门的销售数据，涉及质子泵抑制剂（PPIs；解剖治疗学分类代码A02BC）、HMG - CoA还原酶抑制剂（他汀类药物；C10AA）、二氢吡啶类钙拮抗剂（C08CA）、血管紧张素转换酶抑制剂（ACE - I；C09AA）和选择性5 - 羟色胺再摄取抑制剂（SSRIs；N06AB）。月销售额以每月每1000名参保人群的限定日剂量（DDD/TIM）表示。采用中断时间序列模型估计政策变化后药品使用斜率和水平的变化。使用自回归积分滑动平均模型（ARIMA）校正自相关和平稳性。
政策变化后，仅SSRIs的仿制药使用水平显著上升（0.2 DDD/TIM；P < 0.001），原研药使用量下降（-0.1 DDD/TIM；P < 0.001）。仿制药PPIs的使用量下降（水平0.06 DDD/TIM，P = 0.048；斜率0.01 DDD/TIM，P = 0.043），但原研产品的使用量也有所增加（水平0.05 DDD/TIM，P < 0.001；斜率0.003，P = 0.001）。仿制药钙拮抗剂和ACE - I的斜率增加（0.01 DDD/TIM，P = 0.016；0.02 DDD/TIM，P < 0.001），而原研药的斜率下降（-0.003 DDD/TIM，P = 0.046；-0.01 DDD/TIM，P < 。001）。政策变化前仿制药他汀类药物使用的数据不足，无法进行分析。
强制提供仿制药替代政策在2003年5月后的两年里似乎对使用模式产生了可量化的影响。干预措施实施前已有的管理式医疗干预可能削弱了这一时期所观察到的变化程度。仿制药政策是控制成本努力的一项重要有利规定。然而，官方政策之外做出的决策可能会先于该政策或与之不同，从而产生重要影响。
