Department of Population Medicine, Harvard Medical School, Harvard Pilgrim Health Care Institute, United States of America, Boston, MA 02215, USA. jeanne_
Rev Panam Salud Publica. 2010 Apr;27(4):291-9. doi: 10.1590/s1020-49892010000400008.
To assess the possibility of bias due to the limited target list and geographic sampling of the World Health Organization (WHO)/Health Action International (HAI) Medicine Prices and Availability survey used in more than 70 rapid sample surveys since 2001.
A survey was conducted in Peru in 2005 using an expanded sample of medicine outlets, including remote areas. Comprehensive data were gathered on medicines in three therapeutic classes to assess the adequacy of WHO/HAI's target medicines list and the focus on only two product versions. WHO/HAI median retail prices were compared with average wholesale prices from global pharmaceutical sales data supplier IMS Health.
No significant differences were found in overall availability or prices of target list medicines by retail location. The comprehensive survey of angiotensin-converting enzyme inhibitor, anti-diabetic, and anti-ulcer products revealed that some treatments not on the target list were costlier for patients and more likely to be unavailable, particularly in remote areas. WHO/HAI retail prices and IMS wholesale prices were strongly correlated for higher priced products, and weakly correlated for lower priced products (which had higher estimated retailer markups).
The WHO/HAI survey approach strikes an appropriate balance between modest research costs and optimal information for policy. Focusing on commonly used medicines yields sufficient and valid results. Surveyors elsewhere should consider the limits of the survey data as well as any local circumstances, such as scarcity, that may call for extra field efforts.
评估 2001 年以来 70 多次快速抽样调查中使用的世界卫生组织（世卫组织）/国际健康行动（HAI）药品价格和可及性调查因目标清单有限和地理抽样而产生偏倚的可能性。
2005 年在秘鲁进行了一项调查，使用了扩大的药品销售点样本，包括偏远地区。收集了三个治疗类别中药品的综合数据，以评估世卫组织/HAI 的目标药品清单的充分性以及仅关注两种产品版本的情况。将世卫组织/HAI 的零售中位数价格与全球药品销售数据供应商 IMS Health 的平均批发价格进行了比较。
按零售地点划分，目标清单药品的总体供应情况或价格均无显著差异。对血管紧张素转换酶抑制剂、抗糖尿病和抗溃疡产品的全面调查显示，一些不在目标清单上的治疗方法对患者来说成本更高，而且更有可能无法获得，尤其是在偏远地区。对于较高价格的产品，世卫组织/HAI 的零售价格和 IMS 的批发价格具有很强的相关性，而对于较低价格的产品（零售商加价估计较高）则相关性较弱。
世卫组织/HAI 的调查方法在适度的研究成本和为政策提供最佳信息之间取得了适当的平衡。关注常用药品可获得足够和有效的结果。其他地方的调查人员应考虑调查数据的局限性以及任何可能需要额外实地工作的当地情况，例如短缺。
