and Svensson (2006) that measured stock-out rates in combination with the PETS/QSDS in Uganda, and another study in Kenya that followed the PETS methodology and reported on stock-outs at health care facilities (reviewed in Gauthier 2006). An African initiative of civil society organizations to monitor and pressure governments to reduce stock-outs can be found online (www.stopstockouts.org). This initiative includes periodic visits to facilities in Kenya, Uganda, Zambia and Zimbabwe to determine whether essential medicines are available.

A joint effort by WHO and Health Action International (HAI) in 2008 created a survey tool that is the best currently available for measuring the prices and availability of drugs. The survey tool gathers information on prices paid for key medicines, as well as differences between brand and generic prices, differences between national and international reference prices, the availability of drugs at facilities and pharmacies, and the variation of prices and availability across sectors and regions within countries. The tool is specifically designed to allow cross-country comparisons and has been conducted in more than 55 countries.

In the survey, data are collected on the availability of a selected group of medicines from a sample of outlets in the public and private sectors (both for- and non-profit) in six regions of a country or – in the case of large countries – of a state or province. Up to 50 medicines are chosen, generally comprising: 14 global core medicines; 16 regional core medicines; and 20 supplementary medicines. The global and regional core medicines lists are part of the standard methodology provided by WHO and HAI and are chosen to assist countries in making international comparisons. Price data can be collected quite readily in a randomized representative survey of sites at which medicines are sold. However, measuring stock-out rates is only possible where good stock records exist – which is somewhat more common in the public sector than in the private sector, according to HAI. Applying the survey as designed by HAI and WHO typically costs between US$10,000 and US$20,000.<sup>12</sup>

# _Issues in measuring informal payments_

While informal payments vary significantly across countries, it is still feasible to measure them whenever surveys can identify a clear gap between what patients pay for public health services and what they are legally required to pay. Measuring informal payments poses special challenges in that patients and households are often uncertain about how much they paid for health care services and are often even less knowledgeable about how much they are legally obligated to pay. Different institutional, legal and cultural contexts also create significant variation across countries that can confound cross-country comparisons (Lewis 2000; Gaal et al 2006).

Generally, patients and households are considered to be better sources for data on informal payments. In particular, exit surveys at facilities are best suited to getting reliable answers from patients as to how much they paid for health care services in a setting where the researcher can compare what the respondent paid to an official fee schedule for the services provided. By comparison, questions in household surveys

> 12 Author‟s estimate based on interviews.

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