(October 2009) For 25 years, the Demographic and Health Survey (DHS) program, funded largely by the U.S. Agency for International Development (USAID), has provided decisionmakers with the population and health information they need to plan, monitor, and evaluate population, health, and nutrition programs. There have been 260 surveys in over 90 developing countries since its inception in 1984. Because it is publicly funded, the data are open and accessible to all and widely disseminated and used. The surveys are large and convey nationally representative data, each involving thousands of households in rural and urban areas. Phase III of the DHS program with implementing partner ICF Marco begins this year, with the objective of "improved collection, analysis, and facilitation of data use to promote evidence-based policies, planning, management, and monitoring and evaluation." The current phase will cover family planning, gender, reproductive health, child health, nutrition, HIV/AIDS, infectious diseases such as malaria, and support testing for national rates of HIV, malaria, anemia, and other health threats over the next five years.

But the largest sample survey program in history is facing a transition. Populations in the developing countries that these surveys describe are changing and policy priorities continue to evolve, calling for different data. What do these changes mean for those who conduct, analyze, and use the DHS? What are the tradeoffs and decisions facing those who collect or use population and health data in developing countries? A panel of three experts examined these issues in a discussion to kick off the 2009-2010 PRB Policy Seminar Series.

Jacob Adetunji of the Office of Population and Reproductive Health of USAID uses DHS data and analyses in a policy environment and discussed the history of the DHS program, its reasons for success, and lessons learned. Adetunji highlighted five reasons for the program's success: a strong technical foundation, independence, quality of data, continuous improvement, and a commitment to stay the course with a sense of continuity and history. "The [data collector] contractor is free to...report the findings objectively without any interference from USAID," says Adetunji. Patience and persistence are key, according to Adetunji, who noted that it takes time to build institutional capacity and for governments to adopt evidence-based approaches to policy and program design. As a sign of the DHS' success, more developing country governments are now funding their own country surveys.

Saifuddin Ahmed, associate professor at the Bloomberg School of Public Health at Johns Hopkins University, noted that the DHS program has reduced the need for indirect estimation and increased confidence in data quality in his work over the past 20 years. However, he pointed out the problems in expanding the DHS to include more survey questions (which lead to data fatigue and exasperation from survey respondents) and other programs and data demands "piggybacking" on DHS.

Ann Way, director of DHS with ICF Macro, shared details on what data DHS collects and what challenges and changes are coming in the latest phase of the program. The number of questions and the time involved in interviewing have expanded over the years as demand for new data from sector interests has increased. The first round of DHS included around 250 questions and had increased to over 850 as of a few years ago. In the most recent phase of the DHS, the average female respondent took 45 to 55 minutes answering interviewers' questions and many interviews now take over 90 minutes to complete, testing the patience of those interviewed and risking the quality of the data collected. As a result, efforts are being directed toward streamlining the DHS core questionnaires. Way outlined other changes that are being implemented in the current round of the DHS that will improve the collection and dissemination of data. New technologies such as handheld personal digital assistants (PDAs), GPS mapping, and expanding the biomarkers that are obtained such as dried blood spot samples, can lower the demands on interviews. In addition, expanding data dissemination through new integrated web tools will further open access to DHS data. Capacity-building efforts will be expanded as DHS curriculum is introduced to public health programs at universities in developing countries and a DHS toolkit is produced.

For each speaker, balancing the demand for new data while continuing the focus of DHS and data quality is a central concern. "The quality of data is one of the main strengths of the project," says Adetunji. "When demand for new data threatens data quality in any survey, we tend to resolve the tension in favor of quality data." According to Way, there are no easy answers to the challenge of maintaining the balance, but "one approach is to reduce what is included in the core instruments to allow room for more country-specific adaptation. We review the DHS core instruments at the beginning of each round of the project...Although the process is not completely final, we have made significant reductions in the overall number of questions that will be in the core DHS questionnaires for this round. The increasing use of computer-assisted interviewing is another promising tool."

Eric Zuehlke is an editor at the Population Reference Bureau.