Background. After 2 decades of focused efforts to eradicate polio, the impact of eradication activities on health systems continues to be controversial. This study evaluated the impact of polio eradication activities on routine immunization (RI) and primary healthcare (PHC).
We used a combination of qualitative and quantitative methods to examine the relationship between polio eradication activities, RI, and PHC. This research was approved by the Middlebury College Institutional Review Board. Informed consent was obtained from all participants. A detailed description of our methods is available in an open-access article [20], and the full qualitative protocol is accessible online (available at: http://sites.middlebury.edu/polio_eradication_impacts_study/qualitative-research-guide/). In a global cross-national time series analysis, we evaluated (1) a hypothesized “scale-up” effect of polio immunization campaigns involving an initial benefit to RI and PHC and (2) the impact of campaign intensity, or number of campaigns. The Supplementary Materials contain further technical details about the global analysis and information on 4 country-specific analyses. Our analyses used multiple regression to examine the degree to which polio eradication campaigns explain observed rates of change in diphtheria-tetanus-pertussis (DTP3) vaccination and attended birth coverage. The 3 dependent variables were DTP3 vaccine coverage estimates from the WHO and UNICEF (United Nations Children’s Fund), from 1990–2010; DTP3 vaccine coverage estimates from the Institute for Health Metrics and Evaluation (IHME), from 1995–2006 [21–24]; and attended birth coverage from the World Bank’s World Development Indicators, from 1996–2010 [25]. We operationalized campaign intensity, our independent variable, in 2 ways: the number of polio eradication campaigns per year, and the cumulative percentage of the under-five population targeted by polio eradication campaigns in a given year. The regressions controlled for (1) the initial levels of the dependent variable; (2) political instability, regime type, and wealth and education levels [26–28]; (3) other health financing [29, 30]; and (4) the number of nonpolio health campaigns. By use of R [31], models were fit with each of the 3 different dependent variables to examine the effect of each of the 2 different measures of campaign intensity. For each of these models, we proceeded by first fitting a parsimonious baseline model, using step-down regression, to explain country-wise variability in the dependent variable in terms of the control variables. Then, the resulting baseline model was augmented with one of the measures of campaign intensity to evaluate its additional explanatory power. We used the resulting full model to evaluate the magnitude and direction of the partial effect of polio eradication activities. Our qualitative work was performed in 8 districts evenly divided between South Asia and sub-Saharan Africa (Figure (Figure2).2). Six-week case studies provided an in-depth understanding of the relationship between polio eradication, RI, and PHC within the focal district, not the entire country. Case study districts were purposively selected on the basis of specific guidelines described in our published protocol. Our case studies are drawn from regions with ongoing polio eradication activities and do not represent the current or historical experience of regions of the world (such as the Americas or Southeast Asia) where polio was eliminated relatively quickly. Qualitative case studies. To ensure that we collected comparable information in each site, we followed a standardized protocol involving a comprehensive document review; semistructured interviews with approximately 50 respondents, including community members, ground-level staff, and district and national leadership; and participant observation in polio eradication, RI, and PHC activities. While the protocol included national-level interviews and document review, we focused on evaluating impacts at the district level. The Qualitative Research Guide contains a full description of our qualitative methods [29]. We coded all documents, interview transcripts, and field notes, using the qualitative analysis program NVivo [32], and compared key variables across the case studies. While we endorse the broad definition of PHC framed at Alma-Ata, we used maternal health indicators as a proxy for PHC in our quantitative work because there exist few other reasonably reliable and comparable indicators of PHC across time and space. In qualitative work, we defined PHC as the provision of healthcare at the basic health unit level and below, including services provided by community health workers. We also considered health education, nutrition, and water and sanitation. We did not evaluate the impacts of polio eradication on other vertical programs, such as measles campaigns.