Assessing the Effectiveness of House-to-House Visits on Routine Oral Polio Immunization Completion and Tracking of Defaulters

"The usefulness of household visitation as a strategy to improving coverage of routine polio vaccination, one of the four pillars of the global polio eradication strategy, has not been documented previously."

Recognising that strengthening routine immunisation (RI) is one of the 4 prongs of the Global Polio Eradication Initiative (GPEI), these researchers assessed the communication strategies developed by the CORE Group Polio Project (CGPP) to support the GPEI's core objective: detect and stop the transmission of poliovirus through surveillance and immunisation.

Working only in high-risk areas in Angola, Ethiopia, and India (at the time of this writing), CGPP implements: (i) community-based acute flaccid paralysis (AFP) surveillance, (ii) support for oral polio immunisation OPV provision through the RI system by promotion in the community and system strengthening for healthcare providers, and (iii) participation in supplementary immunisation campaigns. The CGPP uses a variety of social mobilisation/communication strategies to promoting RI and complementing mass media's social mobilisation activities conducted by GPEI partners among hard-to-reach populations. The focus of this study is on the household visits carried out by community health workers (CHWs), who maintain a list of children younger than five years of age in their catchment areas and visit the households to encourage the family to bring their children to receive OPV as well as other antigens at RI opportunities. Contents discussed in training and ongoing supportive supervision of CHWs had different emphases in each country, based on concerns of the local community. For example, in India, community health workers received training on how the vaccine was produced to reassure families that the vaccine contained no ingredients that violated Muslim religious requirements. In Angola, by contrast, where demand was high but awareness of specific vaccination opportunities was low, contents focused on when and where the vaccine would be available. CHWs also held health education activities. The timing and frequency of the visits ranged from 15 to 30 minutes, on average; they occurred as often as every 2 months for families with children still needing routine vaccinations.

This paper examines the effectiveness of these house-to-house health promotion visits by lay health workers in increasing completion of at least 3 doses of OPV through the RI system compared to residents of the intervention catchment area, who did not report receiving a household visit by health workers. The researchers collected data through 30-cluster sample household surveys of caretakers of children aged 12-23 months in Angola, Ethiopia, and India. The study involved simple frequency tables, as well as bivariate and multivariate logistic regression analyses.

Table 1 presents the rate of full RI coverage against polio in CGPP areas in each country. In Ethiopia, 75.8% of children had received at least 3 routine doses of OPV, compared to 69.2% in India and 61.8% in Angola. Results are also elaborated; for example, in Ethiopia, completed polio vaccination was significantly and positively associated with caregivers' knowing the correct timing of the first dose of polio vaccination, speaking the main dialect of the area, and working outside the home ["Work outside the home in the intervention areas of rural Ethiopia may be paired with greater exposure to towns where health posts are located and, therefore, more with greater access to vaccination services."]

In short: "The evidence presented supports the conclusion that the CGPP approach of targeting high-risk areas for house-to-house visits played a role in increasing routine OPV3 completion. The child of a caregiver who reported a visit by a health worker to the home was more likely to have completed the routine polio immunization series in all three countries, even after controlling for potential confounding variables. The effect-size was strong, and the association was statistically significant in India and Ethiopia. The association observed in Angola was not significant but was positive."