Dataset Information

Zero-dose children and the immunisation cascade: Understanding immunisation pathways in low and middle-income countries.

ABSTRACT:

Introduction

Zero-dose prevalence refers to children who failed to receive any routine vaccination. Little is known about the "immunisation cascade" in low- and middle-income countries (LMICs), defined as how children move from zero dose to full immunisation.

Methods

Using data from national surveys carried out in 92 LMICs since 2010 and focusing on the four basic vaccines delivered in infancy (BCG, polio, DPT and MCV), we describe zero-dose prevalence and the immunisation cascade in children aged 12 to 23 months. We also describe the most frequent combinations of vaccines (or co-coverage) among children who are partially immunized. Analyses are stratified by country income groups, household wealth quintiles derived from asset indices, sex of the child and area of residence. Results were pooled across countries using child populations as weights.

Results

In the 92 countries, 7.7% were in the zero-dose group, and 3.3%, 3.4% and 14.6% received one, two or three vaccines, respectively; 70.9% received the four types and 59.9% of the total were fully immunised with all doses of the four vaccines. Three quarters (76.8%) of children who received the first vaccine received all four types. Among children with a single vaccine, polio was the most common in low- and lower-middle income countries, and BCG in upper-middle income countries. There were sharp inequalities according to household wealth, with zero-dose prevalence ranging from 12.5% in the poorest to 3.4% in the wealthiest quintile across all countries. The cascades were similar for boys and girls. In terms of dropout, 4% of children receiving BCG did not receive DPT1, 14% receiving DPT1 did not receive DPT3, and 9% receiving DPT3 did not progress to receive MCV.

Interpretation

Focusing on zero-dose children is particularly important because those who are reached with the first vaccine are highly likely to also receive remaining vaccines.

SUBMITTER: Cata-Preta BO

PROVIDER: S-EPMC8314014 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:ObjectiveTo support evidence informed decision-making, we systematically examine the effectiveness and cost-effectiveness of community engagement interventions on routine childhood immunisation outcomes in low-income and middle-income countries (LMICs) and identify contextual, design and implementation features associated with effectiveness.DesignMixed-methods systematic review and meta-analysis.Data sources21 databases of academic and grey literature and 12 additional websites were searched in May 2019 and May 2020.Eligibility criteria for selecting studiesWe included experimental and quasi-experimental impact evaluations of community engagement interventions considering outcomes related to routine child immunisation in LMICs. No language, publication type, or date restrictions were imposed.Data extraction and synthesisTwo independent researchers extracted summary data from published reports and appraised quantitative risk of bias using adapted Cochrane tools. Random effects meta-analysis was used to examine effects on the primary outcome, full immunisation coverage.ResultsOur search identified over 43 000 studies and 61 were eligible for analysis. The average pooled effect of community engagement interventions on full immunisation coverage was standardised mean difference 0.14 (95% CI 0.06 to 0.23, I2=94.46). The most common source of risk to the quality of evidence (risk of bias) was outcome reporting bias: most studies used caregiver-reported measures of vaccinations received by a child in the absence or incompleteness of immunisation cards. Reasons consistently cited for intervention success include appropriate intervention design, including building in community engagement features; addressing common contextual barriers of immunisation and leveraging facilitators; and accounting for existing implementation constraints. The median intervention cost per treated child per vaccine dose (excluding the cost of vaccines) to increase absolute immunisation coverage by one percent was US$3.68.ConclusionCommunity engagement interventions are successful in improving outcomes related to routine child immunisation. The findings are robust to exclusion of studies assessed as high risk of bias.

Project description:BACKGROUND:The majority of children who die from vaccine-preventable diseases (VPDs) live in low-income and-middle-income countries (LMICs). With the rapid urbanisation and rural-urban migration ongoing in LMICs, available research suggests that migration status might be a determinant of immunisation coverage in LMICs, with rural-urban migrant (RUM) children being less likely to be immunised. OBJECTIVES:To examine and synthesise the data on immunisation coverage in RUM children in LMICs and to compare coverage in these children with non-migrant children. METHODS:A multiple database search of published and unpublished literature on immunisation coverage for the routine Expanded Programme on Immunisation (EPI) vaccines in RUM children aged 5 years and below was conducted. Following a staged exclusion process, studies that met the inclusion criteria were assessed for quality and data extracted for meta-analysis. RESULTS:Eleven studies from three countries (China, India and Nigeria) were included in the review. There was substantial statistical heterogeneity between the studies, thus no summary estimate was reported for the meta-analysis. Data synthesis from the studies showed that the proportion of fully immunised RUM children was lower than the WHO bench-mark of 90% at the national level. RUMs were also less likely to be fully immunised than the urban-non-migrants and general population. For the individual EPI vaccines, all but two studies showed lower immunisation coverage in RUMs compared with the general population using national coverage estimates. CONCLUSIONS:This review indicates that there is an association between rural-urban migration and immunisation coverage in LMICs with RUMs being less likely to be fully immunised than the urban non-migrants and the general population. Specific efforts to improve immunisation coverage in this subpopulation of urban residents will not only reduce morbidity and mortality from VPDs in migrants but will also reduce health inequity and the risk of infectious disease outbreaks in wider society.

Project description:Background With nearly 90% of annual hypertension-related deaths occurring in low- and middle-income countries (LMICs), there is an urgent need to measure the coverage of health services that effectively manage hypertension. However, there is little agreement on how to define effective coverage and the existing hypertension care cascade (hypertension prevalence, percent aware, percent treated, and percent controlled) does not account for the quality of care received by patients. This study reviews definitions of effective coverage and service quality for hypertension management services and proposes an expanded hypertension care cascade to improve measurement of health systems performance. Methods A systematic scoping review of literature published in six electronic databases between January 2000 and October 2020 identified studies that defined effective coverage of hypertension management services or integrated dimensions of service quality into population-based estimates of hypertension management in LMICs. Findings informed an expanded hypertension care cascade from which quality-adjusted service coverage can be calculated to approximate effective coverage. Results The review identified 18 relevant studies, including 6 that defined effective coverage for hypertension management services and 12 that reported a measure of service quality in a population-based study. Based on commonly reported barriers to hypertension management, new steps on the proposed expanded care cascade include (i) population screened, (ii) population linked to quality care, and (iii) population adhering to prescribed treatment. Conclusion There is little consensus on the definition of effective coverage of hypertension management services, and most studies do not describe the quality of hypertension management services provided to populations. Incorporating aspects of service quality to the hypertension care cascade allows for the calculation of quality-adjusted coverage of relevant services, enabling an appropriate measurement of health systems performance through effective coverage. Supplementary Information The online version contains supplementary material available at 10.1186/s12913-022-08190-0.