Today, more than one third of children in need are not receiving the life-saving benefits of vitamin A supplementation

Vitamin A deficiency is the leading cause of preventable childhood blindness and increases the risk of death from common childhood illnesses such as diarrhoea. Periodic, high-dose vitamin A supplementation is a proven, low-cost intervention[1] which has been shown to reduce all-cause mortality by 12 to 24 per cent[2], and is therefore an important programme in support of efforts to reduce child mortality. The World Health Organization has classified vitamin A deficiency as a public health problem affecting about one third of children aged 6 to 59 months in 2013, with the highest rates in sub-Saharan Africa (48 per cent) and South Asia (44 per cent).

As supplementation is a key child survival intervention, discussions of progress focus largely on coverage of that intervention. Despite the potential benefits, only 64 per cent of targeted children were reached in 2016, with West and Central Africa achieving the lowest coverage at 54 per cent. Of 82 countries deemed ‘priorities’[3] for national-level vitamin A supplementation programmes, 57  had two-dose coverage estimates available for 2016. Just over one third of these 57 countries, or 20 countries, achieved coverage of 80 per cent or more in that year.  Future efforts will need to focus on strengthening systems so that more children can be protected.

Data

Vitamin A supplementation

Notes on the data

Guidelines for monitoring vitamin A supplement coverage

Guidelines from the Global Alliance for Vitamin A (GAVA) provide more information on monitoring and reporting of vitamin A supplementation programmes targeted at 6- to 59-month-old children through one guideline for district-level managers as well as a separate guideline for national-level managers.

This section on data notes comprises the following information:

1. Indicator definitions for vitamin A supplementation coverage
1.1 Indicator definitions for the global database (administrative data)
1.2 Other indicator definitions (survey-based data)
2. Major sources of data for administrative coverage estimates
3. UNICEF Global VAS coverage database (used in this report)
4. Population weighted global and regional estimates

Indicators

Table 1. Indicator definitions for vitamin A supplementation coverage

Indicator name Indicator definition Numerator Denominator
1.1 VAS coverage indicators in UNICEF’s global database
1.1a Semester 1 VAS Coverage (January to June) Percentage of children 6–59 months of age who received an age appropriate dose of vitamin A in semester 1 through the main distribution mechanism[1] Number of children aged 6–59 months that received an age appropriate dose of  vitamin A through the main distribution mechanism* in semester 1 Total population of 6–59 month olds
1.1b Semester 2 VAS Coverage (July to December)

 

Percentage of children 6–59 months of age who received an age appropriate dose of vitamin A in semester 2 through the main distribution mechanism* Number of children aged 6–59 months that received an age appropriate dose of vitamin A through the main distribution mechanism* in semester 2 Total population of 6–59 month olds
1.1c Two-dose VAS  coverage (composite indicator of Semester 1 and 2) The semester which achieved the lower VAS coverage for children aged 6-59 months in a given calendar year Number of children aged 6–59 months that received an age appropriate dose of vitamin A through the main distribution mechanism* in the semester with the lower coverage in the calendar year Total population of 6–59 month olds
1.2 Other VAS coverage indicators (not used in UNICEF’s global database)
1.2a VAS coverage in a specific event

 

The percentage of children aged 6–59 months who received a dose of vitamin A in the specific event asked about in the survey. Number of children aged 6–59 months whose care-giver reported they received a dose of vitamin A in the specific event

 

Total number of 6–59 month olds surveyed

 

1.2b VAS coverage in the last 6 months The percentage of children aged 6–59 months who received a dose of vitamin A in the 6 months before their survey interview date. Number of children aged 6–59 months whose care-giver reported they received a dose of vitamin A in the previous 6 months Total number of 6–59 month olds surveyed

 

 1.1 Indicator definitions for the global database (administrative data)

Two-does VAS coverage is the main indicator for monitoring VAS programmes. Two-dose VAS coverage is an estimate of the percentage of children aged 6–59 months who received two doses of VAS spaced about 4 to 6 months apart in a calendar year. The semester which achieved the lower coverage between semester 1 and semester 2, is used (e.g. if semester 1 is 98 per cent and semester 2 is 50 per cent, the two-dose coverage is 50 per cent). In cases where there are only data for one of the two annual semesters (i.e. the other semester did not have any data or did not have an approved coverage estimate), the two dose coverage is listed as “no data”. In cases where more than 8 months has occurred between the event in semester 1 and semester 2, the two dose coverage is listed as 0 per cent.

Although international recommendations call for vitamin A supplementation every four to six months, current monitoring efforts are unable to capture the proportion of children covered who are receiving both annual doses of vitamin A with appropriate spacing. Approximations of two-dose coverage presented by UNICEF assume that in countries providing more than one round of supplementation, the same children  are probably bypassed in both distributions. The assumption is that the proportion of children reached by one campaign but not by the other would be minimal. Therefore, the lower of two coverage data points for a given year is assumed to be roughly equivalent to the proportion of children receiving two appropriately spaced doses of vitamin A. UNICEF and its partners are working to develop more refined methods for measuring the proportion of children fully protected.

1.2 Other indicator definitions (survey-based data)

Survey-based data are not used in the UNICEF global VAS database given that they are available too infrequently and/or do not align well with semesters.

One indicator (1.2a) refers to VAS coverage at a specific event.  This indicator is typically used in household surveys implemented very soon after an event (e.g. within 4–6 weeks of a Child Health Event) with a main purpose of assessing coverage as well as collecting other information related to the specific event. In most cases these are undertaken infrequently and are generally subnational in scale, but can also be nationally representative. These estimates can be compared with the semester-wise data from administrative estimates.

Another survey-based estimate (1.2b) collected is about VAS coverage in the 6 months preceding the survey. This indicator is typically used in large multi-topic household surveys such as the Demographic and Health Surveys (DHS). Given that the dates of survey do not necessarily align with any given semester, and may cross more than one semester and even more than one calendar year, they are usually not comparable with the administrative semester-based estimates.

Using the sample calendar above, all of those interviewed from 12 October to 21 December would report on the Polio SIA on 15-17 June and if reported correctly, that group, comprising about two-thirds of the interview duration, would have reported a coverage of 98%. Those interviewed from 22 Dec 2015 to 20 January 2016 would report receipt (or not) at the December Child Health Event and if reported correctly, that group, comprising about one third of the interview duration, would have reported a coverage of 74%.  However, for 2015, the coverage in the global database would have been 98% for semester 1 and 74% for semester 2 with 74% for two-dose coverage.  The coverage in the survey report would be around 90% as the previous 6 months from the interview date would have been a combination of different events and semesters and would not align with the global database in terms of coverage rate or semester or two-dose coverage.

2. Major sources of data for administrative coverage estimates

Data collection and reporting

Data on coverage of high-dose vitamin A supplementation in 6- to 59-month-old children, which are compiled in UNICEF’s global database, come from administrative reports filled in by national governments, UNICEF country office staff and other partners. The numerators for country-level coverage estimates are generally derived from the following two in-country sources:

  • Tally sheetsare generally used during outreach or campaign-style events. These can include Child Health Days, Polio Supplementary Immunization Activities (SIAs)and Measles SIAs and capture the total number of doses delivered to children during an event. Tallies from each distribution/event site are summed up to provide the total number reached at the national level.
  • Health information system reports generally capture the total number of supplements delivered through routine health system contacts – that is, the doses delivered to children when they go to a health centre to receive well-child visit services such as vaccinations. These data are generally rolled up to the central level together with information on vaccines or essential drugs.

Selection of coverage data for the vitamin A programme database

The following rules are used during the annual reviews to select or adjust coverage figures for entry into UNICEF’s database and publication in The State of the World’s Children.

  • National programmes:The database only reports coverage of countries that have programmes that are, or should be, national in scope. Coverage figures are therefore excluded for country programmes that are geographically targeted. For example, coverage data have been excluded for Peru, where specific supplementation efforts regularly reach upwards of 90 per cent of children in areas of the country with an elevated prevalence of vitamin A deficiency or a high under-five mortality rate.
  • Nationally representative data:Only ‘nationally representative’ coverage data are included in the database. Since these data are based on administrative reports, the coverage of reporting is used to gauge whether the data are nationally representative. In addition to reporting on the number of children reached in each semester, countries also report on the number of districts (or lower-level administrative units such as health posts) that submitted a report for each semester. Data must be available from at least 80 per cent of districts (or 80 per cent of lower-level administrative units) to be included in UNICEF databases.
  • Timing between doses: The amount of time between the distribution dates must be about 4 to 6 months to be included in the database. This is because the protective effects of high-dose vitamin A supplements last about 4 to 6 months.  For example, if country A distributed vitamin A supplements during a Child Health Event in March for semester 1, and again in September for semester 2, both of these points would be accepted since they are six months apart, thereby allowing optimal protection. On the contrary, if country B distributed vitamin A supplements through a Child Health Day in June and reported this for semester 1 with 81 per cent coverage, and a Polio National Immunization Day in August reported as semester 2 with 93 per cent coverage, only one of the two points can be used.  Even though each event occurred in a different ‘semester’, the short span of time between the two distributions (one to two months between doses) would not confer optimal protection to the children reached. In such a case, the higher of the two (Polio National Immunization Day) would be used and the other point discarded.  In the case of country B, the administrative data from routine health system contacts from January to June, if not already submitted through the report, would be sought and, if available, used to report coverage for semester 1. If country B did not have data related to vitamin A supplementation through routine health system contacts for semester 1, the country would be reported as not having data (-) for two-dose coverage for that year in UNICEF’s database.
  • Selection of data:Where coverage data from more than one distribution mechanism are available for a given semester, only data from one of them can be used, to prevent double counting of children who may have received a dose through each of the two. When data for both an outreach/campaign style event and routine health system contact are available for the same country in one semester, the coverage estimate is based on only one – the higher of the two.  However, since the main distribution mechanisms may vary between sub-age groups of 6- to 11-month-olds and 12- to 59-month-olds, countries are asked to report on these two age groups separately. When numerators and denominators are available for these two main sub-age groups for two different distribution mechanisms in a given semester, they may be combined in different ways, with the aim of giving an estimate with the highest coverage. To take one example: In semester 1, country C reached 90 per cent of 6- to 11-month-olds through routine contact, but only 38 per cent of them through a campaign-style event. It reached 12 per cent of 12- to 59-month-olds through routine contact and 96 per cent of them through an outreach/campaign-style event. In this case, the routine data for 6- to 11-month-olds would be combined with the event data for 12- to 59-month-olds to generate the overall coverage for 6- to 59-month-olds.
  • Adjustment of denominators:When reviewing the denominator data provided through country reports, one of the checks is a comparison with United Nations Population Division estimates for the target age group. Where the denominator in the country report is ≥90 per cent of the UN population estimate, the country-reported denominator is used in conjunction with the country-reported numerator to estimate the coverage. If the country-reported denominator is <90 per cent of the UN estimate, the UN population estimate is used as the denominator in coverage calculations.
  • Timely submission of reporting forms:Final reports submitted and cleared prior to a cut-off date which can vary by year and which is generally based on release of The State of the World’s Children Report. For countries that could not meet this deadline, opportunities to update UNICEF’s global databases are possible at any time pending submission of final reports and clearance of these rules.
  • Capped coverage figures:Coverage data points ≥100 per cent were capped at 99 per cent.
  • Age-targeted programmes: Coverage for programmes targeting children other than those aged 6 to 59 months are reported as targeted (that is, the proportion of the targeted age range receiving supplements) and marked with a footnote in The State of the World’s Children(for example, Viet Nam targets children aged 6 to 36 months in some provinces and 6 to 59 months in other provinces).

Coverage gaps in the database

Ideally, coverage data are available from all 82 priority countries, that is countries deemed ‘priorities’ for national-level vitamin A supplementation programmes. This would allow aggregated estimates to be representative of the full population of children at risk. However, some priority countries are not included because they do not submit a -report or due to issues with completeness of reporting of data quality concerns. In most years, some 50 to 60 priority countries have two-dose coverage estimates in the database. As the countdown advances towards international development goals, further efforts will be needed to ensure timely, accurate and complete reporting on coverage of this critical child survival intervention.

[1] See UNICEF’s micronutrient pages for more information.

[2] Imad et al. (2011) Vitamin A supplementation for preventing morbidity and mortality in children from 6 months to 5 years of age. The Cochrane Collaboration and published in The Cochrane Library 2011, Issue 1.

[3] Priority countries for national vitamin A supplementation programmes are identified as those having high under-five mortality rates (more than 70 per 1,000 live births), and/or evidence of vitamin A deficiency among this age group, and/or a history of vitamin A supplementation programmes.