Haematology Division, ICMR-Regional Medical Research Centre, North East Region, Dibrugarh, Assam, India
BMJ Glob Health. 2022 Jul;7(7). doi: 10.1136/bmjgh-2021-007972.
Vitamin A supplementation (VAS) is yet to reach all Indian children aged 9-59 months, despite guidelines for universal coverage. This study mapped geospatial patterns underlying VAS coverage across two policy-relevant administrative unit levels (states and districts) in India. The relationship between spatial distribution of VAS coverage and vitamin A deficiency (VAD) prevalence was also investigated.
The study draws on nationally representative cross-sectional data collected during National Family and Health Survey 4 (NFHS-4) and Comprehensive National Nutritional Survey (CNNS). VAS coverage was estimated using information obtained during NFHS-4 from mothers about whether their children (n=204 645) had received VAS within 6 months of the survey. VAD prevalence estimates were based on serum retinol measurements during CNNS in under-five children (n=9563). State-level and district-level choropleth maps of VAS coverage were constructed. Spatial patterns were probed using Moran's statistics, scatter plots and local indicators of spatial association (LISA). Relationship between VAS coverage (as an explanatory variable) and VAD prevalence was explored using spatial autoregressive models.
VAS coverage in India (overall 60.5%) ranged from 29.5% (Nagaland) to 89.5% (Goa) across the various states/union territories. Among districts, it ranged from 12.8% (Longleng district, Nagaland) to 94.5% (Kolar district, Karnataka). The coverage exhibited positive spatial autocorrelation, more prominently at the district-level (univariate Moran's I=0.638, z-value=25.614, pseudo p value=0.001). LISA maps identified spatial clusters of high coverage and low coverage districts. No significant spatial association was observed between VAS coverage and VAD prevalence in the states during spatial error (R=0.07, =0.30, p value=0.14) and spatial lag (R=0.05, ρ=0.25, p value=0.23) regression.
Two out of every five eligible Indian children were not supplemented with vitamin A. The coverage was geographically heterogeneous with discernible spatial patterns. Their consequences on vitamin A status and associated health effects in the community deserve close monitoring.
尽管有普及覆盖的指南，但印度仍有 9-59 月龄儿童未能获得维生素 A 补充（VAS）。本研究在印度两个与政策相关的行政单位级别（邦和区）上绘制了 VAS 覆盖范围的地理空间模式。还调查了 VAS 覆盖范围的空间分布与维生素 A 缺乏症（VAD）流行率之间的关系。
本研究利用全国代表性的横断面数据，这些数据是在国家家庭健康调查 4（NFHS-4）和综合国家营养调查（CNNS）期间收集的。通过 NFHS-4 期间从母亲那里获得的有关其子女（n=204645 人）是否在调查前 6 个月内接受 VAS 的信息，估计 VAS 覆盖范围。VAD 流行率估计是根据 CNNS 中五岁以下儿童（n=9563）的血清视黄醇测量值得出的。构建了 VAS 覆盖范围的邦级和区级等值线图。使用 Moran 统计量、散点图和局部空间关联指标（LISA）探测空间模式。使用空间自回归模型探讨了 VAS 覆盖范围（作为解释变量）与 VAD 流行率之间的关系。
印度的 VAS 覆盖率（总体为 60.5%）在各邦/联邦属地之间从 29.5%（那加兰邦）到 89.5%（果阿邦）不等。在各地区，其范围从 12.8%（那加兰邦隆伦区）到 94.5%（卡纳塔克邦科拉尔区）不等。该覆盖率表现出正空间自相关，在区县级更为明显（单变量 Moran's I=0.638，z 值=25.614，伪 p 值=0.001）。LISA 地图确定了高覆盖率和低覆盖率地区的空间聚类。在空间误差（R=0.07，ρ=0.30，p 值=0.14）和空间滞后（R=0.05，ρ=0.25，p 值=0.23）回归中，各州的 VAS 覆盖率与 VAD 流行率之间未观察到显著的空间关联。
每五个符合条件的印度儿童中就有两个没有补充维生素 A。覆盖范围在地理上存在异质性，存在明显的空间模式。它们对社区中维生素 A 状况和相关健康影响的后果值得密切监测。
