Birat Nepal Medical Trust (BNMT), READ-It Project, Kathmandu, Nepal.
Centre for Evidence Synthesis in Global Health, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
PLoS One. 2022 May 18;17(5):e0268507. doi: 10.1371/journal.pone.0268507. eCollection 2022.
The World Health Organization has recommended Vitamin A supplementation for children in low- and middle-income countries for many years to reduce child mortality. Nepal still practices routine Vitamin A supplementation. We examined the potential current impact of these programs using national data in Nepal combined with an update of the mortality effect estimate from a meta-analysis of randomized controlled trials.
We used the 2017 Cochrane review as a template for an updated meta-analysis. We conducted fresh searches, re-applied the inclusion criteria, re-extracted the data for mortality and constructed a summary of findings table using GRADE. We applied the best estimate of the effect obtained from the trials to the national statistics of the country to estimate the impact of supplementation on under-five mortality in Nepal.
The effect estimates from well-concealed trials gave a 9% reduction in mortality (Risk Ratio: 0.91, 95% CI 0.85 to 0.97, 6 trials; 1,046,829 participants; low certainty evidence). The funnel plot suggested publication bias, and a meta-analysis of trials published since 2000 gave a smaller effect estimate (Risk Ratio: 0.96, 95% CI 0.89 to 1.03, 2 trials, 1,007,587 participants), with the DEVTA trial contributing 55.1 per cent to this estimate. Applying the estimate from well-concealed trials to Nepal's under-five mortality rate, there may be a reduction in mortality, and this is small from 28 to 25 per 1000 live births; 3 fewer deaths (95% CI 1 to 4 fewer) for every 1000 children supplemented.
Vitamin A supplementation may only result in a quantitatively unimportant reduction in child mortality. Stopping blanket supplementation seems reasonable given these data.
世界卫生组织多年来一直建议中低收入国家为儿童补充维生素 A，以降低儿童死亡率。尼泊尔仍在常规补充维生素 A。我们使用尼泊尔的国家数据结合随机对照试验荟萃分析中死亡率影响估计的更新，检查了这些计划的潜在当前影响。
我们使用 2017 年 Cochrane 综述作为更新荟萃分析的模板。我们进行了新的搜索，重新应用纳入标准，重新提取死亡率数据，并使用 GRADE 构建了发现总结表。我们将从试验中获得的最佳效果估计应用于该国的国家统计数据，以估计补充剂对尼泊尔五岁以下儿童死亡率的影响。
隐蔽良好的试验的效果估计表明死亡率降低了 9%（风险比：0.91，95%置信区间 0.85 至 0.97，6 项试验；1046829 名参与者；低确定性证据）。漏斗图表明存在发表偏倚，对 2000 年后发表的试验进行荟萃分析得出的效果估计较小（风险比：0.96，95%置信区间 0.89 至 1.03，2 项试验，1007587 名参与者），DEVTA 试验对此估计的贡献为 55.1%。将隐蔽良好的试验的估计应用于尼泊尔五岁以下儿童死亡率，死亡率可能会降低，从每 1000 例活产 28 例降至 25 例；每 1000 名补充维生素 A 的儿童中，死亡人数减少 3 人（95%置信区间减少 1 至 4 人）。
维生素 A 补充剂可能只会导致儿童死亡率的少量降低。考虑到这些数据，停止普遍补充似乎是合理的。
