Vitamin A Supplementation at Birth and Atopy in Childhood
The Effect of Vitamin A Supplementation at Birth on the Development of Atopy in Childhood: Long-term Follow-up of a Randomised Placebo-controlled Trial
INTRODUCTION Eight trials studying the effect of providing neonatal vitamin A supplementation (NVAS) have been reported, and another four are underway to test whether NVAS should become WHO policy. Three of the four African trials were conducted by the Bandim Health Project (BHP) in Guinea-Bissau. One of them was a two-by-two factorial trial among low-birth-weight children. From 2004-2008, the children were randomly allocated to 25,000 IU vitamin A or placebo at birth, and furthermore to BCG vaccination at birth or later as is local policy. In 2011, the investigators conducted a follow-up study. A remarkably strong harmful effect of NVAS on atopy and wheezing was found (manuscript under review).
Seen in the context that NVAS may soon become a WHO policy it is obviously worrying if NVAS is associated with a higher risk of atopy and wheezing. The investigators therefore aim to conduct a similar follow-up study of participants in the first NVAS trial conducted in Guinea-Bissau from 2002-2004, among normal-birth-weight infants, to test whether NVAS is associated with an increased risk of atopy and wheezing and other allergic symptoms as well as growth.
METHODS
Study population:
From 2002-2004 BHP conducted a randomised trial of NVAS. The investigators recruited newborns when they came for BCG vaccination. Provided parental consent, they received an oral supplement of 50,000 IU vitamin A or placebo.
Study design:
This study will be a follow-up study of the cohort of children randomised to NVAS (intervention) or placebo (current policy) together with BCG vaccine at birth.
Other exposures:
The investigators will also investigate the effect of receiving an additional dose of measles vaccine and the timing of DTP vaccine on the development of atopy.
Assessment of outcomes:
The investigators will visit all children at the last known address. Height, weight and mid upper arm circumference will be measured. BCG scar will be examined and vaccination card details recorded by the field assistant. Children will be excluded from skin prick testing (SPT) if they have a history suggestive of anaphylaxis or are currently using anti-histamine medication. SPT will be performed using aero-allergens, food allergens and positive histamine and negative saline control. The mother or guardian will be interviewed by a local assistant. Symptoms of eczema and asthma as well as food allergy will be assessed.
Statistical analysis:
Effect of randomisation group and other factors on outcomes will be analysed in multivariable regression models. All analyses will be adjusted for skin prick tester. All analyses will be conducted stratified by sex.
研究概览
研究类型
注册 (预期的)
联系人和位置
学习地点
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Bissau Codex
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Bissau、Bissau Codex、几内亚比绍、1004
- Bandim Health Project
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参与标准
资格标准
适合学习的年龄
接受健康志愿者
有资格学习的性别
取样方法
研究人群
描述
Inclusion Criteria:
- Enrolled at birth in NCT00168610
Exclusion Criteria:
- Children with history suggestive of anaphylaxis will be excluded from skin prick testing but included in the study population
学习计划
研究是如何设计的?
设计细节
研究衡量的是什么?
主要结果指标
结果测量 |
措施说明 |
大体时间 |
---|---|---|
Atopic sensitisation
大体时间:Single observation on day of recruitment
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Skin prick test positivity.
A wheal >=3mm will be considered positive.
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Single observation on day of recruitment
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次要结果测量
结果测量 |
措施说明 |
大体时间 |
---|---|---|
Symptoms of asthma
大体时间:Single observation on day of recruitment
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Questionnaire based on ISAAC survey for 6-7 year olds
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Single observation on day of recruitment
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Symptoms of eczema
大体时间:Single observation on day of recruitment
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Questionnaire based on ISAAC survey for 6-7 year olds
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Single observation on day of recruitment
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Symptoms of food allergy
大体时间:Single observation of day of recruitment
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Questionnaire based on Health Nuts survey
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Single observation of day of recruitment
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其他结果措施
结果测量 |
措施说明 |
大体时间 |
---|---|---|
Weight
大体时间:Single observation on day of recruitment
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Single observation on day of recruitment
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Height
大体时间:Single observation on day of recruitment
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Single observation on day of recruitment
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Mid-upper arm circumference
大体时间:Single observation on day of recruitment
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Single observation on day of recruitment
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Hospitalisations
大体时间:Single observation on day of recruitment
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Single observation on day of recruitment
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Infectious diseases
大体时间:Single observation on day of recruitment
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History of chickenpox or measles
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Single observation on day of recruitment
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合作者和调查者
调查人员
- 首席研究员:Christine Benn, DMSc、Statens Serum Institut
出版物和有用的链接
研究记录日期
研究主要日期
学习开始
初级完成 (实际的)
研究完成 (预期的)
研究注册日期
首次提交
首先提交符合 QC 标准的
首次发布 (估计)
研究记录更新
最后更新发布 (估计)
上次提交的符合 QC 标准的更新
最后验证
更多信息
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