Sloan N L, Rosen D, de la Paz T, Arita M, Temalilwa C, Solomons N W
Population Council, New York, NY 10017, USA.
Am J Public Health. 1997 Feb;87(2):186-91. doi: 10.2105/ajph.87.2.186.
The prevalence of vitamin A deficiency has traditionally been assessed through xerophthalmia or biochemical surveys. The cost and complexity of implementing these methods limits the ability of nonresearch organizations to identify vitamin A deficiency. This study examined the validity of a simple, inexpensive food frequency method to identify areas with a high prevalence of vitamin A deficiency.
The validity of the method was tested in 15 communities, 5 each from the Philippines, Guatemala, and Tanzania. Serum retinol concentrations of less than 20 micrograms/dL defined vitamin A deficiency.
Weighted measures of vitamin A intake six or fewer times per week and unweighted measures of consumption of animal sources of vitamin A four or fewer times per week correctly classified seven of eight communities as having a high prevalence of vitamin A deficiency (i.e., 15% or more preschool-aged children in the community had the deficiency) (sensitivity = 87.5%) and four of seven communities as having a low prevalence (specificity = 57.1%).
This method correctly classified the vitamin A deficiency status of 73.3% of the communities but demonstrated a high false-positive rate (42.9%).
传统上通过干眼症或生化调查来评估维生素A缺乏症的患病率。实施这些方法的成本和复杂性限制了非研究组织识别维生素A缺乏症的能力。本研究检验了一种简单、廉价的食物频率法识别维生素A缺乏症高发地区的有效性。
在15个社区对该方法的有效性进行了测试，其中5个社区来自菲律宾、危地马拉和坦桑尼亚。血清视黄醇浓度低于20微克/分升定义为维生素A缺乏。
每周维生素A摄入量加权测量值为6次或更少，以及每周动物源性维生素A摄入量未加权测量值为4次或更少，正确地将8个社区中的7个归类为维生素A缺乏症高发地区（即社区中15%或更多的学龄前儿童患有该缺乏症）（敏感性=87.5%），并将7个社区中的4个归类为低发地区（特异性=57.1%）。
该方法正确地对73.3%的社区的维生素A缺乏状况进行了分类，但显示出较高的假阳性率（42.9%）。
