Risk factors of iron-deficiency anemia in infants under 2 years of age in Yerevan: a case-control study

Abstract

Iron-deficiency anemia (IDA) is the most prevalent nutritional disorder among infants throughout the world, especially in developing countries. In low-income countries IDA causes poor performance on mental and motor tests among infants and children. It is a serious public health problem among children in Armenia as well. According to statistical data from the Ministry of Health that was available only for 1998, the national figure of iron deficient anemia from mild to moderate among infants was 26 %. In urban areas IDA was found in 15%-16% of infants, while in rural areas this figure accounts for 38% of infants. Since IDA is a disease with significant consequences on child development, the only practical way to approach this problem is prevention of IDA in infancy. Thus, the purpose of this study is the identification of potential risk factors mostly contributing to IDA in infants in Armenia. As a result, data could be used to develop programs for effective prevention. No epidemiological studies have been done before in Armenia concerning risk factors of IDA in infants. A case control study will be used as a tool for identification of main risk factors contributing to IDA in children under 2 years of age in Yerevan. The case definition for this study includes all children under 2 years of age from Yerevan, who are diagnosed for the first time with iron-deficiency anemia identified from the Children's Republic Clinical Hospital and the Children's Clinical Hospital # 3 during the time of the survey. The control definition includes all children under 2 years of age from Yerevan, who do not have iron-deficiency anemia identified from the Children's Republic Clinical Hospital and the Children's Clinical Hospital # 3 during the time of the survey and in the medical history. Cases and controls will be matched on age and gender of children, and hospital of admission. The study will be conducted during the time period of January 1, 2000 - October 1,2000. 173 cases and 346 controls are necessary for this study. The influence of following factors will be measured: demographic characteristics of the child (age, gender, birth weight, and maturity); personal medical history of the child (previous diseases, blood losses, and surgical manipulations); diet of the child; anemia of pregnancy; maternal coffee consumption; educational level of caretakers; and expenditure on food per person. The data will be collected using the same questionnaire for cases and controls, and from medical records. Following a definition of the variables of interest a questionnaire was developed. It will be used in face-to face interviews or in phone interviews, if a patient had blood test and left the hospital before the interview. Data will be entered into Stata computer program. Statistical analysis will be done with use of chi-square tests and logistic-regression models, and will be based on estimation of odds ratios and 95% confidence intervals.