Prevalence of Anemia in Children Three to 12 Months Old in a Health Service in Ribeirão Preto , SP , Brazil

Iron deficiency anemia is the most common nutritional deficiency among children. This crosssectional, descriptive and quantitative study is part of a multicenter project, which verified the prevalence of anemia in children aged three to 12 months, treated by a health service unit in Ribeirão Preto, SP, Brazil. Interviews with mothers and determining hemoglobin dosage were carried out with 121 children who participated in the study. Two international criteria were adopted as parameters of anemia according to the children’s age. Descriptive statistics, measures of central tendency and associations were used for data analysis. The prevalence of anemia among 69 children aged three to 5 months was 20.2% and 48.0% among 52 children aged six to 12 months. The total prevalence of anemia was 32.2%. There was significant association between anemia and children’s age, and anemia and the consumption of liquid cow’s milk.


Introduction
Anemia is defined by the World Health Organization as a condition in which the content of hemoglobin in the blood is below normal levels for a given age, gender and physiological condition due to a deficiency of one or more essential nutrients, among them iron, folic acid, zinc, vitamin B12 and proteins (1) .
According to the United Nations Children's Fund, 90% of all types of anemia in the world are due to deficiency of iron.Anemia in Latin and Central America is caused by a deficiency of iron, which has been characterized as a severe public health problem, affecting approximately 50% of pregnant women and children (2) .
Studies addressing the prevalence of anemia in developing countries, as in the case of Brazil, and in low-income populations have been recommended (3) .
There is no national data in Brazil describing the prevalence of iron deficiency anemia, though studies carried out in several regions in the country have shown a significant increase of the prevalence and severity of iron deficiency anemia in risk groups in recent years (2,4) .Regional data were obtained by a systematic review addressing the prevalence of anemia in Brazil in studies published between 1996 and 2007.More studies were developed in the Southeast geographic region than in other regions, though the North and Midwest, the least investigated regions, presented a high prevalence of Rev. Latino-Am.Enfermagem 2010 Jul-Aug; 18(4):792-9.
anemia: more than half of the studied children presented the disease (5) .Its prevalence varies from 22.7% to 77.0% in the different regions and these discrepancies are related to socioeconomic factors (4) .
The causes of iron deficiency anemia may begin in the intra-uterine period due to a deficiency in the mother, since the physiological reserves of iron in the fetus are formed in the last period of pregnancy.This reserve jointly with iron acquired from maternal milk supports the infant's needs up to the sixth month of life.
The problem is aggravated in early childhood due to incorrect feeding habits, especially during weaning, when, maternal milk is frequently replaced by food that is poor in iron.Cow's milk is an example.Despite the fact it presents the same level of iron as maternal milk, its bioavailability is low (6) .The quantity of iron in maternal milk is 0.1 to 1.6 mg/L with high bioavailability, which enables the infant's system to absorb high levels of iron, reaching about 50% to 70% of it.This process is optimized by the presence of lactose, which participates in the mechanisms of calcium and iron absorption, a fact that has reinforced the evidence that maternal milk is one of the most important sources of protection against anemia in infants (7) .Maternal nutrient deficiency during lactation may reduce the concentration of some of these nutrients in maternal milk with consequent depletion in the child.Coupled with this, iron absorption from maternal milk diminishes up to 80% when other foods begin to be consumed (8) .Therefore, we propose an investigation to address anemia in children three to 12 months of age in a health unit of Ribeirão Preto, SP, Brazil.This study is part of a multicenter (9) study in which three cities in the Brazilian southeast region participated: Ribeirão Preto-SP; São Paulo-SP and Rio de Janeiro-RJ.The results of this study will contribute to other studies and support the improvement of actions and protocols directed to childcare and follow-up in health services.
The objective was to verify the prevalence of anemia in children aged three to 12 months associated with variables for children's: age, gender, weight at birth, gestational age, use of iron supplementation, hemoglobin value (Hb) at the day of collection in a health service in Ribeirão Preto.The age limits between three to 12 months of age were established due to the fact that the concentration of hemoglobin reaches the lowest value observed in the child's entire developmental period because of the transformation of fetal hemoglobin to adult hemoglobin that occurs in the first two months of life, which is referred to as "physiologic anemia of infancy" (2) .The influence of breastfeeding on anemia is better verified in children younger than six months of age, and it is not predictive of iron deficiency after this period (10) .However, we consider it important to analyze the prevalence of anemia among children six to 12 months of age since this is a period in which children's diet is changed, that is, it is a critical stage, which can frequently lead to the disease when the child does not receive an appropriate diet (11) .
The following variables were considered for the study's descriptive analysis: maternal variables -age, schooling, number of children and occupation; and children's variables -age, gender, weight at birth, gestational age, iron supplementation, hemoglobin value (Hb) at the day of collection.Two criteria were used as indicators of anemia: Hb < 10.3 g/dl (Saarinen's standard) (12) for children younger than six months of age and Hb < 11.0 g/dl (WHO standard) (13) for children aged six to 12 months.Other studied variables were related to families' life style and housing: type of housing, basic sanitation and variables related to breastfeeding and liquid feeding.The categories proposed by PAHO/WHO (14) were used to classify breastfeeding and the categories The presence or absence of anemia, categorized by the two mentioned international standards according to age, was considered the dependent variable in the association analysis and the independent variables were those related to the children and their diet focusing on the types of breastfeeding, types of formulas, use of water and tea.
Interviews with the mothers to complete the form and blood collection from the children occurred after medical consultation.Blood samples were collected from the children's calcaneous to dose hemoglobin (Hb), a procedure performed with a portable photometer (HemoCue R ) for the direct and immediate reading of samples.This equipment is recommended in population investigations to verify the prevalence of anemia.A small quantity of non-diluted blood is used; it promotes a smaller risk of errors and presents immediate results (15) .
The hemoglobin value was disclosed to mothers and recorded on the children's medical files so measures were taken to diagnose and treat anemia if necessary.

Results
A total of 121 mothers were interviewed.The majority (93;76.6%) lived with their partners; 90 (74.6%) were housewives.The age of the mothers varied from 15 to 41 years old, with an average of 25.5 (sd=6.4) and median of 24 years.In regard to schooling, 66 (54.5%) had primary school (incomplete or complete); 2 (1.7%) were illiterate and three (2.5%) had a bachelor's degree.The average age of the children was 1.9; 56 (46.3%) were primiparous.The majority of families, 113 (93.4%), lived in masonry houses, while 55 (45.5%) lived in their own houses; 100% were connected to electricity; 95% had a water connection; and 99.2% had garbage collection.The majority of families (71;58.7%)lived with four people and one or two family members contributed to the family income (80.2%).
In regard to the 121 children, 66 (54.5%) were male; 110 (91.0%) born at term; 69 (57.0%) were younger than six months, the average age was 189.9 days (sd=80.3)and the median was 169 days.The lowest weight at birth was 2,020 grams, the highest was 4,165 grams and the average was 3,188.4grams (sd = 447.4).
Of the 52 (100.0%)children older than six months of age, two (3.8%) were PB, 23 (44.2%) were B and 15 of these were in mixed feeding (eight children received liquid cow's milk and seven dried cow's milk), eight were B; 27 (52%) were weaned and one of them was never breastfed.
For the total of 121 children, the average duration of EB was 81.1 days (sd = 52.5)and the median was 90 days.For the total of 78 children who were being breastfed, the average duration of B was 170.7 days (5.7 months) and the median was 151.5 days (5 months).
(33.3%) out of the total of 69 children younger than six months of age were receiving liquid and dried cow's milk respectively.The consumption of liquid cow's milk increased to 61.5% in children older than six months of age, while the consumption of dried milk diminished to 23.1%.The consumption of water and/or tea was 82.6% for the 69 children younger than six months.
Of the total of 121 children aged three to 12 months (incomplete) distributed according to age and the hemoglobin value measured at the time of data collection, average value and median of hemoglobin was 11.1g/dL; standard deviation was 1.41.The lowest value of hemoglobin found was 7.3 and the highest was 15.4 g/dL.
Tables 1 and 2 present the distribution of children aged three to 12 months (incomplete) according to age and anemia criteria.For the total of 69 (100%) children aged three to 5 months (incomplete), the prevalence of anemia was 20.2% ( 14) (Table 1).For children aged six to 12 months (incomplete), (n= 52) the prevalence of anemia was 48.0%, based on the WHO criteria (Table 2).No statistical association was found between anemia and children's variables in the bivariate analysis: gender, weight at birth, gestational age and iron supplementation.However, we observed a higher of prevalence of anemia among male children (34.8%), among those whose weight at birth was above or equal to 2,500 grams (32.4%), those whose gestational age was above 37 weeks (32.7%) and among those who did not take iron supplements (Table 3).There was a strong association between anemia and children older than six months of age (complete) (x 2 = 10.48,p<0.001).

Anemia (Saarinen
Of the total of 121 children aged three to 12 months, the prevalence of anemia was 32.2% (29) based on Saarinen's standard for children younger than six months of age (Table 1) and WHO standard for children older than six months of age (Table 2).use of water and/or tea (Table 4).There was statistically significant association between the use of liquid cow's milk and anemia (x 2 =6.68, p=0.010).Nursing practice allows the development of these attributes, especially with women, to guide mothers/ women concerning their children's care.
This is a cross-sectional, observational, descriptive and quantitative study.Three health services were included in the overall study: BHU Vila Virginia, Ribeirão Preto-SP; The Health Center School in Butantã, São Paulo-SP, and the pediatric outpatient clinic in the Institute Fernandes Figueira, Rio de Janeiro, RJ, Brazil.The multicenter project and this study were approved by Ethics Research Committee at the University of São Paulo at Ribeirão Preto, College of Nursing, protocols n° 342/2003 and 0538/2005 -CEP-EEUSP respectively, in compliance with Resolution 196/96 of the National Health Council.Data were collected in the Basic Health Unit (BHU) in Vila Virginia, in Ribeirão Preto-SP, which is located in the south area of the city and was chosen because it presents one of the highest rates of live birth in the city.Other factors such as the significant increase in exclusive breastfeeding rates in children younger than four months of age and the systematization of actions to promote breastfeeding were also relevant to this choice.Data were collected from December 1 st 2005 to July 30 th 2006.Study participants were mothers who agreed to participate in the study and their children aged three to 12 months (incomplete) with appointments scheduled in the pediatric service of the BHU Vila Virginia, Monday through Friday in the afternoon, according to inclusion and exclusion criteria.Inclusion criteria included: children aged three to 12 months (incomplete), from any ethnic group and social class with appointments scheduled in the unit in the afternoon and who were accompanied by their mothers.Exclusion criteria: children with no medical file in the unit; or with an acute infectious condition at the day of the interview; or who were cared for in the pediatric emergency care unit.
Weaning (W) and Never Breastfed (NB) were included.Exclusive Breastfeeding (EB): the child receives only maternal milk directly from the breast or extracted from it and no other liquid or solid food, with the exception of medication or vitamin supplements; Predominant Breastfeeding (PB): the child receives breast milk and also water or water-based beverages (teas, juices) and no other liquid or solid food; Breastfeeding (B): the child receives breast regardless of any other liquid or solid foods, including other types of milk; Weaning (W): the child does not receive breast milk, but other types of milk, liquid or solid foods are offered; Never Breastfed (NB): the child never received breast milk.
performed using the Statistical Package for Social Sciences (SPSS ® , version 11.5).Central tendency measures were used for continuous quantitative variables: average, standard deviation, median, minimum and maximum values.Chisquare and Fisher's exact test with level of significance α = 0.05 were used to associate anemia and children's variables and diet.
in children aged three to 12 months (incomplete), cared for in the childcare service in the BHU Vila Virginia, in the afternoon, from September 2005 to July 2006, Ribeirão Preto, SP, Brazil *Statistically significant at 5% level of significance on the hypothesis that the causal effect is due to random sampling Reis MCG, Nakano AMS, Silva IA, Gomes FA, Pereira MJB.Vila Virginia, in the afternoon, varied according to the children's age and standard used to detect anemia: 20.2% of the 69 children aged three to 5 months and 48% for 52 children aged six to 12 months (incomplete).The prevalence of anemia in the 121 children aged three to 12 months was 32.2% according to the Saarinen's and WHO standards.Statistically significant association was found between anemia and children's age and the consumption of liquid cow's milk.We draw attention to care provided to children in this age range in the prevention, diagnosis and treatment of this deficiency.Challenges and strengths are presented for the multi-professional team involved with childcare.Support for mothers/women concerning how to provide a diet appropriate for the growth and development of their children requires a synergistic relationship between technical efficiency and the proper use of relational technology in order to welcome, listen to and take co-responsibility with mothers/women.

Table 1 -
Distribution of children aged three to 5 months old*, cared for in the pediatric service of the BHU Vila

Table 3 -
Distribution of children's variables (age, weight at birth, gestational age, iron supplement) associated with anemia (Saarinen's and WHO standards) for children aged three to 12 months (incomplete), cared for in the childcare service of the BHU Vila Virginia, in the afternoon, from September 2005 to July 2006, , Ribeirão Preto, SP, Brazil Reis MCG, Nakano AMS, Silva IA, Gomes FA, Pereira MJB.

Table 3 -
Continuation Statistically significant at 5% level of significance on the hypothesis that the causal effect is due to random sampling *

Table 4 -
Distribution of variables breastfeeding/liquid feeding associated with anemia(Saarinen and WHO standards)