Effectiveness of two programs of intermittent ferrous supplementation for treating iron-deficiency anemia in infants: randomized clinical trial

ABSTRACT CONTEXT AND OBJECTIVE: Low compliance among mothers regarding the treatment of anemic children using daily doses of ferrous sulfate administered at home has been reported. This study aimed to establish the effectiveness of weekly doses administered by mothers at home compared with weekly supplements administered directly by healthcare professionals, to reduce the prevalence of anemia. DESIGN AND SETTING: This was a randomized clinical trial at a public healthcare clinic in São José do Rio Preto, Brazil. METHODS: This iron supplementation study was carried out using two intervention groups. The sample population was 130 infants, randomly allocated to two groups of 65 children. All of them received 12 weekly doses of 25 mg of elemental iron, administered either in the public healthcare clinic or at their homes. RESULTS: Treatment compliance was shown in both groups. The prevalence of anemia among all of the children was 75% at the beginning of supplementation and 46.3% at the end of the period (P < 0.0005), corresponding to a reduction in the number of anemic children of 38.3%. The average increases in hemoglobin concentration levels were 0.75 g/dl and 0.65 g/dl, respectively for home interventions and healthcare clinic administration (P < 0.00005). CONCLUSION: Weekly supplementation of 25 mg of iron was proven to be efficient in reducing anemia, using interventions both at home and in healthcare clinics. Compliance among the mothers was achieved because weekly supplementation was easy to administer and had few side effects. The results showed that the treatment presented low cost and fast benefits. CLINICAL TRIAL REGISTRATION NUMBER: NCT00655408.


INTRODUCTION
Nutritional anemia, according to the World Health Organization (WHO), is a state in which low blood hemoglobin concentration is a consequence of defi ciency of one or more essential nutrients, for any reason.Anemia due to insuffi cient iron is known as iron-defi ciency anemia.[5][6][7][8][9][10] The main factors implicated in the etiology of anemia during early childhood are iron reserves at birth, speed of growth, diet and the rate of iron loss. 11Reduction of blood hemoglobin concentrations impairs oxygen transport to tissues, thereby reducing cognitive functions, altering thermoregulation and affecting immunity. 12Research has shown that children with iron defi ciency have lower performance in psychomotor tests compared with non-anemic children. 12,13For infants aged between six and 24 months, iron supplementation is the main treatment for iron defi ciency.In this age range, the prevalence of anemia is at least 20%. 14he most common procedure for treatment and prophylaxis of anemic children attended in both private and public healthcare clinics has been to counsel mothers regarding iron supplementation at home.However, studies have shown a low rate of compliance among mothers over the recommended period.6][17][18] Some studies have shown satisfactory results in relation to reducing the prevalence of iron defi ciency using weekly doses of ferrous sulfate, 4,[19][20][21][22] thereby avoiding these side effects.

OBJECTIVE
This study aimed to compare the effectiveness of low-dose weekly ferrous sulfate supplementation administered to children in a public healthcare clinic in São José do Rio Preto, Brazil, with its administration by their mothers at home, in order to reduce the prevalence of anemia.

PATIENTS AND METHOD
A clinical randomized study involving two intervention groups was carried out between April 2003 and January 2004.The development of this study followed the ethical requirements and all regulatory policies involved in research on humans, as laid down by Resolution 196/96 of the National Health Council of the Ministry of Health, 1996.This study was approved by the Research Ethics Committee of Faculdade de Medicina de São José do Rio Preto (Famerp).
The research population was initially 173 children aged 6 to 24 months who were registered at a public healthcare clinic in the district of Solo Sagrado in São José do Rio Preto.From this initial sample, 43 children were excluded from the study in accordance with specifi c predefi ned criteria such as the presence of an infectious process at the time of the first consultation or two weeks prior to the intervention, 23 positive results from the Guthrie test, 24 previous use of ferrous sulfate supplements and blood hemoglobin concentration of less than 7 g/dl. 25Iron supplementation was therefore started for 130 infants.
The subjects were randomly allocated to two intervention groups of 65 infants each by using a table of randomly distributed numbers.Sample size calculations indicated that, with ≥ 33 children per group, it would be possible to detect hemoglobin changes with a power of 0.8 and P value of 0.05, considering anemia prevalence of around of 60% 4 and a reduction of 40%. 21The two groups included both anemic (serum hemoglobin concentration less than 11 g/dl) 1 and nonanemic children.One group received weekly ferrous sulfate supplementation in the healthcare clinic and the other group received the same supplementation administered by their mothers or by another adult responsible for the child, at home.
Before starting the iron supplementation, during a private consultation, the parent or guardian of each child received a single initial explanation about the nature of the study, filled out a questionnaire to give information about the child and received instructions about the iron supplementation, according to the group to which each child was allocated.All parents or guardians of the children that participated in the study also signed written consent forms.
All of the infants underwent anthropometric evaluations and 2 ml of venous was drawn for blood tests (measurement of serum hemoglobin concentrations).In order to classify the children according to their anemic state, the criteria proposed by the WHO were adopted, i.e. identifying anemia when the hemoglobin values were less than 11.0 g/dl.Other studies 4,21,22 have shown that the main cause of anemia in under-24-month-old children is iron deficiency, and therefore the hemoglobin concentration was used to define the prevalence of anemia, without evaluating organic mineral reserves (serum ferritin).
In order to evaluate the children's nutritional state, their weight (kg) and height (cm) measurements were taken before and after the period of iron supplementation.Weight and height data from the National Center for Health Statistics (NCHS) in the United States, 26 were taken as the references.
The dose of ferrous sulfate was chosen based on two studies of weekly iron supplementation.In a study by Palupi et al., 20 weekly supplements of 30 mg of elemental iron resulted in a significant increase in hemoglobin among children aged two to five years old.In another study, Thu et al. 21used doses of 20 mg of elemental iron supplemented by vitamin C to improve iron absorption in children aged six to 24 months.In the present study, for both groups, a weekly dose of 1 ml of ferrous sulfate oral solution (Fer-in-Sol ® ) was used, corresponding to 25 mg of elemental iron.Thus, this was a dose lower than 30 mg, because the children were younger than those of Palupi at al., 20 but higher than 20 mg because the children did not receive supplementary vitamin C as in the study of Thu et al. 21n the thirteenth week of the trial, i.e. one week after the final dose, each child was again assessed using the same blood tests as used initially, to measure blood hemoglobin concentrations.Hence, the prevalence of anemia was calculated at the beginning and the end of the treatment period.
All the mothers of the children in both groups were asked to record the dates on which the weekly supplements were administered and also any occurrences of side effects, on a standard questionnaire that was similar to a vaccination card.

Statistical analysis
In order to analyze the anthropomorphic data, the Epi-Info (version 6.04) 27 statistical package was used.Descriptive statistics were used to analyze data relating to the effects of ferrous sulfate supplementation on the children in both groups.To compare means between three classes, analysis of variance (ANOVA) was used.To compare means between pairs of groups, the t-test for two samples was used, and to compare the likelihood of events in both groups, the test for normal approximation of two proportions was used or the McNemar test when recommended.The statistical analyses were performed using the Minitab software, version 12.22.The statistical significance level was defined as an alpha error of 5% (P-value < 0.05).

RESULTS
The study showed compliance by the mothers in both study groups.Only 22 children (16.9%) did not complete the full 12 weeks of treatment, and this occurred because the mother or guardian had difficulties in traveling to the healthcare clinic or did not have time to take the child; or because the family moved to another region or there was a lack of interest in continuing the treatment.Hence, 108 children completed the entire treatment program, of whom 56 were treated at home and 52 in the public healthcare clinic.
The characteristics of the study population according to mean age, gender and anthropomorphic data (weight and height) are shown in Table 1.Statistical analysis comparing the two groups did not identify any significant differences in the variables analyzed (P > 0.05).
The mean number of doses taken by the children in the study was 11 (standard deviation, SD = 2.79) out of a possible 12 for the complete period.Side effects such as vomiting and diarrhea were observed in only 4% of the children.With regard to these data, no significant differences were observed between the two groups (P = 0.32).
The data relating to the prevalence of anemia in the 108 infants before and after the treatment program are summarized in Figure 1.Before treatment, anemia was identified in 81 (75%) of the 108 children, of whom 41 were attended in the clinic and 40 at home.The anemia rate at the end of the treatment was 46.3%, corresponding to a reduction of around 38.3% (P < 0.0005).Considering each group separately, for the infants supplemented at home, the initial prevalence of 71.4% decreased to 42.8% at the end of the treatment.For the children supplemented in the clinic, the prevalence dropped from 78.8% to 50%.Significant reductions occurred in both groups (P < 0.0005).On the other hand, comparison of the reductions between the two groups did not identify any significant differences (P = 0.35).
At the end of the supplementation period, a significant increase of 0.70 g/dl (SD = 0.91) in mean hemoglobin concentrations was found (P < 0.00005).When considering the two groups separately, the initial and final mean blood hemoglobin concentrations were as presented in Table 2. Once again, no significant differences were found between the two groups (P = 0.13).
Table 3 shows the increase in hemoglobin concentrations at the end of the supplementation period compared with the initial concentrations.The data shown in this table illustrate an inversely proportional relationship between blood hemoglobin concentration increases and the initial hemoglobin level.The children whose initial hemoglobin values were in the lower two categories (< 9.5 g/dl and between 9.5 and < 11.0 g/dl) presented significantly greater increases at the end of the intervention than did those in the third category (≥ 11.0 g/dl) (P < 0.02).

DISCUSSION
The results from this study showed that both programs were efficient in reducing anemia.There were no significant differences in the characteristics of intermittent iron supplementation using ferrous sulfate between administration in a public healthcare clinic and administration at home, with regard to reduction in anemia, increased blood hemoglobin concentrations, compliance with the treatment among the mothers and side effects.
Reduction of the occurrence of irondeficiency anemia is a priority worldwide, especially among under-two-year-old children.This age range is the period of greatest brain development, as has been previously reported. 12In Brazil, because of the high prevalence of this disease, children's development is compromised.][21][22] The present study showed treatment compliance in both groups: out of the 12 scheduled doses during the treatment period, an average of 11 doses was administered, and only 22 children (16.9%) out of the total of 130 did not complete the treatment.This result may have been achieved because the supplementation took place weekly, with the use of standard records to control administration of the doses.This procedure facilitated the treatment considerably because it significantly reduced the effort required from mothers.Furthermore, weekly supplementation reduced the incidence of side effects.][17][18] In the present study the rate of reported side effects was low (4%).
Gillespie et al. 28 recommended that the prophylactic doses of ferrous sulfate supplementation for children between six months and two years old should be 1 mg/kg/day.Since infants, on average, weigh approximately 7 kg at six months and 13 kg at two years of age, the total weekly doses would be 49 mg and 91 mg of iron, respectively.
In the present study, the significant reduction in the prevalence of anemia was achieved using single weekly doses of only 25 mg for 12 weeks, independently of the age or weight of the child, i.e. a dose that was lower than the prophylactic dose recommended.The same significant results were achieved in relation to the mean increase in blood hemoglobin concentrations.Other studies using intermittent supplementation have reported results that

REFERENCES
were similar to those of the present study, 20 or results that were even better, through the use of higher iron doses, longer intervention periods and/or associated administration of vitamins and minerals. 21,22he mean increases in blood hemoglobin concentrations at the end of the intervention were more evident among infants who presented lower initial hemoglobin concentrations (lower than 9.5 g/l), i.e. among the most anemic children.On the other hand, when the initial concentrations indicated that there was no anemia (concentrations greater than or equal to 11.0 g/dl), there were even some decreases.The difference between the initial and final concentrations in the non-anemic group was significantly smaller than it was for children with some degree of anemia.This means that the organism efficiently absorbs iron according to its needs, and that the iron uptake may increase by up to 90% in severely anemic children. 29

CONCLUSIONS
In conclusion, simple and inexpensive programs of weekly iron supplementation can be used in public healthcare clinics or at home to effectively reduce the prevalence of iron-deficiency anemia.The results showed that both intervention programs described in this study fulfilled the requirements of providing easily administered iron supplementation and involving minimal human resources at low cost, because of the weekly doses.

Figure 1 .
Figure 1.Prevalence of anemia among the 108 infants as percentages, before and after supplementation (respectively, in gray and black): Group 1 represents the children who received supplementation at home and Group 2, the children who received supplementation in the public healthcare clinic.0 10 20 30 40 50 60 70 80

Table 1 .
Characteristics of the 108 children at the beginning of the study according to treatment location (home or healthcare clinic), mean age, gender and anthropometric data (weight and height)

Table 3 .
Hemoglobin (Hb) change at the end of the intervention period, according to initial anemia SD = standard deviation.*The two first groups significantly differed from the third group regarding blood hemoglobin concentration change at the end of the intervention period (P < 0.02).

Table 2 .
Mean initial and final blood hemoglobin concentrations and change at the end of the supplementation program, for both groups of infants