Detection of Anemia in Schoolchildren Aged 6-18 Years With Hematocrit Percentile Charts and the Impact of Economic Status in Southern Brazil.

OBJECTIVE

To generate hematocrit percentile charts for schoolchildren aged 6-18 years and determine the prevalence of anemia by socioeconomic status class in southern Brazil.

METHODS

This is a cross-sectional study utilizing data collected between 2014 and 2017 from southern Brazil. The study's sample consists of 4802 schoolchildren, aged 6 to 18 years. The percentile charts for sex-specific hematocrit were developed using the LMS (Lambda-Mu-Sigma) method. The simplified economic classification, based on ABEP criteria, was used to group individuals into A + B (high), C (middle), and D + E (low) income classes. Anemia was defined as hematocrit z-score ≤ -1.96 for age and sex.

RESULTS

Among boys, 58 (2.86%) were anemic, 1955 (94.81%) had normal hematocrit levels, and 48 (2.33%) had high hematocrit. Girls showed a similar pattern, with 73 (2.73%) anemic, 2534 (94.90%) with normal hematocrit, and 63 (2.36%) with high hematocrit. For girls, a higher prevalence of non-anemic hematocrit was observed in class A (39.33%) compared to anemic children (23.28%), with significant standardized residuals. For boys, significant residuals were observed for a higher prevalence of anemic children in the lower socioeconomic class DE (13.79%) compared to non-anemic children (5.18%), and a higher prevalence of non-anemic children in the upper socioeconomic class A (42.63%) compared to anemic children (22.41%).

CONCLUSION

The percentile charts generated from hematocrit levels enabled the comparison of anemia prevalence across socioeconomic status classes. A higher prevalence of anemia was found among boys in lower socioeconomic classes, while girls in higher socioeconomic classes showed a lower prevalence of anemia.