School height censuses are reliable and valid tools for small-area targeting of nutrition interventions in Honduras

Mala nutrición en población escolar mexicana: factores geográficos y escolares asociados

OBJETIVOS

Determinar prevalencias de mala nutrición [sobrepeso u obesidad (Sp+O) y talla baja (TB)] en población mexicana de 6 a 12 años de edad de nivel básico de primaria, y su asociación con características geográficas (ámbito, marginación y región del país), y de la escuela (tipo, turno y grado).

MÉTODOS

Con información de 10 528 676 escolares, se estimaron prevalencias (e I.C. 95%), a nivel nacional y por características de interés, y su asociación mediante modelos de regresión logística.

RESULTADOS

La prevalencia nacional de Sp+O fue 34.4%, 36.5% en ámbito urbano y 40.2% en escuelas privadas. La prevalencia nacional de TB fue 8.7%; en área rural, 13.7% y 28.8% en escuelas tipo indígenas. El Sp+O y la TB se asociaron significativamente con características geográficas y de escuelas.

CONCLUSIONES

Existe una polarización nutricional en el contexto escolar del país. Es importante continuar con sistemas de monitoreo y vigilancia nutricional.

Overweight and obesity of school-age children in El Salvador according to two international systems: a population-based multilevel and spatial analysis

BACKGROUND

The World Health Organization (WHO-2007) and the International Obesity Task Force (IOTF-Cole) systems assess child weight status. However, derived estimations often differ. We aimed to a) compare the prevalence of overweight and obesity, b) analyze individual and contextual factors associated with child weight using multilevel analysis and c) explore the spatial distribution of overweight and obesity using both classification systems.

METHODS

We used data from the 2015/2016 National School Height and Weight Census in El Salvador. Information on 111,991 children aged 6.0-9.9 years attending the first grade was analyzed. Body mass index Z-score (BMIZ), overweight and obesity were defined with both classification systems. Weighted kappa was used to measure agreement. Child, school and municipal potential determinants of BMIZ were examined by multilevel analysis. Municipal spatial clustering of overweight and obesity was tested using Moran's Index and Getis-ord Gi* statistics.

RESULTS

The combined prevalence of overweight and obesity was higher according to the WHO system than the IOTF (30.4% vs 23.1%). The weighted kappa was 0.83. Boys, children attending urban schools, children attending private schools, and children residing in municipalities with high human development index had higher BMIZ than their counterparts. The Moran's indexes were positives and significant. Clusters of high prevalence (above the national prevalence) of overweight and obesity were found in 29 municipalities using the WHO and IOTF systems. For obesity, 28 and 23 municipalities in clusters of high prevalence were detected using the WHO and IOTF criteria, respectively.

CONCLUSIONS

Overweight and obesity is high among school-age children in El Salvador. The prevalence of overweight and obesity was higher when using the WHO system, as compared to the IOTF system. Irrespective of the classification system, the multilevel and spatial analysis derived similar interpretations. These results support the need for national preventive interventions with targeting strategies to reduce overweight and obesity in school-age children.

The reliability of weight-for-length/height Z scores in children

The World Health Organisation (WHO) recommends weight‐for‐length/height (WFL/H), represented as a Z score for diagnosing acute malnutrition among children aged 0 to 60 months. Under controlled conditions, weight, height and length measurements have high degree of reliability. However, the reliability when combined into a WFL/H Z score, in all settings is unclear. We conducted a systematic review of published studies assessing the reliability of WFL/Hz on PubMed and Google scholar. Studies were included if they presented reliability scores for the derived index of WFL/Hz, for children under 5 years. Meta‐analysis was conducted for a pooled estimate of reliability overall, and for children above and below 24 months old. Twenty six studies on reliability of anthropometry were identified but only three, all community‐based studies, reported reliability scores for WFL/Hz. The overall pooled intra‐class correlation coefficient (ICC) estimate for WFL/Hz among children aged 0 to 60 months was 0.81 (95% CI 0.64 to 0.99). Among children aged less than 24 months the pooled ICC estimate from two studies was 0.72 (95% CI 0.67 to 0.77) while the estimate reported for children above 24 months from one study was 0.97 (95% CI 0.97 to 0.99). Although WFL/Hz is recommended for diagnosis of acute under nutrition among children below 5 years, information on its reliability in all settings is sparse. In community settings, reliability of WFL/Hz is considerably lower than for absolute measures of weight and length/height, especially in younger children. The reliability of WFL/Hz needs further evaluation.