An evaluation of a global vitamin and mineral nutrition surveillance system / Evaluación de un sistema global de vigilancia nutricional sobre vitaminas y minerales

Evaluation at all levels is a fundamental function at World Health Organization (WHO). Evaluation of public health surveillance systems is essential to ensure that problems of public health importance are monitored efficiently and effectively. The WHO's Vitamin and Mineral Nutrition Information System (VMNIS) was evaluated from the perspective of public health surveillance and informatics. Steps included: engaging the stakeholders of the evaluation; describing the surveillance system; focusing the evaluation design; gathering credible evidence regarding system performance; justifying and stating conclusions and recommendations, and sharing lessons learned from the evaluation. Following this assessment, WHO has begun major efforts to upgrade and expand the VMNIS and now the database is more flexible and efficient. The database evaluation summarized in this paper provides a good example of how public health evaluation frameworks can lead to improved surveillance and enhanced information systems, thus making progress toward the ultimate goal of improving public health.

La evaluación en todos los niveles es una función fundamental en la Organización Mundial de la Salud (OMS). La evaluación de los sistemas de vigilancia epidemiológica es esencial para asegurar que los problemas de importancia para la salud pública sean monitorizados de manera eficiente y efectiva. El Sistema de Información Nutricional sobre Vitaminas y Minerales (VMNIS, por sus siglas en inglés) se evaluó desde la perspectiva de sistema de vigilancia e informática en salud pública. Los pasos incluyeron: el involucramiento de las partes interesadas en la evaluación, la descripción del sistema de vigilancia, el enfoque del diseño para la evaluación, la recopilación de pruebas fiables sobre el rendimiento del sistema, la justificación y desarrollo de conclusiones y recomendaciones, y la diseminación de las lecciones aprendidas de la evaluación. Después de este proceso, la OMS inició importantes esfuerzos para mejorar y ampliar el Sistema de Información Nutricional sobre Vitaminas y Minerales para lograr una base de datos más flexible y eficiente. Este artículo resume la evaluación de esta base de datos para documentar un buen ejemplo de cómo los marcos de evaluación en salud pública pueden llevar a mejorar la información en los sistemas de vigilancia contribuyendo de esta manera al objetivo final de mejorar la salud pública.

Impact of a school-based intervention program on obesity risk factors in Mexican children.

OBJECTIVE: To evaluate the impact of an 18-month school obesity prevention intervention on the health behaviors of 4th and 5th grade students based on ecological principles and formative research conducted in Mexico. MATERIALS AND METHODS: A Randomized Control Trial (RCT), design was used to assign 27 schools to one of three conditions: basic or plus interventions and control. School environment measures, children's eating and physical activity behaviors, and body mass index were assessed four times over a 2-year period in a sample of 830 students. RESULTS: In the intervention schools, the availability of healthy foods increased with a concomitant decrease in unhealthy food availability. Food intake showed the same trend. In the intervention schools, children did not engage in more moderate to vigorous physical activity (MVPA) in physical education (PE) class or recess but increased steps taken. Obesity prevalence did not change. CONCLUSION: The intervention improved the school food environment and child healthy behaviors.

An evaluation of a global vitamin and mineral nutrition surveillance system.

Evaluation of public health surveillance systems is essential to ensure that problems of public health importance are monitored efficiently and effectively. The WHO's Vitamin and Mineral Nutrition Information System (VMNIS) was evaluated from the perspective of public health surveillance and informatics. Steps included: engaging the stakeholders of the evaluation; describing the surveillance system; focusing the evaluation design; gathering credible evidence regarding system performance; justifying and stating conclusions and recommendations, and sharing lessons learned from the evaluation. Following this assessment, WHO has begun major efforts to upgrade and expand the VMNIS and now the database is more flexible and efficient. The database evaluation summarized in this paper provides a good example of how public health evaluation frameworks can lead to improved surveillance and enhanced information systems, thus making progress toward the ultimate goal of improving public health.

Impact of a school-based intervention program on obesity risk factors in Mexican children / Impacto de un programa de intervención en escuelas para la prevención de factores de riesgo de la obesidad en niños mexicanos

Objective. To evaluate the impact of an 18-month school obesity prevention intervention on the health behaviors of 4th and 5th grade students based on ecological principles and formative research conducted in Mexico. Materials and methods. A Randomized Control Trial (RCT), design was used to assign 27 schools to one of three conditions: basic or plus interventions and control. School environment measures, children's eating and physical activity behaviors, and body mass index were assessed four times over a 2-year period in a sample of 830 students. Results. In the intervention schools, the availability of healthy foods increased with a concomitant decrease in unhealthy food availability. Food intake showed the same trend. In the intervention schools, children did not engage in more moderate to vigorous physical activity (MVPA) in physical education (PE) class or recess but increased steps taken. Obesity prevalence did not change. Conclusion. The intervention improved the school food environment and child healthy behaviors.

Objetivo. Evaluar el impacto de una intervención de 18 meses para la prevención de obesidad en escolares de 4o y 5o grados basada en el modelo ecológico en conductas saludables en México. Material y métodos. Diseño experimental para asignar 27 escuelas a uno de los tres tratamientos: intervenciones básicas, intervenciones plus y control. Se midió el impacto en el ambiente escolar, la alimentación y la actividad física e índice de masa corporal en niños. La evaluación se llevó a cabo en dos años en 830 estudiantes. Resultados. En las escuelas de intervención, la disponibilidad de alimentos sanos aumentó y la disponibilidad de alimentos poco saludables disminuyó. La ingesta de alimentos en niños no mostraron las mismas tendencias. En las escuelas de intervención, los niños no participaron más en actividad física moderada y vigorosa. La prevalencia de obesidad no se modificó. Conclusión. La intervención mejoró el entorno alimentario escolar y las conductas saludables de alimentación y actividad física.

Effect of a school-based intervention on physical activity: cluster-randomized trial.

PURPOSE: Physical activity in childhood has many health benefits; however, the majority of children in many countries, including Mexico, are insufficiently active. The objective of this investigation was to test the effect of a school-based environmental intervention on the physical activity and physical fitness of students attending public primary schools in Mexico City. METHODS: Twenty-seven schools were randomly assigned to basic or plus intervention or control. The basic and plus groups were exposed to school environment and policy changes to enhance physical activity. Physical activity was evaluated in 699 randomly selected fourth- and fifth-grade students by measuring school-day and all-day (24 h) steps using pedometers worn for 5 d before and after the 6-month intervention. Physical fitness was assessed by measuring the 9-min run, flexibility, and sit-ups. We calculated the average change in school-day and all-day steps and fitness measures from baseline to follow-up. Using linear regression, we tested the effect of intervention on change controlling for baseline measures and covariates and accounting for the design effect of school. Using logistic regression, we tested the effect of intervention on reaching step cutoffs at baseline and follow-up. RESULTS: The plus group significantly (P < 0.05) increased school-day steps relative to control (change = 687 vs -639). Significantly (P < 0.05) more participants in the basic (25.8%) and plus (36.4%) groups reached step cutoffs during school relative to control (12.0%). The basic group significantly (P < 0.05) increased all-day steps relative to control (change = 581 vs -419). The plus group significantly (P = 0.05) increased sit-ups relative to control (change = 0.3 vs -1.7). CONCLUSIONS: A school-based environmental intervention improved student physical activity during school in public schools in Mexico City.

Knowledge and adoption of community mitigation efforts in Mexico during the 2009 H1N1 pandemic.

BACKGROUND: The public's ability and willingness to adopt community mitigation efforts during a pandemic are debated in the literature. PURPOSE: Awareness and adoption of community mitigation efforts in Mexico during the 2009 pandemic influenza A (H1N1) (pH1N1) outbreak were measured to evaluate if the population received, understood, and acted on public health messages. METHODS: A cross-sectional representative household survey in Mexico City; San Luis Potosi (high case ratio); and Queretaro (low case ratio) was conducted in May and June 2009. Accounting for the complex survey design, percentages and 95% CI for answers to all questions were generated and compared based on living inside or outside Mexico City, high versus low prevalence of infection in the community, and perceived severity and knowledge of the virus. RESULTS: Greater than 90% of respondents received community mitigation messages and adopted one or more community mitigation efforts. There were few differences among cities. Respondents reported high cost of masks, soaps, and gels as barriers to community mitigation-effort adoption. Nearly one fifth of respondents, disproportionally from the lower socioeconomic tertile, found some messages confusing. Half of all households reported a negative economic impact resulting from the outbreak. CONCLUSIONS: Mexico's community mitigation campaign reached the majority of the population in three surveyed cities. Confusion regarding messages and economic barriers to community mitigation-effort adoption were sometimes reported.

Some indicators of nutritional status are associated with activity and exploration in infants at risk for vitamin and mineral deficiencies.

Severe malnutrition, both protein-energy and micronutrient deficiency, results in decreased activity, but the results regarding mild-to-moderate malnutrition are equivocal. Our objective in this investigation was to describe the activity and exploratory behavior of Mexican infants and describe the relationship among nutritional status, activity, and exploration in this population at high risk for mild-to-moderate micronutrient deficiency, but at low risk for severe malnutrition. The participants were infants, 4-12 mo old, of low socioeconomic status from 3 states in southern Mexico. We measured anthropometrics using standard techniques. We measured hemoglobin (Hb) concentration in the field and adjusted values for altitude before analysis. We measured activity and exploration by direct observation during 15 min of individual play in a novel environment. Cluster analysis generated mutually exclusive activity clusters and exploration clusters based on patterns of bodily movement and exploratory behavior, respectively. We categorized the clusters as higher or lower activity or higher or lower exploration. A higher Hb concentration and height-for-age Z-score (HAZ) significantly increased the odds of being in the high-activity cluster. Iron deficiency, stunting, and wasting significantly decreased the odds of being in the high-activity cluster. Higher HAZ and weight-for-age Z-score significantly increased the odds of being in a higher exploration cluster. In Mexican infants at risk for mild-to-moderate micronutrient deficiency but at low risk of severe malnutrition, some indicators of nutritional status were related to increased activity and exploration.

Physical activity during the school day in public primary schools in Mexico City.

OBJECTIVE: To quantify the physical activity (PA) of students and describe the school environment surrounding PA. MATERIAL AND METHODS: Between November 2005 and March 2006, in Mexico City, we conducted quantitative and qualitative observations to describe the PA and the school context. RESULTS: Recess and physical education class (PE) were the only opportunities to participate in PA. PE occurred one time per week with a duration of 39.8+/-10.6 minutes which is less than national and international recommendations. Students participated in moderate-to-vigorous PA 29.2+/-17.8% of PE. The dynamics of PE did not promote the inclusion of all students or PA. During recess there was overcrowding of the school patio and no equipment for PA or organization of PA. DISCUSSION: The PA of students in public schools in Mexico City can be improved by increasing the quantity and quality of PE and increasing opportunities for activity during recess.

Physical activity during the school day in public primary schools in Mexico City / La actividad física durante la jornada escolar en escuelas primarias públicas en la Ciudad de México

OBJECTIVE: To quantify the physical activity (PA) of students and describe the school environment surrounding PA. MATERIAL AND METHODS: Between November 2005 and March 2006, in Mexico City, we conducted quantitative and qualitative observations to describe the PA and the school context. RESULTS: Recess and physical education class (PE) were the only opportunities to participate in PA. PE occurred one time per week with a duration of 39.8±10.6 minutes which is less than national and international recommendations. Students participated in moderate-to-vigorous PA 29.2±17.8 percent of PE. The dynamics of PE did not promote the inclusion of all students or PA. During recess there was overcrowding of the school patio and no equipment for PA or organization of PA. DISCUSSION: The PA of students in public schools in Mexico City can be improved by increasing the quantity and quality of PE and increasing opportunities for activity during recess.

OBJETIVO: Cuantificar la actividad física (AF) en niños escolares y describir el entorno escolar relacionado con la AF. MATERIAL Y MÉTODOS: Entre noviembre de 2005 y marzo de 2006 en la Ciudad de México, se realizó observación directa cuantitativa y cualitativa para describir el nivel de AF y el contexto escolar durante recreo y clases de educación física (CEF). RESULTADOS: El recreo y las CEF fueron los únicos espacios en los que se realizó AF. Las CEF se impartieron una vez a la semana y duraron 39.8±10.6 minutos, lo que está por debajo de las recomendaciones internacionales. Se participó en actividades moderadas-vigorosas 29.2±17.8 por ciento de las CEF. La dinámica de las CEF no favoreció la AF. Durante el recreo se observó saturación del patio y no se realizaron actividades organizadas ni se utilizaron materiales para promover la AF. DISCUSIÓN: Se recomienda incrementar la calidad y la cantidad de las CEF y el tiempo dedicado a jugar durante el recreo.