ABSTRACT
Objective To establish a suitable exponential smoothing prediction model for school absentees due to illness, to discuss its application value for predicting school absences due to illness, and to provide a basis for early warning of absence due to illness. Methods Numbers of schools absences by year and month due to illness in 30 primary schools from November 2015 to June 2017 were collected from symptom monitoring system of border county, southern Yunnan and Simple seasonal model, Winters addition model and Winters multiplication model were used to build simulation. The data of July 2017 to December 2017 were used for model validation. The three models were overall compared and evaluated through indicator analysis, statistical analysis and residual diagram analysis. The best model was selected to predict school absences due to illness from January 2018 to March 2018. Results Simple seasonal model, Winters addition model and Winters multiplication model were used to fit the variation trend of number of school absences due to illness in time series. The root mean square error (RMSE) of three models were 445.11, 420.99 and 258.75; R2adj were 0.72, 0.72 and 0.77; R2 were 0.92, 0.93 and 0.98; P values of Ljung-Box Q were 0.54, 0.43 and 0.21. As for prediction method linear trend, Alpha were 0.999, 1.000 and 0.298. The average relative error between predicted value and actual value was 9.62%, 21.90% and 7.52%. Conclusion Winters multiplication model has practical value to predict school absence due to illness and provide scientific basis for early identification of abnormal signals.
ABSTRACT
Objetivos: Determinar la prevalencia de dismenorrea y sus factores asociados en estudiantes de tres colegios de Lima de estratos socioeconómicos diferentes. Diseño: Estudio de tipo observacional, de corte transversal y comparativo. Institución: Universidad Nacional Mayor de San Marcos. Participantes: Adolescentes estudiantes de tres colegios. Intervenciones: Se realizó una encuesta anónima a 392 adolescentes de 3 colegios: Newton College (estrato A), De Jesús (estrato B) y Ciro Alegría (estrato C). Principales medidas de resultados: Presencia de dismenorrea. Resultados: La edad promedio de las adolescentes entrevistadas fue 14,8 ± 1,0 años e IMC 22,7 ± 12,9, con edad de menarquía a los 11,9 años. Los días promedio de sangrado menstrual fueron 4,9 días. El porcentaje de adolescentes con dismenorrea fue de 51,7%. El dolor menstrual duró en promedio 1,95 días. El ausentismo escolar fue señalado en 34,2%, 26,4% y 21,3%, en los estratos A, B y C, respectivamente. El antecedente materno tuvo un OR 1,85 (1,38 a 2,58) y p 0,0240, el ejercicio físico OR 0,93 (0,81 a 1,25) y p 0,7794, el consumo de pescado OR 0,96 (0,66 a 1,40) y p 0,0836, el consumo de tabaco OR 1,33 (0,68 a 2,60) y p 0,4207. El consumo de tabaco fue claramente mayor en el estrato A, casi 16% frente al 4% del estrato C. Conclusiones: La edad de la menarquía fue la misma de estudios nacionales. La duración del periodo menstrual fue 4,9 días, superior en un día a lo encontrado en mujeres adultas. Una de cada dos adolescentes presentó dismenorrea y el dolor menstrual duró en promedio dos días. Hubo ausentismo escolar en una de cada cuatro alumnas, por causa del dolor menstrual, mayor en el estrato social alto. La presencia de dismenorrea estuvo relacionada significativamente con el antecedente materno. El consumo de pescado, la actividad física y el hábito de fumar no estuvieron asociados a la presencia de dismenorrea. El consumo de tabaco fue elevado en los estratos sociales altos en comparación con los bajos.
Objectives: To determine dysmenorrhea prevalence and associated factors in three Lima schools students from different socioeconomic strata. Design: Observational, cross-sectional and comparative study. Setting: Universidad Nacional Mayor de San Marcos. Participants: Adolescent students. Interventions: Anonymous survey to 392 teenagers from three schools: Newton College (stratum A), De Jesus (stratum B) and Ciro Alegría (stratum C). Main outcome measures: Dysmenorrhea. Results: Average age of adolescents was 14.8 ± 1.01 years, BMI was 22.7 ± 12.9 and menarche was reported occurring at age 11.9 years average. Average menstrual bleeding was 4.9 days. Percentage of adolescents with dysmenorrhea was 51.7%. Menstrual pain lasted 1.95 days average. School absenteeism was 34.2%, 26.4%, 21.3% in strata A, B and C respectively. Maternal history of dysmenorrhea had an OR = 1.85 (1.38-2.58) and p = 0.0240; fish consumption had an OR = 0.96 (0.66-1.40) and p = 0.0836; tobacco consumption had an OR = 1.33 (0.68-2.60) and p = 0.4207. Tobacco consumption was clearly higher in stratum A, almost 16% compared with 4% in stratum C. Conclusions: Age of menarche was similar to national studies. Duration of menstrual period was 4.9 days, higher in one day to that reported in adult women. One in two teenagers presented dysmenorrhea and menstrual pain lasted 2 days average. School absenteeism was one in each four students because of menstrual pain, mainly in high social status students. Presence of dysmenorrhea was significantly related to maternal history. Fish consumption, physical activity and smoking were not associated with dysmenorrhea. Tobacco consumption was high in social strata A compared with low strata.