ABSTRACT OBJECTIVE Defining priority vaccination groups is a critical factor to reduce mortality rates. METHODS We sought to identify priority population groups for covid-19 vaccination, based on in-hospital risk of death, by using Extreme Gradient Boosting Machine Learning (ML) algorithm. We performed a retrospective cohort study comprising 49,197 patients (18 years or older), with RT-PCR-confirmed for covid-19, who were hospitalized in any of the 336 Brazilian hospitals considered in this study, from March 19th, 2020, to March 22nd, 2021. Independent variables encompassed age, sex, and chronic health conditions grouped into 179 large categories. Primary outcome was hospital discharge or in-hospital death. Priority population groups for vaccination were formed based on the different levels of in-hospital risk of death due to covid-19, from the ML model developed by taking into consideration the independent variables. All analysis were carried out in Python programming language (version 3.7) and R programming language (version 4.05). RESULTS Patients’ mean age was of 60.5 ± 16.8 years (mean ± SD), mean in-hospital mortality rate was 17.9%, and the mean number of comorbidities per patient was 1.97 ± 1.85 (mean ± SD). The predictive model of in-hospital death presented area under the Receiver Operating Characteristic Curve (AUC - ROC) equal to 0.80. The investigated population was grouped into eleven (11) different risk categories, based on the variables chosen by the ML model developed in this study. CONCLUSIONS The use of ML for defining population priorities groups for vaccination, based on risk of in-hospital death, can be easily applied by health system managers

ABSTRACT OBJECTIVE Defining priority vaccination groups is a critical factor to reduce mortality rates. METHODS We sought to identify priority population groups for covid-19 vaccination, based on in-hospital risk of death, by using Extreme Gradient Boosting Machine Learning (ML) algorithm. We performed a retrospective cohort study comprising 49,197 patients (18 years or older), with RT-PCR-confirmed for covid-19, who were hospitalized in any of the 336 Brazilian hospitals considered in this study, from March 19th, 2020, to March 22nd, 2021. Independent variables encompassed age, sex, and chronic health conditions grouped into 179 large categories. Primary outcome was hospital discharge or in-hospital death. Priority population groups for vaccination were formed based on the different levels of in-hospital risk of death due to covid-19, from the ML model developed by taking into consideration the independent variables. All analysis were carried out in Python programming language (version 3.7) and R programming language (version 4.05). RESULTS Patients’ mean age was of 60.5 ± 16.8 years (mean ± SD), mean in-hospital mortality rate was 17.9%, and the mean number of comorbidities per patient was 1.97 ± 1.85 (mean ± SD). The predictive model of in-hospital death presented area under the Receiver Operating Characteristic Curve (AUC - ROC) equal to 0.80. The investigated population was grouped into eleven (11) different risk categories, based on the variables chosen by the ML model developed in this study. CONCLUSIONS The use of ML for defining population priorities groups for vaccination, based on risk of in-hospital death, can be easily applied by health system managers

RESUMO Objetivos: analisar a relação da idade materna e da fonte pagadora da assistência com as vias de nascimento em hospitais nacionais públicos e privados entre os anos de 2012 a 2017, e o tempo de permanência hospitalar. Métodos: estudo transversal com 91.894 mulheres que tiveram seus filhos em hospitais públicos e privados entre 2012 a 2017. Os dados foram coletados a partir do sistema Diagnosis-Related Groups Brasil e submetidos à análise comparativa entre pacientes do atendimento público e da saúde suplementar. Resultados: no atendimento público, a maioria dos nascimentos ocorreram por via vaginal e o inverso ocorreu na saúde suplementar. Observou-se que a proporção de cesariana foi maior na faixa etária de 31 a 40 anos, em ambos os serviços, e maior tempo de permanência hospitalar nas mulheres submetidas à cesariana. Conclusões: idade materna elevada e fonte de financiamento influenciam nas vias de nascimento, que interferem no tempo de permanência hospitalar.

ABSTRACT Objectives: to analyze the relationship between maternal age and the source of healthcare payment with mode of delivery in public and private national hospitals between the years 2012 to 2017, and the length of hospital stay. Methods: cross-sectional study of 91,894 women who had children in public and private hospitals between 2012 and 2017. Data were collected from the Diagnosis-Related Groups Brazil system and a comparative analysis was performed between patients in public care and those in supplementary healthcare. Results: in public care, the majority were vaginal deliveries and the reverse occurred in supplementary health. The proportion of cesarean sections was higher in the age group 31 to 40 years old in both services. The hospital stay was longer among women who underwent a cesarean section. Conclusions: high maternal age and the source of healthcare payment influence the mode of delivery, which interfere with the length of hospital stay.

RESUMEN Objetivos: analizar la relación entre la edad materna y la fuente de pago de la atención con las rutas de nacimiento en hospitales nacionales públicos y privados entre los años 2012 a 2017, y la duración de la estancia hospitalaria. Métodos: estudio transversal con 91.894 mujeres que tuvieron hijos en hospitales públicos y privados entre 2012 y 2017. Se recopilaron datos del sistema Diagnosis-Related Groups Brasil y se realizó un análisis comparativo entre pacientes en atención pública y aquellos en atención médica complementaria. Resultados: en la atención pública, la mayoría fueron partos vaginales y lo contrario ocurrió en la atención complementaria. La proporción de cesáreas fue mayor en el grupo de edad de 31 a 40 años en ambos servicios. La estadía en el hospital fue más larga entre las mujeres que se sometieron a una cesárea. Conclusiones: La edad materna elevada y la fuente de pago influyen en la ruta de nacimiento, lo que interfiere con la duración de la estancia hospitalaria.

ABSTRACT Objectives: to analyze the relationship between maternal age and the source of healthcare payment with mode of delivery in public and private national hospitals between the years 2012 to 2017, and the length of hospital stay. Methods: cross-sectional study of 91,894 women who had children in public and private hospitals between 2012 and 2017. Data were collected from the Diagnosis-Related Groups Brazil system and a comparative analysis was performed between patients in public care and those in supplementary healthcare. Results: in public care, the majority were vaginal deliveries and the reverse occurred in supplementary health. The proportion of cesarean sections was higher in the age group 31 to 40 years old in both services. The hospital stay was longer among women who underwent a cesarean section. Conclusions: high maternal age and the source of healthcare payment influence the mode of delivery, which interfere with the length of hospital stay.

RESUMEN Objetivos: analizar la relación entre la edad materna y la fuente de pago de la atención con las rutas de nacimiento en hospitales nacionales públicos y privados entre los años 2012 a 2017, y la duración de la estancia hospitalaria. Métodos: estudio transversal con 91.894 mujeres que tuvieron hijos en hospitales públicos y privados entre 2012 y 2017. Se recopilaron datos del sistema Diagnosis-Related Groups Brasil y se realizó un análisis comparativo entre pacientes en atención pública y aquellos en atención médica complementaria. Resultados: en la atención pública, la mayoría fueron partos vaginales y lo contrario ocurrió en la atención complementaria. La proporción de cesáreas fue mayor en el grupo de edad de 31 a 40 años en ambos servicios. La estadía en el hospital fue más larga entre las mujeres que se sometieron a una cesárea. Conclusiones: La edad materna elevada y la fuente de pago influyen en la ruta de nacimiento, lo que interfiere con la duración de la estancia hospitalaria.

RESUMO Objetivos: analisar a relação da idade materna e da fonte pagadora da assistência com as vias de nascimento em hospitais nacionais públicos e privados entre os anos de 2012 a 2017, e o tempo de permanência hospitalar. Métodos: estudo transversal com 91.894 mulheres que tiveram seus filhos em hospitais públicos e privados entre 2012 a 2017. Os dados foram coletados a partir do sistema Diagnosis-Related Groups Brasil e submetidos à análise comparativa entre pacientes do atendimento público e da saúde suplementar. Resultados: no atendimento público, a maioria dos nascimentos ocorreram por via vaginal e o inverso ocorreu na saúde suplementar. Observou-se que a proporção de cesariana foi maior na faixa etária de 31 a 40 anos, em ambos os serviços, e maior tempo de permanência hospitalar nas mulheres submetidas à cesariana. Conclusões: idade materna elevada e fonte de financiamento influenciam nas vias de nascimento, que interferem no tempo de permanência hospitalar.

RESUMO OBJETIVO Avaliar se grupo etário, complicações ou comorbidades estão associados ao tempo de internação de mulheres submetidas à cesariana. MÉTODOS Estudo transversal realizado entre junho de 2012 e julho de 2017, com 64.437 mulheres submetidas à cesariana e que não apresentaram condições adquiridas durante o tempo de permanência hospitalar. Os dados foram coletados a partir da alta hospitalar nas instituições nacionais de saúde, utilizando o sistema Diagnosis-Related Groups [Grupos de Diagnósticos Relacionados] (DRG Brasil®). Foram incluídos os DRG referentes à cesariana com complicações ou comorbidades adicionais ao diagnóstico inicial (DRG 765) e cesariana sem complicações ou comorbidades associadas (DRG 766). A influência do grupo etário e comorbidades ou complicações presentes na admissão sobre o tempo de permanência hospitalar foi avaliada por meio da análise de variância. O tamanho do efeito foi verificado pelo d de Cohen, que permite avaliar a relevância clínica. Os níveis de criticidade foram identificados utilizando o teste de Duncan. RESULTADOS O maior tempo de permanência hospitalar foi observado nos grupos etários de 15 a 17 anos e 45 anos ou mais. Mulheres que apresentaram complicações ou comorbidades presentes à admissão também apresentaram maior tempo de permanência hospitalar. Quantos aos níveis de criticidade, notou-se que seu aumento estava associado ao aumento na média do tempo de permanência hospitalar. CONCLUSÕES O tempo de permanência hospitalar de mulheres é maior entre aquelas pertencentes aos grupos etários de 15 a 17 anos e 45 anos ou mais. A presença de comorbidades associadas, como a eclâmpsia, o distúrbio hipertensivo pré-existente com proteinúria superposta e a hipertensão gestacional (induzida pela gravidez) com proteinúria significativa aumentam o tempo de permanência hospitalar. Este estudo possibilitou a construção de perfis distintos de níveis de criticidade a partir da combinação de grupos etários e das principais comorbidades, os quais se apresentaram diretamente relacionados ao tempo de permanência hospitalar.

ABSTRACT OBJECTIVE To evaluate whether age group, complications or comorbidities are associated with the length of hospitalization of women undergoing cesarean section. METHODS A cross-sectional study was carried out between June 2012 and July 2017, with 64,437 women undergoing cesarean section and who did not acquire conditions during their hospital stay. Hospital discharge data were collected from national health institutions, using the Diagnosis-Related Groups system (DRG Brasil®). The DRG referring to cesarean section with additional complications or comorbidities (DRG 765) and cesarean section without complications or associated comorbidities (DRG 766) were included in the initial diagnosis. The influence of age group and comorbidities or complications present at admission on the length of hospital stay was assessed based on the means of the analysis of variance. The size of the effect was verified by Cohen’s D, which allows evaluating clinical relevance. The criticality levels were identified using the Duncan test. RESULTS The longest length of hospital stay was observed in the age group from 15 to 17 years old and among those aged 45 years old or more. The hospital stay of women with complications or comorbidities at the time of admission was also longer. Moreover, it was noted that the increase in criticality level was associated with an increase in the mean length of hospital stay. CONCLUSIONS The length of hospital stay of women is higher among those belonging to the age group ranging from 15 to 17 years old and for those aged 45 years old or more. The presence of associated comorbidities, such as eclampsia, pre-existing hypertensive disorder with superimposed proteinuria and gestational hypertension (induced by pregnancy) with significant proteinuria increase the length of hospital stay. This study enabled the construction of distinct criticality level profiles based on the combination of age groups and the main comorbidities, which were directly related to the length of hospital stay.

RESUMO OBJETIVO Avaliar se grupo etário, complicações ou comorbidades estão associados ao tempo de internação de mulheres submetidas à cesariana. MÉTODOS Estudo transversal realizado entre junho de 2012 e julho de 2017, com 64.437 mulheres submetidas à cesariana e que não apresentaram condições adquiridas durante o tempo de permanência hospitalar. Os dados foram coletados a partir da alta hospitalar nas instituições nacionais de saúde, utilizando o sistema Diagnosis-Related Groups [Grupos de Diagnósticos Relacionados] (DRG Brasil®). Foram incluídos os DRG referentes à cesariana com complicações ou comorbidades adicionais ao diagnóstico inicial (DRG 765) e cesariana sem complicações ou comorbidades associadas (DRG 766). A influência do grupo etário e comorbidades ou complicações presentes na admissão sobre o tempo de permanência hospitalar foi avaliada por meio da análise de variância. O tamanho do efeito foi verificado pelo d de Cohen, que permite avaliar a relevância clínica. Os níveis de criticidade foram identificados utilizando o teste de Duncan. RESULTADOS O maior tempo de permanência hospitalar foi observado nos grupos etários de 15 a 17 anos e 45 anos ou mais. Mulheres que apresentaram complicações ou comorbidades presentes à admissão também apresentaram maior tempo de permanência hospitalar. Quantos aos níveis de criticidade, notou-se que seu aumento estava associado ao aumento na média do tempo de permanência hospitalar. CONCLUSÕES O tempo de permanência hospitalar de mulheres é maior entre aquelas pertencentes aos grupos etários de 15 a 17 anos e 45 anos ou mais. A presença de comorbidades associadas, como a eclâmpsia, o distúrbio hipertensivo pré-existente com proteinúria superposta e a hipertensão gestacional (induzida pela gravidez) com proteinúria significativa aumentam o tempo de permanência hospitalar. Este estudo possibilitou a construção de perfis distintos de níveis de criticidade a partir da combinação de grupos etários e das principais comorbidades, os quais se apresentaram diretamente relacionados ao tempo de permanência hospitalar.

ABSTRACT OBJECTIVE To evaluate whether age group, complications or comorbidities are associated with the length of hospitalization of women undergoing cesarean section. METHODS A cross-sectional study was carried out between June 2012 and July 2017, with 64,437 women undergoing cesarean section and who did not acquire conditions during their hospital stay. Hospital discharge data were collected from national health institutions, using the Diagnosis-Related Groups system (DRG Brasil®). The DRG referring to cesarean section with additional complications or comorbidities (DRG 765) and cesarean section without complications or associated comorbidities (DRG 766) were included in the initial diagnosis. The influence of age group and comorbidities or complications present at admission on the length of hospital stay was assessed based on the means of the analysis of variance. The size of the effect was verified by Cohen’s D, which allows evaluating clinical relevance. The criticality levels were identified using the Duncan test. RESULTS The longest length of hospital stay was observed in the age group from 15 to 17 years old and among those aged 45 years old or more. The hospital stay of women with complications or comorbidities at the time of admission was also longer. Moreover, it was noted that the increase in criticality level was associated with an increase in the mean length of hospital stay. CONCLUSIONS The length of hospital stay of women is higher among those belonging to the age group ranging from 15 to 17 years old and for those aged 45 years old or more. The presence of associated comorbidities, such as eclampsia, pre-existing hypertensive disorder with superimposed proteinuria and gestational hypertension (induced by pregnancy) with significant proteinuria increase the length of hospital stay. This study enabled the construction of distinct criticality level profiles based on the combination of age groups and the main comorbidities, which were directly related to the length of hospital stay.