National retrospective cohort study to identify risk factors for in-hospital 30-day lethality in laboratory-confirmed cases of influenza.

OBJECTIVE: To identify factors associated with the risk of death in adolescent and adult inpatients with laboratory-positive (reverse-transcription polymerase chain reaction) influenza in Mexico during consecutive influenza seasons (2018-2020). METHODS: A retrospective cohort study used national surveillance system data, enrolling 3.422 individuals. The association between various risk factors and 30-day in-hospital lethality were evaluated through risk ratios (RRs) and 95% confidence intervals (CIs). RESULTS: The lethality rate was 18.1%. Flu vaccination history (RR=0.56, 95% CI 0.42-0.78), early antiviral drug administration (≤2 days from symptom onset [reference ≥5 days], RR=0.68, 95% CI 0.58-0.81), and a history of asthma (RR=0.66, 95% CI 0.47-0.95) showed protective effects against influenza-attributable death. Mechanical ventilator support produced the highest increase in death risk (RR=3.31, 95% CI 2.89-3.79). Male sex, older age, AH1N1 subtype, and other chronic diseases were also associated with fatal in-hospital influenza-related outcomes. CONCLUSIONS: Our findings highlight the major relevance of promoting immunization in high-risk individuals, together with ensuring early and effective antiviral management in suspected influenza cases.

Estudio de cohorte retrospectivo nacional para identificar los factores de riesgo de letalidad por hospitalización durante 30 días en casos de gripe confirmados por laboratorio / National retrospective cohort study to identify risk factors for in-hospital 30-day lethality in laboratory-confirmed cases of influenza

Objetivo Identificar los factores asociados a riesgo de muerte en pacientes adolescentes y adultos hospitalizados con gripe confirmada en laboratorio (reacción en cadena de la polimerasa con transcriptasa inversa) en México durante temporadas consecutivas de gripe (2018-2020). Pacientes y métodos Estudio de cohorte retrospectivo en el que se utilizaron datos del sistema de vigilancia nacional con 3.422 sujetos inscritos. Se evaluó la asociación entre el riesgo a la exposición y el riesgo de letalidad hospitalaria durante 30 días mediante el estudio de los riesgos relativos (RR) y los intervalos de confianza (IC) del 95%. Resultados La tasa de letalidad fue del 18,1%. Los antecedentes de vacunación frente a la gripe (RR = 0,56; IC 95%: 0,42-0,78), la administración de fármacos antivirales (≤ dos días desde la aparición de los síntomas [referencia: ≥ 5 días]; RR = 0,68; IC 95%: 0,58-0,81) y el historial de asma (RR = 0,66; IC 95%: 0,47-0,95) mostraron efectos protectores frente a la muerte atribuible a la gripe. La ventilación mecánica causó el mayor aumento del riesgo de muerte (RR = 3,31; IC 95%: 2,89-3,79). También se asoció a una mayor letalidad hospitalaria por gripe el hecho de ser hombre, tener edad avanzada, el subtipo AH1N1 y otras enfermedades crónicas. Conclusiones Nuestros hallazgos recalcan la gran importancia de fomentar la inmunización de individuos de alto riesgo, a la vez que se asegura un tratamiento antiviral temprano y eficaz en los casos sospechosos de gripe (AU)

Objective To identify factors associated with the risk of death in adolescent and adult inpatients with laboratory-positive (reverse-transcription polymerase chain reaction) influenza in Mexico during consecutive influenza seasons (2018-2020). Patients and methods A retrospective cohort study used national surveillance system data, enrolling 3422 individuals. The association between various risk factors and 30-day in-hospital lethality were evaluated through risk ratios (RR) and 95% confidence intervals (CI). Results The lethality rate was 18.1%. Flu vaccination history (RR = 0.56, 95% CI 0.42-0.78), early antiviral drug administration (≤ two days from symptom onset [reference ≥ 5 days], RR = 0.68, 95% CI 0.58-0.81), and a history of asthma (RR = 0.66, 95% CI 0.47-0.95) showed protective effects against influenza-attributable death. Mechanical ventilator support produced the highest increase in death risk (RR = 3.31, 95% CI 2.89-3.79). Male sex, older age, AH1N1 subtype, and other chronic diseases were also associated with fatal in-hospital influenza-related outcomes. Conclusions Our findings highlight the major relevance of promoting immunization in high-risk individuals, together with ensuring early and effective antiviral management in suspected influenza cases (AU)

National retrospective cohort study to identify risk factors for in-hospital 30-day lethality in laboratory-confirmed cases of influenza. / Estudio de cohorte retrospectivo nacional para identificar los factores de riesgo de letalidad por hospitalización durante 30 días en casos de gripe confirmados por laboratorio.

OBJECTIVE: To identify factors associated with the risk of death in adolescent and adult inpatients with laboratory-positive (reverse-transcription polymerase chain reaction) influenza in Mexico during consecutive influenza seasons (2018-2020). PATIENTS AND METHODS: A retrospective cohort study used national surveillance system data, enrolling 3422 individuals. The association between various risk factors and 30-day in-hospital lethality were evaluated through risk ratios (RR) and 95% confidence intervals (CI). RESULTS: The lethality rate was 18.1%. Flu vaccination history (RR = 0.56, 95% CI 0.42-0.78), early antiviral drug administration (≤ two days from symptom onset [reference ≥ 5 days], RR = 0.68, 95% CI 0.58-0.81), and a history of asthma (RR = 0.66, 95% CI 0.47-0.95) showed protective effects against influenza-attributable death. Mechanical ventilator support produced the highest increase in death risk (RR = 3.31, 95% CI 2.89-3.79). Male sex, older age, AH1N1 subtype, and other chronic diseases were also associated with fatal in-hospital influenza-related outcomes. CONCLUSIONS: Our findings highlight the major relevance of promoting immunization in high-risk individuals, together with ensuring early and effective antiviral management in suspected influenza cases.