Predictors of mortality in subjects hospitalized with acute lower respiratory tract infections

Abstract

Objective: To identify the predictors of mortality due to acute lower respiratory tract infection (ALRI).

Design: Prospective cohort study.

Setting: Urban tertiary care teaching hospital.

Methods: 201 cases with ALRI between 2 weeks to 5 years of age were prospectively enrolled and followed up to determine outcome. Detailed history and clinical evaluation were recorded on a pretested proforma. Significant independent predictors of mortality were determined by comparison of dead subjects (n = 21) with surviving children (n = 180) in a multiple logistic analytic framework.

Results: The case fatality rate (CFR) was 10.45%. Significant independent predictors of mortality were (OR, 95% CI) age less than 1 year (23.1, 2.7-197.5), inability to feed (6.2, 1.3-30.7), associated loose stools (5.1,1.2-27.3), weight for age Z score < -3 (3.9,1.01-9.7), short duration of fever (1.2,1.0-1.5) and bandemia (1.1,1.05-1.2). The WHO guidelines identified 91% of children diagnosed as ALRI by clinical and investigative criteria. The CFR was related to severity of WHO classification ("pneumonia"-0%, "severe pneumonia"-8.7% and "very severe pneumonia"-47.0%). However, 2 of the 18 subjects with a diagnosis of "no pneumonia" expired (CFR 11.1% and 10% of total mortality).

Conclusion: Even in settings of high case fatality, predictors of mortality can be identified in under five children suffering from ALRI. In this context, age below 1 year, inability to feed, presence of loose stools and severe malnutrition merit attention for interventional purposes.

PIP: In a prospective cohort study (1993-94) conducted at a tertiary care teaching hospital in New Delhi, India, the predictors of mortality in 201 children 2 weeks to 5 years of age admitted with acute lower respiratory infection (ALRI) were investigated. There were 21 deaths in this series, for a case fatality rate of 10.45%. Mortality was inversely associated with age. Multivariate logistic regression identified the following significant predictors of mortality: age less than 12 months (odds ratio (OR), 23.1), inability to feed (OR, 6.2), associated loose stools (OR, 5.1), weight-for-age Z score under 3 (OR, 3.9), short duration of fever (OR, 1.2), and bandemia (OR, 1.1). The clinical and investigative criteria set forth in the World Health Organization (WHO) guidelines successfully identified 91% of children with ALRI. The case fatality rate was related to the severity of the WHO classification: pneumonia, 0%; severe pneumonia, 8.7%; and very severe pneumonia, 47.0%. However, 2 of the 18 children without any pneumonia died. At present, children under 2 months of age are designated as high-risk ALRI cases and targeted for close monitoring, referral, and therapy. The finding of this study of a 23-fold increased risk of mortality in children under 12 months of age suggests this cut-off should be expanded to 12 months.