Abstract:
Background: Childhood pneumonia is the leading infectious cause of mortality in
children younger than 5 years old. Recent updates to World Health Organization
pneumonia guidelines recommend outpatient care for a population of children previously
classified as high risk. This revision has been challenged by policymakers in Africa,
where mortality related to pneumonia is higher than in other regions and often
complicated by comorbidities. This study aimed to identify factors that best discriminate
inpatient mortality risk in non-severe pneumonia and explore whether these factors offer
any added benefit over the current criteria used to identify children with pneumonia
requiring inpatient care.
Methods: We undertook a retrospective cohort study of children aged 2-59 months
admitted with a clinical diagnosis of pneumonia at 14 public hospitals in Kenya between
February 2014 and February 2016. Using machine learning techniques, we analysed
whether clinical characteristics and common comorbidities increased the risk of inpatient
mortality for non-severe pneumonia. The topmost risk factors were subjected to decision
curve analysis to explore if using them as admission criteria had any net benefit above
the current criteria.
Results: Out of 16,162 children admitted with pneumonia during the study period,
10,687 were eligible for subsequent analysis. Inpatient mortality within this non-severe
group was 252/10,687 (2.36%). Models demonstrated moderately good performance; the
partial least squares discriminant analysis model had higher sensitivity for predicting
mortality in comparison to logistic regression. Elevated respiratory rate (≥70 bpm), age
2-11 months and weight-for-age Z-score (WAZ) < -3SD were highly discriminative of
mortality. These factors ranked consistently across the different models. For a risk
threshold probability of 7-14%, there is a net benefit to admitting the patient subpopulations with these features as additional criteria alongside those currently used to
classify severe pneumonia. Of the population studied, 70.54% met at least one of these
criteria. Sensitivity analyses indicated that the overall results were not significantly
affected by variations in pneumonia severity classification criteria.
Conclusions: Children with non-severe pneumonia aged 2-11 months or with respiratory
rate ≥ 70 bpm or very low WAZ experience risks of inpatient mortality comparable to
severe pneumonia. Inpatient care is warranted in these high-risk groups of children.