Nomogram for pneumonia prediction among children and young people with cerebral palsy: A population-based cohort study

Abstract

Background: Pneumonia is the leading cause of death among children and young people (CYP) with severe cerebral palsy (CP). Only a few studies used nomogram for assessing risk factors and the probability of pneumonia. Therefore, we aimed to identify risk factors and devise a nomogram for identifying the probability of severe pneumonia in CYP with severe CP.

Methods: This retrospective nationwide population-based cohort study examined CYP with newly diagnosed severe CP before 18 years old between January 1st, 1997 and December 31st, 2013 and followed them up through December 31st, 2013. The primary endpoint was defined as the occurrence of severe pneumonia with ≥ 5 days of hospitalization. Logistic regression analysis was used for determining demographic factors and comorbidities associated with severe pneumonia. These factors were assigned integer points to create a scoring system to identify children at high risk for severe pneumonia.

Results: Among 6,356 CYP with newly diagnosed severe CP, 2,135 (33.59%) had severe pneumonia. Multivariable logistic regression analysis revealed that seven independent predictive factors, namely age <3 years, male sex, and comorbidities of pressure ulcer, gastroesophageal reflux, asthma, seizures, and perinatal complications. A nomogram was devised by employing these seven significant predictive factors. The prediction model presented favorable discrimination performance.

Conclusions: The nomogram revealed that age, male sex, history of pressure ulcer, gastroesophageal reflux, asthma, seizures, and perinatal complications were potential risk factors for severe pneumonia among CYP with severe CP.

Fig 1. Nomogram plot for predicting severe pneumonia in CP children.

For an individual patient, each variable corresponds to a point in the 8^th row (names “score”). The total points were summed up by all points and are indicated in the 10^th row (the bottom row). Drawing a vertical line from total point to the 9^th row will show the corresponding probability of pneumonia.

Fig 2. The calibration curve for the radiomics nomogram plot.

Dashed line indicates ideal reference line where predicted probabilities would match the observed proportions (the diagonal square) and, of which a closer fit to the diagonal dotted line represents a better prediction. The Hosmer-Lemeshow test showed the p-value is 0.178.