Abstract
BACKGROUND: Continuous scores have greater power and better predictive value than categorical scores in epidemiological studies.
OBJECTIVES: (i) To generate a continuous score that summarize the respiratory health of children, (ii) to evaluate its predictive ability against the risk of hospitalization for respiratory diseases
METHODS: 3,854 children (3-14 years) were surveyed in 2006 through a parental questionnaire, containing questions about the children's respiratory symptoms and potential risk factors, and hospital discharge records were obtained for the years 2007-9. Children respiratory conditions and symptoms in the previous 12 months were synthetized in a continuous score using a factor analysis with tetrachoric correlation matrix. A Cox regression model was used to evaluate the ability of the score to predict hospital admissions for diseases of respiratory system (ICD-9-CM: 465-519) in children.
RESULTS: We identified one factor that explains 93% of common variance of respiratory symptoms and conditions. The children's respiratory health was synthesized in a one-dimensional, continuous score (mean:0.35; range: 0-3) with a quasi-gamma distribution. A unitary increase in the score was associated with 116% greater risk of being hospitalized for respiratory diseases (HR: 2.16, 95%CI:1.66-2.82).
CONCLUSIONS: The children's respiratory health score has good ability to predict future respiratory hospitalizations, and might be a promising tool in population studies.
- © 2014 ERS