Inflection Risk data Jiaying Wang Data Overview ID Stay Age - PowerPoint PPT Presentation

Inflection Risk data Jiaying Wang

Data Overview ID Stay Age InfctRsk Culture Xray Beds MedSchool Region Census Nurses Facilities 1 7.13 55.7 4.1 9 39.6 279 2 4 207 241 60 2 8.82 58.2 1.6 3.8 51.7 80 2 2 51 52 40 3 8.34 56.9 2.7 8.1 74 107 2 3 82 54 20 4 8.95 53.7 5.6 18.9 122.8 147 2 4 53 148 40 Stay: Average length of stay of all patients in hospital (in days) Age: Average age of patients (in years) InfctRsk: Average estimated probability of acquiring infection in hospital (in percent) Culture: Ratio of number of cultures performed to number of patients without signs or symptoms of hospital-acquired infection, times 100 Xray: Ratio of number of X-rays performed to number of patients without signs or symptoms of pneumonia, times 100 Beds: Average number of beds in hospital during study period MedSchool: Medical school affiliation (1=Yes, 2= No) Region: Geographic region (1=NE, 2=NC, 3=S, 4=W) Census: Average number of patients in hospital per day during study period Nurses: Average number of full-time equivalent registered and licensed practical nurses during study period Facilities: Percent of 35 potential facilities and services that are provided by the hospital

Data Overview

Data Overview Beds, Census, Nurses and Facilities are highly correlated

Data Overview VIF of full model VIF of reduced model (without Beds and Census)

Model Selection

Diagnostic plots

Summary No notable outliers Normal assumptions hold The “Best” model is: !"#$%&'( = −1.45 + 0.25 ∗ 3%45 + 0.05 ∗ 678%79: + 0.01 ∗ ;945 + 0.27 ∗ &:=>?" + 0.02 ∗ #4$>8>%>:'

References • Special Issue, “The SENIC Project,” American Journal of Epidemiology III (1980), pp 465-653. Data obtained from Robert W. Haley, M.D., Hospital Infections Program, Center for Infectious Diseases, Center for Disease Control, Atlanta, Georgia 30333.