title: [Development of a predictive model of death or urgent hospitalization to identify frail elderly].
abstract: OBJECTIVE
  to develop and validate a predictive model of mortality or emergency hospitalization in all subjects aged 65 years and over.
  
  
  METHODS
  cohort study based on 9 different databases linked with each other.
  
  
  METHODS
  the model was developed on the population aged 65 years and over resident at 01.01.2011 for at least two years in the city of Bologna (Emilia-Romagna Region, Northern Italy); 96,000 persons were included.
  
  
  METHODS
  the outcome was defined in case of emergency hospitalization or death during the one-year follow-up and studied with a logistic regression model. The predictive ability of the model was evaluated by using the area under the Roc curve, the Hosmer-Lemeshow test, and the Brier score in the derivation sample (2/3 of the population). These tests were repeated in the validation sample (1/3 of the population) and in the population of Bologna aged 65 years and over on 01.01.2012, after applying the coefficients of the variables obtained in the derivation model. By using the regression coefficients, a frailty index (risk score) was calculated for each subject later categorized in risk classes.
  
  
  RESULTS
  the model is composed of 28 variables and has good predictive abilities. The area under the Roc curve of the derivation sample is 0.77, the Hosmer-Lemeshow test is not significant, and the Brier score is 0.11. Similar performances are obtained in the other two samples. With increasing risk class, the mean age, number of hospitalizations, emergency room service consultations, and multiple drug prescriptions increase, while the average income decreases.
  
  
  CONCLUSIONS
  the model has good predictive ability. The frailty index can be used to support a proactive medicine and stratify the population, plan clinical and preventive activities or identify the potential beneficiaries of specific health promotion projects.
authors.affiliation: UOC epidemiologia, promozione della salute e comunicazione del rischio, AUSL di Bologna. paolo.pandolfi@ausl.bologna.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Pandolfi
authors.affiliation: UOC epidemiologia, promozione della salute e comunicazione del rischio, AUSL di Bologna.
authors.forename: Natalina
authors.initials: N
authors.lastname: Collina
authors.affiliation: UOC epidemiologia, promozione della salute e comunicazione del rischio, AUSL di Bologna.
authors.forename: Paolo
authors.initials: P
authors.lastname: Marzaroli
authors.affiliation: UOC epidemiologia, promozione della salute e comunicazione del rischio, AUSL di Bologna.
authors.forename: Elisa
authors.initials: E
authors.lastname: Stivanello
authors.affiliation: UOC epidemiologia, promozione della salute e comunicazione del rischio, AUSL di Bologna.
authors.forename: Muriel Assunta
authors.initials: MA
authors.lastname: Musti
authors.affiliation: UOC epidemiologia, promozione della salute e comunicazione del rischio, AUSL di Bologna.
authors.forename: Chiara
authors.initials: C
authors.lastname: Giansante
authors.affiliation: UOC epidemiologia, promozione della salute e comunicazione del rischio, AUSL di Bologna.
authors.forename: Vincenza
authors.initials: V
authors.lastname: Perlangeli
authors.affiliation: UOC epidemiologia, promozione della salute e comunicazione del rischio, AUSL di Bologna.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Pizzi
authors.affiliation: UOC epidemiologia, promozione della salute e comunicazione del rischio, AUSL di Bologna.
authors.forename: Sara
authors.initials: S
authors.lastname: De Lisio
authors.affiliation: Direzione dipartimento di sanità pubblica, AUSL di Bologna.
authors.forename: Fausto
authors.initials: F
authors.lastname: Francia
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D004630:Emergencies / Q000453:epidemiology*; D005500:Follow-Up Studies; D016330:Frail Elderly / Q000706:statistics & numerical data; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors