title: A frailty index predicts survival and incident multimorbidity independent of markers of HIV disease severity.
abstract: OBJECTIVE
  Aging with HIV is associated with multisystem vulnerability that might be well characterized by frailty. We sought to construct a frailty index based on health deficit accumulation in a large HIV clinical cohort and evaluate its validity including the ability to predict mortality and incident multimorbidity.
  
  
  METHODS
  This is an analysis of data from the prospective Modena HIV Metabolic Clinic cohort, 2004-2014. Routine health variables were screened for potential inclusion in a frailty index. Content, construct, and criterion validity of the frailty index were assessed. Multivariable regression models were built to investigate the ability of the frailty index to predict survival and incident multimorbidity (at least two chronic disease diagnoses) after adjusting for known HIV-related and behavioral factors.
  
  
  RESULTS
  Two thousand, seven hundred and twenty participants (mean age 46 ± 8; 32% women) provided 9784 study visits; 37 non-HIV-related variables were included in a frailty index. The frailty index exhibited expected characteristics and met validation criteria. Predictors of survival were frailty index (0.1 increment, adjusted hazard ratio 1.63, 95% confidence interval 1.05-2.52), current CD4 cell count (0.48, 0.32-0.72), and injection drug use (2.51, 1.16-5.44). Predictors of incident multimorbidity were frailty index (adjusted incident rate ratio 1.98, 1.65-2.36), age (1.07, 1.05-1.09), female sex (0.61, 0.40-0.91), and current CD4 cell count (0.71, 0.59-0.85).
  
  
  CONCLUSIONS
  Among people aging with HIV in northern Italy, a frailty index based on deficit accumulation predicted survival and incident multimorbidity independently of HIV-related and behavioral risk factors. The frailty index holds potential value in quantifying vulnerability among people aging with HIV.
authors.affiliation: aDepartment of Medical and Surgical Sciences for Adults and Children, Clinic of Infectious Diseases, University of Modena and Reggio Emilia, Modena, Italy bFaculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada cDepartment of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy dDepartment of Community Health and Epidemiology, Dalhousie University, Halifax, Nova Scotia eChronic Viral Illness Service, McGill University Hospital Center, Montreal, Quebec fDepartment of Medicine (Geriatric Medicine and Neurology), Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Guaraldi
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Brothers
authors.forename: Stefano
authors.initials: S
authors.lastname: Zona
authors.forename: Chiara
authors.initials: C
authors.lastname: Stentarelli
authors.forename: Federica
authors.initials: F
authors.lastname: Carli
authors.forename: Andrea
authors.initials: A
authors.lastname: Malagoli
authors.forename: Antonella
authors.initials: A
authors.lastname: Santoro
authors.forename: Marianna
authors.initials: M
authors.lastname: Menozzi
authors.forename: Chiara
authors.initials: C
authors.lastname: Mussi
authors.forename: Cristina
authors.initials: C
authors.lastname: Mussini
authors.forename: Susan
authors.initials: S
authors.lastname: Kirkland
authors.forename: Julian
authors.initials: J
authors.lastname: Falutz
authors.forename: Kenneth
authors.initials: K
authors.lastname: Rockwood
mesh_terms: D000328:Adult; D015897:Comorbidity; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000401:mortality*; D054624:Health Status Disparities; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013534:Survival