title: Incidence and predictors of multimorbidity in the elderly: a population-based longitudinal study.
abstract: BACKGROUND
  We aimed to calculate 3-year incidence of multimorbidity, defined as the development of two or more chronic diseases in a population of older people free from multimorbidity at baseline. Secondly, we aimed to identify predictors of incident multimorbidity amongst life-style related indicators, medical conditions and biomarkers.
  
  
  METHODS
  Data were gathered from 418 participants in the first follow up of the Kungsholmen Project (Stockholm, Sweden, 1991-1993, 78+ years old) who were not affected by multimorbidity (149 had none disease and 269 one disease), including a social interview, a neuropsychological battery and a medical examination.
  
  
  RESULTS
  After 3 years, 33.6% of participants who were without disease and 66.4% of those with one disease at baseline, developed multimorbidity: the incidence rate was 12.6 per 100 person-years (95% CI: 9.2-16.7) and 32.9 per 100 person-years (95% CI: 28.1-38.3), respectively. After adjustments, worse cognitive function (OR, 95% CI, for 1 point lower Mini-Mental State Examination: 1.22, 1.00-1.48) was associated with increased risk of multimorbidity among subjects with no disease at baseline. Higher age was the only predictor of multimorbidity in persons with one disease at baseline.
  
  
  CONCLUSIONS
  Multimorbidity has a high incidence at old age. Mental health-related symptoms are likely predictors of multimorbidity, suggesting a strong impact of mental disorders on the health of older people.
authors: Department of Geriatric Medicine/Nijmegen Alzheimer Centre 925, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors: René
authors: R
authors: Melis
authors: Geriatric Unit, Department of Clinical and Experimental Science, University of Brescia, Brescia, Italy; Aging Research Center (ARC), Karolinska Institutet (Neurobiology, Care Science and Society Department) and Stockholm University, Stockholm, Sweden.
authors: Alessandra
authors: A
authors: Marengoni
authors: Aging Research Center (ARC), Karolinska Institutet (Neurobiology, Care Science and Society Department) and Stockholm University, Stockholm, Sweden.
authors: Sara
authors: S
authors: Angleman
authors: Aging Research Center (ARC), Karolinska Institutet (Neurobiology, Care Science and Society Department) and Stockholm University, Stockholm, Sweden; Stockholm Gerontology Research Center, Stockholm, Sweden.
authors: Laura
authors: L
authors: Fratiglioni
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003071:Cognition / Q000502:physiology; D015897:Comorbidity; D005260:Female; D006801:Humans; D015994:Incidence; D008019:Life Style; D008137:Longitudinal Studies; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology; D008603:Mental Health / Q000706:statistics & numerical data; D009483:Neuropsychological Tests; D011379:Prognosis; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology