title: The influence of age, gender and socio-economic status on multimorbidity patterns in primary care. First results from the multicare cohort study.
abstract: BACKGROUND
  Multimorbidity is a phenomenon with high burden and high prevalence in the elderly. Our previous research has shown that multimorbidity can be divided into the multimorbidity patterns of 1) anxiety, depression, somatoform disorders (ADS) and pain, and 2) cardiovascular and metabolic disorders. However, it is not yet known, how these patterns are influenced by patient characteristics. The objective of this paper is to analyze the association of socio-demographic variables, and especially socio-economic status with multimorbidity in general and with each multimorbidity pattern.
  
  
  METHODS
  The MultiCare Cohort Study is a multicentre, prospective, observational cohort study of 3.189 multimorbid patients aged 65+ randomly selected from 158 GP practices. Data were collected in GP interviews and comprehensive patient interviews. Missing values have been imputed by hot deck imputation based on Gower distance in morbidity and other variables. The association of patient characteristics with the number of chronic conditions is analysed by multilevel mixed-effects linear regression analyses.
  
  
  RESULTS
  Multimorbidity in general is associated with age (+0.07 chronic conditions per year), gender (-0.27 conditions for female), education (-0.26 conditions for medium and -0.29 conditions for high level vs. low level) and income (-0.27 conditions per logarithmic unit). The pattern of cardiovascular and metabolic disorders shows comparable associations with a higher coefficient for gender (-1.29 conditions for female), while multimorbidity within the pattern of ADS and pain correlates with gender (+0.79 conditions for female), but not with age or socioeconomic status.
  
  
  CONCLUSIONS
  Our study confirms that the morbidity load of multimorbid patients is associated with age, gender and the socioeconomic status of the patients, but there were no effects of living arrangements and marital status. We could also show that the influence of patient characteristics is dependent on the multimorbidity pattern concerned, i.e. there seem to be at least two types of elderly multimorbid patients. First, there are patients with mainly cardiovascular and metabolic disorders, who are more often male, have an older age and a lower socio-economic status. Second, there are patients mainly with ADS and pain-related morbidity, who are more often female and equally distributed across age and socio-economic groups.
  
  
  BACKGROUND
  ISRCTN89818205.
authors.affiliation: Department of Primary Medical Care, University Medical Center Hamburg-Eppendorf, Germany. in.schaefer@uke.uni-hamburg.de
authors.forename: Ingmar
authors.initials: I
authors.lastname: Schäfer
authors.forename: Heike
authors.initials: H
authors.lastname: Hansen
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schön
authors.forename: Susanne
authors.initials: S
authors.lastname: Höfels
authors.forename: Attila
authors.initials: A
authors.lastname: Altiner
authors.forename: Anne
authors.initials: A
authors.lastname: Dahlhaus
authors.forename: Jochen
authors.initials: J
authors.lastname: Gensichen
authors.forename: Steffi
authors.initials: S
authors.lastname: Riedel-Heller
authors.forename: Siegfried
authors.initials: S
authors.lastname: Weyerer
authors.forename: Wolfgang A
authors.initials: WA
authors.lastname: Blank
authors.forename: Hans-Helmut
authors.initials: HH
authors.lastname: König
authors.forename: Olaf
authors.initials: O
authors.lastname: von dem Knesebeck
authors.forename: Karl
authors.initials: K
authors.lastname: Wegscheider
authors.forename: Martin
authors.initials: M
authors.lastname: Scherer
authors.forename: Hendrik
authors.initials: H
authors.lastname: van den Bussche
authors.forename: Birgitt
authors.initials: B
authors.lastname: Wiese
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease / Q000453:epidemiology*; D015331:Cohort Studies; D015897:Comorbidity / Q000639:trends; D003953:Diagnosis-Related Groups / Q000706:statistics & numerical data; D005194:Family Practice; D005260:Female; D005858:Germany / Q000453:epidemiology; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D015995:Prevalence; D011320:Primary Health Care / Q000191:economics / Q000592:standards; D011446:Prospective Studies; D011788:Quality of Life; D012307:Risk Factors; D012737:Sex Factors; D012923:Social Class; D011795:Surveys and Questionnaires