title: Prevalence of multimorbidity in a geographically defined American population: patterns by age, sex, and race/ethnicity.
abstract: OBJECTIVE
  To describe the prevalence of multimorbidity involving 20 selected chronic conditions in a geographically defined US population, emphasizing age, sex, and racial/ethnic differences.
  
  
  METHODS
  Using the Rochester Epidemiology Project records linkage system, we identified all residents of Olmsted County, Minnesota, on April 1, 2010, and electronically extracted the International Classification of Diseases, Ninth Revision codes associated with all health care visits made between April 1, 2005, and March 31, 2010 (5-year capture frame). Using these codes, we defined the 20 common chronic conditions recommended by the US Department of Health and Human Services. We counted only persons who received at least 2 codes for a given condition separated by more than 30 days, and we calculated the age-, sex-, and race/ethnicity-specific prevalence of multimorbidity.
  
  
  RESULTS
  Of the 138,858 study participants, 52.4% were women (n=72,732) and 38.9% had 1 or more conditions (n=54,012), 22.6% had 2 or more conditions (n=31,444), and 4.9% had 5 or more conditions (n=6853). The prevalence of multimorbidity (≥2 conditions) increased steeply with older age and reached 77.3% at 65 years and older. However, the absolute number of people affected by multimorbidity was higher in those younger than 65 years. Although the prevalence of multimorbidity was similar in men and women overall, the most common dyads and triads of conditions varied by sex. Compared with white persons, the prevalence of multimorbidity was slightly higher in black persons and slightly lower in Asian persons.
  
  
  CONCLUSIONS
  Multimorbidity is common in the general population; it increases steeply with older age, has different patterns in men and women, and varies by race/ethnicity.
authors.affiliation: Division of Epidemiology, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN; Department of Neurology, College of Medicine, Mayo Clinic, Rochester, MN. Electronic address: rocca@mayo.edu.
authors.forename: Walter A
authors.initials: WA
authors.lastname: Rocca
authors.affiliation: Division of Geriatric Medicine and Gerontology, School of Medicine, Johns Hopkins University, Baltimore, MD.
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Boyd
authors.affiliation: Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Brandon R
authors.initials: BR
authors.lastname: Grossardt
authors.affiliation: Department of Psychiatry, College of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: William V
authors.initials: WV
authors.lastname: Bobo
authors.affiliation: Division of Epidemiology, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN; Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, College of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Lila J
authors.initials: LJ
authors.lastname: Finney Rutten
authors.affiliation: Division of Epidemiology, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN; Division of Cardiovascular Diseases, Department of Internal Medicine, College of Medicine, Mayo Clinic, Rochester, MN; Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, College of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Véronique L
authors.initials: VL
authors.lastname: Roger
authors.affiliation: Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, College of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Jon O
authors.initials: JO
authors.lastname: Ebbert
authors.affiliation: Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Terry M
authors.initials: TM
authors.lastname: Therneau
authors.affiliation: Division of Epidemiology, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN; Department of Research, Olmsted Medical Center, Rochester, MN.
authors.forename: Barbara P
authors.initials: BP
authors.lastname: Yawn
authors.affiliation: Division of Epidemiology, Department of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN; Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, College of Medicine, Mayo Clinic, Rochester, MN.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: St Sauver
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity / Q000639:trends; D004194:Disease / Q000208:ethnology*; D005006:Ethnicity / Q000208:ethnology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D015995:Prevalence; D011379:Prognosis; D017678:Sex Distribution; D055815:Young Adult