title: Association between underweight and hospitalization, emergency room visits, and mortality among patients in community medical homes.
abstract: BACKGROUND
  In older adults, underweight (body mass index [BMI] <18.5) has been associated with increased mortality. This increased mortality risk may be associated with increased health care utilization. We evaluated the relationship between underweight and hospitalization, emergency room visits, and mortality.
  
  
  METHODS
  An analysis of a retrospective cohort study was conducted at a multisite academic primary care medical practice in Minnesota. The patients were ≥60 years of age, impaneled within primary care on January 1, 2011, and had a BMI measurement recorded between January 1, 2011, and December 31, 2011. Individuals were excluded if they refused review of their medical record. The primary measurement was BMI, which was categorized as underweight (BMI < 18.5) or normal and obese (BMI ≥ 18.5). The outcomes were hospitalization, emergency room visits, and mortality in the 2011 calendar year. Associations between underweight and each outcome were calculated using logistic regression. Interactions between underweight and gender were assessed in the logistic regression models. The final results were adjusted for age, gender, comorbid health conditions, and single living status.
  
  
  RESULTS
  The final cohort included 21,019 patients, of whom 220 (1%) were underweight. Underweight patients had a higher likelihood of hospitalization compared with patients with higher BMI (adjusted odds ratio [OR] 1.64; 95% confidence interval [CI] 1.21-2.22). Underweight patients were also more likely to visit the emergency room (adjusted OR 1.70; 95% CI 1.28-2.25) or to die (adjusted OR 3.64; 95% CI 2.33-5.69). Men with a BMI < 18.5 compared with those having a BMI ≥ 18.5 had the highest odds of hospitalization (OR 3.45; 95% CI 1.59-7.48).
  
  
  CONCLUSIONS
  Underweight older adults, especially men, have higher odds of hospitalization, emergency room visits, and mortality. Future work on underweight might involve improving weight status, which may reduce the risk of hospitalization, emergency room visits, and mortality.
authors: Division of Primary Care Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors: Paul Y
authors: PY
authors: Takahashi
authors: Jennifer L St
authors: JL
authors: Sauver
authors: Timothy C
authors: TC
authors: Olson
authors: Jill M
authors: JM
authors: Huber
authors: Stephen S
authors: SS
authors: Cha
authors: Jon O
authors: JO
authors: Ebbert
keywords: aging; health care utilization; nutrition; population health
references: Epidemiology. 2003 May;14(3):293-9
references: 12859029
references: BMC Health Serv Res. 2010 Dec 13;10:338
references: 21144042
references: J Nutr Health Aging. 2011 May;15(5):388-91
references: 21528166
references: Obes Res. 1997 Nov;5(6):542-8
references: 9449138
references: Int J Obes. 1990 Dec;14(12):997-1003
references: 2086502
references: J Chronic Dis. 1987;40(5):373-83
references: 3558716
references: J Nutr Health Aging. 2011 Aug;15(8):599-604
references: 21968852
references: Med Care. 2005 Jun;43(6):607-15
references: 15908856
references: J Am Geriatr Soc. 2003 Nov;51(11):1615-20
references: 14687392
references: Int J Obes Relat Metab Disord. 2003 Apr;27(4):498-504
references: 12664083
references: Arch Intern Med. 2005 Jan 10;165(1):55-61
references: 15642875
references: J Am Geriatr Soc. 1997 May;45(5):614-7
references: 9158585
references: Scand J Public Health. 2008 Mar;36(2):169-76
references: 18519281
references: Int J Obes (Lond). 2012 Aug;36(8):1121-6
references: 21986709
references: J Gerontol A Biol Sci Med Sci. 2007 Dec;62(12):1389-92
references: 18166690
references: Med Care. 1991 May;29(5):452-72
references: 1902278
references: J Evid Based Soc Work. 2011 Oct 26;8(5):445-68
references: 22035470
references: J Am Med Dir Assoc. 2011 May;12(4):287-94
references: 21527170
references: J Gerontol A Biol Sci Med Sci. 2001 Mar;56(3):M146-56
references: 11253156
references: Nutr Clin Pract. 2011 Oct;26(5):593-7
references: 21947642
references: Clinicoecon Outcomes Res. 2012;4:21-30
references: 22347802
references: J Am Geriatr Soc. 2009 Dec;57(12):2306-10
references: 19874405