title: Comorbidity and functional mobility in persons with Parkinson disease.
abstract: OBJECTIVE
  To report the frequency, severity, and types of comorbidities in people with Parkinson disease (PD) using a validated self-report comorbidity screening tool, and to determine the relationship between comorbidity and functional mobility.
  
  
  METHODS
  A secondary analysis and cross-sectional observational study design.
  
  
  METHODS
  University hospital; outpatient balance disorders laboratory.
  
  
  METHODS
  Persons with mild to moderate idiopathic PD (N=76).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  The Cumulative Illness Rating Scale-Geriatric (CIRS-G) and a comprehensive mobility assessment including gait (distance walked in 3 min), balance (mini-Balance Evaluation Systems Test), and physical function (Physical Performance Test).
  
  
  RESULTS
  All participants reported comorbidities in addition to their diagnosed PD. The average ± SD number of comorbidities was 6.96 ± 2.0 (range, 2-11), and the total CIRS-G score ± SD was 12.7 ± 4.8. The most commonly reported organ systems with comorbidity were eyes and ears (89%), psychiatric (68%), musculoskeletal (64%), lower gastrointestinal (62%), respiratory (60.5%), upper gastrointestinal (59.2%), and genitourinary (53.9%). The total CIRS-G score was significantly related to functional mobility: gait (r=-.53, P=.0001), balance (r=-.43, P=.0003), and physical performance (r=-.36, P=.0041). Of the original 14 organ systems measured, there were 7 systems that, when combined, best predicted gait performance, 6 systems combined that best predicted balance performance, and 4 systems combined that predicted functional performance.
  
  
  CONCLUSIONS
  This study reports a high frequency of multiple medical system comorbidity in people with mild to moderate PD. Furthermore, comorbidity scores were associated with mobility disability: gait, balance, and physical function. Early intervention is important to delay mobility disability in PD, and we recommend that people with PD found to have comorbidities should be screened for balance and gait deficits.
authors.affiliation: Department of Neurology, Oregon Health & Science University, Portland, OR. Electronic address: kingla@ohsu.edu.
authors.forename: Laurie A
authors.initials: LA
authors.lastname: King
authors.affiliation: Department of Neurology, Oregon Health & Science University, Portland, OR.
authors.forename: Kelsey C
authors.initials: KC
authors.lastname: Priest
authors.affiliation: Department of Neurology, Oregon Health & Science University, Portland, OR.
authors.forename: John
authors.initials: J
authors.lastname: Nutt
authors.affiliation: Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, OR.
authors.forename: Zunqiu
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Physical Therapy, San Francisco State University, San Francisco, CA; Department of Physical Therapy and Rehabilitation Science, University of California San Francisco, San Francisco, CA.
authors.forename: Marsha
authors.initials: M
authors.lastname: Melnick
authors.affiliation: Department of Neurology, Oregon Health & Science University, Portland, OR.
authors.forename: Fay
authors.initials: F
authors.lastname: Horak
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D010300:Parkinson Disease / Q000453:epidemiology* / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology*; D011597:Psychomotor Performance; D012720:Severity of Illness Index
keywords: Comorbidity; Parkinson disease; Postural balance; Rehabilitation
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