Comorbidity and Functional Mobility in Persons with Parkinson Disease

ObjectivesTo 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.DesignA secondary analysis and cross-sectional observational study design.SettingUniversity hospital; outpatient balance disorders laboratory.ParticipantsPersons with mild to moderate idiopathic PD (N=76).InterventionNot applicable.Main Outcome MeasuresThe Cumulative Illness Rating Scale-Geriatric (CIRS-G) and a comprehensive mobility assessment including gait (distance walked in 3min), balance (mini-Balance Evaluation Systems Test), and physical function (Physical Performance Test).ResultsAll 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.ConclusionsThis 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.