Braun T.1,2, Schulz R.-J.3, Thiel C.1, Grüneberg C.1
1Hochschule für Gesundheit, Department of Applied Health Sciences, Bochum, Germany, 2University of Cologne, Medical Faculty, Cologne, Germany, 3St. Marien-Hospital, Department of Geriatric Medicine, Cologne, Germany
Background: Older individuals with dementia and other cognitive dysfunctions constitute to a significant number of geriatric inpatients, with prevalence values reported between 41% and 76% [Meziere 2013; Yiannopoulou 2012; Zapatero 2013]. Mobility is a key outcome in geriatric care, impacting older individual's independence and quality of life [Brown 2013]. To monitor mobility changes of geriatric patients over time, reliable outcome measures are arbitrary. The de Morton Mobility Index (DEMMI) is an unidimensional and valid measurement instrument of mobility in older individuals [de Morton 2008; Braun 2015]. The test-retest reliability is excellent with intra-class correlation coefficients (ICC) between 0.86 and 0.92 [de Morton 2008]. The reliability of the DEMMI in older acute medical patients with cognitive impairment is unclear.
Purpose: To analyse the test-retest reliability of the DEMMI in older acute medical patients with cognitive impairment.
Methods: We included older acute medical patients with cognitive impairment indicated by a Mini Mental State Examination (MMSE) score below 25 points. Participants were assessed within the first 7 days after hospital admission.
The DEMMI was assessed two times on one single day. Both measures were performed by the same assessor, a physical therapists experienced with the clinical application of mobility outcomes. Patients who reported a change in their physical or mental condition with respect to the first assessment were excluded.
Test-retest reliability was examined using the ICCAGREEMENT (two-way random effects model) [McGraw 1996; Vet 2011]. An ICC of ≥0.7 or higher was deemed acceptable [Terwee 2007]. The minimal detectable change (MDC) with 90% and 95% confidence was calculated based on the test-retest reliability data.
Results: The mean age of the 65 participants was 82 ± 6 (range: 71 to 97) years, 55% were female and the mean MMSE score was 20 ± 4 (range: 10 to 24) points. The mean time between both assessments was 218 ± 86 (range: 60 to 405) minutes. The ICCAGREEMENT was 0.99 (95% confidence interval: 0.98 to 0.99). The MDC90 was 5.3 points and the MDC95 was 6.3 points.
Conclusion(s): These results indicate excellent [Terwee 2007] test-retest reliability of the DEMMI in geriatric inpatients with cognitive impairment. A DEMMI change score must be at least 6 points to have 90% confidence that this score is beyond measurement error, and 7 points to have 95% confidence, as the DEMMI scale consists of whole numbers only.
Implications: The DEMMI seems to be a reliable measurement instrument of the mobility of older people with cognitive impairment and dementia if it is applied by a trained physical therapist.
Funding acknowledgements: None.
Topic: Older people
Ethics approval: Ethical Review Board of the University Cologne (registration number: 14-110)
All authors, affiliations and abstracts have been published as submitted.
