Physical activity among hospitalized older adults - an observational study.

Background: Low level of physical activity is common among hospitalized older adults and is associated with worse prognosis. The aim of this paper is to describe the pattern and level of physical activity in a group of hospitalized older adults and to identify factors associated with physical activity.
Methods: We measured physical activity on day three after admission using accelerometer based activity monitors and time in upright position as outcome measure. We collected data of physical function (Short Physical Performance Battery, SPPB. 0-12), cognitive function (Mini Mental Status Examination, MMSE, 0-30 and diagnosis of cognitive impairment at discharge, yes/no), personal Activities of Daily Living (p-ADL, Barthel Index, BI, 0-20) and burden of disease (Cumulative Illness Rating Scale, CIRS, 0-56). We analyzed data using univariable and multivariable linear regression models, with time in upright position as dependent variable.
Results: We recorded physical activity in a consecutive sample of thirty-eight geriatric patients. Their (mean age 82.9 years, SD 6.3) mean time in upright position one day early after admission was 117.1 min (SD 90.1, n = 38). Mean SPPB score was 4.3 (SD 3.3, n = 34). Mean MMSE score was 19.3 (SD 5.3, n = 30), 73% had a diagnosis of cognitive impairment (n = 38). Mean BI score was 16.4 (SD 4.4, n = 36). Mean CIRS score was 17.0 (SD 4.2, n = 38). There was a significant association between SPPB score and time in upright position (p = 0.048): For each one unit increase in SPPB, the expected increase in upright time was 11.7 min. There was no significant association between age (p = 0.608), diagnosis of cognitive impairment (p = 0.794), p-ADL status (p = 0.127), CIRS score (p = 0.218) and time in upright position. The overall model fit was R ² 0.431.
Conclusion: Participants' mean time in upright position one day early after admission was almost two hours, indicating a high level of physical activity compared to results from similar studies. Physical function was the only variable significantly associated with physical activity indicating that SPPB could be a useful screening tool and that mobilization regimes should be delivered routinely for patients with reduced physical function.