Functional decline in geriatric rehabilitation ward; is it ascribable to hospital acquired infection? A prospective cohort study

BACKGROUND: In some European countries, including France, older patients with functional decline in acute units are transferred to geriatric rehabilitation units. Some patients may not benefit from their stay in a geriatric rehabilitation unit and paradoxically worsened their functional status. Previous prognostic models of functional decline are based on only baseline parameters. However, some events can occur during rehabilitation and modify the association between baseline parameters and rehabilitation performance such as heart failure episode, falls or hospital-acquired infection (HAI). The incidence of functional decline in these units and factors associated with this decline have not been clearly identified. METHODS: We used a prospective cohort of consecutive patients aged ≥75 years admitted to a geriatric rehabilitation unit in a French university hospital. The main endpoint was functional decline defined by at least an one-point decrease in Activities of Daily Living (ADL) score during the stay. Baseline social and geriatric characteristics were recorded and comorbidities were sought by the Cumulative Illness Rating Scale for Geriatrics (CIRS-G). During follow-up, hospital-acquired infection (HAI) was recorded, as was ADL score at discharge. Multivariate logistic regression and mediation analyses were used to identify factors associated with ADL decrease. RESULTS: Among the 252 eligible patients, 160 (median age 84 years [interquartile range (IQR) 80–88] had available ADL scores at baseline (median score 7 [IQR 4–10]) and at discharge (median 9 [6–12]). Median CIRS-G score was 11 [8–13], 23 (14%) had a pulmonary HAI; 28 (17.5%) showed functional decline. On multivariable analysis, functional decline was associated with comorbidities (global CIRS-G score, P = 0.02, CIRS-G for respiratory disease [CIRS-G-R] ≥2, P = 0.02, or psychiatric disease, P = 0.02) and albumin level < 35 g/l (p = 0.03). Significant associations were found between functional decline and CIRS-G-R (OR 3.07 [95%CI 1.27–7.41], p = 0.01), between functional decline and pulmonary HAI (OR 3.12 [1.17–8.32],p = 0.02), and between CIRS-G-R and pulmonary HAI (OR 12.9[4.4–37.7], p = 0.0001). Theses associations and the reduced effect of CIRS-G-R on functional decline after adjusting for pulmonary HAI (OR 2.26 [0.83–6.16], p = 0.11) suggested partial mediation of pulmonary HAI in the relation between CIRS-G-R and functional decline. CONCLUSION: Baseline comorbidities were independently associated with functional decline in patients hospitalized in a geriatric rehabilitation unit. Pulmonary HAI may have mediated this association. We need to better identify patients at risk of functional decline before transfer to a rehabilitation unit and to test the implementation of modern and individual programs of rehabilitation outside the hospital for these patients.