Functional outcomes of adult patients with West Nile virus admitted to a rehabilitation hospital

Abstract

Background and purpose: The clinical manifestation of West Nile Virus (WNV) varies in individuals from mild flu-like symptoms to acute flaccid paralysis. Advanced age is the most significant risk factor for developing severe neurological disease and for death. The broad range of neurologic symptoms associated with WNV infection leads to varied body structure and function limitations and participation restrictions that may require rehabilitation. The purpose of this study is to describe the functional impairments upon admission and the functional outcomes at discharge of 48 adult patients admitted with WNV to a rehabilitation facility in the Midwest from 2002 to 2009.

Methods: A retrospective chart review was completed on 48 patients (29 male, 19 female) with mean age 67.8 (SD = 16.6, range = 24-91) years and median age 72.5 years, admitted to inpatient rehabilitation with a diagnosis of WNV after January 1, 2002, and discharged prior to December 31, 2009. General information (sex, age, social history, employment, and living environment), past medical history, and information specific to the current hospitalization (medical conditions, functional status and activity level on admission and discharge as measured by the Functional Independence Measure [FIM], lengths of stay [LOSs] in the acute care and rehabilitation hospital, physical therapy care, discharge destination, and follow-up care provisions) were gathered. The standardized response mean (SRM) was calculated for total, motor, and cognitive FIM scores to provide insight into the effect size and the responsiveness of the FIM for the patients with WNV in this study.

Results: All patients were admitted to the rehabilitation hospital from acute care hospitals following LOSs ranging from 1 to 62 days. The rehabilitation hospital LOS ranged from 2 to 304 days. These patients had significant comorbidities including hypertension (43.75%), diabetes mellitus (41.67%), acute respiratory failure (37.5%), ventilator dependency/tracheostomy (33.33%), and pneumonia (29.17%). Their admission FIM scores ranged from 13 to 116 (mean = 45.8 ± 28.2) and discharge FIM scores ranged from 18 to 121 (mean = 75.1 ± 34.2). The change in FIM during inpatient rehabilitation was statistically significant (P < .001). The calculated SRM for the total (1.06) and motor (1.12) FIM indicate a large effect size, whereas the SRM for the cognitive FIM (0.79) indicates a moderate effect. The majority of patients were discharged home or to a nursing facility (46%), skilled or extended care (38%) with a need for continued rehabilitation services.

Discussion and conclusions: The manifestation of the WNV and functional outcomes after comprehensive rehabilitation vary from patient to patient. Higher numbers of comorbid conditions lead to more complex presentation and challenge rehabilitation professionals to design individualized plans of care to enable these patients to achieve the highest functional outcomes. Most patients require follow-up physical therapy care after discharge from rehabilitation.