Among hospitalized, disabled older women, frailty predicts disability progression among a cohort of disabled older community-dwelling women, suggesting that frailty confers a vulnerability to the acute stressor illness at a severity necessitating hospitalization. In this study, three quarters of disabled, community-dwelling women recover function partially after a post-hospitalization decline over the next two years. While most recovery occurs by 6 months, a significant proportion of women recover over the next 2 years. These results have implications for the timing and duration of rehabilitation services. Most rehabilitative services are offered and covered in the first month after hospitalization. Given the clinical and societal implications of optimizing physical function in our aging society, these results suggest that evaluating whether some patients respond best to rehabilitative interventions of longer duration would be worthwhile.
Predictors of functional decline in disabled older women who are hospitalized include older age, frailty, higher education, and length of hospital stay. Length of stay likely represents severity of the illness and hospitalization.32
The association between older age and functional decline diminished, but remains, after association for physiologic factors and other established predictors of disability among hospitalized people.5
The finding that higher education predicted functional decline was surprising; we performed sensitivity analyses to determine if this was a result of women who were more highly educated having a greater number of ADL dependencies at baseline. There was no change in the observed association, and this may merit investigation in other populations. Previously, both frailty and hospitalization have been shown to independently predict functional decline among disabled older, community-dwelling women, suggesting that both vulnerability and the acute stress of hospitalization are associated with functional decline among community-dwelling, disabled older women.2
Our results build on this prior work by showing that among disabled older women who are hospitalized, frailty is a strong predictor of functional decline in activities of daily living. Frailty may be a useful tool for clinical evaluation for older persons who are admitted to the hospital urgently or for elective surgery in order to help identify those at risk for functional decline.33
Prior work on the natural history of functional recovery suggests that by one month, less than one quarter of hospitalized older adults with functional decline have improved physical function.34
The natural history of long-term functional outcomes following hospitalization has not been previously well-described, but suggest that functional improvement may occur after the acute period.15-17, 35, 36
Our results suggest that many disabled, community-dwelling older women eventually experience both full and partial recovery, but that duration of time to recovery may be as much as 18 months.
These results have implications for health-care delivery. These results support testing of alternate models of rehabilitation, with patients not making progress in the short-term, offered aggressive rehabilitation at later time points or interventions of longer duration. Patients who are not able to participate in 3 hours a day of therapy may benefit from less intense, but longer duration rehabilitation services. It is possible that a certain degree of physical recovery from the sentinel illness is necessary to see functional improvement. In skilled nursing facilities, outpatient settings and at home, most therapy is offered within one month of discharge.37, 38
In part, this is due to the changes in financing including shortening the length of home care and roll-out of prospective payment systems. Providing prehabilitation to older community-dwelling persons at risk of functional decline may prevent episodes of disability.
These results apply to the one third most disabled of community-dwelling women. Hospitalized women who are not disabled and hospitalized men may have different predictors of functional decline and different trajectories and likelihood of recovery. However, older disabled women are frequently hospitalized and are among the most likely to experience functional decline associated with hospitalization for acute illness19
There are several limitations to this work but also relevant strengths. We cannot identify function immediately prior to the acute illness leading to the hospitalization. We have variable follow-up due to variable timing of hospitalization as well as study dropout. Skipped visits and loss to follow up are likely not at random as women who are sicker are more likely to be missing and there is competing risk of death. However, reported hazard ratios have valid “cause-specific” interpretations to recovery as opposed to dropout or death.39
Moreover, retention in WHAS was high and we have more than 1.5 years of follow-up after hospitalization on 59.9% of women. We also cannot identify the exact time that functional recovery occurred and, thus, describe our results as to whether recovery has occurred by a specific time point. Given our assessment of six-month intervals, it is likely that some women had recovery and subsequent decline in between our assessments. Prior work has shown that there is a significant amount of variability in functional status among community-dwelling older adults with multiple episodes of disability and recovery.11
Six-month assessments of functional status are believed to be appropriate and valid.40
We also do not account for the cause of hospitalization or utilization of rehabilitative services here. The reason for hospitalization is often complex and due, in part, to multiple diagnoses. During the period of the study, there was little utilization of rehabilitative services, although changes in the structure of hospital financing have led to greater use of post-acute services. In 1995, less than one percent of elders hospitalized with heart failure, chronic obstructive pulmonary disease (COPD), pneumonia, other respiratory infections, or genitourinary infections received inpatient acute rehabilitation, with more patients utilizing home health care and SNFs.41
The rates of patients with stroke, COPD, pneumonia, congestive heart failure, and hip fracture receiving inpatient post acute rehabilitation services upon discharge ranged from 0.2% - 13% based on Medicare Standard Analytic Files from 1996-1998, with the highest rates observed for stroke and hip fracture.42
These issues will be explored in future work. We view as particular strengths of this study our analysis of a population-based cohort and the measurement of function and predictors at regular intervals before and after hospitalization, with timing and method independent of the hospitalization per se.