Preventing Rehospitalization in Lung Transplant Recipients Utilizing mHealth

Mission and Specific Aims: Lung transplantation has several important aims: 1) extend survival; 2) relieve disability, and 3) improve health-related quality of life (HRQL) for adults suffering from end-stage lung disease. Advances in medical therapies and changes in the US organ allocation system in 2005 have prioritized lung transplant for sicker and older patients. This achievement has come at substantial cost, including recent trends in recipients towards increased disability, poorer HRQL, and increased longer-term mortality.

Reflecting these trends, lung transplant recipients have the highest risk of unexpected readmission after the index admission among solid organ transplant patients, with published rates of 38-43%. Over the course of the first post-transplant year, the investigators have shown that 60% of lung transplant recipients have a readmission within 30 days of a hospital discharge, of which 30% occur after initial discharge (as above) and 70% occur after a subsequent readmission (2). Each readmission increases the risk for another unplanned rehospitalization as well as long-term mortality, suggesting that this is a particularly vulnerable population.

Over the last year, the investigators performed a single center cohort study to identify risk factors for readmission after index lung transplant discharge. As part of this initiative, the investigators have been evaluating the role of frailty as measured by the Short Physical Performance Battery (SPPB) test. The SPPB is a three-component battery of lower extremity performance, measures that includes gait speed, chair stands, and balance. The investigators have previously demonstrated that frailty is a risk factor for delisting and death among wait listed lung transplant recipients as well as a significant predictor of mortality within the first year after transplant (Figure 1)(3). In a recent single center cohort study of 90 Penn lung transplant recipients, the investigators demonstrated that patients who are frail at index hospitalization discharge based on SPPB are 3.4 times more likely to have an unplanned re-hospitalization within the next 30 days, regardless of whether they are discharged home or to acute rehab. Interestingly, patients are not frail at the time of listing for transplant - frailty develops during the hospital stay for lung transplantation suggesting that physical frailty is dynamic over a short period of time and may be amenable to intervention. The frequent re-admissions, in part due to significant frailty, lead to 1) increased healthcare expenditures (the median professional and hospital payments at Penn for an unplanned hospitalization following discharge was $13048, 2) severely impact the patient's quality of life, and 3) lead to increased mortality.

The investigators have previously found that, among recipients who were frail at discharge and who were enrolled in an intensive outpatient physical therapy program, the median improvement in SPPB was 6 points and 85.7% became not frail (unpublished data). Although this demonstrates that frailty can be reversed in the lung transplant population, the impact of reduced frailty on subsequent readmission has not been evaluated. It remains unknown whether there are other, less resource intensive, mechanisms for improving frailty. The investigator's belief is that improving access to individualize exercise training plans that are modified based on a patient's progress and needs will greatly improve transplant recipient's level of physical fitness and independence, and decrease the risk of hospital readmission. This will lead to an overall improvement in a patient's quality of life. This study, therefore, targets a population of lung transplant recipients at highest risk for readmission and further complications.

Specific Aim: Evaluate the impact of targeted physical therapy rehabilitation plans utilizing a customizable app based interface on the subsequent readmission rates of lung transplant patients at the highest rate of readmission. Patients who are 1) frail at the time of discharge (SPPB≤8) or 2) have already been readmitted after their transplant hospitalization are at the highest risk of subsequent readmission. The investigators hypothesize that targeted, individualized rehabilitation plans will reduce the risk of subsequent readmission.