Trajectories of Physical Resilience Among Older Veterans With Stage 4 CKD

Abstract

Rationale & objective: Although functional impairment is common among older adults with chronic kidney disease (CKD), functional reserve before an acute health event and physical resilience after the event have not been characterized in this population. The purpose of this study was to identify distinct patterns of physical function before and after an acute health event among older veterans with stage 4 CKD.

Study design: Prospective cohort study.

Setting & participants: National sample of veterans≥70 years of age with an estimated glomerular filtration rate (eGFR) of<30mL/min/1.73m² who had an acute care encounter (emergency department visit or hospitalization) during the follow-up period (n = 272).

Predictors: Demographic characteristics, eGFR, basic and instrumental activities of daily living (ADL/IADL) difficulty, symptom burden, cognition, depressive symptoms, social support.

Outcome: Function measured using the life-space mobility assessment obtained by telephone survey before and after an acute care encounter.

Analytical approach: General growth mixture models to identify classes of functional trajectories. Calculation of percentages for demographic characteristics and means for eGFR, ADL/IADL difficulty, symptom burden, cognition, depressive symptoms, and social support by trajectory class.

Results: Four trajectory classes were identified and characterized by different levels of life-space mobility before (reserve) and change in life-space mobility after (resilience) an acute care encounter: (1) low reserve, low resilience (n=91), (2) high reserve, high resilience (n=23), (3) moderate reserve, moderate resilience (n=89), and (4) high reserve, low resilience (n=69). Mean levels of ADL/IADL difficulty, symptom burden, cognition, and depressive symptoms, but not demographic characteristics, eGFR, or social support, differed by trajectory class.

Limitations: Veteran cohort was primarily male.

Conclusions: Among older adults with stage 4 CKD, physical function trajectories before and after an acute health event vary. Integrating reserve and resilience into care for this population may be useful for anticipating changes in function and developing tailored treatment plans.

Keywords: Acute health event; chronic kidney disease; resilience; veterans.

Figure 1.. Study cohort.

The cohort includes PREPARED participants who were detected as having a health stressor in the VA electronic health record (EHR; n=202) and those who self-reported a health stressor only (n=72). Health stressors were defined as an acute care encounter (hospitalization or emergency department visit). Two participants who were detected as having a health stressor died prior to the first call following the health stressor and were not included in the final analyses (final n=272, gray box).

Figure 2.. Physical resilience trajectories classes.

Follow-up time defined relative to the health stressor where time 0 is the telephone survey immediately following the health stressor. Function based on life-space mobility score which ranges from 0 to 120 with higher scores indicating better function. Gray horizontal dashed-lines indicate clinically meaningful restrictions in life-space at the level of one’s neighborhood (<60) and one’s home (<30). The following labels were chosen by the research team by visually examining these mean patterns: Class 1: low reserve, low resilience (n=91), Class 2: high reserve, high resilience (n=23), Class 3: moderate reserve, moderate resilience (n=89), and Class 4 high reserve, low resilience (n=69).

Figure 3.. Individual trajectories of participants assigned to each of the four trajectory classes.

Observed trajectories of life-space mobility are shown in gray. Entropy for all four trajectory classes ≥0.75 indicating a high probability of assignment to only one trajectory class.