Symptom-Illness Severity Profiles and Healthcare Use Among Lung Transplant Candidates

Abstract

<h3>Purpose</h3> Symptoms experienced by lung transplant candidates are heterogenous and may not reflect objective measures of illness severity. Both may contribute to healthcare use. We aimed to identify distinct profiles using integrated data on symptoms and illness severity and examine differences in healthcare use among observed profiles. <h3>Methods</h3> This was a single-center prospective study of adult lung transplant candidates. Symptoms were assessed within 3 months of transplant with the Memorial Symptom Assessment Scale (MSAS). Two subscales, the MSAS physical and psychological, were calculated by averaging the severity, frequency, and distress scores for 12 physical and 6 psychological symptoms (score range 0-4, higher=more severe). The LAS, a score (0-100) that represents illness severity and survival benefit, was our measure of illness severity and obtained from the health record at time of MSAS completion. Latent class analysis was used to identify distinct symptom-illness severity profiles based on two MSAS subscales and LAS. Differences in pretransplant hospitalization rates and posttransplant length of stay (LOS) among profiles were determined by comparative statistics. <h3>Results</h3> Among 93 candidates, three distinct symptom-illness severity profiles were identified: 71% had congruent symptom-illness severity; mild symptoms (MSAS phys 0.49; MSAS psych 0.57) matched mild illness severity (LAS 39.75) and 29% had symptom-illness severity mismatch; 9% had moderate symptoms (MSAS phys 0.88; MSAS psych 1.47) but severe illness severity (LAS 83.59) and 20% had severe symptoms (MSAS phys 1.30; MSAS psych 1.94) but mild illness severity (LAS 42.64). Compared to the congruent profile, mismatch profiles were younger (65 vs 53 and 52 years, p=0.007), more racially diverse (% white: 88 vs 62 and 63, p=0.002), with higher psychosocial risk scores (7.5 vs 10.5 and 13, p=0.03). Hospitalization at time of transplant was more common among the mismatch profiles compared to the congruent profile (11% vs 50% and 26%, p=0.02). Post-transplant hospital LOS did not significantly differ (p= 0.5). <h3>Conclusion</h3> We found incongruence between symptom and illness severity in a subset of patients. Higher rates of pretransplant hospitalization were observed among the mismatch profiles suggesting that both severity of symptoms and illness may be clinically relevant drivers of pretransplant healthcare use.