Prevalence and Impact of Potentially Inappropriate Medication Use on Post-Transplant Outcomes Among Older Adults with Plasma Cell Dyscrasias Receiving an Autologous Stem Cell Transplant

Background

Polypharmacy and potentially inappropriate medication (PIM) use is a healthcare concern in older adults with cancer, predisposing them to multiple adverse outcomes. While there is no standard definition on the number of medications needed for polypharmacy, polypharmacy negatively impacts patient outcomes with an increase in adverse drug events, drug interactions, and hospitalizations. The prevalence and impact of PIM use on post-transplant outcomes among older adults with plasma cell dyscrasias (PCD) undergoing autologous stem-cell transplantation (ASCT) has not been adequately studied.

Methods

Using data from the Cancer and Aging Resilience Evaluation in Hematologic Malignancies (CARE-Heme) study, a single-center prospective observational registry of older adults with hematologic malignancies, we identified adults who were ≥50y at the time of referral to ASCT for plasma cell dyscrasia from January 2020 to March 2022. Eligible patients underwent a comprehensive geriatric assessment at the time of their pre-transplant visit along with a comprehensive review of their medication history by either a pharmacist, registered nurse, or physician. We defined polypharmacy as use of ≥5 medications and used the American Geriatrics Society (AGS) Beers 2019 criteria for assessment of PIM. The primary outcome was 30-day readmission following ASCT. Secondary outcomes included length of hospitalization during transplant, incident falls, and health related quality of life (HRQoL) (using PROMIS global 10 measure) at 90 days post-ASCT. Modified Poisson regression with robust variance estimator was used to compute adjusted relative risk of readmission and incident falls and multiple linear regression used to compute the adjusted mean difference of length of stay (LOS) and physical and mental HRQoL between those with one or more PIM use vs those without. All models were adjusted for age, sex, race (white vs other), comorbidity, frailty (using a 44-item deficit accumulation index) and melphalan dose.

Results

Of 112 adults enrolled in the registry, 101 proceeded with ASCT. The median age at transplant was 64 yrs (range 50-79); 59% were male and 58% were non-Hispanic white. The median number of medications was 9 (Interquartile range, IQR 6-12); 88% were taking ≥5 medications, whereas 57% were taking ≥9 medications. Overall, 38% (95% CI 28-48%) of the patients had evidence of at least one PIM (median 1, range 1-5). The prevalence of PIM was 26%, 43%, and 45% in the age groups 50-60 yrs, 60-70 yrs, and >70 yrs, respectively (Figure 1). The most prescribed PIM therapeutic category was anticholinergics (n = 15), non-cyclooxygenase selective oral NSAIDs (n= 10), skeletal muscle relaxants (n= 6), and central nervous system antidepressants (n = 6). Overall, 9% of patients were readmitted within 30 days whereas 16% of patients had falls within 90 days of ASCT. Patients with at least one PIM vs those without had an increased risk of readmission within 30 days (RR 6.07; 95%CI 1.01-36.7; p = 0.046). Furthermore, those with PIM vs without had a trend towards increased risk of falls (RR 2.13; 95%CI 0.86-5.32; p = 0.10) and worse physical (β -4.04; 95% CI -8.31-0.23; p = 0.06) and mental HRQoL (-3.65; 95% CI -7.61-0.31; p = 0.07) at 90 days. Meanwhile, there was no significant difference in the LOS index between the two groups (β 1.09; 95% CI -1.02-3.21; p = 0.30). (Table 1)

Conclusion

Our study showed a high prevalence of PIM use among older adults with PCD undergoing ASCT. Use of PIM was associated with a significantly increased risk of readmission and a trend towards increased risk of falls and worse HRQoL. Our findings are limited by our small sample size and need to be confirmed by larger studies that may pave the way for de-prescribing interventions to minimize PIM use in this population to improve post-transplantation outcomes of this vulnerable population.

Watts:Bristol-Myers Squibb: Consultancy. Bal:Adaptive Biotechnologies: Consultancy. Costa:AbbVie: Research Funding; Adaptive Biotechnologies: Consultancy, Honoraria; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Genentech: Research Funding; Sanofi: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding. Giri:OncLive: Honoraria; CareVive: Honoraria, Research Funding; Pack Health: Research Funding.