The Impact of Physiotherapy Prehabilitation on Physical Fitness, Length of Stay (LoS), Readmission Rates, Quality of Life (QoL) and Patient Level Costing (PLICS) for Haematopoietic Stem Cell Transplant (HSCT) and Chimeric Antigen Receptor T- Cell (CA

Introduction Prehabilitation (prehab) can improve cancer patients' resilience to treatment, cardiovascular fitness and QoL, and helps to create positive health behaviour changes impacting long term health.1 There are limited data regarding the benefits of prehab in HSCT and CAR-T recipients or how prehab may affect costings and LoS associated with these cellular therapies. 2,3 A multidisciplinary prehab service comprising physiotherapy, occupational therapy, psychology, pharmacy and dietetics was started by the South Wales Blood and Marrow Transplant (SWBMT) Programme in April 2022. We hypothesised that patients would benefit from short- and long-term improvements including physical fitness, shorter LoS, reduced readmissions, resulting in financial savings and improved QoL. We report the outcomes associated with physiotherapy interventions. Methods All patients who attended prehab and received cellular therapy by the SWBMT Programme between April 2022-April 2024 were included in the analysis. This cohort was matched by age, sex, diagnosis and cellular therapy type with a control group (no prehab) treated in 2021/2022. A comprehensive physiotherapy assessment involving 8 outcome measures was conducted at prehab and included 1 minute sit to stand (1MSTS), FACIT - F, Godin's-Shepard Physical Activity Questionnaire (Godin's), 6 Minute Walk Test, Short Physical Performance Battery, EQ-5D-5L, EQ VAS, Clinical Frailty Scale. Patients received an average of 3 physiotherapy sessions over the mean length of 7 weeks until admission, daily whilst an inpatient, with subsequent review and outcome measure collection at discharge, week 6 and months 3, 6, 12 post-cellular therapy. QoL was assessed using FACT-BMT (v4.10), collected at similar timepoints. Readmission data were collected centrally by Digital Health and Care Wales (DHCW) and included all readmission to any Welsh hospital in a 365-day period post-cellular therapy. LoS and readmission costs were calculated using PLICS data in both patient groups. Measures of central tendency, paired t test and Wilcoxon signed-rank test and minimal clinical importance differences (MCID) were used in the analysis as appropriate.4,5,6,7,8 Results 174 prehab patients, 62 (36%) female, median age 59 (range 16-75) years received autologous HSCT (n= 75), allogeneic HSCT (n= 74) or CAR-T (n=24) for lymphoid or myeloid disorders. The control group (n=89) and the subset (n=52) for whom physiotherapy outcome data were available did not differ from the prehab group. All 8 outcome measures improved between prehab and day 0, meeting MCID thresholds, particularly for 1MSTS (p<0.02), Godin's (p=0.0002) and FACIT-F in allo HSCT (p=0.001), auto HSCT (p=0.00), but not CART (p=0.1). As expected, all scores fell at discharge, reflecting the negative acute impact of cellular therapy. Day 0 prehab scores were higher than controls, particularly for FACIT-F (p=0.001) which measures fatigue. Interestingly, reduced fatigue did not impact on FACT-BMT QoL scores which were similar at all timepoints between prehab and controls. Godin's, which measures physical activity, showed that time to return to day 0 baseline was similar between prehab and controls, although the control baseline was lower than prehab. Reduction in LoS was seen in allo HSCT and CART but not auto HSCT and averaged 2 bed days in the prehab group, equating to savings of £202,502 (excluding overheads), resulting in an opportunity cost saving of £144,000 when a bed day cost is applied to the difference in mean length of stay. Emergency readmissions within 1 year were lower in prehab versus controls following allo HSCT (n=34, 205 days v n=36, 324 days) and CART (n=4, 39 days v n=4, 49 days) but not after auto HSCT (N=36, 180 days v n=50, 148 days), which may reflect post-HSCT therapy in myeloma. Conclusion Patients who received multidisciplinary prehab improved baseline physiotherapy outcome measures by admission for cellular therapy which was also higher than controls who received no prehab. Improvement was particularly significant regarding fatigue and physical activity measures implying better short- and long-term physical fitness. Allo HSCT and CART recipients also experienced shorter length of stay and fewer emergency readmissions leading to cost savings. Further research is needed to investigate longer-term health benefits and to correlate with other prehab interventions and cellular therapy outcomes.