G.P.308: Perception of efficacy in adult patients affected by Spinal Muscular Atrophy (SMA) treated with salbutamol

Abstract

One possible therapeutic approach in SMA is based on attempts at increasing the amount of SMN2-fl transcripts. Salbutamol is a well tolerated drug and it has been demonstrated to significantly increase SMN2 transcripts. Despite no significant improvement has been demonstrated in treated adult patients, they usually report a subjective improvement. The aim of this study is to better understand patient's perception of salbutamol treatment efficacy. Seven patients were enrolled (6 SMA type 3, 1 type 2; 4 ambulant), mean age 40.1years; mean disease duration 26.7years; mean treatment duration 2.4years. A mix-method (qualitative and quantitative approach) was used. Patients, treated with salbutamol for at least one year, were invited to participate. An in-depth interview was carried out to evaluate patients' perceptions of change after treatment, then patients were asked to complete the WHO Disability Assessment Schedule II (WHODAS-II) and the Fatigue Severity Scale (FSS). Patients were requested to report how they feel at the moment of interview (post-test "T1") and how they felt before starting treatment (then-test "T0"). Content analysis was performed to identify patients' main themes. Non parametric Wilcoxon test for paired samples were performed to compare WHODAS II and FSS mean scores at T0 and T1. Four main themes were identified during the interviews: improvement in patients' resistance and strength with relevant decrease of fatigue perceived; feeling of being more motivated and autonomous; slowdown of disease progression; all patients would suggest salbutamol therapy to other SMA patients. Statistically significant differences were detected for WHO DAS II scores (Summary score; Getting Around; Household Activities, sig. 0.018; 0.026, 0.024 respectively) and FSS score (sig. 0.017) between T0 and T1, with lower scores at T1. If confirmed on a larger group of patients our protocol could be useful to point out patients' perception of efficacy in clinical trials.