Therapeutic Decision-Making Under Uncertainty in the Management of Spinal Muscular Atrophy: Results From DECISIONS-SMA Study.

INTRODUCTION

There are many uncertainties about treatment selection and expectations regarding therapeutic goals and benefits in the new landscape of spinal muscular atrophy (SMA). Our aim was to assess treatment preferences and expectations of pediatric neurologists caring for patients with SMA.

METHODS

DECISIONS-SMA is a non-interventional, cross-sectional pilot study that assessed pediatric neurologists with expertise in SMA from across Spain. Participants were presented with 11 simulated case scenarios of common encounters of patients with SMA type 1 and 2 to assess treatment initiation, escalation, or switches. We also asked for the expected benefit with new therapies for four simulated case scenarios. Participants completed a behavioral battery to address their tolerance to uncertainty and aversion to ambiguity. The primary outcome was therapeutic inertia (TI), defined as the number of simulated scenarios with lack of treatment initiation or escalation when warranted over the total (11) presented cases.

RESULTS

A total of 35 participants completed the study. Participants' mean (SD) expectation for achieving an improvement by starting a new therapy for SMA type 1 (case 1, a 5-month-old) and SMA type 2 (case 6, a 1-year-old) were both 59.6% (± 21.8), but declined to 20.2% (± 12.2) for a case scenario of a 16-year-old treatment-naïve patient with long-standing SMA type 2 with severe disability. The mean (SD) TI score was 4.2 (1.7), and 3.29 (1.5) for treatment initiation. Of a total 385 individual responses, TI was observed in 147 (38.2%) of treatment choices. The multivariable analysis showed that lower aversion to ambiguity (p = 0.019) and lower expectation of treatment response (p = 0.007) were associated with higher TI after adjustment for participants' age and years of experience. Older age (p = 0.019), lower years of experience (p = 0.035), lower aversion to ambiguity (p = 0.015), and lower expectation of treatment benefits (p = 0.006) were associated with inertia for treatment initiation.

CONCLUSIONS

Pediatric neurologists managing patients with SMA were optimistic regarding treatment improvement in cases with early diagnosis, but had lower expectations when treatment delays and advanced patient age were present. Low aversion to ambiguity, low expectation of treatment benefits, and lower clinical experience were more likely to make suboptimal decisions, resulting in lack of treatment initiation, escalation, and TI.