Measurement of respiratory function decline in patients with Duchenne muscular dystrophy: a conjoint analysis

AIM: In Duchenne muscular dystrophy (DMD), little attention has been paid to severity of respiratory function decline (RFD) based on disease progression. We performed a conjoint analysis among 123 Italian clinicians to generate a scale for RFD in DMD patients. METHODS: Before the interview, 11 attributes were selected by discussion among experts. 32 'patient profiles' were generated. Each physician assessed the severity of RFD for each profile. Each level/attribute was assigned an estimated usefulness to understand its impact on RFD. RESULTS: The identified attributes were forced vital capacity, forced vital capacity decline, dysphagia, type of ventilation and peak cough flow. These results allowed the development of a scale for RFD severity. CONCLUSION: This scale can stratify DMD patients according to the severity of their RFD.