OBJECTIVES : Non-dystrophic myotonias (NDM) are an extremely rare group of muscle disorders where muscles clench tightly and are slow to relax. Limited information on NDM healthcare resource utilization (HRU) was retrieved from a systematic literature review. This study aimed to confirm HRU categories, quantify the proportion of patients using these, and the frequency to support economic modelling of best supportive care (BSC) to mexiletine.

METHODS : A two-round Delphi panel was conducted, focusing on UK HRU with a pre-specified consensus threshold of 70%. Six UK experts were recruited although one dropped out at each round. To investigate the generalizability of HRU categories in other European countries, one expert was recruited for Denmark, France and Germany, respectively. Pre-specified HRU categories were presented and questions aimed to elicit the proportion of patients using each resource, the frequency of HRU and if any resources were omitted

RESULTS : The pre-specified HRU categories were generalizable across countries. However, the proportion of patients per HRU was variable, confirming the need for local HRU data. 75% (n= 3/4) of the responding UK experts (Round 2) agreed that, when comparing BSC to mexiletine, the proportion of NDM patients utilizing any resource and the number of HRU visits were 1.9 and 1.8 times higher, respectively. From Round 1, there was a consensus (83%; n = 5/6) that the proportion of patients requiring mental health support was lower for patients receiving mexiletine; with 75% of the responding experts (n = 3/4) in Round 2 agreeing mental health support was approximately 2.7 times higher for patients receiving BSC.

CONCLUSIONS : This study helps to clarify the HRU categories relevant for NDM patients. Using the validated Delphi technique, it was found that mexiletine can be expected to reduce the number of NDM patients requiring specific HRU, in addition to reducing the frequency of use of these resources.