Methodology and design of a national epidemiological study on adult neuromuscular disease

There have been no previous population-based studies of adult neuromuscular disease (NMD) in the Republic of Ireland (RoI). This article describes methods and case-ascertainment strategies used to identify patients with inherited and acquired NMD for the purpose of obtaining the prevalence of these disorders in the RoI.

This epidemiological study was conducted between January 2012 and January 2014. Prospective and retrospective (until 1990) case identification of adults with inherited and acquired NMD have been carried out. Multiple countrywide patient identification sources including neuromuscular clinics, hospital neurology databases, the hospital in-patient enquiry (HIPE) system of each hospital and the records of Muscular Dystrophy Ireland, a nonprofit organisation, were used.

In total, 3,724 potential cases were identified. Of these, 1,083 were excluded because 869 cases represented duplicates or triplicates, 133 were coded incorrectly in HIPE, 74 patients were deceased and 7 patients had moved out of the country. The highest number of cases was identified in neurology databases and HIPE (1,724 and 884, respectively). A total of 2,641 individuals fulfilled the inclusion criteria and were included in the study.

Detailed epidemiological data of this nature is difficult to acquire in the current structure of the Irish health service, requiring multiple sources including input from voluntary patient organisations. The development of a national patient registry for some or all of these conditions would greatly facilitate standardised data recording, giving a true picture of the burden of neuromuscular diseases in a population.