Epidemiology of seropositive myasthenia gravis in Greece

Objectives-To study the epidemiological characteristics of myasthenia gravi s in Greece. Methods-A population based study was carried out of seropositive myasthenia . gravis in Greece for the period from 1 January 1983 to 30 June 1997; 843 patients were studied. Results-The average annual incidence for the period 1992-7, for which the d atabase is complete, was 7.40/million population/year (women 7.14; men 7.66 ). On 1 July 1997, there were 740 prevalent cases. The point prevalence rat e was 70.63/million (women 91.58; men 59.39). The average overall annual mo rtality rate in the patients was 0.67/million population (women 0.53; men 0 .82), arid the mortality rate attributed to myasthenia gravis was 0.43/mill ion population (women 0.41; men 0.45). The average age at onset was 46.50 y ears (women 40.16; men 54.46), and the mean age of the prevalent patients w as 52.58 (women 47.65; men 59.48). The women:men incidence ratio was 1:1.04 , and the prevalence ratio was 1.41:1. It is predicted that the prevalence and women: men prevalence ratio would increase if the patient list included all patients with a date of onset before 1983. Conclusions-The largest epidemiological study ever performed on myasthenia gravis is presented. The most important epidemiological indexes are provide d.