Construction of a new scale measuring the severity of myasthenia gravis based on Delphi method and previous evaluation of source scales / 中华神经科杂志

ABSTRACT

Objective To develop the preliminary version of a new scale on the severity of myasthenia gravis ( MG) suitable for Chinese patients .Methods The item pool was established based on the four widely used MG severity scales .Then the Delphi method was applied to collect the opinions from MG experts in China.Based on the consistency of expert opinions and previous evaluation of the items in source scales , the preliminary version of a new scale was developed .Results The item pool consists of 19 items from the above four scales .The enthusiasm coefficients of experts in two rounds of survey are 91.4%(32/35) and 96.9%(31/32).The authority coefficients are 0.79 and 0.80.The Kendall′s coefficients of concordance of expert opinions are 0.22 (χ2 =127.01, P<0.01) and 0.42 (χ2 =231.56, P<0.01), respectively.The preliminary version consists of 10 items, which cover six commonly involved muscle groups in MG, including the ocular, bulbar, facial, limb, axial and the respiratory muscles.Conclusion The preliminary version of the MG severity scale was established by combining Delphi method with the previous evaluation of items from source scales .