Statistical procedure for the preoperative prediction of the result of cochlear implantation

Predicting the result of a cochlear implant preoperatively continues to be the best way to prevent an unfavourable outcome. Data from 28 cases (subdivided into two groups by their results) formed the basis for discriminant analysis using different parameters. Allocation to the two groups was found to be satisfactory. Since a jack-knifed design was used, allocation was done on the basis of data material from cases not included in this programme's analysis. Data correlation was described by an equation from which the result can be predicted with adequate accuracy using language competence, duration of deafness on the operated side, speech discrimination and threshold of acoustical sensations on promontory electrostimulation. The equation is applicable to all patients, irrespective of whether their deafness is prelingual or postlingual. Since the patient material was enlarged by 19 additional cases, we were able to confirm that the formula enables a prognosis of sufficient quality.