Cross-cultural adaptation and measurement properties of the Brazilian Version of the Michigan Neuropathy Screening Instrument

Abstract

BackgroundThe Michigan Neuropathy Screening Instrument is an easy-to-use questionnaire aimed at screening and detecting diabetic polyneuropathy. ObjectiveTo translate and cross-culturally adapt the MNSI to Brazilian Portuguese and evaluate its measurement properties. MethodsTwo bilingual translators translated from English into Brazilian Portuguese and made a synthetic version. The synthetic version was back translated into English. A committee of specialists and the translator checked the cultural adaptations and developed a pre-final questionnaire in Brazilian Portuguese (prefinal version). In pretesting, the prefinal version was applied to a sample of 34 subjects in which each subject was interviewed to determine whether they understood each item. For the later assessment of measurement properties, 84 subjects were assessed. ResultsA final Brazilian Portuguese version of the instrument was produced after obtaining 80% agreement (SEM<0.01%) among diabetic patients and specialists. We obtained excellent intra-rater reliability (ICC3,1=0.90), inter-rater reliability (ICC2,1=0.90) and within-subject reliability ICC3,1=0.80, excellent internal consistency (Cronbach's alpha>0.92), reasonable construct validity for the association between the MNSI and Neuropathy Symptom Score (r=0.46, p<0.05) and excellent association between the MNSI and Neuropathy Disability Score (r=0.79, p<0.05). We did not detect floor and ceiling effects (<9.5% of patients with maximum scores). ConclusionsThe Brazilian Portuguese version of the MNSI is suitable for application in the Brazilian diabetic population and is a reliable tool for the screening and detection of DPN. The MNSI can be used both in clinical practice and also for research purposes.