Linguistic validation of a questionnaire for assessing the prevalence of epilepsy in Portugal

To present the results of the linguistic and cultural validation of two short questionnaires into Portuguese for use in interviews with the general population, adults, and parents/carers of epilepsy patients to assist in future epidemiological studies into the prevalence of epilepsy in Portugal.

The questionnaires were translated and validated using the ISPOR methodology. Two professional forward translators and one backtranslator were used to ensure the final translation was accurate, understandable, and culturally appropriate. The final translation was tested on six respondents from the target population and reviewed by the translation project manager and the medical steering committee before being proofread and finalized.

The validation process was successful and resulted in a questionnaire that was culturally and linguistically relevant to the target population. The results show that the translations were produced in participant-friendly, clear and direct language that would be easily understandable by participants of any educational and social background. This was confirmed by the six respondents in the cognitive debriefing, who unanimously considered the questionnaires to be understandable and culturally appropriate.

Following successful linguistic and cultural validation, the Ottman et al. instrument for screening epilepsy is now available and validated for European Portuguese. The newly translated questionnaire paves the way for future research into epilepsy prevalence in Portugal and the Portuguese speaking countries.