The questionnaire as a tool for collecting information in support of medical researchers

In medical and epidemiological research, multi-item questionnaires are often used to assess changes in the health of a particular group of subjects over a certain period. They can target a selected population sample based on specific exposure characteristics or target the whole population. Also, they can constitute an objective tool to help health professionals improve the quality of life and guide patients to the most appropriate care suitable [1,2]. Trying to complete an entirely new questionnaire or translating an existing questionnaire from another language can be difficult. The biggest challenge is making a questionnaire that is effective for use in research and clinical conditions. This article tries to guide for adapting validated and translated questionnaires to apply them to various population categories. We want to support readers less familiar with the process of developing and adapting validated questionnaires. Although using an existing questionnaire will save time and resources, a questionnaire that includes all items of interest to the researcher may not be available, or the current questionnaire may not be translated into the language required for respondents. If no already validated questionnaires are available or suitable, it is necessary to design a new questionnaire. For this, there are several steps to follow that one must take into account.