Essential elements of questionnaire design and development.

AIMS The aims of this paper were (1) to raise awareness of the issues in questionnaire development and subsequent psychometric evaluation, and (2) to provide strategies to enable nurse researchers to design and develop their own measure and evaluate the quality of existing nursing measures. BACKGROUND The number of questionnaires developed by nurses has increased in recent years. While the rigour applied to the questionnaire development process may be improving, we know that nurses are still not generally adept at the psychometric evaluation of new measures. This paper explores the process by which a reliable and valid questionnaire can be developed. METHODS We critically evaluate the theoretical and methodological issues associated with questionnaire design and development and present a series of heuristic decision-making strategies at each stage of such development. The range of available scales is presented and we discuss strategies to enable item generation and development. The importance of stating a priori the number of factors expected in a prototypic measure is emphasized. Issues of reliability and validity are explored using item analysis and exploratory factor analysis and illustrated using examples from recent nursing research literature. CONCLUSION Questionnaire design and development must be supported by a logical, systematic and structured approach. To aid this process we present a framework that supports this and suggest strategies to demonstrate the reliability and validity of the new and developing measure. RELEVANCE TO CLINICAL PRACTICE In developing the evidence base of nursing practice using this method of data collection, it is vital that questionnaire design incorporates preplanned methods to establish reliability and validity. Failure to develop a questionnaire sufficiently may lead to difficulty interpreting results, and this may impact upon clinical or educational practice. This paper presents a critical evaluation of the questionnaire design and development process and demonstrates good practice at each stage of this process.