ABSTRACT
This chapter describes most of the issues that need to be considered to build and chose new items for instruments with excellent psychometric properties. There is a plethora of instruments available today, which can assess a wide range of health constructs with excellent psychometric properties. Once the construct is determined, its position within a framework of health outcome tools should be determined. The item generation includes a number of practical steps, which should be followed to ensure acceptance of the tool being developed. The involvement of patients in the early stages of item generation allows the development of items that are closer to the "real world". Response options for each item should be consistent with its purpose and intended use. Cognitive interviewing is crucial for the evaluation of comprehensibility and the identification of problematic items that may create response error and decrease questionnaire response rates.
