Introduction to special section: test construction

In the last few decades, it has been recognized that it is imperative to include quality of life (QoL) as an outcome measure in the evaluation of treatment effects. Typically, QoL—due to its subjective nature—is measured using patient-reported outcomes (PROs). PROs allow the clinician to gain insight into the way patients perceive their own health, and facilitate the evaluation of treatment effectiveness beyond the physical domain measured by clinical outcomes. Since QoL has become increasingly recognized as a key outcome, the development and application of PROs in clinical settings has increased tremendously. PRO development has been accompanied by an increased interest in test theory and psychometrics, including more advanced latent variable modeling techniques and test administration procedures. PRO developers have become increasingly concerned with selecting the most appropriate techniques to ensure test quality. …