The ultimate goal of good measurement is to generate a numeric score that has meaning so that we can use it to represent a given concept (depression, health, disease activity) in our statistical analyses in a given population. Measurement is like the "basic science" of clinical epidemiology and impact on our measurement of causal, prognostic and outcome variables. The purpose of this course is to learn principles of measurement (good scale development, clinical usefulness, validity, and reliability) so that they can be applied to the critical appraisal of a given instrument when a measurement need is defined.

In this course we will help you define a particular measurement need — what do you need to measure, in whom, and why? — and from that move to the appraisal of a scale of your choice to see if it would be appropriate for that application. Students taking this course will focus on measures that are based on expertise, clinical judgment, experience, or the subjective perceptions of either the providers or consumers of health care. These might include clinimetric indices which are aggregated scores across various domains — such as disease activity indices, or prognostic indices; or more psychometric scales where there are multiple items to tap a single concept like depression, health, performance, or function. Measures that are single items, or which are uncontested or irrefutable gold standards of truth would not be good selections for work in this course. The classes are split into two: lecture (instructors or guest lecturer) and student-led presentations/seminars. Tutorials are offered in the hour preceding the course on certain topics.

Objectives: The students will work through the principles of measurement, and at each stage reflect on this for their chosen measurement instrument and need. The assignment is best done as the course progresses. By the end of the course, students are to apply measurement principles and methods in the critical assessment and development of measures employed in clinical and epidemiological research. Many of our students have published their final assignments.