Measurement scales in clinical research of the upper extremity, part 1: General principles, measures of general health, pain, and patient satisfaction

Measurement is a fundamental cornerstone in all aspects of scientific discovery, including clinical research. To be useful, measurement instruments must meet several key criteria, the most important of which are satisfactory reliability, validity, and responsiveness. Part 1 of this article reviews the general concepts of measurement instruments and describes the measurement of general health, pain, and patient satisfaction.