Gandek B, et al. - Researchers assessed the data to generate 12-item short forms (KOOS-12, HOOS-12) of the 42-item Knee injury and Osteoarthritis Outcome Score (KOOS) and 40-item Hip disability and Osteoarthritis Outcome Score (HOOS) representing the full-length instruments to present joint-specific pain, function and quality of life (QOL) domain and summary joint impact scores. They recorded a pain frequency item and 3 items covering pain during frequently difficult activities (sitting/lying, walking, up/down stairs); function items about standing, rising from sitting, getting in/out of a car, and twisting/pivoting (KOOS-12) or walking on an uneven surface (HOOS-12); and the original 4-item QOL scale. They confirmed the profits of analyzing patient-reported outcome measures using modern psychometric methods, to create short forms with various content providing domain-specific and summary joint impact scores.