Fig. 2From: The Chinese version of the Perceived Stress Questionnaire: development and validation amongst medical students and workersCategory probability curves for the Chinese PSQ-13. This figure displays the category probability curves for the questionnaire which includes 13 items, demonstrating ordered thresholds. The four curves from left to right represent 4 response categories (1 = almost never, 2 = sometimes, 3 = often, and 4 = usually)Back to article page