Evaluation of the minimal important difference for the feeling thermometer and the St. George's Respiratory Questionnaire in patients with chronic airflow obstruction

BACKGROUND/OBJECTIVES: The chronic respiratory questionnaire (CRQ), the St. Georges Respiratory Questionnaire (SGRQ), and the feeling thermometer (FT) evaluate change in health-related quality of life (HRQL) in patients with chronic airflow limitation (CAL). Although the interpretability, and in particular the minimal important difference (MID) in score changes, is well established for the CRQ, this is not the case for the SGRQ and FT. The …