Assessing health status over time: impact of recall period and anchor question on the minimal clinically important difference of copd health status tools

Table 3 Correlations between health status change scores and the Global Rating of Change anchor questions

	15-point GRC T1	15-point GRC T2	15-point GRC T3	15-point GRC T4	15-point GRC T5	Five-point GRC T5
N of Patients	451	355	319	304	309	309
CAT change score	− 0.23	− 0.33	− 0.40	− 0.43	− 0.41	0.46
CCQ total change score	−0.29	− 0.42	− 0.44	−0.48	− 0.47	0.50
SGRQ total change score	−0.30	−0.48	− 0.51	−0.58	− 0.54	0.57

Data reported as Pearson or Spearman correlation coefficients between the health status change scores and the anchor questions. Correlations ≥0.50 are highlighted bold
CAT COPD Assessment Test, CCQ Clinical COPD Questionnaire, GRC Global Rating of Change scale, SGRQ St. George’s Respiratory Questionnaire, T1 Measurement at discharge, T2 3 months follow-up, T3 6 months follow-up, T4 9 months follow-up, T5 12 months follow-up

ISSN: 1477-7525