Evaluating minimal important differences and responder definitions for the asthma symptom diary in patients with moderate to severe asthma

Journal of Patient-Reported Outcomes

Table 3 Responsiveness of ASD Minimal Symptom Days in a 7-Day Period at Weeks 12 and 24

	Responders Mean (SE)	Non-Responders Mean (SE)	Difference	P-Value
Minimal Symptom Days-1
Week 12
ACQ > 0.5	2.29 (0.17)	0.61 (0.18)	1.68	p < 0.001
Effect size	0.80	0.21	1.68	p < 0.001
ACQ > 1.0	2.41 (0.20)	0.96 (0.16)	1.45	p < 0.001
Effect size	0.85	0.34	1.45	p < 0.001
PGA	2.46 (0.17)	0.48 (0.17)	1.98	p < 0.001
Effect size	0.86	0.17	1.98	p < 0.001
Week 24
ACQ > 0.5	2.91 (0.18)	0.50 (0.24)	2.41	p < 0.001
Effect size	1.02	0.18	2.41	p < 0.001
ACQ > 1.0	3.21 (0.21)	0.98 (0.20)	2.23	p < 0.001
Effect size	1.13	0.34	2.23	p < 0.001
PGA	3.01 (0.19)	0.63 (0.23)	2.38	p < 0.001
Effect size	1.06	0.22	2.38	p < 0.001
Minimal Symptom Days-2
Week 12
ACQ > 0.5	1.93 (0.16)	0.04 (0.17)	1.97	p < 0.001
Effect size	0.85	0.02	1.97	p < 0.001
ACQ > 1.0	2.29 (0.19)	0.29 (0.15)	2.05	p < 0.001
Effect size	1.01	0.13	2.05	p < 0.001
PGA	1.79 (0.17)	0.20 (0.18)	1.59	p < 0.001
Effect size	0.79	0.09	1.59	p < 0.001
Week 24
ACQ > 0.5	2.26 (0.18)	0.06 (0.28)	2.20	p < 0.001
Effect size	1.00	0.03	2.20	p < 0.001
ACQ > 1.0	2.61 (0.21)	0.44 (0.19)	2.17	p < 0.001
Effect size	1.15	0.19	2.17	p < 0.001
PGA	2.14 (0.19)	0.42 (0.24)	1.72	p < 0.001
Effect size	0.94	0.19	1.72	p < 0.001

Minimal Symptom Days-1 defined as mean of the 10 ASD daily symptom items ≤1 and no single symptom item score > 1
Minimal Symptom Days-2 defined as no single ASD daily symptom item score > 1, and activity limitations or nighttime awakening item scores = 0