Table 7

MID Estimates for the QOL-B scales

	AIR-BX1		AIR-BX2		Final MID*
QOL-B V.3.0 scale and method of estimating MID	MID	n	MID	n	Final MID*
Respiratory Symptoms					8.0
Anchor-based†	6.7	56	11.4	77
1/2 SD‡	8.0	266	7.7	274
SEM§	7.7	266	8.2	274
Physical Functioning					10.0
Anchor-based†	8.7	61	11.3	53
1/2 SD‡	10.1	266	9.9	274
SEM§	8.4	266	8.6	274
Vitality					10.0
Anchor-based†	11.9	49	8.9	51
1/2 SD‡	9.5	266	9.4	274
SEM§	10.0	266	11.6	274
Role Functioning					8.0
Anchor-based†	11.8	49	0.0	34
1/2 SD‡	8.6	266	8.2	274
SEM§	10.0	266	10.1	274
Health Perceptions					8.0
Anchor-based†	7.6	50	3.6	58
1/2 SD‡	8.2	266	7.9	274
SEM§	9.8	266	10.1	274
Emotional Functioning					7.0
Anchor-based†	5.1	44	4.6	40
1/2 SD‡	7.1	266	6.8	274
SEM§	8.2	266	8.8	274
Social Functioning					9.0
Anchor-based†	10.3	37	2.0	33
1/2 SD‡	7.8	266	7.3	274
SEM§	12.6	266	13.3	274
Treatment Burden					9.0
Anchor-based†	6.9	37	5.9	45
1/2 SD‡	9.8	247	10.0	232
SEM§	11.3	247	11.6	232

*Final MIDs were the average of the 6 MID values obtained for each scale, rounded to the nearest integer.
†Anchor-based MID=mean change from baseline QOL-B score at day 14 for patients with minimal change on the corresponding GRCQ (>0.5 to 1.5 improvement or worsening of scores on −3 to 3 scale).
‡1/2 SD of mean change from baseline QOL-B score at day 14.
§SEM for baseline scores; SEM=SD√(1-α), with SD of mean baseline score and α=Cronbach's α.
GRCQ, Global Rating of Change Questionnaire; MID, minimal important difference; QOL-B, Quality of Life-Bronchiectasis; SEM, SE of measurement.