Efficacy of brief motivational interviewing to improve adherence to inhaled corticosteroids among adult asthmatics: results from a randomized controlled pilot feasibility trial

Figures & data

Figure 1 Study flow chart.

Abbreviations: HSCM, Hôpital du Sacré-Coeur de Montréal; BD, twice-daily; MI, motivational interviewing; ACQ, Asthma Control Questionnaire; ICS, inhaled corticosteroid; PRN, as needed; ITT, intent-to-treat; PP, per-protocol; mo, months.

Table 1 Participants’ characteristics at baseline

	Total (n=54)	MI (n=26)	Control (n=28)	Missing data, n
Sociodemographics
Age, years	50 (16)	52 (15)	49 (16)	–
Men, n (%)	21 (39)	13 (50)	8 (29)	–
Cohabitation (yes), n (%)	30 (56)	16 (62)	14 (50)	–
Employed (yes), n (%)	27 (50)	13 (50)	14 (50)	–
Education level (≥12 years), n (%)	30 (56)	12 (46)	18 (64)	–
Clinical and functional profile
Refill: β2LA + ICS or ICS alone, n (%)	21 (39)	11 (42)	10 (36)	–
Refill: combined β2LA + ICS, n (%)	33 (61)	15 (58)	18 (64)	–
Total dose of combined β2LA and/or ICS, mg	723 (501)	705 (585)	740 (419)	–
Anti-leukotrienes, n (%)	12 (22)	5 (19)	7 (25)	–
Anti-rhinitics, n (%)	19 (35)	8 (31)	11 (39)	–
FEV1, L	2.1 (0.8)	2.1 (0.8)	2.0 (0.9)	3
FEV1, % predicted.	69 (24)	71 (30)	67 (15)	3
FVC, L	2.5 (1.1)	2.5 (1.0)	2.5 (1.3)	3
FVC, % predicted	70 (32)	72 (40)	67 (20)	3
FEV1/FVC, % predicted	102 (17)	102 (15)	103 (18)	3
Atopic, n (%)	43 (80)	19 (73)	24 (86)	–
Current smoker (yes), n (%)	7 (13)	4 (15)	3 (11)	–
BMI, kg · m^−2	31 (7)	29 (5)	32 (9)	–
Waist circumference, cm	95 (15)	100 (18)	89 (9)	1
Asthma duration, years	24 (18)	21 (17)	26 (20)	–
Bronchodilator use, number last week	7 (12)	9 (14)	6 (10)	4
ACT scores (5–25)	17 (4)	17 (4)	17 (4)	1
ACQ scores (0–6)	1.9 (1.0)	1.7 (0.9)	2.1 (1.1)	1
ASES total scores (1–5)	2.6 (0.8)	2.6 (0.9)	2.6 (0.7)	1
Morisky scores (5–30)	22 (5)	22 (5)	22 (5)	1
AQLQ scores (1–7)				1
Total	4.9 (1.0)	4.9 (0.9)	4.8 (1.1)
Activity limitations	4.5 (1.2)	4.6 (1.0)	4.5 (1.4)
Symptoms	5.0 (1.0)	5.1 (1.0)	4.9 (1.1)
Emotional function	5.4 (1.2)	5.3 (1.2)	5.4 (1.2)
Exposure	4.7 (1.4)	4.7 (1.3)	4.7 (1.6)

Notes: Data are expressed as mean (SD) or n (%).

Abbreviations: MI, motivational interviewing; β2LA, long-acting beta2-agonists; ICS, inhaled corticosteroid; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; BMI, body mass index; AQLQ, asthma quality-of-life questionnaire; ACT, Asthma Control Test; ACQ, Asthma Control Questionnaire; ASES, Asthma Self-Efficacy Scale.

Table 2 Means and changes at follow-up (ITT analyses)

	Mean* (95% CI)						Within-group change* (95% CI)				Between–group differences (95% CI)		ES (d)#
	MI			Control			MI		Control		MI – Control
	Baseline	6 mo	12 mo	Baseline	6 mo	12 mo	6 mo	12 mo	6 mo	12 mo	6 mo	12 mo
Refill (0–100%)	26 (14;37)	38 (26;51)	37 (26;47)	27 (16;38)	33 (20;45)	33 (23;44)	+13 (−0.3;26)	+11 (−0.2;23)	+6 (−7;18)	+7 (−4;18)	+6 (−12;24)	+3 (−11;18)	0.20
ACT scores (5–25)	17 (15;19)	19 (17;20)	19 (17;21)	17 (15;18)	18 (17;19)	18 (16;20)	+2 (−0.2;4)	+2 (−0.1;4)	+1 (−0.6;3)	+1 (−1;3)	+0.7 (−1.3;2.7)	+1.1 (−1.6;3.7)	0.18
ACQ scores (0–6)	1.7 (1.3;2.1)	1.8 (1.4;2.2)	1.7 (1.2;2.2)	2.1 (1.7;2.4)	1.9 (1.6;2.3)	2.2 (1.8;2.7)	+0.1 (−0.2;0.4)	0 (−0.5;0.5)	−0.1 (−0.5;0.2)	+0.1 (−0.3;0.5)	−0.2 (−0.7;0.4)	−0.5 (−1.2;0.1)	0.12
ASES total scores (1–5)	2.6 (2.3;2.9)	2.9 (2.7;3.2)	2.9 (2.5;3.3)	2.6 (2.3;2.9)	2.6 (2.3;2.8)	2.5 (2.2;2.8)	+0.2 (−0.0;0.4)	+0.2 (−0.1;0.4)	−0.0 (−0.2;0.2)	−0.2 (−0.4;0.1)	+0.4 (−0.0;0.7)	+0.4 (−0.0;0.9)	0.46
Morisky (5–30)	21 (20;23)	24 (22;26)	23 (21;26)	22 (20;24)	24 (22;26)	22 (20;25)	+3 (−0.1;5)	+2 (−1;4)	+2 (−0.5;4)	0 (−2;3)	0 (−4;3)	+1 (−3;4)	0.14
AQLQ score (1–7)
Total	4.9 (4.5;5.2)	5.1 (4.7;5.5)	5.0 (4.5;5.4)	4.8 (4.4;5.2)	4.9 (4.6;5.3)	4.7 (4.3;5.1)	+0.2 (−0.1;0.6)	+0.1 (−0.3;0.5)	+0.2 (−0.3;0.6)	−0.1 (−0.4;0.3)	+0.1 (−0.4;0.7)	+0.2 (−0.4;0.9)	0.14
Activity limitations	4.6 (4.1;5.1)	4.8 (4.2;5.3)	4.6 (4.0;5.2)	4.4 (3.9;4.9)	4.5 (3.9;5.0)	4.3 (3.7;5.0)	+0.2 (−0.2;0.6)	+0.1 (−0.4;0.5)	+0.1 (−0.4;0.6)	−0.1 (−0.6;0.4)	+0.3 (−0.4;1.1)	+0.2 (−0.8;1.2)	0.12
Symptoms	5.0 (4.6;5.4)	5.3 (4.8;5.7)	5.1 (4.6;5.5)	4.9 (4.5;5.3)	5.1 (4.6;5.6)	4.9 (4.4;5.3)	+0.2 (−0.2;0.7)	+0.1 (−0.4;0.5)	+0.2 (−0.3;0.7)	−0.0 (−0.5;0.5)	+0.1 (−0.6;0.9)	+0.2 (−0.4;0.8)	0.06
Emotional function	5.3 (4.8;5.8)	5.4 (4.9;5.9)	5.5 (4.9;6.0)	5.4 (5.0;5.9)	5.7 (5.2;6.1)	5.4 (4.9;5.9)	+0.1 (−0.4;0.6)	+0.2 (−0.3;0.7)	+0.2 (−0.2;0.7)	−0.1 (−0.6;0.4)	−0.3 (−1.0;0.4)	+0.1 (−0.6;0.8)	0.18
Exposure	4.6 (4.0;5.1)	4.6 (4.0;5.2)	4.6 (3.9;5.3)	4.7 (4.1;5.2)	4.7 (4.1;5.2)	4.6 (3.9;5.4)	−0.0 (−0.6;0.6)	+0.1 (−0.6;0.6)	−0.0 (−0.7;0.7)	−0.1 (−0.8;0.7)	−0.1 (−1.0;0.8)	+0.0 (−1.1;1.1)	0.07

Notes:

* Estimates adjusted for covariates (age, sex, total ICS dose, and current smoking).

# The ES (d) was calculated within each treatment condition, and then the control group ES was subtracted from the MI group ES to compute the overall ES. The ES for each treatment condition is defined as the baseline minus the 12 months change in mean score divided by the standard deviation of change score.

Abbreviations: ITT, intent-to-treat; CI, confidence interval; MI, motivational interviewing; ES, effect size; AQLQ, asthma quality-of-life questionnaire; ACT, Asthma Control Test; ACQ, Asthma Control Questionnaire; ASES, Asthma Self-Efficacy Scale; mo, months.

Table 3 Means and changes at follow-up (PP analyses)

	Mean* (95% CI)						Within–group change* (95% CI)				Between–group differences* (95% CI)		ES (d)#
	MI			Control			MI		Control		MI – Control
	Baseline	6 mo	12 mo	Baseline	6 mo	12 mo	6 mo	12 mo	6 mo	12 mo	6 mo	12 mo
Refill (0–100%)	24 (12;36)	42 (27;57)	40 (27;53)	27 (16;38)	33 (19;47)	35 (23;47)	+18 (2;34)	+16 (1;31)	+7 (−8;22)	+9 (−4;22)	+9 (−11;29)	+4 (−13;21)	0.23
ACT scores (5–25)	16 (14;18)	19 (18;21)	18 (16;20)	17 (15;19)	18 (17;20)	18 (16;20)	+3 (+0.3;5)	+2 (−0.4;4)	+1 (−1;4)	+1 (−1;3)	+0.7 (−1.4;2.8)	+0.2 (−2.4;2.8)	0.15
ACQ scores (0–6)	1.7 (1.4;2.1)	1.8 (1.4;2.1)	1.7 (1.3;2.1)	2.0 (1.6;2.3)	1.8 (1.5;2.2)	2.1 (1.7;2.5)	+0.0 (−0.4;0.4)	−0.0 (−0.4;0.4)	−0.1 (−0.5;0.2)	0.1 (−0.3;0.5)	−0.1 (−0.5;0.4)	−0.3 (−0.9;0.2)	0.13
ASES total scores (1–5)	2.7 (2.3;3.0)	2.9 (2.6;3.2)	2.8 (2.5;3.2)	2.6 (2.2;2.9)	2.5 (2.3;2.8)	2.4 (2.1;2.7)	+0.2 (0;0.4)	+0.2 (−0.4;0.1)	0 (−0.2;0.2)	−0.2 (−0.4;0.1)	+0.4 (0;0.7)	+0.3 (−0.2;0.8)	0.53
Morisky scores (5–30)	21 (19;23)	24 (22;26)	22 (20;25)	22 (20;24)	24 (22;26)	23 (20;25)	+3 (1;5)	+2 (−1;4)	+1 (−1;4)	0 (−2;3)	+0.2 (−3;3)	−0.2 (−4;3)	0.23
AQLQ scores (1–7)
Total	4.9 (4.5;5.3)	5.1 (4.7;5.5)	5.0 (4.6;5.5)	4.8 (4.5;5.2)	5.0 (4.6;5.3)	4.7 (4.3;5.1)	+0.2 (−0.2;0.5)	+0.1 (−0.3;0.5)	+0.1 (−0.2;0.5)	−0.2 (−0.5;0.2)	+0.1 (−0.4;0.6)	+0.4 (−0.2;0.9)	0.31
Activity limitations	4.6 (4.1;5.1)	4.9 (4.4;5.4)	4.8 (4.3;5.4)	4.4 (4.0;4.8)	4.5 (4.0;4.9)	4.2 (3.7;4.7)	+0.3 (−0.1;0.7)	+0.2 (−0.3;0.7)	+0.1 (−0.3;0.4)	−0.2 (−0.6;0.2)	+0.4 (−0.2;1.1)	+0.6 (−0.1;1.4)	0.36
Symptoms	5.1 (4.7;5.5)	5.3 (4.9;5.7)	5.0 (4.5;5.5)	5.0 (4.6;5.3)	5.2 (4.8;5.5)	4.8 (4.4;5.3)	+0.2 (−0.2;0.6)	−0.1 (−0.6;0.4)	+0.2 (−0.2;0.6)	−0.1 (−0.6;0.3)	+0.1 (−0.4;0.7)	+0.2 (−0.4;0.8)	0.03
Emotional function	5.2 (4.6;5.7)	5.3 (4.8;5.8)	5.5 (4.9;6.0)	5.5 (5.0;6.0)	5.7 (5.3;6.2)	5.3 (4.8;5.8)	+0.1 (−0.3;0.5)	+0.3 (−0.3;0.9)	+0.2 (−0.2;0.6)	−0.2 (−0.7;0.3)	−0.4 (−1.1;0.3)	+0.1 (−0.6;0.9)	0.36
Exposure	4.6 (4.0;5.2)	4.7 (4.2;5.2)	4.9 (4.2;5.5)	4.7 (4.1;5.3)	4.8 (4.2;5.3)	4.5 (3.9;5.1)	+0.1 (−0.4;0.6)	+0.3 (−0.4;0.9)	+0.1 (−0.5;0.6)	−0.2 (−0.7;0.4)	+0.1 (−0.8;0.7)	+0.3 (−0.6;1.3)	0.32

Notes:

* Estimates adjusted for covariates (age, sex, total ICS dose, and current smoking).

# The ES (d) was calculated within each treatment condition, and then the control group ES was subtracted from the MI group ES to compute the overall ES. The ES for each treatment condition is defined as the baseline minus the 12 month change in mean score divided by the standard deviation of change score.

Abbreviations: PP, per-protocol; CI, confidence interval; MI, motivational interviewing; ES, effect size; AQLQ, asthma quality-of-life questionnaire; ACT, Asthma control Test; ACQ, Asthma Control Questionnaire; ASES, Asthma Self-Efficacy Scale; ICS, inhaled corticosteroid, mo, months.

Table S1 Participants’ characteristics at baseline

	Completers (n=40)	Withdrawals (n=14)	P
Sociodemographics
Age, years	51 (15)	50 (17)	0.83
Men, n (%)	14 (35)	7 (50)	0.32
Cohabitation (yes), n (%)	24 (60)	6 (43)	0.27
Employed (yes), n (%)	18 (45)	9 (65)	0.21
Education level (≥12 years), n (%)	21 (52)	9 (64)	0.44
Clinical and functional profile
Refill: β2LA + ICS or ICS alone, %	15 (38)	6 (33)	0.72
Refill: combined β2LA + ICS, %	25 (62)	8 (57)
Total dose of combined β2LA and/or ICS, mg	739 (461)	675 (618)	0.68
Anti-leukotrienes, n (%)	11 (27)	1 (7)	0.15
Anti-rhinitics, n (%)	13 (32)	6 (43)	0.53
FEV1, L	2.0 (0.7)	2.2 (1.1)	0.51
FEV1, % predicted	67 (15)	74 (39)	0.51
FVC, L	2.4 (1.1)	2.7 (1.3)	0.53
FVC, % predicted	67 (17)	77 (54)	0.47
FEV1/FVC, % predicted	103 (17)	102 (18)	0.78
Atopic, n (%)	33 (82)	10 (72)	0.45
Current smoker (yes), n (%)	4 (10)	3 (21)	0.36
BMI, kg · m^−2	31 (8)	29 (6)	0.53
Waist circumference, cm	95 (16)	95 (10)	0.98
Asthma duration, years	25 (20)	21 (12)	0.44
Bronchodilator use, # last week	6 (8)	12 (19)	0.25
Bronchodilator use, # per puff	1.5 (0.5)	1.4 (0.5)	0.30
ACT scores (5–25)	17 (4)	18 (3)	0.22
ACQ scores (0–6)	1.9 (0.9)	2.0 (1.3)	0.61
ASES total scores (1–5)	2.6 (0.1)	2.6 (0.2)	0.91
Morisky scores (5–30)	22 (5)	22 (4)	0.93
AQLQ scores (1–7)
Total	4.9 (0.9)	4.9 (1.2)	0.94
Activity limitations	4.5 (1.2)	4.6 (1.4)	0.75
Symptoms	5.0 (0.9)	4.9 (1.2)	0.78
Emotional function	5.4 (1.2)	5.5 (1.3)	0.77
Exposure	4.7 (1.4)	4.7 (1.4)	0.96

Notes: Data are expressed as mean (SD) or n (%).

Abbreviations: MI, motivational interviewing; β2LA, long-acting beta2-agonists; ICS, inhaled corticosteroid; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; BMI, body mass index; AQLQ, asthma quality-of-life questionnaire; ACT, Asthma Control Test; ACQ, Asthma Control Questionnaire; ASES, Asthma Self-Efficacy Scale.