Treatment satisfaction in cystic fibrosis: early patient experience with tobramycin inhalation powder

Figures & data

Figure 1 Flowchart of patient participation.

Abbreviations: CFQ-R, Cystic Fibrosis Questionnaire-Revised; TIP, tobramycin inhalation powder; TSQM, Treatment Satisfaction Questionnaire for Medication.

Table 1 Patient baseline sociodemographic and clinical characteristics

Characteristic	All patients (N=80)	Currently taking TIP (n=46)	Stopped TIP (n=34)
Sex, n (%)
Male	34 (42.5)	23 (50.0)	11 (32.4)
Female	46 (57.5)	23 (50.0)	23 (67.6)
Age, years
Mean (SD)	24.4 (9.4)	24.8 (9.7)	23.9 (9.1)
Range	10–50	10–50	10–50
Race/ethnicity, n (%)
Caucasian	76 (95.0)	45 (97.8)	31 (91.2)
Other	4 (5.0)	1 (2.2)	3 (8.8)
Marital status,a n (%)
Single/never married	51 (70.8)	30 (71.4)	21 (70.0)
Married/with partner	20 (27.8)	12 (28.6)	8 (26.7)
Divorced	1 (1.4)	0 (0.0)	1 (3.3)
Education,a n (%)
Vocational school or less	22 (30.6)	13 (31.0)	9 (30.0)
Some college or higher	50 (69.4)	29 (69.0)	21 (70.0)
Employment status,a n (%)
Working/full-time education	53 (73.6)	31 (73.8)	22 (73.3)
Not working	19 (26.4)	11 (26.2)	8 (26.7)
FEV1 % predicted
Mean (SD)	67.1 (27.3)	60.2 (27.6)	76.5 (24.3)
Median (Q1, Q3)	71.0 (43.0, 90.0)	62.0 (34.0, 81.0)	83.5 (57.0, 95.0)
BMI
Mean (SD)	21.1 (3.0)	20.9 (3.4)	21.3 (2.5)
Median (Q1, Q3)	20.6 (19.2, 22.9)	20.0 (19.0, 22.5)	21.3 (19.5, 22.9)

Note:

a Administered only to adolescent and adult patients (n=72).

Abbreviations: BMI, body mass index; FEV₁, forced expiratory volume in 1 second; Q, quartile; SD, standard deviation; TIP, tobramycin inhalation powder.

Table 2 Preference between TIP and nebulized antibiotic (n=35)

Device attribute	Prefer TIP, n (%)	No preference, n (%)	Prefer nebulized antibiotic, n (%)
Administration time	35 (100.0)	0 (0.0)	0 (0.0)
Time it takes to clean	34 (97.1)	0 (0.0)	1 (2.9)
Portability	34 (97.1)	1 (2.9)	0 (0.0)
Ease of use	33 (94.3)	0 (0.0)	2 (5.7)
Effectiveness	18 (51.4)	13 (37.1)	4 (11.4)
Side effects	17 (48.6)	15 (42.9)	3 (8.6)

Abbreviation: TIP, tobramycin inhalation powder.

Table 3 Patient priorities for features of inhaled antibiotic treatments

Device antibiotic	Inhaled attribute treatment		TIP
	Most important, n (%)	Least important, n (%)	Most important, n (%)	Least important, n (%)
Administration time	17 (48.6)	0 (0.0)	16 (45.7)	2 (5.7)
Ease of use	3 (8.6)	1 (2.9)	9 (25.7)	1 (2.9)
Portability	1 (2.9)	6 (17.1)	5 (14.3)	5 (14.3)
Effectiveness	11 (31.4)	0 (0.0)	3 (8.6)	0 (0.0)
Cost	0 (0.0)	25 (71.4)	0 (0.0)	25 (71.4)
Other	1 (2.9)	1 (2.9)	0 (0.0)	0 (0.0)

Abbreviation: TIP, tobramycin inhalation powder.

Table 4 OLS regression on TSQM global satisfaction domain scores (n=46)

Independent variable	Estimate (SE)	95% CI	P-value
Initial model (R-squared =0.59)
TSQM effectiveness score	0.76 (0.16)	0.45, 1.06	<0.001
TSQM side-effects score	0.21 (0.14)	−0.06, 0.48	0.119
TSQM convenience score	−0.08 (0.14)	−0.34, 0.19	0.561
Patient sex (0= female, 1= male)	4.94 (4.93)	−4.73, 14.61	0.317
Patient age	−1.35 (1.01)	−3.34, 0.64	0.183
Squared patient age	0.02 (0.02)	−0.02, 0.05	0.284
Work/school statusa	−1.87 (4.91)	−11.50, 7.76	0.704
Education levelb	7.49 (4.47)	−1.27, 16.25	0.094
FEV1	−0.15 (0.09)	−0.33, 0.03	0.108
BMI	0.46 (0.79)	−1.09, 2.01	0.561
CFQ-R respiratory score	−0.06 (0.18)	−0.41, 0.30	0.750
CFQ-R health perception score	0.15 (0.14)	−0.12, 0.42	0.281
CFQ-R treatment burden score	0.03 (0.12)	−0.20, 0.26	0.803
Number of TIP cycles completedc	−0.71 (4.25)	−9.05, 7.62	0.867
Intercept	13.57 (24.98)	−35.40, 62.53	0.587
Final model following stepwise elimination (R-squared =0.54)
TSQM effectiveness score	0.75 (0.12)	0.52, 0.98	<0.001
TSQM side effects score	0.23 (0.12)	−0.02, 0.47	0.069
Education levelb	5.77 (4.03)	−2.12, 13.67	0.152
Intercept	−4.14 (13.40)	−30.41, 22.13	0.757

Notes:

a Asked of parent or caregiver for children 6–13 years old; 0= not currently working/at school, 1= currently working/at school;

b Asked of parent or caregiver for children 6–13 years old; 0= less than college education, 1= some college education or higher;

c 0=4 or more cycles, 1=3 or fewer cycles.

Abbreviations: BMI, body mass index; CFQ-R, Cystic Fibrosis Questionnaire-Revised; CI, confidence interval; FEV₁, forced expiratory volume in 1 second; OLS, ordinary least squares; SE, standard error; TSQM, Treatment Satisfaction Questionnaire for Medication; TIP, tobramycin inhalation powder.