Barriers to adherence in adolescents and young adults with cystic fibrosis: a questionnaire study in young patients and their parents

Figures & data

Table 1 The six questionnaires with internal consistencies (Cronbach’s alpha) and test-retest Spearman’s correlation

Item	Items (n)	Adolescent Cronbach’s α	Parent Cronbach’s α	Adolescent test-retest Spearman’s correlation	Parent test-retest Spearman’s correlation
Barriers to adherence	5	0.76	0.82	0.84	0.81
Difficulty finding time to take CF treatment
Forgetting to take CF treatment
Choose to be with friends instead of taking CF treatment
Too tired to take CF treatment
Will not take CF treatment in public
Adherence during past month	7	0.73	0.88	0.95	0.86
Antibiotic tablets
Pulmozyme^®
Positive expiratory pressure mask
Enzymes
Vitamins
Asthma medication
Inhaled antibiotics
Reactions from mother	8	0.82		0.75
Reactions from father	8	0.91		0.64
Says you are good at remembering treatment
Scolds you for forgetting treatment
Asks you to take your treatment although you are doing something else
Quarrels with you about treatment
Praises your effort to take your treatment
Helps you only when you ask for help
Checks that you have taken your treatment
Trusts that you have taken your treatment
Reactions from adolescent	5	0.91		0.79
Get annoyed when parents ask me to take treatment
Tell my parents that I appreciate their help
Get sullen when my parents ask me to take treatment
Ask parents to mind their own business
Quarrel with parents about treatment
Communication about CF in family	6	0.90		0.83
We communicate openly about CF
We are good at supporting each other when CF takes up all the time
We can express our feelings towards each other regarding CF
We can talk about everything concerning CF
We can talk about our anxiety concerning CF
We can communicate about CF although we are depressed

Abbreviation: CF, cystic fibrosis.

Table 2 Characteristics of participants, nonparticipants, and re-test participants

	Participants	Nonparticipants	Significance (two-tailed)	Retest participants
Adolescents (n)	88	58		24
Male/female (%)a	40/60	64/36	0.008c	29/71
Age (mean ± SD)b	19.3 ± 3.2	18.7 ± 3.5	0.217	19.9 ± 3.6
FEV1% (mean ± SD)b	82.6 ± 22.7	74.8 ± 22.5	0.046c	77.9 ± 20.8
BMI (mean ± SD)b	20.6 ± 3.6	19.9 ± 2.4	0.381	20.5 ± 4.4
Parents (n)	161	108		61
Male/female (%)a	42/58	57/43	0.023c	38/62
Child’s FEV1% (mean ± SD)b	81.5 ± 22.9	76.3 ± 23.3	0.082	82.1 ± 21.9

a Notes: Pearson Chi-square;

b independent-samples Mann-Whitney U test;

c significant at 0.05 level (two-tailed).

Abbreviations: BMI, body mass index; FEV₁%, forced expiratory volume in one second as percent of predicted; SD, standard deviation.

Table 3 Frequency data for adolescent and parental reports of type and number of barriers to adherence

	Adolescent reports % (n)	Mothers’ reports % (n)	Fathers’ reports % (n)
Types of barriers
Difficult to find time to take CF treatment	40 (35)	29 (27)	31 (21)
Forget to take CF treatment	40 (35)	36 (33)	21 (14)
Choose to be with friends instead of taking CF treatment	25 (22)	24 (22)	16 (11)
Too tired to take CF treatment	25 (22)	27 (25)	19 (13)
Will not take CF treatment in public	33 (29)	28 (26)	37 (25)
Number of barriers
0 barrier	39 (34)	41 (38)	40 (27)
1 barrier	17 (15)	20 (18)	27 (18)
2 barriers	14 (12)	15 (14)	15 (10)
3 barriers	11 (10)	7 (6)	6 (4)
4 barriers	12 (11)	12 (11)	9 (6)
5 barriers	7 (6)	5 (5)	3 (2)

Abbreviation: CF, cystic fibrosis.

Table 4 Correlations between barriers to adherence and adherence, reactions from mother, reactions from father, reactions from adolescent, communication about CF in family, age, BMI, FEV₁, and CFQ measures

	Spearman’s correlation	Significance value (two-tailed)
Adherence	0.54	0.001a
Reactions from mother	0.26	0.016a
Reactions from father	0.28	0.021a
Reactions from adolescent	0.31	0.008a
Communication about	0.26	0.016a
CF in family
Age	−0.03	0.784
BMI	0.22	0.040a
FEV1% average of 2009 measures	0.15	0.164
CF-related quality of life (CFQ)
Physical functioning	−0.07	0.551
Role limitations	−0.23	0.030a
Vitality	−0.17	0.127
Emotional functioning	−0.25	0.020a
Social functioning	−0.15	0.169
Body image	−0.05	0.638
Eating disturbances	−0.05	0.670
Treatment burden	−0.38	0.001a
Health perceptions	−0.12	0.260
Weight problems	0.04	0.694
Respiratory symptoms	−0.31	0.004a
Digestive symptoms	−0.28	0.009a

a Note: Significant at 0.05 level (two-tailed).

Abbreviations: BMI, body mass index; FEV₁%, forced expiratory volume in one second as percent of predicted; CF, cystic fibrosis; CFQ, Cystic Fibrosis Quality of Life Questionnaire.

Table 5 Frequency data for adolescent and parental reports of adolescent adherence

Report from	n	High adherence	Medium adherence	Low adherence
Adolescents (all)	88	42%	43%	15%
Parents	137	59%	32%	9%
Adolescents with one or more barriers to adherence	54	26%	56%	18%
Adolescents with no barriers to adherence	34	68%	23%	9%

Table 6 Comparison of mean item scores from the questionnaires exploring reactions from mother, father, and adolescent, and family communication about CF in the barrier group and the no-barrier group

	n	Adolescents with barriers mean (SD)	Adolescents with no barriers mean (SD)	Mann-Whitney U test significance
Reactions from mothera
Says you are good at remembering treatment	70	3.33 (0.80)	2.80 (0.91)	0.014c
Scolds you for forgetting treatment	75	1.82 (0.91)	1.46 (0.78)	0.069
Asks you to take your treatment although you are doing something else	72	2.17 (1.17)	2.20 (1.15)	0.906
Quarrels with you about treatment	76	1.60 (0.73)	1.15 (0.37)	0.006c
Praises your effort to take treatment	69	3.22 (0.81)	3.00 (0.95)	0.392
Helps you only when you ask for help	63	2.77 (1.03)	2.22 (1.08)	0.042c
Checks that you have taken your treatment	76	2.31 (1.29)	2.32 (1.28)	0.950
Trusts that you have taken your treatment	77	1.65 (0.55)	1.18 (0.99)	0.015c
Reactions from fathera
Says you are good at remembering treatment	59	3.50 (0.70)	2.83 (0.94)	0.004c
Scolds you for forgetting treatment	58	1.46 (0.60)	1.32 (0.48)	0.423
Asks you to take your treatment although you are doing something else	59	1.57 (0.90)	1.95 (1.21)	0.263
Quarrels with you about treatment	62	1.35 (0.48)	1.09 (0.29)	0.027c
Praises your effort to take treatment	59	3.49 (0.65)	2.82 (0.91)	0.004c
Helps you only when you ask for help	56	3.09 (0.88)	2.30 (1.02)	0.004c
Checks that you have taken your treatment	61	1.84 (1.00)	1.96 (1.15)	0.860
Trusts that you have taken your treatment	65	1.78 (1.12)	1.28 (0.79)	0.034c
Reactions from adolescenta
Get annoyed when parents ask me to take treatment	62	2.51 (1.12)	2.04 (0.93)	0.111
Tell parents that I appreciate their help	64	3.43 (0.71)	3.29 (0.75)	0.467
Get sullen when parents ask me to take treatment	65	2.31 (1.07)	1.61 (0.66)	0.010c
Ask parents to mind their own business	66	1.74 (0.88)	1.09 (0.29)	0.001c
Quarrel with parents about treatment	66	1.80 (0.88)	1.21 (0.41)	0.003c
Communication about CF in familyb
We communicate openly about CF	88	1.30 (0.57)	1.15 (0.36)	0.205
We are good at supporting each other when CF takes up time	88	1.65 (0.85)	1.29 (0.52)	0.044c
We can express our feelings towards each other regarding CF	88	1.93 (0.89)	1.53 (0.71)	0.034c
We can talk about everything concerning CF	88	1.63 (0.85)	1.35 (0.54)	0.188
We can talk about our anxiety concerning CF	88	1.70 (0.90)	1.47 (0.56)	0.421
We can communicate about CF even if we are depressed	88	1.83 (0.93)	1.41 (0.56)	0.040c

a Notes: Likert scale (1 = daily, 2 = weekly, 3 = monthly, 4 = never);

b Likert scale (1 = strongly agree, 2 = agree, 3 = disagree, 4 = strongly disagree);

c Significant at 0.05 level (two-tailed).

Abbreviations: CF, cystic fibrosis; SD, standard deviation.