Validity and Reliability of the Assessment of Burden of Chronic Conditions Scale in the Netherlands

Danny Claessens; Esther A. Boudewijns; Lotte C. E. M. Keijsers; Annerika H. M. Gidding-Slok; Bjorn Winkens; Onno C. P. van Schayck

doi:10.1370/afm.2954

Article Figures & Data

Figures

Tables
Additional Files

Download figure
Open in new tab
Download powerpoint
Figure 1.
Visual representation of the ABCC scale outcomes.
ABCC = Assessment of Burden of Chronic Conditions; BMI = body mass index; DM = diabetes mellitus; Hypo = hypoglycemia.
The outcomes of the ABCC scale are visualized into a balloon chart. High green balloons indicate low burden. Low red balloons indicate high burden. Orange and yellow balloons indicate changes between red and green. The results from the previous visit are depicted in gray for easy monitoring.

View popup

Table 1.

Outcomes for Each Subgroup

Outcome	COPD		Asthma		T2D
Convergent validity
Comparator instrument	SGRQ		AQLQ-S		ADDQoL19
Comparisons	ABCC total	SGRQ total	ABCC total	AQLQ-S total	ABCC total	ADDQoL19 total
	Physical limitations	All subscales	Physical limitations	Total Symptoms Activity	Feelings and emotions	Self confidence Feelings about the future
	Pulmonary complaints	All subscales	Feelings and emotions	Emotional functioning	Physical limitations	Physical Depend on others
	…	…	…	…	Sexuality	Sex life
	…	…	…	…	Eating and drinking	Freedom to eat Freedom to drink
Threshold for validity, r	r ≥0.7		r ≤−0.7^{^a}		Total score r <−0.7^{^a} Subscores −0.7 < r <−0.3^{^a},^{^b}
Known group validity^{^c}
Known group 1	Exacerbation count: <2 vs ≥2^{^d}		Exacerbation count: 0 vs ≥1^{^d}		Insulin use: none vs any
Hypothesized distinguishable ABCC domains	Total score Night’s rest Physical limitation Relations and work Pulmonary complaints		Total score Night’s rest Feelings and emotions Relations and work Asthma complaints		Total Feelings and emotions Physical limitations Relations and work Hypoglycemia Worry about future
Known group 2	Depression: HADS <8 vs HADS ≥8		GINA: Controlled vs not		Complications: none vs any^{^e}
Hypothesized distinguishable ABCC domains	Total score Fatigue Feelings and emotions Physical limitations Relations and work Pulmonary complaints		Total score Night’s rest Feelings and emotions Physical limitations Relations and work Sexuality Asthma complaints		Total Feelings and emotions Physical limitations Relations and work
Known group 3	…		…		Obesity: BMI <30 vs ≥30
Hypothesized distinguishable ABCC domains	…		…		Total Feelings and emotions Physical limitations Relations and work Eating and drinking
Internal consistency Accepted threshold, α	Total scale α ≥0.9; subscales α ≥0.7
Test-retest reliability Accepted threshold, ICC	ICC ≥0.9

α = Chronbach’s alpha; ABCC = Assessment of Burden of Chronic Conditions; ADDQoL19 = 19-item Audit of Diabetes-Dependent Quality of Life; AQLQ-S = Standardized Asthma Quality of Life Questionnaire; BMI = body mass index; COPD = chronic obstructive pulmonary disease; GINA = Global Initiative for Asthma; HADS = Hospital Anxiety and Depression Scale; ICC = intraclass coefficient; QoL = quality of life; r = Pearson correlation coefficient; SGRQ = Saint George Respiratory Questionnaire; T2D = type 2 diabetes.
↵a As the ABCC scale implies high burden at high scores, and both the AQLQ and ADDQoL19 imply high burden (or low QoL) at low scores, the correlation between these scales is inverse and thus negative.
↵b Both scales have single-item domains/subscores, therefore the hypothesized correlation is expected to be moderate.
↵c Significant difference in groups, P ≤.05.
↵d Based on Dutch medical guidelines.^14,15
↵e Any of the following complications: nephropathy, neuropathy, retinopathy, sexual dysfunction, amputation of any limb, diabetic foot, cardiovascular disease.

View popup

Table 2.

Baseline Characteristics for Each Subgroup

Characteristic	COPD (n = 65)	Asthma (n = 62)	T2D (n = 60)
Male sex, No. (%)	39 (60.0)	19 (30.6)	30 (50.0)
Age, mean (SD), y	66 (6.9)	56 (13.4)	66 (9.5)
Highest level of education, No. (%)^{^a}
Low^{^b}	26 (40.0)	18 (29.0)	29 (48.3)
Middle^{^c}	3 (4.6)	10 (16.1)	6 (10.0)
High^{^d}	36 (55.4)	34 (54.8)	25 (41.7)
Diagnosed since, No. (%), y
<1	1 (1.5)	1 (1.6)	1 (1.7)
1-3	4 (6.2)	4 (6.5)	…
>3	60 (92.3	57 (91.9)	…
1-15	…	…	40 (66.7)
>15	…	…	19 (31.7)
Smoking status, No. (%)
Never	6 (9.2)	34 (54.8)	…
Former	58 (89.2)	28 (45.2)	…
Current	1 (1.5)	0 (0.0)	…
Treated by, No. (%)
General practitioner	11 (17.5)	17 (31.5)	48 (82.8)
Medical specialist	52 (82.5)	37 (68.5)	10 (17.2)
Unknown	2	8	2
Exacerbations, previous year, No. (%)
0	19 (29.2)	16 (25.8)	…
1	19 (29.2)	8 (12.9)	…
2	9 (13.8)	15 (24.2)	…
>2	18 (27.7)	23 (37.1)	…
Medication, No. (%)
No medication	0 (0.0)	1 (1.6)	5 (8.3)
Any of the following:
SABA/SAMA	40 (61.5)	45 (72.6)	…
LABA/LAMA	49 (75.4)	22 (35.5)	…
ICS	17 (26.2)	37 (59.7)	…
Combination medication (ICS + LABA/LAMA)	35 (53.8)	43 (69.4)	…
Metformin	…	…	40 (66.7)
Gliclazide, glimepiride, or tolbutamide	…	…	22 (36.7)
Insulin	…	…	27 (45.0)

COPD = chronic obstructive pulmonary disease; ICS = inhaled corticosteroids; LABA = long-acting β2-agonist; LAMA = long-acting muscarinic antagonists; SABA = short-acting β2-agonist; SAMA = short-acting muscarinic antagonists; T2D = type 2 diabetes.
↵a According to the Education Systems in the Netherlands.³⁹
↵b Elementary school, pre-vocational secondary education and training, or secondary vocational education and training.
↵c Senior general secondary education or pre-university education.
↵d Higher professional education or university education.

View popup

Table 3.

Psychometric Properties of the ABCC Scale for People with COPD (n = 65)

Convergent validity, SGRQ, r
ABCC domains	Total	Activity	Impact	Symptoms
ABCC total	0.866^{^a}	0.797^{^a}	0.806^{^a}	0.734^{^a}
Physical limitation	0.829^{^a}	0.831^{^a}	0.743^{^a}	0.668
Pulmonary complaints	0.761^{^a}	0.636	0.697	0.773^{^a}

Known group validity, median (IQR)
	<2 Exacerbations E (n = 33)	≥2 Exacerbations (n = 32)	P value
ABCC total	1.6 (0.9-2.6)	2.6 (2.4-3.6)	<.001
Night’s rest	2.0 (0.5-2.5)	2.5 (2.0-3.0)	.006
Feelings and emotions	1.0 (0.3-2.0)	2.0 (1.0-2.7)	.010
Physical limitations	2.3 (1.0-4.2)	3.7 (3.0-4.9)	.003
Relations and work	1.0 (0.5-3.0)	3.0 (2.0-4.0)	<.001
Pulmonary complaints	2.3 (1.6-3.0)	3.3 (2.6-3.9)	<.001
	Not depressed^{^b} (n = 50)	Depressed^{^b} (n = 15)	P value
ABCC total	2.1 (1.2-2.9)	3.1 (2.5-3.9)	.001
Fatigue	3.0 (2.0-4.0)	4.0 (3.0-5.0)	.022
Feelings and emotions	1.0 (0.3-2.0)	2.0 (1.7-2.7)	.001
Physical limitations	3.0 (1.3-4.3)	3.7 (3.0-4.7)	.057
Relations and work	2.0 (1.0-3.0)	3.0 (3.0-4.0)	.002
Pulmonary complaints	2.6 (1.8-3.5)	3.0 (2.5-4.0)	.061

Reliability measures
Internal consistency, Cronbach’s α (95% CI)
Total scale	0.90 (0.86-0.93)
Physical limitations	0.92 (0.88-0.95)
Feelings and emotions	0.77 (0.64-0.85)
Pulmonary complaints	0.65 (0.49-0.77)
Test-retest reliability, ICC (95% CI) (n = 60)
0.95 (0.92-0.97)

ABCC = Assessment of Burden of Chronic Conditions; COPD = chronic obstructive pulmonary disease; ICC = intraclass coefficient; IQR = interquartile range; HADS = Hospital Anxiety and Depression Scale; r = Pearson correlation coefficient; SGRQ = Saint George Respiratory Questionnaire.
↵a r >0.7.
↵b Depression determined with HADS score, <8 not depressed, ≥8 depressed.

View popup

Table 4.

Psychometric Properties of the ABCC Scale for People With Asthma (n = 62)

Convergent validity, AQLQ-S, r
ABCC domains	Total	Symptoms	Activity Limitation	Emotional Function
ABCC total	−0.851^{^a}	−0.842^{^a}	−0.831^{^a}	…
Feelings and emotions	…	…	…	−0.725^{^a}
Physical limitation	−0.777^{^a}	−0.782^{^a}	−0.797^{^a}	…
Asthma complaints	−0.835^{^a}	−0.865^{^a}	−0.805^{^a}	…

Known group validity, median (IQR)
	No Exacerbations (n = 16)	≥1 Exacerbations (n = 46)	P value
ABCC total	1.5 (0.9-1.9)	2.5 (1.8-3.1)	<.001
Night’s rest	2.0 (1.0-2.0)	3.0 (2.0-4.0)	.001
Feelings and emotions	1.0 (0.8-1.3)	1.3 (0.6-2.0)	.049
Physical limitations	1.7 (0.7-2.0)	2.3 (1.7-3.3)	<.001
Relations and work	1.0 (0.0-2.0)	3.0 (2.0-4.0)	.001
Asthma complaints	0.8 (0.5-1.6)	3.0 (2.0-3.8)	<.001
	Controlled^{^b} (n = 18)	Uncontrolled^{^b} (n =43)	P value
ABCC total	1.4 (1.0-1.8)	2.7 (2.0-3.2)	<.001
Night’s rest	2.0 (1.0-3.0)	3.0 (2.0-4.0)	0.003
Feelings/emotions	0.5 (0.0-1.0)	1.3 (1.0-2.0)	<.001
Physical limitations	1.0 (0.7-2.0)	2.3 (1.7-3.3)	<.001
Relations and work	1.0 (0.0-2.0)	3.0 (2.0-4.0)	<.001
Sexuality	0.5 (0.0-2.0)	2.0 (0.0-3.0)	.042
Asthma complaints	0.8 (0.2-1.5)	3.0 (2.3-3.8)	<.001

Reliability measures
Internal consistency, Cronbach’s α (95% CI)
Total scale	0.92 (0.89-0.95)
Physical limitations	0.88 (0.82-0.93)
Feelings and emotions	0.74 (0.60-0.83)
Asthma complaints	0.73 (0.61-0.83)
Test-retest reliability, ICC (95% CI) (n = 60)
0.93 (0.87-0.96)

ABCC = Assessment of Burden of Chronic Conditions; AQLQ-S = Standardized Asthma Quality of Life Questionnaire; ICC = intraclass coefficient; IQR = interquartile range; GINA = Global Initiative for Asthma; r = Pearson correlation coefficient.
↵a r < −0.7.
↵b Groups determined by GINA guidelines. Well and partially controlled combined into single group.

View popup

Table 5.

Psychometric Properties of the ABCC Scale for People With T2D (n = 60)

Convergent validity, ADDQoL19, r
ABCC domains	ADDQoL19 domains	r
ABCC total	Average WI	−0.548
Feelings and emotions	Self-confidence	−0.260
Feelings and emotions	Feelings about the future	−0.379^{^a}
Physical limitations	Physical	−0.391^{^a}
Physical limitations	Depend on others	−0.459^{^a}
Relations and work	Leisure	−0.441^{^a}
	Work	−0.664^{^a}
	Family life	−0.413^{^a}
	Friendships and social life	−0.448^{^a}
Sexuality	Sex life	−0.650^{^a}
Eating and drinking	Freedom to eat	−0.346^{^a}
Eating and drinking	Freedom to drink	−0.167

Known group validity, median (IQR)
	Insulin independent (n = 32)	Insulin dependent (n = 27)	P value
ABCC total	1.1 (0.7-1.5)	1.9 (1.4-2.7)	.001^{^a}
Feelings and emotions	1.0 (0.5-1.9)	1.5 (1.0-3.0)	.025^{^a}
Physical limitations	1.0 (0.3-1.7)	2.7 (1.3-3.0)	.004^{^a}
Relations and work	0.0 (0.0-1.0)	2.0 (0.0-3.0)	.005^{^a}
Hypoglycaemia	1.0 (0.0-1.8)	2.0 (0.0-2.0)	.038^{^a}
Worry about future	1.0 (0.0-2.0)	2.0 (1.0-3.0)	.051
	No complications (n = 12)	≥1 complications (n = 48)	P value
ABCC total	0.9 (0.4-1.3)	1.7 (1.1-2.6)	.001^{^a}
Feelings/emotions	0.5 (0.0-1.0)	1.3 (1.0-2.5)	.001^{^a}
Physical limitations	0.5 (0.0-1.5)	1.7 (1.0-3.0)	.007^{^a}
Relations and work	0.0 (0.0-1.0)	1.0 (0.0-2.0)	.031^{^a}
	BMI <30 (n = 44)	BMI ≥30 (n = 16)	P value
ABCC total	1.2 (0.8-2.1)	1.9 (1.5-2.8)	.008^{^a}
Feelings and emotions	1.0 (0.5-1.9)	1.8 (1.0-2.5)	.003^{^a}
Physical limitations	1.2 (0.3-2.6)	2.9 (1.4-3.6)	.003^{^a}
Relations and work	0.0 (0.0-2.0)	2.0 (1.0-2.0)	.018^{^a}
Eating and drinking	2.0 (1.0-2.8)	1.5 (1.0-3.8)	.830

Reliability measures
Internal consistency, Cronbach’s α (95% CI)
Total scale	0.91 (0.87-0.94)
Physical limitations	0.87 (0.80-0.92)
Feelings and emotions	0.76 (0.60-0.85)
Test-retest reliability, ICC (95% CI)
0.95 (0.91-0.97)

ABCC = Assessment of Burden of Chronic Conditions; ADDQoL19 = 19-Item Audit for Diabetes-Dependent Quality of Life; BMI = body mass index; ICC = intraclass coefficient; IQR = interquartile range; r = Pearson correlation coefficient; WI = weighted impact.
↵a r < −0.7 for total scales or −0.7 < r < −0.3 for single item-correlations.