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 ≤−0.7a | Total score r <−0.7a Subscores −0.7 < r <−0.3a,b | |||
| Known group validityc | ||||||
| Known group 1 | Exacerbation count: <2 vs ≥2d | Exacerbation count: 0 vs ≥1d | 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 anye | |||
| 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.