Appendix K. Sample Descriptives – Condition-Specific Measures of Quality of Life - Adults and Children

The impact of living with a food hypersensitivity, and hence the gain to be valued if it was removed, was captured using three approaches: 
•    Baseline and contingent EQ-5D;
•    Baseline and contingent Visual Analogue Scale (VAS);
•    Condition-specific measures (FAQLQ, FIQLQ, or CDQ) for children.

This section of the report covers condition-specific measures (FAQLQ, FIQLQ, and CDQ).

Adult Results: FAQLQ, FIQLQ, and CDQ 

Food Allergy: FAQLQ

The FAQLQ is scored between 1 and 7 - the mean score in the adult sample was 4.8 and the median score was 5.1.

Table 1. Summary statistics: FAQLQ index

-	Mean	Std. Dev	N	min	p25	Median	p75	max
FAQ total	4.76	1.49	385	1.14	3.66	5.1	6	7

The adult distribution of FAQLQ scores is shown in Figure 1

Figure 1 Distribution of FAQLQ scores (adult allergy)

Women’s FAQLQ scores were on average than men’s, mean their allergy impacts were greater than those for men.

Table 2. Summary statistics:  FAQLQ Index by sex

Sex	mean	sd	N	min	p25	Median	p75	max
Female	4.96	1.44	226	1.31	3.93	5.38	6.1	7
Male	4.18	1.47	85	1.21	3.17	4.24	5.28	7

The FAQLQ scores were similar across age groups except for those over 65 whose scores were lower than the younger age groups.

Table 3 Summary statistics:  FAQLQ Index by age

Age	mean	sd	N	min	p25	Median	p75	max
Below 35 years old	4.9	1.3	104	1.79	3.91	5.22	5.97	7
35-54 years old	4.87	1.59	140	1.21	3.62	5.38	6.12	7
55-64 years old	1.9	1.41	71	1.76	3.97	5.07	6.21	6.97
65 years old and above	4.23	1.56	69	1.14	2.83	4.59	5.45	7

Coeliac Disease: CDQ

The 20 items of the CDQ are scored 1 to 5 meaning that the instrument can takes values between 20 and 100. The mean CDQ score in the sample was 48 and the median score was 47.

Table 4. Summary statistics: CDQ index

-	Mean	Std. Dev.	N	min	p25	Median	p75	max
CDQ total	48.35	16.91	601	20	34	47	61	95

The distribution of CDQ scores is shown in Figure 2.

Figure 2 Distribution of CDQ scores (adult coeliacs)

Male and female CDQ scores are very similar

Table 5. Summary statistics: CDQ Index by sex 

Sex	mean	sd	N	min	p25	Median	p75	max
Female	50.263	16.648	293	21	37	48	63	89
Male	49.355	17.139	76	20	35	48	61.5	88

The CDQ scores declined as age increases- older people typically report less severe impacts of coeliac disease on their life. Epidemiological studies support that coeliac disease can develop at any age in the lifecourse [Dube et al (2005)]. The non-specific symptoms and/or asymptomatic nature of coeliac disease mean it is often diagnosed later (~ 40 to 50 years of age) in life but as people age they may adjust to living with their diagnosis such that it impacts less on day-to-day activities and wellbeing (see Table 6) [Paez et al (2017); Zipser et al (2003); Ludvigsson et al (2014)]. 

Table 6. Summary statistics:    CDQ Index by age

Age	mean	sd	N	min	p25	Median	p75	max
Below 35 years old	57	15.42	79	27	44	58	67	89
35-54 years old	51.31	17.36	164	21	37	51	65	95
55-64 years old	46.65	15.99	177	20	34	44	55	90
65 years old and above	43.42	16.06	180	20	30	41	54	88

Food Intolerance: FIQLQ

The FIQLQ is scored between 1 and 7 - the mean score in the adult sample was 4.5 and the median score was 4.7.

Table 7 Summary statistics: FIQLQ Index

-	Mean	Std. Dev.	N	min	p25	Median	p75	max
FIQ total	4.49	1.53	440	1.06	3.28	4.67	5.72	7

Figure 3 Distribution of FIQLQ scores (adult intolerance)

Women’s FIQLQ scores were on average higher than men’s, mean their food intolerance impacts were greater than those for men.

Table 8. Summary statistics:   FIQLQ Index by sex 

Sex	mean	sd	N	min	p25	Median	p75	max
Female	4.46	1.46	276	1.17	3.39	4.56	5.61	7
Male	4.18	1.56	92	1.06	2.97	4.33	5.47	6.72

The scores were similar across age groups except for those over 65 whose scores were lower than the younger age groups.

The FIQLQ scores increased as age increases - older people typically report more severe impacts of their food intolerance.

Table 9. Summary statistics:  FIQLQ Index by age 

Age	mean	sd	N	min	p25	Median	p75	max
Below 35 years old	4.27	1.49	62	1.56	3.06	4.17	5.5	6.94
35-54 years old	4.46	1.5	158	1.06	3.22	4.72	5.61	7
55-64 years old	4.51	1.49	124	1.17	3.39	4.69	5.67	7
65 years old and above	4.66	1.68	93	1.06	3.56	5.11	6.11	7

Child Results: 

Child Food Allergy: FAQLQ-PF and FAQLQ-PFT

The Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF) was used for children aged 0-12 and the Food Allergy Quality of Life Questionnaire – Parent Form – for Adolescents (FAQLQ-PFT) was used for adolescents aged 13-17.  These forms were completed by parents.

Both instruments, like the adult FAQLQ, comprises multiple items scored 1 to 7. The scores are averaged across the items to generate an individual-level score between 1 and 7.

The child/youth mean and median FAQLQ scores was 4.1.

Table 10. Summary statistics: child/youth FAQLQ index

-	Mean	Std. Dev.	N	min	p25	Median	p75	max
FAQ	4.1	1.41	496	1	3.04	4.07	5.15	7

Figure 4. Distribution of FAQLQ scores (child, allergy)

Child Food Intolerance: FIQLQ-PF

The Food Intolerance Quality of Life Questionnaire- Parent Form (FIQLQ-PF) was used for all children (although the questions used differ according to the age of the child).  These assessments were completed by parents. The mean FIQLQ-PF score was 3.6 and the distribution of scores is shown in Figure 5.

Table 11. Summary statistics: FIQLQ-PF Index

-	Mean	Std. Dev.	N	min	p25	Median	p75	max
FIQ	3.63	1.4	147	1.16	2.55	3.5	4.68	6.8

Figure 5. Distribution of FIQLQ scores (child, intolerance)

Child Coeliac Disease: Celiac Disease DUX (CCDUX)
The Coeliac Disease DUX (CCDUX) is a validated HRQOL proxy questionnaire that parents complete about their children's condition. Responses are rated on a five-picture facial expression Likert scale on which a higher score indicates a worse quality of life. 

Table 12. Summary statistics: CCDUX index

-	Mean	Std. Dev.	N	min	p25	Median	p75	max
CCDUX	41.66	9.18	73	15	36	42	48	60

Figure 6. Distribution of CCDUX scores (child, coeliac)