Appendix H: Sample Descriptives: Demographics and Food Hypersensitivity

A sample of 2276 adults was achieved, comprising people who either 

• have one or more Food Hypersensitivity, or 
• are a parent/carer of one or more children with a Food Hypersensitivity (FHS).

The sample was recruited in July-November 2021.

The survey sources are:

• people who completed a survey as part of Workstream 1 of this project and agreed to be recontacted
• a market research commercial sample recruited from Pureprofile
• people recruited from marketing / publicity distributed by support groups (Anaphylaxis UK, etc).

The sample was reduced to 2142 after removal of people who completed the survey excessively quickly (an issue most common in the purchased sample).

We now summarise the characteristics of the Adult and then Parents sample.

Demographic Information: Adult sample

The adult sample is now described, first in terms of demographics, and then in terms of their food hypersensitivity.

Sex: The sample was overwhelmingly (77%) female.

Table 1. Tabulation of sex 

Sex	Frequency	Percent
Male	326	22.89
Female	1098	77.11
Total	1424	100.00

Age: The modal age category was 35 to 54 years old. 

Table 2: Tabulation of age category

Age	Frequency	Percent	Cumulative
Below 35 years old	245	17.24	17.24
35 to 54 years old	462	32.51	49.75
55 to 64 years old	372	26.18	75.93
65 years old and above	342	24.07	100.00
Total	1421	100.00	-

The mean age was 52 years, and the median age of respondents was 55 years old with ages distributed between 17 and 90 years. 

Table 3: Adult age statistics

-	Mean	Std Dev	N	Min	p25	Median	p75	max
Age	52.36	15.68	1421	17	41	55	64	90

Figure 1: Age Distribution Analysis

Income: For those who stated their income, the modal income category is £25,000-£34,999 but nearly 20% of respondents refused to state their income.

Figure 2: Income distribution, Adults

Distribution of Food Hypersensitivities: Adult sample

Accounting for Multiple Conditions

Just over a third of the sample reported having a food allergy, over 40% reported having coeliac disease or a food intolerance. The distribution of conditions shown (with percent values summing to more than 100) reflect that some people reported having more than one condition. The sample included people with a clinical diagnosis and those whose condition was self-assessed.

Table 4. Distribution of food hypersensitivity Conditions, adults

Food hypersensitivity conditions	Frequency	Percent
Food Allergy	495	34.7
Coeliac Disease	630	44.2
Food Intolerance	607	42.6
Total	1426	100

Decomposing these figures into single and multiple conditions gives:

Table 5. Distribution of food hypersensitivity Conditions accounting for multiple conditions, adults

Food hypersensitivity conditions	Frequency	Percent	Cum.
Food Allergy	274	19.21	19.21
Coeliac Disease	508	35.62	54.84
Food intolerance	365	25.60	80.43
Multiple	279	19.57	100.00
Total	1426	100.00	-

Figure 3: Distribution of conditions, including multiple conditions, adults

The specific combinations of conditions are shown in Table 9.6 which indicates only 1.9% of respondents report having all 3 conditions, and 18% of respondents report having 2 conditions.

Table 6. Tabulation of food hypersensitivity conditions and combinations 

Food hypersensitivity conditions	Frequency	Percent	Cum.
Food Allergy	274	19.21	19.21
Coeliac Disease	508	35.62	54.84
Food intolerance	365	25.60	80.43
Allergy and Coeliac	37	2.59	83.03
Allergy and intolerance	157	11.01	94.04
Coeliac and intolerance	58	4.07	98.11
Allergy, coeliac and intolerance	27	1.89	100.00
Total	1426	100.00	-

Figure 4: Distribution of conditions, including specific multiple conditions, adults

The distribution of conditions by sex is shown here, with 40% of males report having coeliac disease whereas 45% of females report having coeliac disease. Coeliac disease is the most commonly reported condition among both male and female adults, food allergy is the least common condition in both groups. Note that people reporting multiple conditions means these percentage values do not sum to 100.

Table 7: Tabulation of food hypersensitivity conditions by sex 

Female	mean	sd
Food Allergy	34.8	.48
Coeliac	45.4	.5
Food Intolerance	43.8	.5

 

Male	mean	sd
Food Allergy	34.7	.48
Coeliac	39.6	.49
Food Intolerance	38.7	.49

Figure 5: Distribution of conditions, by sex

40% of males report having coeliac disease whereas 45% of females report doing so. 

The distributions of the 3 conditions between the 4 age groups we use to disaggregate the data are shown in Figure 6.  (Singh et al’s 2018 meta-analysis reports that biopsy-confirmed coeliac disease is 1.5 times more common in females than in males).

Figure 6: Distribution of conditions by age

Multiple conditions are much less commonly reported in those aged 65 and over (22% compared to 27-29% of the other groups). Food allergies are relatively uncommon amongst the 65 plus group: 14% of over 65s have only a food allergy whereas 32% of under 35s do so.

Pearson's chi-squared tests indicate that the distributions of conditions are different at the 1% level across age brackets (χ_9^2= 62.5956, Pr = 0.000). Therefore, the null hypothesis of no difference is rejected. 

Identifying the ‘worst’ condition for those with multiple FHS

Twenty percent of the adult sample reported having more than one food hypersensitivity. The tabulations of those conditions, for people’s only or worst condition are shown here – where the sample size is 1426 and the percentage values sum to 100 as each person indicates only a single food hypersensitivity.

Table 8. Tabulation of food hypersensitivity worst or only condition
 

Food hypersensitivity condition	Frequency	Percent	Cum.
Food Allergy	385	27.00	27.00
Coeliac Disease	601	42.15	69.14
Food Intolerance	440	30.86	100.00
Total	1426	100.00	-

Figure 7: Distribution of worst or only condition, adults

Coeliac disease was the condition most commonly (by 42%) identified as only/worst food hypersensitivity, just under a third reported food intolerance as only/worst FHS condition, and 27% indicated this was true of food allergy.

Distribution of only or worst condition

The distribution of these conditions between male and female respondents is shown here.

Table 9: Distribution of worst or only food hypersensitivity, by sex

Only or Worst condition	Number in each sex: Male (%)	Number in each sex: Female (%)	Number in each sex: Total (%)
Frequencies: Food Allergy	96	289	385
Cell percentages: Food Allergy	6.74	20.29	27.04
Frequencies: Coeliac Disease	124	475	599
Cell percentages: Coeliac Disease	8.71	33.36	42.06
Frequencies: Food Intolerance	106	334	440
Cell percentages: Food Intolerance	7.44	23.46	30.90
Frequencies: total	326	1098	1424
Cell percentages: total	22.89	77.11	100.00

38% of Males say that coeliac disease affects them the most, whereas 43% of Females do so. 

Pearson's chi-squared tests (Pearson chi2(2) =   2.8974   Pr = 0.235)) indicate that the distributions of worst conditions are not statistically different across sex. 

Figure 8: Distribution of worst or only condition, by sex, adults

The distribution of these conditions by age group is shown in Table 10 and Figure 9. 

Table 10: Distribution of worst or only food hypersensitivity, by age

Only or Worst condition	Below 35 years old	35 to 54 years old	55 to 64 years old	65 years old and above	Total
Frequencies: Food Allergy	104	140	71	69	384
Cell percentages: Food Allergy	42.45	303.30	19.09	20.18	27.02
Frequencies: Coeliac Disease	79	164	177	180	600
Cell percentages: Coeliac Disease	32.24	35.50	47.58	52.63	42.22
Frequencies: Food Intolerance	62	158	124	93	437
Cell percentages: Food Intolerance	25.31	34.20	33.33	27.19	30.75
Frequencies: total	245	462	372	342	1421
Cell percentages: total	100.00	100.00	100.00	100.00	100.00

Pearson chi2(6) = 66.4119   Pr = 0.000

Figure 9. Distribution of Worst or Only Condition, by age group, Adults 

Sampled adults below 35 are most likely to report food allergy as their only (or worst) FHS, whereas people aged over 55 are much less likely to do so; about half of the sample over 55 report Coeliac coeliac Disease disease as their only or worst condition. Those recruited with food intolerances are more evenly distributed across the age groups.

These results are consistent with Coeliac coeliac disease tending to be diagnosed later in life (often at 40-50 years of age) (Paez et al (2017); Zipser et al (2003); Ludvigsson et al (2014)). Care must be taken not to over-interpret these distributions. The sample includes many people with multiple FHS – for them it could be that the symptoms of their multiple conditions differ as they age, it could be that they adapt better to one than the other. Pearson's chi-squared tests indicate that the distributions of only/worst conditions are different at the 1% level across age groups (χ_6^2= 66.4119, Pr = 0.000); the null hypothesis of no difference is rejected. 

Demographic Information: Child Sample

The child sample is now described, first in terms of child and parent demographics, and then in terms of the children’s food hypersensitivity.

Child Age

The children were aged between1 and 17 years old with a mean age of 8.7 years.

Table 11. Summary statistics: child age

-	Mean	Std. Dev	N	Min	p25	Median	p75	max
Age	8.66	4.72	716	1	5	8	13	17

The median age of the children that parents responded about was 8 years old.

Figure 10 Distribution of Child age

Parental income

For those who stated their income, the modal (household) income category is £55,000-£74,999 but it should be noted that 12% of respondents declined to state their household income.

Table 12. Tabulation of income, parents

Income	Frequency	Percent	Cumulative
Below £6,000	18	2.51	2.51
£6,500 to £11,499	35	4.89	7.4
£11,500 to £17,499	21	2.93	10.34
£17,500 to £24,999	48	6.7	17.04
£25,000 to £34,999	88	12.29	29.33
£35,000 to £44,999	66	9.22	38.55
£45,000 to £54,999	70	9.78	48.32
£55,00 to £74,999	115	16.06	64.39
£75,000 to £99,999	80	11.17	75.56
£75,000 to £99,999	33	4.61	80.17
£75,000 to £99,999	19	2.65	82.82
£150,00 to £199,999	21	2.93	85.75
More than £150,000 to £199,999	16	2.23	87.99
Prefer not to say	86	12.01	100
Total	716	100.00	-

Figure 11: Distribution of income, child sample

Distribution of Food Hypersensitivities: Child Sample

Accounting for Multiple Child Conditions
Just over 70% the sample reported their child had a food allergy, 29% reported their child had a food intolerance. The numbers reporting their child had coeliac disease was much lower at 12%.

These data reflect that some people reported having more than one condition

Table 13. Distribution of child conditions

Condition	Mean	Std. Dev
Food Allergy	72.2	.448
Coeliac Disease	11.9	.3242
Food Intolerance	28.5	.452

Decomposing these figures into single and multiple conditions gives this breakdown with 11% of the sample reporting their child had more than one (??) of the 3 conditions.

Table 14.   Tabulation of child conditions, including multiple conditions  

Food hypersensitivity conditions	Frequency	Percent	Cum.
Food Allergy	440	61.45	61.45
Coeliac Disease	60	8.38	69.83
Food intolerance	135	18.85	88.69
Multiple	81	11.31	100.00
Total	716	100.00	-

Figure 12: Distribution of conditions including multiple conditions, children

The specific combinations of child conditions that people report are shown in Table 15. 

Table 15: Tabulation of Children's food hypersensitivity conditions and combinations

Food hypersensitivity	Frequency	Percent	Cumulative
Food Allergy	440	61.45	61.45
Coeliac Disease	60	8.38	69.83
Food Intolerance	135	18.85	88.69
Allergy and Coeliac	12	1.68	90.36
Allergy and Intolerance	56	7.82	98.18
Coeliac and Intolerance	4	0.56	98.74
Allery, Coeliac and Intolerance	9	1.26	100.00
Total	716	100.00	-

Figure 13: Distribution of conditions including specific combinations conditions, children

10% of respondents report their child having 2 conditions, and only 1.3% of respondents report their child having all 3 conditions. 

Table 16: Tabulation of number of conditions per child

Number of conditions	Frequency	Percent	Cum.
1 Condition	635	88.69	88.69
2 Conditions	72	10.06	98.74
3 Conditions	9	1.26	100.00
Total	716	100.00	-

Identifying the 'worst' condition for those children with multiple FHS

In the child sample 11% reported their child had more than one food hypersensitivity, and so were asked to indicate which one had the greatest impact on their child’s quality of life. 

The tabulations of those conditions, for people’s only or worst condition are shown here – where the sample size is 716 and the percentage values sum to 100 as each person indicates only a single food hypersensitivity.

Table 17. Distribution of child’s only or worst condition

Type of condition	Frequency	Percent	Cumulative
Food Allergy	496	69.27	69.27
Coeliac Disease	73	10.20	79.47
Food Intolerance	147	20.53	100.00
Total	716	100.00	-

69.3% of respondents say that Food Allergy if their only or worst condition, and only 10% reported that coeliac disease was their child’s only or worst condition.

This is a strong contrast with the adult sample in which coeliac disease was the condition most commonly (42%) identified as only or worst condition.