Table 2.

Item probabilities for each of the individual barrier indicators, according to the five barrier classes identified in the latent class analysis (in mothers who did not disagree with immunisation, N = 4994).

Class labels:	1. Minimal barriers	2. Lone parent, mobile families with good support	3. Low social contact and service info; psychological distress	4. Larger families, not using formal childcare	5. Child health issues/concerns
Class membership probabilities:	0.68	0.05	0.15	0.08	0.05
Item response probabilities:
Perceived contraindications
Concerned about child's health/development/behaviour	0.04	0.10	0.12	0.03	0.39
Child > average medical needs	0.02	0.03	0.01	0.03	0.85
Access to health services
<7 antenatal visits	0.06	0.16	0.12	0.21	0.08
Poor access to services	0.03	0.04	0.17	0.05	0.09
1+ moves since birth of child	0.15	0.51	0.27	0.07	0.11
Can’t find info on services	0.03	0.06	0.31	0.05	0.11
Interpreter used at interview	0.02	0.03	0.10	0.04	0.04
Social support
Low contact with friends, family etc.	0.08	0.32	0.52	0.29	0.20
Need help, but don’t get	0.04	0.00	0.26	0.16	0.11
Lone parent family	0.03	0.97	0.10	0.20	0.10
Psychological well being
Psychologically distressed	0.00	0.06	0.19	0.04	0.07
Competing pressures
3+ children	0.17	0.26	0.20	0.98	0.27
Rushed	0.06	0.02	0.24	0.25	0.15
Cluttered home	0.06	0.25	0.12	0.22	0.09
Childcare
Formal childcare	0.15	0.17	0.13	0.02	0.20
%a children assigned to class	71.94%	5.40%	9.02%	9.17%	4.46%

Item probabilities indicate the likelihood of individuals in a given class displaying each item. Bold highlights indicate class homogeneity (high absolute probabilities [>0.5]), and italic highlights indicate class separation (high relative difference in the item response probabilities [+/−3]).

^aWeighted to account for sample design. For measures of model fit, see Appendix 1.