A general practice case-control study of delayed immunisation in under two year old children.
OBJECTIVE
To identify social factors which characterise the household of children with delayed immunisation.


METHODS
The study was done in 15 general practices in the Wellington city region with a case-control design where preschool children who were not up to date (cases) for their immunisations were compared with children who were up to date (controls).


RESULTS
There were 215 cases where immunisation was delayed among 3723 children at the time of audit in June 1996. Ethnic status was available from general practice records in 33% of cases and 40% of controls. There were more Maori and Pacific Island children among the cases compared to controls (39% versus 21%, odds ratio (OR) = 2.39, 95% confidence interval (CI) 1.12-5.10, p = 0.022. CASE SAMPLE HOUSEHOLDS COMPARED WITH CONTROLS HAD: (1) more children in the households (mean 2.27 versus 1.98, p = 0.01); (2) more households with a female as the only adult (35% versus 24%, OR = 1.61, 95% CI 1.04-2.51, p = 0.034). There was no difference in the proportions of male only adults (0.02% versus 0.01%, p = 0.70); (3) more mothers who were under 30 years of age (38% versus 25%, OR = 1.61, 95% CI 1.04-2.51, p = 0.034); and more fathers under 30 years of age (20% versus 10%, OR = 2.16, 95% CI 0.97-4.84, p = 0.06); (4) fewer mothers who were up to date with their recorded cervical smear status (66% versus 83%, OR = 0.69, 95% CI 0.23-0.63, p < 0.001); (5) more parents with an active community services card (38% versus 25%, OR 1.82, 95% CI 1.17-2.82, p = 0.007); (6) fewer siblings being immunised (70% versus 94%, OR = 0.14, 95% CI 0.07-0.28, p < 0.001).


CONCLUSIONS
There is a distinct group of New Zealand children for whom immunisation is delayed. Such children live in households which can be characterised by various social factors easily obtainable from general practice records. The identified households could be targeted for efficient preventive care by general practices.
Kljakovic
M
M
Department of General Practice, Wellington School of Medicine.
McLeod
D
D
D000328:Adult; D016022:Case-Control Studies; D005060:Europe / Q000208:ethnology; D005194:Family Practice / Q000592:standards*; D005260:Female; D006801:Humans; D007114:Immunization / Q000592:standards*; D007223:Infant; D008297:Male; D008485:Medical Audit; D009520:New Zealand; D010139:Pacific Islands / Q000208:ethnology; D010342:Patient Acceptance of Health Care / Q000208:ethnology / Q000706:statistics & numerical data*; D012307:Risk Factors; D012959:Socioeconomic Factors; D014504:Urban Health