Factors Associated with Five Routine immunization in Akita, Japan

Routine immunization is one of the most cost-effective interventions for the prevention of infectious disease. We have investigated the factors associated with the completion of five routine immunizations in Japan. About one thousand children who underwent a health checkup from April to December in 2004 participated in the study. A structured questionnaire was used to collect information on characteristics of the child: age at immunization, guardians' knowledge and attitude, and Child-Rearing. Immunization coverage rate was calculated. Associations between immunization and knowledge and attitude were calculated to get crude and adjusted odds ratios, using a logistic regression analysis. The coverage rate for the five vaccines was 70.5% in children under 3-year-old. BCG had the highest coverage rate (94.2%) of the five vaccines. The best source of information was notification from the local government at 92.4%. Completion of the administration of five immunizations was significantly associated with PCH-Pocketbook (OR=1.31, 95%CI:1.01-1.70); Child-Rearing Magazine (OR=1.77, 95%CI:1.23-2.55); intention to finish all the immunizations (OR=2.93, 95%CI:2.20-3.91); child care at a nursing school during the day (OR=0.49, 95%CI:0.37-0.64); and living in an urban area (OR=1.33, 95%CI:1.02-1.73). Adjusted odds ratios included child care at a nursing school during the day and living in an urban area, and they were significantly associated with Child-Rearing Magazine (OR=1.82, 95%CI:1.25-2.64) and intention to finish all the immunizations (OR=3.00, 95%CI:2.23-4.03). Our results suggested that Child-Rearing Magazine and scheduling all the immunizations promoted the administration of five vaccines to children under 3-year-old until newspapers and television suppressed the administration of the vaccines.