RISK-FACTORS FOR DELAYED IMMUNIZATION AGAINST MEASLES, MUMPS, AND RUBELLA IN COLORADO 2-YEAR-OLDS

Objectives. 1) To examine a wide range of potential risk factors for d elayed childhood immunization against measles, mumps, and rubella and 2) to determine the parental response to proposed solutions regarding the problem of delayed childhood immunization. Design. A case-control study in which subjects had (controls) or had not (cases) received mea sles, mumps, and rubella vaccine (MMR) by 2 years of age. Parents of s ubjects were also surveyed to find out whether they thought selected p roposals to improve immunization rates would be successful. Results. M aternal education of high school or less at the time of the child's bi rth, more than or equal to two moves between birth and age 2, maternal age <21 years of age at the time of the child's birth, more than or e qual to two older siblings, participation in The Special Supplemental Food Program for Women, Infants, and Children (WIC), participation in the federal food stamp program, and incorrect knowledge of the recomme nded age for MMR significantly elevated the odds ratio (OR) for delaye d immunization. At least two older siblings (OR = 3.2), maternal age < 21 years of age at the time of the child's birth (OR = 2.8), and incor rect knowledge of the recommended age for MMR (OR = 2.7) remained sign ificant risk factors in a multivariate logistic regression model. Insu rance status and cost factors were not significant risk factors for de layed immunization. Parents thought that reminders for immunizations a nd a central record system would have made obtaining immunizations eas ier. Conclusions. Based on our findings of the importance of immunizat ion knowledge and demographic characteristics as risk factors for dela yed immunization, we suggest that a message (the recommended age for i mmunizations) and a target group for that message (families who move f requently, have older children, and are headed by younger parents) be evaluated as an intervention to improve immunization rates.