Errors and correlates in parental recall of child immunizations: effects on vaccination coverage estimates.
OBJECTIVE
We evaluated the accuracy of parental recall of children's immunization histories as compared with provider records and examined how errors in parental recall correlate with sociodemographic characteristics.


METHODS
The validation study was part of a population-based household survey designed to assess immunization levels among Texas children under age 2 years. For 72% (n = 3278), interviewers used vaccination records from the parent to copy dates for the diphtheria and tetanus toxoids and pertussis vaccine (DTP), oral polio vaccine (OPV), and measles, mumps, and rubella (MMR) shots. For parents without shot records (n = 1216), interviewers asked about each vaccine, whether the child had received the shot, how many, and at what age. Of these, 85% (n = 1029) were validated with health provider records.


RESULTS
Measured against provider records, only 34% of parents accurately recalled the number of DTP shots a child had. More often (42%) parents underestimated the number of DTP shots than overestimated (24%). Agreement between parental recall and provider records was high (83%) for the single dose of MMR. Accuracy of parents' recall did not differ by race/ethnicity, education level, or type of health insurance coverage, but decreased as child's age increased. Having a vaccination record at home was associated with a higher immunization status. Hispanic, lower educated, and uninsured parents were more likely to have a vaccination record than non-Hispanic, higher educated, and privately insured parents.


CONCLUSIONS
Validity of parental recall of children's immunization histories depends on the vaccine and the age of the child, which is highly correlated with the number of shots parents must recollect. Results suggest that inclusion of parent recall information from vaccination surveys underestimates DTP:OPV:MMR coverage. This underestimation is consistent across economic and race/ethnic groups. Thus, community surveys based on cards and recall should provide reliable conclusions about which groups need intensive program efforts. For the routine monitoring of vaccination coverage, reasonable estimates can be obtained by combining parent-held record and parent recall data. Caution is required when comparing coverage estimates from different surveys since the source of information and method of derivation will produce widely varying coverage rates.
Suarez
L
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Associateship for Disease Control and Prevention, Texas Department of Health, Austin, TX 78756, USA.
Simpson
D M
DM
Smith
D R
DR
D001741:Black or African American; D002675:Child, Preschool; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000008:administration & dosage; D004282:Documentation / Q000706:statistics & numerical data*; D004522:Educational Status; D019538:Health Care Surveys; D006630:Hispanic or Latino; D006801:Humans; D007114:Immunization / Q000706:statistics & numerical data*; D007115:Immunization Schedule; D007223:Infant; D007231:Infant, Newborn; D019458:Insurance Coverage / Q000706:statistics & numerical data; D008458:Measles Vaccine / Q000008:administration & dosage; D022542:Measles-Mumps-Rubella Vaccine; D008487:Medical History Taking / Q000706:statistics & numerical data*; D008499:Medical Records / Q000706:statistics & numerical data*; D011939:Mental Recall; D009108:Mumps Vaccine / Q000008:administration & dosage; D010290:Parents / Q000523:psychology*; D011055:Poliovirus Vaccine, Oral / Q000008:administration & dosage; D011159:Population Surveillance; D011897:Random Allocation; D015203:Reproducibility of Results; D012411:Rubella Vaccine / Q000008:administration & dosage; D012959:Socioeconomic Factors; D013781:Texas; D017778:Vaccines, Combined / Q000008:administration & dosage; D044465:White People
D015721:Diphtheria-Tetanus-Pertussis Vaccine; D008458:Measles Vaccine; D022542:Measles-Mumps-Rubella Vaccine; D009108:Mumps Vaccine; D011055:Poliovirus Vaccine, Oral; D012411:Rubella Vaccine; D017778:Vaccines, Combined