EHRs Utilized In Vaccine Refusal Study
By Christine Kern, contributing writer
The study used spatial analysis software and EHRs to pinpoint and address low vaccine areas.
A study published in Pediatrics used spatial analysis software and EHRs to identify clusters of underimmunization and vaccine refusal in Northern California by reviewing the immunization records of more than 154,000 Kaiser Permanente Northern California members up to age three. The study, Geographic Clusters in Underimmunization and Vaccine Refusal, was led by Tracy A. Lieu, MD, MPH.
The study asserts there has been an increase in parental refusal and delay of childhood vaccines, believed to be clustered by communities. The point of the research, then, was to identify potential cluster communities to compare them and evaluate whether or not vaccine refusal clusters could pose barriers to achieving overall high immunization rates.
The Centers for Disease Control’s recommended immunization schedule includes at least 17 separate injections before a child reaches 24 months of age, and links underimmunization to elevated risk of vaccine-preventable disease.
The study authors explained, “For optimal public health and patient care, clinicians and health care systems ideally should tailor care to their communities. The ability to identify clusters of underimmunization and vaccine refusal would help providers focus their efforts on the parents in communities with the greatest concerns, as well as identify areas at elevated risk for outbreaks of vaccine-preventable diseases.”
While identification of disease clusters has been used in many public health problems, in evaluating underimmunization, geographic clustering has been applied in only a few studies focused on nonmedical exemptions, thus giving rise to the current study. The researchers identified five statistically significant clusters, with underimmunization rates ranging from 18 to 23 percent, compared to 11 percent outside the clusters.
“This research confirms anecdotal reports of under-immunization clusters,” Lieu said in a press release. “In addition, we found clusters in places we hadn’t anticipated.” Lieu noted this study will be useful for targeting outreach efforts in particular areas, although it was not designed to figure out why children in some areas are less likely to be fully immunized.
The analysis further found spatial scan statistics could be used to identify incipient clusters of shot limiting and refusal, and therefore may be a useful tool to identify locations that deserve increased public health and clinical attention. Thus, the study could prove useful to target outreach efforts in specific areas, recognizing that it might be more challenging for healthcare providers in certain communities to achieve high immunization coverage rates. Because these rates are used in national quality metrics, some physician groups are at risk for being evaluated as delivering lower-quality care based in part on factors that may arise from the social environment.
Ultimately, the article contends, “Underimmunization and vaccine refusal cluster geographically. Spatial scan statistics may be a useful tool to identify locations with challenges to achieving high immunization rates, which deserve focused intervention.”