Immunization status among children newly enrolled in a health plan: a new frontier for quality measurement?

Background: The National Scientific Panel on Immunization Measurement Standards recently recommended that the assessment population for the childhood immunization measure of the Health Plan Employer Data and Information Set include 24-month-olds with > or = 6 months of continuous enrollment in a health plan. The current inclusion criterion is > or = 12 months of continuous enrollment. The new recommendation would expand the assessment population to include children with more recent enrollment.