Health Information Solutions has developed customized linkage algorithms for several linkage situations. For instance, we have developed probabilistic techniques for linking the infant hospital discharge record, maternal hospital discharge record, and vital statistics birth records with linkage percentages exceeding 98%. We have also developed a probabilistic linkage technique for matching re-hospitalizations and transfers of under-one-year olds to their birth hospitalization as well as for matching maternal prenatal and postnatal hospitalizations.

Starting with birth cohort year 2006, we have extended the linkage to also include a) any matches of infants under 1 year of age to ambulatory surgery and emergency department records, and b) any matches of maternal prenatal (within 9 months prior to the delivery) or maternal postnatal (within 1 year of the delivery) to ambulatory surgery and emergency department records. For more information on obtaining access to these linked data files, contact the California Healthcare Information Resource Center.

Additional linkage projects include, but are not limited to, matching Medicare beneficiary data to California hospital discharge data, linkages for the California Coronary Artery Bypass Graft (CABG) Outcome Reporting Program (CCORP), linkage of pediatric emergency department encounters and inpatient admissions, linkage of emergency medical system (EMS) and emergency department/inpatient encounter data, and linkage of maternal postpartum deaths to vital statistics birth data.