Consistency of self‐reported and documented historical influenza vaccination status of US healthcare workers

BACKGROUND: Healthcare personnel (HCP) are a priority group for annual influenza vaccination. Few studies have assessed the validity of recall of prior influenza vaccination status among HCP, especially for more than one preceding season. METHODS: Using data from a randomized controlled trial of influenza vaccination among 947 HCP from two US healthcare systems, we assessed agreement between participant self‐report and administrative record documentation of influenza vaccination status during the preceding five influenza seasons; kappa coefficients and sensitivity values were calculated. Administrative record documentation was considered the gold standard. Documented vaccination sources included electronic medical records, employee health records, outside immunization providers, and the state immunization information system. RESULTS: Among 683 HCP with prior influenza immunization information, 89.7% (95% CI: 87.2%, 91.9%) of HCP were able to self‐report their vaccination status for the season preceding the survey. By the fifth preceding season, 82.6% (95% CI: 79.5%, 85.3%) of HCP were able to self‐report. Among HCP who self‐reported their vaccination status, agreement between self‐report and documented vaccination status ranged from 81.9% (95% CI: 77.2%, 86.7%) for the fifth season to 90.5% (95% CI: 87.2%, 93.9%) for the season preceding interview. HCP who received vaccine for only some of the preceding five seasons (18.3%) more commonly had ≥2 errors in their recall compared with those vaccinated all five preceding seasons (55.7% vs. 4.3%). CONCLUSIONS: Self‐reported vaccination status is a reliable source for historical influenza vaccination information among HCP who are consistently vaccinated but less reliable for those with a history of inconsistent vaccination.