Validity of self-reported influenza and pneumococcal vaccination status among a cohort of hospitalized elderly inpatients

Use of self-reported vaccination status is commonplace in assessing vaccination coverage for public health programs and individuals, yet limited validity data exist. We compared self-report with provider records for pneumococcal (23vPPV) and influenza vaccine for 4887 subjects aged ≥65 years from two Australian hospitals. Self-reported influenza vaccination status had high sensitivity (98%), positive predictive value (PPV) (88%) and negative predictive value (NPV) (91%), but low specificity (56%). Self-reported 23vPPV (previous 5 years) had a sensitivity of 84%, specificity 77%, PPV 85% and NPV 76%. Clinicians can be reasonably confident of self-reported influenza vaccine status, and for positive self-report for 23vPPV in this setting. For program evaluation, self-reported influenza vaccination coverage among inpatients overestimates true coverage by about 10% versus 1% for 23vPPV. Self-report remains imperfect and whole-of-life immunisation registers a preferable goal.