Table 3

Validation of Onomap

EthnicityEthnicity reported by participantEthnicity predicted by OnomapEthnicity correctly predictedSensitivitySpecificity
White British or Irish16811811
Other white32353418
Total white49165229484498.5%77.7%
Indian364239
Pakistani313348
Bangladeshi9688
Chinese5518
Other Asian<10118
Total Asian or Asian British83781160972.8%96.5%
Black – African344142
Black – Caribbean10<10
Other black23<10
Total black or black British37714311229.7%99.5%
Arabic39279
Other<10<10
Other ethnic group452832453.3%96.1%
Mixed234<10
Unclassified/unknown231174<103.5%97.4%
Total66406640558987.4%96.1%
  • Estimated sensitivity and specificity of Onomap by ethnic group. Calculated by measuring the performance of Onomap to predict ethnicity in three clinical data sets* already containing self-reported or healthcare professional-reported ethnicity.

  • *Three data sets that included self-reported or healthcare professional-reported ethnicity were used to validate Onomap: a list of individuals attending a mosque in Wales who were offered screening for hepatitis C (n=189), a list of tuberculosis patients notified by doctors in Wales (n=3267) and a list of patients attending an infectious disease clinic in Poland (n=3184).