Self-performed Rh typing: a cross-sectional study.

Objective: To evaluate whether patients are capable and willing to self-administer and interpret an EldonCard test to determine their Rh status.

Methods: This was a cross-sectional study in Honolulu, HI, USA of pregnancy-capable people aged 14-50 years who did not know their blood type and had never used an EldonCard. Participants independently completed EldonCard testing, determined their Rh type and answered a survey on feasibility and acceptability. Separately, a blinded clinician recorded their interpretation of the participant's EldonCard. When available, we obtained blood type from the electronic health record (EHR). We measured Rh type agreement between participant, clinician and EHR, as well as participant comfort and acceptability of testing.

Results: Of the 330 total participants, 288 (87.3%) completed testing. Patients and clinicians had 94.0% agreement in their interpretation of the EldonCard for Rh status. Patient interpretation had 83.5% agreement with EHR while clinician and EHR had 92.3% agreement. Sensitivity of EldonCard interpretation by patient and clinician was 100%. Specificity was 83.2% for patients and 92.2% for clinicians. Two patients (of 117) had Rh-negative blood type in the EHR. The vast majority of participants found the EldonCard testing easy (94.4%) and felt comfortable doing the testing (93.7%). Participants with lower education levels felt less confident (p=0.003) and less comfortable with testing (p=0.038); however, their ability to interpret results was similar to others (p=0.051).

Conclusions: Patient-performed Rh typing via the EldonCard is an effective and acceptable option for patients, and could be used as a primary screening test for Rh status.