Validity Of Point of Care Pregnancy Testing in the ED Using Serum From Whole Blood Collected At Bedside Linh T Le, M.D. PGY III Division of Emergency Medicine Saint Louis University, School of Medicine
Disclaimer • We would like to thank Sekisui Diagnostics for their donation of the pregnancy test assays. • There was no monetary funding from the company for the study.
Study Team Authors and Co-Investigators • PreetiDalawari, MD, MSPH • Kamal Gursahani, MD, MBA • Eric Lee, MD • Katrina Wade, MD We would like to acknowledge: • ED nursing staff, attendings, residents and medical students
Background • POCT urine pregnancy • Most common practice • Urine can be unobtainable, take time • Serum hCG laboratory test • Increased cost • Prolonged time • POCT serum pregnancy • Easy to perform • May be faster in certain situations • NOT a CLIA waive test
Study Objectives • Demonstrate validity of POCT serum pregnancy to the current standard of care: • POCT urine pregnancy test • Serum hCG qualitative/quantitative laboratory test • Obvious ultrasound evidence of IUP • Compare the tests metrics to see if there is a difference
Hypotheses • We hypothesized that POCT serum pregnancy test can be as reliableas the POCT urine pregnancy test and serum hCG laboratory test. • We also hypothesized that POCT serum pregnancy test may be more efficient in certain clinical scenarios
Study Design • IRB approved, single site cross sectional study at Saint Louis University Hospital • All enrolled patients signed informed consent and HIPPA forms • All of the samples were tested via POCT serum (study test) and a standard of care test
Study Design • Blood sample obtained from patient in a tube with no anticoagulants/additives • Sample was placed up right allow to separate by gravity for >20 mins • Both the POCT urine and serum samples were applied to the OSOM hCG Combo Test • Sensitivity • 20 mIU/mL Urine • 10 mIU/mL Serum • Timing • 3 minutes for urine • 5 minutes for serum
Study Design • Estimated pregnancy prevalence of 8% in the study population • A sample size of 210 subjects is needed to achieve 80% power at a 5% alpha level using a two-sided equivalence test of correlated proportions
Preliminary Results • 76 patients enrolled thus far • Mean age: 28.4 • Standard deviation 7.5 • 22% of the patients were pregnant.
Preliminary Results POCT serum compared to POCT urine • 100% sensitivity and 100% specificity POCT serum compared to laboratory serum hCG • 100% sensitivity and 100% specificity POCT serum compared to bedside ultrasound • 100% sensitivity and 100% specificity
Preliminary Results Time of test order to time of results • POCT urine • Average time: 51 minutes • Standard deviation: 42 minutes • POCT serum • Average time: 97 minutes • Standard deviation: 47 minutes
Limitations May not be true representation of the ED care timeline as consent has be to obtained prior to using patient’s already collected blood – this may increased the “order to result” time for POCT serum test
Limitations Limited by using only the OSOM hCG Combo Test, it is possible that different manufacturer’s assays may have different results
Conclusion POCT pregnancy test using OSOM hCGCombo Test can be done reliably using serum blood at the bedside
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