Abstract
Background: Determining medical abortion outcome commonly includes a costly evaluation such as ultrasonography or serial serum hCG testing. Urine pregnancy testing may represent a less costly alternative. Methods: This prospective diagnostic test evaluation study was part of a multisite randomized trial of 1080 women undergoing medical abortion up to 63 days' gestation who returned 1 and 2 weeks after receiving mifepristone. Low-sensitivity (LS) and high-sensitivity (HS) urine pregnancy tests were performed at each visit, and the results were compared to ultrasonography. Sensitivity, specificity, predictive values and likelihood ratios of each urine test were determined. Results: In the first week following abortion, 14.8% of the LS tests and 7.9% of the HS tests correctly predicted outcome. None of the LS tests and only 0.2% of the HS tests were falsely negative; however, 85.2% of the LS tests and 91.8% of the HS tests were falsely positive. In the second week following abortion, 39.1% of the LS tests and 33.8% of the HS tests correctly predicted the medical abortion outcome. Only 0.2% of the LS tests and 0.3% of the HS were falsely negative; however, 60.8% of the LS tests and 65.8% of the HS tests were falsely positive. Conclusions: Both LS and HS urine pregnancy assays reliably assess clinical outcomes of medical abortions in cases of negative test results. However, the clinical utility of urine assay testing is limited because of the high rate of false-positive results.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 378-382 |
| Number of pages | 5 |
| Journal | Contraception |
| Volume | 75 |
| Issue number | 5 |
| DOIs | |
| State | Published - May 2007 |
| Externally published | Yes |
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Keywords
- Likelihood ratio
- Medical abortion
- Mifepristone
- Predictive value
- Sensitivity
- Specificity
- Urine pregnancy test
ASJC Scopus subject areas
- Medicine(all)
- Obstetrics and Gynecology
Cite this
Clinical utility of urine pregnancy assays to determine medical abortion outcome is limited. / Godfrey, Emily M.; Anderson, Anita; Fielding, Stephen L.; Meyn, Leslie; Creinin, Mitchell D.
In: Contraception, Vol. 75, No. 5, 05.2007, p. 378-382.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Clinical utility of urine pregnancy assays to determine medical abortion outcome is limited
AU - Godfrey, Emily M.
AU - Anderson, Anita
AU - Fielding, Stephen L.
AU - Meyn, Leslie
AU - Creinin, Mitchell D
PY - 2007/5
Y1 - 2007/5
N2 - Background: Determining medical abortion outcome commonly includes a costly evaluation such as ultrasonography or serial serum hCG testing. Urine pregnancy testing may represent a less costly alternative. Methods: This prospective diagnostic test evaluation study was part of a multisite randomized trial of 1080 women undergoing medical abortion up to 63 days' gestation who returned 1 and 2 weeks after receiving mifepristone. Low-sensitivity (LS) and high-sensitivity (HS) urine pregnancy tests were performed at each visit, and the results were compared to ultrasonography. Sensitivity, specificity, predictive values and likelihood ratios of each urine test were determined. Results: In the first week following abortion, 14.8% of the LS tests and 7.9% of the HS tests correctly predicted outcome. None of the LS tests and only 0.2% of the HS tests were falsely negative; however, 85.2% of the LS tests and 91.8% of the HS tests were falsely positive. In the second week following abortion, 39.1% of the LS tests and 33.8% of the HS tests correctly predicted the medical abortion outcome. Only 0.2% of the LS tests and 0.3% of the HS were falsely negative; however, 60.8% of the LS tests and 65.8% of the HS tests were falsely positive. Conclusions: Both LS and HS urine pregnancy assays reliably assess clinical outcomes of medical abortions in cases of negative test results. However, the clinical utility of urine assay testing is limited because of the high rate of false-positive results.
AB - Background: Determining medical abortion outcome commonly includes a costly evaluation such as ultrasonography or serial serum hCG testing. Urine pregnancy testing may represent a less costly alternative. Methods: This prospective diagnostic test evaluation study was part of a multisite randomized trial of 1080 women undergoing medical abortion up to 63 days' gestation who returned 1 and 2 weeks after receiving mifepristone. Low-sensitivity (LS) and high-sensitivity (HS) urine pregnancy tests were performed at each visit, and the results were compared to ultrasonography. Sensitivity, specificity, predictive values and likelihood ratios of each urine test were determined. Results: In the first week following abortion, 14.8% of the LS tests and 7.9% of the HS tests correctly predicted outcome. None of the LS tests and only 0.2% of the HS tests were falsely negative; however, 85.2% of the LS tests and 91.8% of the HS tests were falsely positive. In the second week following abortion, 39.1% of the LS tests and 33.8% of the HS tests correctly predicted the medical abortion outcome. Only 0.2% of the LS tests and 0.3% of the HS were falsely negative; however, 60.8% of the LS tests and 65.8% of the HS tests were falsely positive. Conclusions: Both LS and HS urine pregnancy assays reliably assess clinical outcomes of medical abortions in cases of negative test results. However, the clinical utility of urine assay testing is limited because of the high rate of false-positive results.
KW - Likelihood ratio
KW - Medical abortion
KW - Mifepristone
KW - Predictive value
KW - Sensitivity
KW - Specificity
KW - Urine pregnancy test
UR - http://www.scopus.com/inward/record.url?scp=34047255922&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34047255922&partnerID=8YFLogxK
U2 - 10.1016/j.contraception.2007.01.021
DO - 10.1016/j.contraception.2007.01.021
M3 - Article
C2 - 17434020
AN - SCOPUS:34047255922
VL - 75
SP - 378
EP - 382
JO - Contraception
JF - Contraception
SN - 0010-7824
IS - 5
ER -