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Good Positive and Negative Likelihood Ratios

Good Negative Likelihood Ratio

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Pregnancy: Likelihood Ratios

Introduction: None written.

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Tags: None. Tag this Diagnosis.

The likelihood ratios of findings for Pregnancy are listed below. See the left navigation bar to change the display.

Good Positive and Negative Likelihood Ratios

Finding +LR-LR Comments, Study
Serum beta-hCG Edit inf0

as compared to urine beta hCG, for all comers to an ED for whom pregnancy tests were ordered. In this study, urine beta hCG had sens = 100%, spec = 99.2%

Study: Am J Emerg Med. 1993 Jul;11(4):434-6. PMID: 8216535

Uterine Artery Pulsation Edit 110.3

only 1 study

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Patient Thinks She is Pregnant Edit 2.10.4

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Chadwick Sign Edit 25.50.5

Only 1 study from Dr Chadwick. Sign is "characteristic" deep violet-blue color of anterior vaginal wall. Rarely seen before 7 weeks.

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Good Negative Likelihood Ratio

Finding +LR-LR Comments, Study
Did Not Use Birth Control Edit 1.50.3

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Good Positive Likelihood Ratio

Finding +LR-LR Comments, Study
Vaginal Exam Signs Edit 3.20.9

not explicitly defined

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Palpable Fundus Edit 2.80.9

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Breast Signs on Exam Edit 2.70.6

not specifically defined

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Morning Sickness Edit 2.70.7

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Any Pregnancy Symptoms Edit 2.40.6

morning sickness, breast tenderness / fullness, urinary frequency, or fatigue

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Poorly Diagnostic Findings

Finding +LR-LR Comments, Study
Delayed Menses Edit 1.10.8

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Urine beta-hCG
Duplicate Edit
Sensitivity = 97%

7 days after missed period. Most urine b-hCG tests are sensitive to 20 mIU/ml. If sensitivity is at 0.5 mIU/ml then should be sensitive by 7 days after fertilization.

Study: JAMA 2001 Oct 10;286(14):1759-61. PMID 11594902

Urine beta-hCG
Duplicate Edit
Sensitivity = 90%

on 1st day of missed period. Most urine b-hCG tests are sensitive to 20 mIU/ml. If sensitivity is at 0.5 mIU/ml then should be sensitive by 7 days after fertilization.

Study: JAMA 2001 Oct 10;286(14):1759-61. PMID 11594902

Home Pregnancy Test Edit Sensitivity = 75%

Sens = 75% when used by actual patients but up to 91% when used by volunteers. Specificity not assessed but should be very high (~99%).

Study: Arch Fam Med 1998 Sep-Oct;7(5):465-9. PMID 9755740

Findings With Unspecified Accuracy

Finding +LR-LR Comments, Study
Goodell's Sign Edit No accuracy specified.

softening of the cervix, may be detected by 8 weeks of age

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Hegar's Sign Edit No accuracy specified.

Softening of the lower portion of the corpus of the uterus. May be seen by 6 weeks.

Study: JAMA. 1997 Aug 20;278(7):586-91. PMID: 9268281

Trans-Vaginal Ultrasound Edit No accuracy specified.

Gestational sac by 4.5-5 weeks, double decidual sign by 5.5-6 weeks, yolk sac by 5-6 weeks, cardiac activity by 5.5-6 weeks. Trans-abdominal ultrasound would be less sensitive for these findings.

Study: UpToDate

http://www.utdol.com/online/content/topic.do?topicKey=antenatl/22517