UKMLA PLAB AMC USMLE Prometric MCQ

Question Number 0876
Question:
A woman in the first trimester of pregnancy has an endovaginal scan after complaining of lower abdominal pain. There is no evidence of an intrauterine pregnancy on songraphy and the ultrasound is otherwise normal. Her beta-hCG test is positive. A recent study has shown that patients with a positive beta-hCG who have no sonographic evidence of an intrauterine pregnancy have a positive predictive value of 70% for an ectopic pregnancy. The term 'positive predictive value' is this case is best described as

a) the likelihood that this woman actually has an ectopic pregnancy
b) is the ability to identify the ABSENCE of an ectopic pregnancy in this woman
c) the prevalence of ectopic pregnancies in a population of women with similar findings
d) the ratio of the number of women with similar findings with respect to the total number of women with ectopic pregnancies
e) the likelihood of the pregnancy going to term