Abstract:
:We propose a new, less costly, design to test the equivalence of digital versus analogue mammography in terms of sensitivity and specificity. Because breast cancer is a rare event among asymptomatic women, the sample size for testing equivalence of sensitivity is larger than that for testing equivalence of specificity. Hence calculations of sample size are based on sensitivity. With the proposed design it is possible to achieve the same power as a completely paired design by increasing the number of less costly analogue mammograms and not giving the more expensive digital mammograms to some randomly selected subjects who are negative on the analogue mammogram. The key idea is that subjects who are negative on the analogue mammogram are unlikely to have cancer and hence contribute less information for estimating sensitivity than subjects who are positive on the analogue mammogram. To ascertain disease state among subjects not biopsied, we propose another analogue mammogram at a later time determined by a natural history model. The design differs from a double sampling design because it compares two imperfect tests instead of combining information from a perfect and imperfect test.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Baker SG,Connor RJ,Kessler LGdoi
10.1002/(sici)1097-0258(19981015)17:19<2219::aid-ssubject
Has Abstractpub_date
1998-10-15 00:00:00pages
2219-32issue
19eissn
0277-6715issn
1097-0258pii
10.1002/(SICI)1097-0258(19981015)17:19<2219::AID-Sjournal_volume
17pub_type
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