The University of Southampton
University of Southampton Institutional Repository

Patients' & healthcare professionals' values regarding true- & false-positive diagnosis when colorectal cancer screening by CT colonography: discrete choice experiment

Patients' & healthcare professionals' values regarding true- & false-positive diagnosis when colorectal cancer screening by CT colonography: discrete choice experiment
Patients' & healthcare professionals' values regarding true- & false-positive diagnosis when colorectal cancer screening by CT colonography: discrete choice experiment
Purpose

To establish the relative weighting given by patients and healthcare professionals to gains in diagnostic sensitivity versus loss of specificity when using CT colonography (CTC) for colorectal cancer screening.

Materials and Methods

Following ethical approval and informed consent, 75 patients and 50 healthcare professionals undertook a discrete choice experiment in which they chose between “standard” CTC and “enhanced” CTC that raised diagnostic sensitivity 10% for either cancer or polyps in exchange for varying levels of specificity. We established the relative increase in false-positive diagnoses participants traded for an increase in true-positive diagnoses.

Results

Data from 122 participants were analysed. There were 30 (25%) non-traders for the cancer scenario and 20 (16%) for the polyp scenario. For cancer, the 10% gain in sensitivity was traded up to a median 45% (IQR 25 to >85) drop in specificity, equating to 2250 (IQR 1250 to >4250) additional false-positives per additional true-positive cancer, at 0.2% prevalence. For polyps, the figure was 15% (IQR 7.5 to 55), equating to 6 (IQR 3 to 22) additional false-positives per additional true-positive polyp, at 25% prevalence. Tipping points were significantly higher for patients than professionals for both cancer (85 vs 25, p<0.001) and polyps (55 vs 15, p<0.001). Patients were willing to pay significantly more for increased sensitivity for cancer (p = 0.021).

Conclusion

When screening for colorectal cancer, patients and professionals believe gains in true-positive diagnoses are worth much more than the negative consequences of a corresponding rise in false-positives. Evaluation of screening tests should account for this.
1932-6203
e80767
Boone, D.
b54da3ab-b521-4ef0-a50d-2425809e3569
Mallett, S.
59832f8e-a54f-4ffe-9be5-4ead8aa6c6a1
Zhu, S.
19f66c61-95e9-4f6b-92db-64686bd581ad
Yao, G.L.
d777f84c-cf3d-4fad-bbc1-ea01dec01695
Bell, N.
9502ade5-98f0-4ce9-ae86-7d58590e8c96
Ghanouni, A.
2f7d9446-2127-40f9-82be-7724138b6264
von Wagner, C.
2e0a9eb1-b1cf-41eb-ade1-dfb0234a9f66
Taylor, S.A.
fc691ddd-b33f-4f62-bb4c-641691726d0a
Altman, D.G.
c8c0dc66-dd65-4b27-bbce-40bc744536ff
Lilford, R.
5102134d-1c8d-491a-a8fc-e5b42d1c3009
Halligan, S.
d4660e12-21e6-498c-b52c-96a3262a914c
Boone, D.
b54da3ab-b521-4ef0-a50d-2425809e3569
Mallett, S.
59832f8e-a54f-4ffe-9be5-4ead8aa6c6a1
Zhu, S.
19f66c61-95e9-4f6b-92db-64686bd581ad
Yao, G.L.
d777f84c-cf3d-4fad-bbc1-ea01dec01695
Bell, N.
9502ade5-98f0-4ce9-ae86-7d58590e8c96
Ghanouni, A.
2f7d9446-2127-40f9-82be-7724138b6264
von Wagner, C.
2e0a9eb1-b1cf-41eb-ade1-dfb0234a9f66
Taylor, S.A.
fc691ddd-b33f-4f62-bb4c-641691726d0a
Altman, D.G.
c8c0dc66-dd65-4b27-bbce-40bc744536ff
Lilford, R.
5102134d-1c8d-491a-a8fc-e5b42d1c3009
Halligan, S.
d4660e12-21e6-498c-b52c-96a3262a914c

Boone, D., Mallett, S., Zhu, S., Yao, G.L., Bell, N., Ghanouni, A., von Wagner, C., Taylor, S.A., Altman, D.G., Lilford, R. and Halligan, S. (2013) Patients' & healthcare professionals' values regarding true- & false-positive diagnosis when colorectal cancer screening by CT colonography: discrete choice experiment. PLoS ONE, 8 (12), e80767. (doi:10.1371/journal.pone.0080767). (PMID:24349014)

Record type: Article

Abstract

Purpose

To establish the relative weighting given by patients and healthcare professionals to gains in diagnostic sensitivity versus loss of specificity when using CT colonography (CTC) for colorectal cancer screening.

Materials and Methods

Following ethical approval and informed consent, 75 patients and 50 healthcare professionals undertook a discrete choice experiment in which they chose between “standard” CTC and “enhanced” CTC that raised diagnostic sensitivity 10% for either cancer or polyps in exchange for varying levels of specificity. We established the relative increase in false-positive diagnoses participants traded for an increase in true-positive diagnoses.

Results

Data from 122 participants were analysed. There were 30 (25%) non-traders for the cancer scenario and 20 (16%) for the polyp scenario. For cancer, the 10% gain in sensitivity was traded up to a median 45% (IQR 25 to >85) drop in specificity, equating to 2250 (IQR 1250 to >4250) additional false-positives per additional true-positive cancer, at 0.2% prevalence. For polyps, the figure was 15% (IQR 7.5 to 55), equating to 6 (IQR 3 to 22) additional false-positives per additional true-positive polyp, at 25% prevalence. Tipping points were significantly higher for patients than professionals for both cancer (85 vs 25, p<0.001) and polyps (55 vs 15, p<0.001). Patients were willing to pay significantly more for increased sensitivity for cancer (p = 0.021).

Conclusion

When screening for colorectal cancer, patients and professionals believe gains in true-positive diagnoses are worth much more than the negative consequences of a corresponding rise in false-positives. Evaluation of screening tests should account for this.

Other
fetchObject.action_uri=info_doi%2F10.1371%2Fjournal.pone.0080767&representation=PDF - Version of Record
Available under License Other.
Download (1MB)

More information

Published date: 9 December 2013
Organisations: Primary Care & Population Sciences

Identifiers

Local EPrints ID: 365040
URI: https://eprints.soton.ac.uk/id/eprint/365040
ISSN: 1932-6203
PURE UUID: 0171ad4a-7762-4693-9479-aa94ce01b549

Catalogue record

Date deposited: 19 May 2014 13:23
Last modified: 18 Jul 2017 02:25

Export record

Altmetrics

Contributors

Author: D. Boone
Author: S. Mallett
Author: S. Zhu
Author: G.L. Yao
Author: N. Bell
Author: A. Ghanouni
Author: C. von Wagner
Author: S.A. Taylor
Author: D.G. Altman
Author: R. Lilford
Author: S. Halligan

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×