Research and Reporting Methods
14 June 2022

QUAPAS: An Adaptation of the QUADAS-2 Tool to Assess Prognostic Accuracy Studies

Publication: Annals of Internal Medicine
Volume 175, Number 7


Whereas diagnostic tests help detect the cause of signs and symptoms, prognostic tests assist in evaluating the probable course of the disease and future outcome. Studies to evaluate prognostic tests are longitudinal, which introduces sources of bias different from those for diagnostic accuracy studies. At present, systematic reviews of prognostic tests often use the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2) tool to assess risk of bias and applicability of included studies because no equivalent instrument exists for prognostic accuracy studies.
QUAPAS (Quality Assessment of Prognostic Accuracy Studies) is an adaptation of QUADAS-2 for prognostic accuracy studies. Questions likely to identify bias were evaluated in parallel and collated from QUIPS (Quality in Prognosis Studies) and PROBAST (Prediction Model Risk of Bias Assessment Tool) and paired to the corresponding question (or domain) in QUADAS-2. A steering group conducted and reviewed 3 rounds of modifications before arriving at the final set of domains and signaling questions.
QUAPAS follows the same steps as QUADAS-2: Specify the review question, tailor the tool, draw a flow diagram, judge risk of bias, and identify applicability concerns. Risk of bias is judged across the following 5 domains: participants, index test, outcome, flow and timing, and analysis. Signaling questions assist the final judgment for each domain. Applicability concerns are assessed for the first 4 domains.
The authors used QUAPAS in parallel with QUADAS-2 and QUIPS in a systematic review of prognostic accuracy studies. QUAPAS improved the assessment of the flow and timing domain and flagged a study at risk of bias in the new analysis domain. Judgment of risk of bias in the analysis domain was challenging because of sparse reporting of statistical methods.

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Information & Authors


Published In

cover image Annals of Internal Medicine
Annals of Internal Medicine
Volume 175Number 7July 2022
Pages: 1010 - 1018


Published online: 14 June 2022
Published in issue: July 2022




Department of Epidemiology and Data Science, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands (J.L., M.L., P.M.B.)
Frits Mulder, MD
Department of Vascular Medicine, Cardiovascular Sciences, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands (F.M.)
Mariska Leeflang, DVM, PhD
Department of Epidemiology and Data Science, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands (J.L., M.L., P.M.B.)
Kleijnen Systematic Reviews, Escrick, United Kingdom (R.W.)
Bristol Medical School, University of Bristol, Bristol, United Kingdom (P.W.).
Department of Epidemiology and Data Science, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, the Netherlands (J.L., M.L., P.M.B.)
Acknowledgment: The authors thank Jill Hayden, PhD (Dalhousie University, Faculty of Medicine), for her valuable advice in the earlier stages of planning the development of QUAPAS. They further thank the volunteers for reviewing the tool.
Corresponding Author: Jenny Lee, MSc, Epidemiology and Data Science, Amsterdam UMC, Location AMC, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands; e-mail, [email protected].
Author Contributions: Conception and design: P.M. Bossuyt, J. Lee, M. Leeflang.
Analysis and interpretation of the data: P.M. Bossuyt, J. Lee, M. Leeflang, F. Mulder, R. Wolff.
Drafting of the article: J. Lee.
Critical revision for important intellectual content: P.M. Bossuyt, J. Lee, M. Leeflang, F. Mulder, P. Whiting, R. Wolff.
Final approval of the article: P.M. Bossuyt, J. Lee, M. Leeflang, F. Mulder, P. Whiting, R. Wolff.
Statistical expertise: P.M. Bossuyt, J. Lee, F. Mulder.
Obtaining of funding: P.M. Bossuyt.
Administrative, technical, or logistic support: J. Lee.
Collection and assembly of data: J. Lee, F. Mulder.
This article was published at on 14 June 2022.

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Jenny Lee, Frits Mulder, Mariska Leeflang, et al. QUAPAS: An Adaptation of the QUADAS-2 Tool to Assess Prognostic Accuracy Studies. Ann Intern Med.2022;175:1010-1018. [Epub 14 June 2022]. doi:10.7326/M22-0276

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