Consistently estimating absolute risk difference when translating evidence to jurisdictions of interest

Journal Article


Abstract


  • Economic analysis and assessment of net clinical benefit often requires

    estimation of absolute risk difference (ARD) for binary outcomes (e.g. survival,

    response, disease progression) given baseline epidemiological risk in a

    jurisdiction of interest and trial evidence of treatment effects. Typically, the

    assumption is made that relative treatment effects are constant across baseline

    risk, in which case relative risk (RR) or odds ratios (OR) could be applied

    to estimate ARD. The objective of this article is to establish whether such use

    of RR or OR allows consistent estimates of ARD.

    ARD is calculated from alternative framing of effects (e.g. mortality vs

    survival) applying standard methods for translating evidence with RR and

    OR. For RR, the RR is applied to baseline risk in the jurisdiction to estimate

    treatment risk; for OR, the baseline risk is converted to odds, the OR applied

    and the resulting treatment odds converted back to risk.

    ARD is shown to be consistently estimated with OR but changes with

    framing of effects using RR wherever there is a treatment effect and epidemiological

    risk differs from trial risk. Additionally, in indirect comparisons,

    ARD is shown to be consistently estimated with OR, while calculation with

    RR allows inconsistency, with alternative framing of effects in the direction,

    let alone the extent, of ARD.

    OR ensures consistent calculation of ARD in translating evidence from

    trial settings and across trials in direct and indirect comparisons, avoiding

    inconsistencies from RR with alternative outcome framing and associated

    biases. These findings are critical for consistently translating evidence to inform

    economic analysis and assessment of net clinical benefit, as translation

    of evidence is proposed precisely where the advantages of OR over RR arise.

Authors


  •   Eckermann, Simon
  •   Willan, Andrew R. (external author)
  •   Coory, M (external author)

Publication Date


  • 2011

Citation


  • S. Eckermann, A. Willan & M. Coory, "Consistently estimating absolute risk difference when translating evidence to jurisdictions of interest", PharmacoEconomics 29 2 (2011) 87-96.

Scopus Eid


  • 2-s2.0-78751605031

Ro Metadata Url


  • http://ro.uow.edu.au/gsbpapers/169

Number Of Pages


  • 9

Start Page


  • 87

End Page


  • 96

Volume


  • 29

Issue


  • 2

Place Of Publication


  • http://search.proquest.com.ezproxy.uow.edu.au/docview/840746031/fulltextPDF/1329952234B31BA16B6/1?accountid=15112

Abstract


  • Economic analysis and assessment of net clinical benefit often requires

    estimation of absolute risk difference (ARD) for binary outcomes (e.g. survival,

    response, disease progression) given baseline epidemiological risk in a

    jurisdiction of interest and trial evidence of treatment effects. Typically, the

    assumption is made that relative treatment effects are constant across baseline

    risk, in which case relative risk (RR) or odds ratios (OR) could be applied

    to estimate ARD. The objective of this article is to establish whether such use

    of RR or OR allows consistent estimates of ARD.

    ARD is calculated from alternative framing of effects (e.g. mortality vs

    survival) applying standard methods for translating evidence with RR and

    OR. For RR, the RR is applied to baseline risk in the jurisdiction to estimate

    treatment risk; for OR, the baseline risk is converted to odds, the OR applied

    and the resulting treatment odds converted back to risk.

    ARD is shown to be consistently estimated with OR but changes with

    framing of effects using RR wherever there is a treatment effect and epidemiological

    risk differs from trial risk. Additionally, in indirect comparisons,

    ARD is shown to be consistently estimated with OR, while calculation with

    RR allows inconsistency, with alternative framing of effects in the direction,

    let alone the extent, of ARD.

    OR ensures consistent calculation of ARD in translating evidence from

    trial settings and across trials in direct and indirect comparisons, avoiding

    inconsistencies from RR with alternative outcome framing and associated

    biases. These findings are critical for consistently translating evidence to inform

    economic analysis and assessment of net clinical benefit, as translation

    of evidence is proposed precisely where the advantages of OR over RR arise.

Authors


  •   Eckermann, Simon
  •   Willan, Andrew R. (external author)
  •   Coory, M (external author)

Publication Date


  • 2011

Citation


  • S. Eckermann, A. Willan & M. Coory, "Consistently estimating absolute risk difference when translating evidence to jurisdictions of interest", PharmacoEconomics 29 2 (2011) 87-96.

Scopus Eid


  • 2-s2.0-78751605031

Ro Metadata Url


  • http://ro.uow.edu.au/gsbpapers/169

Number Of Pages


  • 9

Start Page


  • 87

End Page


  • 96

Volume


  • 29

Issue


  • 2

Place Of Publication


  • http://search.proquest.com.ezproxy.uow.edu.au/docview/840746031/fulltextPDF/1329952234B31BA16B6/1?accountid=15112