Student or educator? Sign up with your school email and get 6 months of Pro free.
Cited by 756

The DOI matches its Crossref record; 11 of the 11 references it cites were found in a registry or an index.

Systematic reviews of evaluations of prognostic variables

Open access
Altman, Douglas G·2001·BMJ

Abstract

This is the last in a series of four articles Prognostic studies include clinical studies of variables predictive of future events as well as epidemiological studies of aetiological risk factors. As multiple similar studies accumulate it becomes increasingly important to identify and evaluate all of the relevant studies to develop a more reliable overall assessment. For prognostic studies this is not straightforward. Box 1 summarises the clinical importance of information on prognostic factors. Many of the issues discussed are also relevant to aetiological studies, especially cohort ones. Some features of prognostic studies lead to particular difficulties for the systematic reviewer. Firstly, in most clinical prognostic studies the outcome of primary interest is the time to an event, often death. Meta-analysis of such studies is rather more difficult than that for binary data or continuous measurements. Secondly, in many contexts the prognostic variable of interest is often one of several prognostic variables. When examining a variable of interest researchers should consider other prognostic variables with which it might be correlated. Thirdly, many prognostic factors are continuous variables, for which researchers use a wide variety of methods of analysis. #### Summary points Systematic reviews are applicable to all types of research design, and studies of prognostic variables are an important additional area where appropriate methodology should be applied Prognostic variables should be evaluated in a representative sample of patients assembled at a common point in the course of their disease—ideally they should all have received the same medical treatment or been in a randomised trial When examined critically, a high proportion of prognostic studies are found to be methodologically poor Meta-analysis of published data is hampered by difficulties in extraction of data and variation in the characteristics of the study and patients The poor quality of the published literature is a strong argument in favour …

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1136/bmj.323.7306.224

Cites

11 of 11 references verified0 citation errors · 0 not checkable

Statistics

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cites

Research works printed but not linked: 28

  1. Altman DG .Systematic reviews of evaluations of prognostic variables. In: Egger M Davey Smith G Altman DG eds.Systematic reviews in health care. Meta-analysis in context 2nd ed. London: BMJ Books, 2001:228–247. · DOI
  2. 10.1053/gast.2000.9302 · DOI · Paper page
  3. Moher, 1999, Assessing the quality of reports of randomised trials: implications for the conduct of meta-analyses., Health Technol Assess, 3, 1, 10.3310/hta3120 · DOI · Paper page
  4. Shea B Dubé C Moher D .Assessing the quality of reports of systematic reviews: the QUOROM statement compared to other tools. In: Egger M Davey Smith G Altman DG eds.Systematic reviews in health care: meta-analysis in context 2nd ed. London: BMJ Books, 2001:122–139. · DOI
  5. Kernan, 1991, A methodological appraisal of research on prognosis after transient ischemic attacks., Stroke, 22, 1108, 10.1161/01.STR.22.9.1108 · DOI
  6. Levine, 1991, When is a prognostic factor useful?: a guide for the perplexed., J Clin Oncol, 9, 348, 10.1200/JCO.1991.9.2.348 · doi:10.1200/jco.1991.9.2.348
  7. 10.1001/jama.1994.03520030076032 · DOI · Paper page
  8. 10.1016/S0003-9993(96)90300-7 · DOI
  9. Marx, 1997, Prognosis of idiopathic membranous nephropathy: a methodologic meta-analysis., Kidney Int, 51, 873, 10.1038/ki.1997.123 · DOI
  10. Low, 1998, Can we predict the prognosis of HIV infection? How to use the findings of a prospective study., Sex Transm Infect, 74, 149, 10.1136/sti.74.2.149 · doi:10.1136/sti.74.2.149
  11. 10.1002/(SICI)1097-0258(20000229)19:4<425::AID-SIM347>3.0.CO;2-J · doi:10.1002/(sici)1097-0258(20000229)19:4<425::aid-sim347>3.0.co;2-j
  12. 10.1038/bjc.1994.192 · DOI · Paper page
  13. 10.1111/j.1471-0528.1998.tb10227.x · DOI · Paper page
  14. 10.1001/jama.284.11.1417 · DOI · Paper page
  15. Cohen, 1983, The cost of dichotomization., Appl Psychol Meas, 7, 249, 10.1177/014662168300700301 · DOI · Paper page
  16. 10.2307/2289060 · DOI
  17. 10.1093/ije/28.1.1 · DOI · Paper page
  18. Stephenson, 1998, Systematic review of hormonal contraception and risk of HIV transmission: when to resist meta-analysis., AIDS, 12, 545, 10.1097/00002030-199806000-00002 · doi:10.1097/00002030-199806000-00002
  19. Wang, 1999, Risk of HIV infection in oral contraceptive pill users: a meta-analysis., J Acquir Immune Defic Syndr, 21, 51, 10.1097/00126334-199905010-00007 · DOI
  20. 10.1016/S0895-4356(97)00155-8 · DOI
  21. 10.1002/(SICI)1097-0258(19981230)17:24<2815::AID-SIM110>3.0.CO;2-8 · DOI
  22. Hunink, 1994, Meta-analysis of failure-time data with adjustment for covariates., Med Decis Making, 14, 59, 10.1177/0272989X9401400108 · DOI
  23. 10.2307/2533438 · DOI
  24. 10.1007/BF00666180 · DOI
  25. 10.1001/archinte.158.19.2101 · DOI · Paper page
  26. 10.1016/S0140-6736(96)90806-5 · DOI · Paper page
  27. 10.1001/jama.279.7.535 · DOI · Paper page
  28. 10.1016/S0304-3959(98)00058-X · DOI · Paper page

Cited by

See all 756

Metadata

Authors
Altman, D. G.
Venue
BMJ
Publisher
BMJ
Published
2001-07-28
Volume
323
Issue
7306
Pages
224-228
ISSN
  • 0007-1447 (ISSN-L)
  • 0959-8138
  • 1468-5833
OpenAlex
W1853602163
Cited by
756
References
11
FWCI
4.94
Type
journal article
Language
en
Open access
green
Licence
www.bmj.com/company/legal-information/terms-conditions/legal-information/tdm-licencepolicy (tdm)

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review

Data sources

Bibliographic data: Semantic Scholar, OpenAlex, Crossref.

Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.