PROJECT METHODOLOGY 3

Health Evidence Bulletins - Wales (logo)

Protocol Enhancement Project: Reference page for Critical Appraisal Teams [6‘98]

Statements should include a brief summary of the supporting evidence including, where possible:

Table 1: Strength of the finding (Health Gain Notation)
‘beneficial’ - effectiveness clearly demonstrated (1)
‘likely to be beneficial’ - effectiveness not so firmly established (2)
‘trade-off between beneficial and adverse effects’ - effects weighed according to individual circumstances(3)
‘unknown’ - insufficient/inadequate for recommendation (4)
‘unlikely to be beneficial’ - ineffectiveness is not as clearly demonstrated as for 6 (5)
‘likely to be ineffective or harmful’ - ineffectiveness or harm clearly demonstrated (6)
(adapted from Enkin M, Kierse MJNC, Renfrew M and Neilson J. A guide to effective care in pregnancy and childbirth. 2nd ed. Oxford: Oxford University Press, 1995)

Evidence should be cited:

Table 2: Guidance on Vancouver System
Standard periodical article

You C H, Lee K Y, Chey R Y, Menguy R. Electrogastrographic study of patients with unexplained nausea, bloating and vomiting - Gastroenterology 1980; 79: 311-4.
(NB List all authors when six or less; when seven or more, list only first three and add et al)
Book or monograph
Eisen H N. Immunology: an introduction to molecular and cellular principles of the immune response. 5th ed. New York: Harper and Row, 1974: 406.
Published proceedings
DuPont B. Bone marrow transplantation in severe combined immuno-deficiency with an unrelated MLC compatible donor. In: White H J, Smith R, eds. Proceedings of the third annual meeting of the International Society for Experimental Hematology. Houston: International Society for Experimental Hematology, 1974:44-6.

Table 3: Type of evidence
‘Type I evidence’ - at least one good systematic review (including at least one randomised controlled trial).
‘Type II evidence’ - at least one good randomised controlled trial
‘Type III evidence’ - well designed other trials
‘Type IV evidence’ - well designed non-experimental studies
‘Type V evidence’ - expert opinion

Example:

The Statements The Evidence
1.8c. Proactive telephone counselling of known smokers for smoking cessation is likely to have a small positive effect (odds ratio at 12 to 18 months follow up 1.20 [95% CI: 1.06, 1.37])i.
(Health gain notation - 2 "likely to be beneficial")
i. Liechtenstein E, Glasgow RE, Lando HA, Ossip-Klein DJ. Telephone counseling for smoking cessation: rationales and meta-analytic review of the evidence. Health Education Research1996;11:243-57
(Type I evidence – meta-analysis of systematic review of 13 randomised controlled trials, nine included in the final pooled odds ratio after testing for homogeneity)

Methodology Home Top