Please note: In 2003, the CTF updated its Grades of Recommendations to include an "I Recommendation" for situations where insufficient evidence exists to allow a recommendation to be made. (Formerly, these situations were captured under a "C Recommendation".) This change is not retroactive, and all "C Recommendations" made prior to 2003 have not been reevaluated in light of the new "I" recommendation grade. For a discussion of these recommendation grades, please link to the 2003 article in the Canadian Medical Association Journal here.
| MANEUVER | EFFECTIVENESS | LEVEL OF EVIDENCE <REF> | RECOMMENDATION |
| Obtaining history of sexual practices and injection drug use and counselling people in the general population. | Limited sensitivity for identifying HIV-positive people but may be offered for patient education; it is more sensitive than if history were not obtained. | Expert opinion <6,11,12> (III) | Poor evidence to include in or exclude from periodic health examination (PHE) of asymptomatic people. (C) |
| Reduces but does not eliminate high-risk activities in high-risk populations | Cohort studies <16-20,26-33> (II-2) | ||
| Voluntary screening with an enzyme-linked immunosorbent assay (ELISA) and confirmatory test; repeat test after 6 months for seronegative people at high-risk.* | Combination of ELISA and Western blot technique has almost 100% sensitivity and specificity | ||
| High-risk groups:* AIDS development was delayed with early treatment if CD4 count was less than 0.5x109/L; labelling is a problem. | Randomized controlled trials <21,25> (I) | Good evidence to include offer of screening in PHE of asymptomatic people at high risk. (A)* | |
| Pregnant women: Low rate of HIV infection in Canada raises concerns about poor positive predictive value; should be considered in large cities, where rate is highest. | Cohort studies <1-5,7-11> (II-2) | Poor evidence to include in or exclude from PHE of asymptomatic pregnant women. (C) | |
| Infants of HIV- positive women: Risk of vertical transmission is 20-50% but usual screening methods are not sensitive or specific enough. | Cohort studies <13-15> (II-2) | Fair evidence to include in PHE of children of HIV-positive women. (B) | |
| Voluntary screening with an enzyme-linked immunosorbent assay (ELISA) and confirmatory test. | People at low risk: False positive results may outweigh benefit of treating the few seropositive people identified. | Expert opinion (III) | Poor evidence to include in or exclude from PHE of asymptomatic people at low risk. (C) |
* High-risk groups include homosexual and bisexual men, prostitutes, injection drug users, people with sexually transmitted diseases, people receiving blood products between 1978 and 1985, sexual contacts of HIV-positive people and people from countries with a high prevalence rate of HIV infection.
Link to Full Text of this review
Link to Structured Abstract of this review
Link to Selected References list of this review
Reprinted in modified format by the Canadian
Task Force on Preventive Health Care
with permission.
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© 1994 Minister of Supply and Services Canada.
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Last modified March 27, 1998.
