Screening for HIV: US Preventive Services Task Force Recommendation Statement
US Preventive Services Task Force
This guideline focuses on screening for HIV in adolescents, adults and pregnant women1.
At the end of 2009, the number of people with HIV in the United States who were aged 13 years and older was an estimated 1,148,2002, representing a prevalence of 0.45%. In Canada, the number of people with HIV (including AIDS) was an estimated 71,300 in 20113, representing a prevalence of 0.21%. Similarly, the incidence rate in the United States is nearly twice that of Canada (19.0 vs. 9.9 per 100,000 in 20094 5). Although the proportion of undiagnosed cases is higher in Canada than in the United States (25%3 vs. 18%6), over 50% of some populations in the United States are likely to be unaware of their HIV infection7.
The U.S. Preventive Services Task Force (USPSTF) recommends that clinicians screen all adolescents and adults aged 15 to 65 years for HIV infection. Younger adolescents and older adults who are at increased risk should also be screened.
In addition, the USPSTF recommends that clinicians screen all pregnant women for HIV, including those presenting in labour who have not been tested and whose HIV status is unknown.
All sections of this guideline are applicable to the CTFPHC mandate of prevention in primary care.
The target populations for screening are adolescents and adults aged 15 to 65 years, younger adolescents and older adults at increased risk for infection, and pregnant women.
The USPSTF searched Ovid MEDLINE for the period 2004 to June 2012 and the Cochrane Library through the second quarter of 2012, and reviewed reference lists to identify relevant articles published in English. The search for evidence relevant to adults and adolescents resulted in a total of 10,297 abstracts; 876 full-text articles were reviewed for relevance, of which 25 were included in the evidence synthesis. The search for evidence relevant to pregnant women resulted in a total of 1,636 abstracts; 387 full-text articles were reviewed for relevance, of which 38 studies from 43 publications were included in the evidence synthesis.
The USPSTF assigns 1 of 5 letter grades to each recommendation: A, B, C, D, or I8. These grades are based largely on the level of certainty and magnitude of the net benefit associated with providing the service.
The CTFPHC assessed the methodological quality of this guideline using the Appraisal of Guidelines Research & Evaluation (AGREE II) criteria (Table 1).
This guideline scored above 60% on the domains of Scope and Purpose, Rigour of Development, and Editorial Independence; therefore, the CTFPHC has classified it as a high-quality guideline. Concordance among reviewers, as measured through standard deviation (SD) of AGREE II scores, was high (SD < 1.5) for the majority of domains.
|AGREE II domain||Domain score||Standard deviation|
|Scope and purpose||93%||0.8|
|Rigour of development||88%||0.8|
|Clarity of development||90%||0.8|
The scope and purpose of this guideline are clearly outlined, with age-specific recommendations for adolescents and adults and no age limitations for pregnant women. All relevant professional groups were represented in the development process, and public opinion was sought before release. Further, the recommendations are specific, the methods used were rigorous, and there was no concern about editorial independence.
Although the indirect evidence presented in the USPSTF guideline is strong and logical (demonstrating that screening tests can detect HIV and that treatment of identified HIV will improve outcomes), there is no direct evidence on the effectiveness of screening on clinical outcomes.
In addition, the substantially higher prevalence of HIV in the United States relative to Canada makes this guideline of uncertain relevance to Canadian practice.
Canadian practitioners should consider testing those with clinical indicators of HIV or with factors that increase the risk for exposure to HIV infection, focusing on higher-prevalence groups such as men who have sex with men, people who inject drugs and people from HIV-endemic countries3. Although some Canadian jurisdictions9 10 have moved to recommend routine screening in certain settings (e.g., primary and/or emergency care) in response to their local HIV epidemiology, it is important to note that this practice is not yet supported by direct evidence.
In the opinion of the CTFPHC, primary care practitioners in Canada should continue to offer HIV counselling and testing to individuals who may be at increased risk for exposure to HIV, given the potential benefits of timely detection. Pregnant women should continue to be screened for HIV as per existing guidelines11.
The full guideline can be found at uspreventiveservicestaskforce.org.