Abstract：
In 2014, Ontario\'s Point-of-Care (POC) test providers were advised to focus efforts on provincially defined priority populations who experience a greater risk of HIV. Our objective was to describe the POC program before, during and after this change, including tester characteristics, follow-up testing results, positive predictive value (PPV) over time, and trends and characteristics of those with reactive test results without a confirmatory serological specimen.
Test-level data of POC screening and confirmatory results were extracted from the Public Health Ontario HIV Datamart. Final test results were defined based on results of the confirmatory blood sample, or the POC test for \"non-reactive\" tests. Testing volumes, percent of total tests, percent positivity and PPV were calculated overall, annually, and by exposure group.
Overall testing volumes decreased by 39.8% between 2014 and 2018. The majority of confirmed positive tests were in the men who have sex with men (MSM) exposure category, followed by HIV-endemic and heterosexual - no identified risk (heterosexual-NIR). Overall percent positivity decreased from 0.59% in 2011 to 0.42% in 2015 (change of 0.17%, 95% CI 0.03% to 0.31%), increasing to 0.69% in 2018 (change of 0.27%, 95% CI 0.20% to 0.34%). Increases in percent positivity corresponded with a decrease in the overall proportion of tests conducted in low-risk populations. When compared to the heterosexual-NIR category, PPV was significantly higher for men who have sex with men - people who use injection drugs (MSM-PWID) (52.7% compared to 100%, P < .001), MSM (52.7% compared to 95.4%, P < .001), HIV-endemic (52.7% compared to 91.5%, P < .001), heterosexual - partner with identified risk (heterosexual-PIR) (52.7% compared to 77.3%, P = .042), and people who use injection drugs (PWID) (52.7% compared to 81.3%, P = 0.007). A total of 13.5% of reactive POC results did not have a serological sample submitted.
Targeted testing towards populations at higher risk of HIV improved the overall test performance characteristics of Ontario\'s POC testing program. While not unexpected, the large discrepancies between PPV in higher-risk, compared to lower-risk populations, suggests the need for greater awareness and messaging of the likelihood of false positive test results in different populations.
Test-level data of POC screening and confirmatory results were extracted from the Public Health Ontario HIV Datamart. Final test results were defined based on results of the confirmatory blood sample, or the POC test for \"non-reactive\" tests. Testing volumes, percent of total tests, percent positivity and PPV were calculated overall, annually, and by exposure group.
Overall testing volumes decreased by 39.8% between 2014 and 2018. The majority of confirmed positive tests were in the men who have sex with men (MSM) exposure category, followed by HIV-endemic and heterosexual - no identified risk (heterosexual-NIR). Overall percent positivity decreased from 0.59% in 2011 to 0.42% in 2015 (change of 0.17%, 95% CI 0.03% to 0.31%), increasing to 0.69% in 2018 (change of 0.27%, 95% CI 0.20% to 0.34%). Increases in percent positivity corresponded with a decrease in the overall proportion of tests conducted in low-risk populations. When compared to the heterosexual-NIR category, PPV was significantly higher for men who have sex with men - people who use injection drugs (MSM-PWID) (52.7% compared to 100%, P < .001), MSM (52.7% compared to 95.4%, P < .001), HIV-endemic (52.7% compared to 91.5%, P < .001), heterosexual - partner with identified risk (heterosexual-PIR) (52.7% compared to 77.3%, P = .042), and people who use injection drugs (PWID) (52.7% compared to 81.3%, P = 0.007). A total of 13.5% of reactive POC results did not have a serological sample submitted.
Targeted testing towards populations at higher risk of HIV improved the overall test performance characteristics of Ontario\'s POC testing program. While not unexpected, the large discrepancies between PPV in higher-risk, compared to lower-risk populations, suggests the need for greater awareness and messaging of the likelihood of false positive test results in different populations.
摘要：
目标：2014年，安大略省的医疗点（POC）测试提供者被建议将工作重点放在经历艾滋病毒风险更大的省级定义的优先人群上。我们的目标是描述之前的POC计划，在这种变化期间和之后，包括测试仪特性，后续测试结果，随着时间的推移，阳性预测值(PPV)，以及没有确认血清学标本的反应性测试结果的趋势和特征。
方法：POC筛查和确认结果的测试水平数据是从安大略省公共卫生HIVDatamart中提取的。最终测试结果是根据确认血液样本的结果定义的，或“非反应性”测试的POC测试。测试卷,占总测试的百分比，总体计算阳性百分比和PPV，每年,和曝光组。
结果：2014年至2018年，总体测试量下降了39.8%。大多数确认的阳性测试是在男男性行为者（MSM）暴露类别中，其次是HIV-地方性和异性恋-没有确定的风险（异性恋-NIR）。总体阳性百分比从2011年的0.59%下降到2015年的0.42%(变化为0.17%，95%CI0.03%至0.31%），2018年增至0.69%（变动0.27%，95%CI0.20%至0.34%）。阳性百分比的增加与在低风险人群中进行的测试的总体比例的减少相对应。与异性恋NIR类别相比，与男性发生性关系的男性的PPV明显更高-使用注射药物（MSM-PWID）的人（52.7％与100％相比，P<.001),MSM（52.7%与95.4%相比，P<.001),艾滋病毒流行(52.7%，91.5%，P<.001),异性恋-具有确定风险的伴侣（异性恋-PIR）（52.7％与77.3％相比，P=.042），和使用注射药物（PWID）的人（52.7％，而81.3％，P=0.007)。总共有13.5％的反应性POC结果没有提交的血清学样本。
结论：针对HIV风险较高人群的针对性测试改善了安大略省POC测试计划的整体测试性能特征。虽然并不意外，高风险PPV之间的巨大差异，与低风险人群相比，建议需要提高对不同人群假阳性测试结果可能性的认识和信息传递。
方法：POC筛查和确认结果的测试水平数据是从安大略省公共卫生HIVDatamart中提取的。最终测试结果是根据确认血液样本的结果定义的，或“非反应性”测试的POC测试。测试卷,占总测试的百分比，总体计算阳性百分比和PPV，每年,和曝光组。
结果：2014年至2018年，总体测试量下降了39.8%。大多数确认的阳性测试是在男男性行为者（MSM）暴露类别中，其次是HIV-地方性和异性恋-没有确定的风险（异性恋-NIR）。总体阳性百分比从2011年的0.59%下降到2015年的0.42%(变化为0.17%，95%CI0.03%至0.31%），2018年增至0.69%（变动0.27%，95%CI0.20%至0.34%）。阳性百分比的增加与在低风险人群中进行的测试的总体比例的减少相对应。与异性恋NIR类别相比，与男性发生性关系的男性的PPV明显更高-使用注射药物（MSM-PWID）的人（52.7％与100％相比，P<.001),MSM（52.7%与95.4%相比，P<.001),艾滋病毒流行(52.7%，91.5%，P<.001),异性恋-具有确定风险的伴侣（异性恋-PIR）（52.7％与77.3％相比，P=.042），和使用注射药物（PWID）的人（52.7％，而81.3％，P=0.007)。总共有13.5％的反应性POC结果没有提交的血清学样本。
结论：针对HIV风险较高人群的针对性测试改善了安大略省POC测试计划的整体测试性能特征。虽然并不意外，高风险PPV之间的巨大差异，与低风险人群相比，建议需要提高对不同人群假阳性测试结果可能性的认识和信息传递。
