BHIVA: Rapid, community-based HIV antibody testing 'highly acceptable' (corrected)

The first analysis of the impact of a pilot scheme of community-based rapid HIV antibody testing services in England has found them to be highly acceptable to users - many of whom had never previously tested - expanding choice and increasing capacity. However, the study, presented to last week's British HIV Association (BHIVA) conference in London, also found that establishing community-based rapid testing sites is expensive and that they do not appear to diagnose people any earlier in their disease than standard sexual health clinics.

In order to increase uptake of HIV testing services - and to alleviate some of the burden on sexual health services, which have significant waiting-times despite government targets to improve them - Europe's largest sexual health charity, Terrence Higgins Trust (THT), has set up a series of community-based HIV and other sexually transmitted infection (STI) screening services, many of which provide HIV antibody results within one hour.

Peter Weatherburn, Director of Sigma Research, who characterised the United Kingdom as “not an HIV testing culture”, presented data on behalf of the FasTest study group regarding the feasibility, cost, acceptability and efficiency of a pilot community-based rapid HIV antibody testing scheme.

The study focused on six community-based sites in England that provided rapid (one-hour) HIV antibody testing between October 2004 and December 2005. Three were outside London - at THT offices in Brighton, Bristol and Leeds. Another three were based in London – two at THT Lighthouse facilities in south central and north west London and one at a public sports and leisure centre in south east London.

Rapid HIV antibody testing was provided free, on a no appointment, 'first come, first served' basis one evening per week. Clinical services were provided by NHS staff using Abbott Laboratories' Determine HIV-1/2 antibody testing kit.

A 2004 study found that sensitivity of this test - the ability to detect all true positive results - was 100%, and the test's specificity - the number of negative tests correctly identified as negative - was 99.9%. However, according to the most recent guidance from the British Association for Sexual Health and HIV (BASHH) this test detects HIV antibodies about three days later than the most sensitive standard ELISA test. In addition, as with all rapid antibody tests, there is the possibility of an occasional false positive result. Consequently, all positive results were confirmed by standard ELISA testing.

There were three elements to the evaluation: monitoring of service provision and follow-up through sexual health and HIV clinics; a self-complete questionnaire; and a follow-up telephone interview for people who subsequently tested HIV antibody positive.

During the evaluation period there were 192 FasTest sessions, utilising 1278 clinical staff hours and resulting in 1721 HIV tests. This resulted in one HIV antibody test for every 45 minutes of clinical staff time.

Who used the community-based sites?

A total of 102 different countries of birth were represented in the sample (n=1564) that filled-in the four-page questionnaire, resulting in a 91% response rate. Just over 60% were born in the UK; 13% were born in another other European country; and further 12% were African-born.

Just over half (51%) were gay men, the vast majority of whom were of white ethnicity, and whose average age was 31 years. Although all of the respondents were generally well educated, the gay men were the least well educated of the sample.

Another quarter (27%) of respondents were heterosexual men, of whom 60% were white, 20% were of black African ethnicity and the remainder were other ethnic minorities. Their average age was 30 years.

A further 21% were heterosexual women, of whom about half were black African, black Caribbean or other ethnic minorities. Their average age was 27 years.

Although 1% of those utilising the community testing sites were lesbian or bisexual women, no demographic data were presented, and the remaining presentation focused on the gay men and heterosexual men and women.

Previous testing and risk-taking

One-in-four (26%) of the gay men who used a community-based HIV antibody testing site had not previously undergone HIV antibody testing, despite many admitting high levels of HIV risk. In the year before testing, 28% of gay men had had sex with at least thirteen male partners; 71% had had unprotected anal intercourse (UAI ) with another man; and 25% had had sex with a man they knew to be HIV-positive.

Almost half (48%) of the heterosexual males had not previously undergone HIV antibody testing. In the year before testing, 14% of heterosexual males had five or more female partners; 4% had had sex with another man, half of whom had UAI; and 80% had had unprotected intercourse (UI) with a woman. None had had sex with someone they knew to be HIV-positive.

Just under half (46%) of the heterosexual females had not previously undergone HIV antibody testing. In the year before testing, 9% of heterosexual females had had five or more male partners; 83% had had UI, and 5% had had sex with a man they knew to be HIV-positive.

Why choose community-based testing?

More than half (52%) chose community-based HIV antibody testing because the test result was available at the same visit.

One-in-three (32%) said that it was more convenient than attending a sexual health clinic.

More than one-in-six (16%) said they had experienced difficulty making an appointment at a sexual health clinic.

And more than one-in-eight (12%) said that they did not know where else to take an HIV antibody test.

HIV antibody test results

In total, 3% (43 out of the 1453) of individuals who had completed the questionnaire, were not repeat testers, and had not previously tested HIV antibody positive, received a positive result.

Of these 43, 22 (51%) had never taken an HIV antibody test before. Another 16 (37%) had tested HIV antibody negative more than a year ago. The remaining five (12%) had tested HIV antibody negative in the year prior to accessing community-based screening.

However, only 38 (88%) of the 43 positive rapid tests were able to be confirmed by standard ELISA tests because FasTest staff were unable to obtain blood samples from five individuals given a positive result.

In addition to these 43 positive results, there was one additional false-positive out of the 1721 HIV antibody tests taken (0.06%), which was likely due to infection with another virus at the time of testing.

Evaluation

The study concluded by noting that although community-based HIV testing is feasible, the sites are not easy to establish, maintain or fund. In addition, although each Determine kit costs just £12, it was estimated that the cost of providing each test was £135 (range £85-175 depending on the volume of users attending the site). However, this did include substantial one-off set-up costs. More data are needed, noted Mr Weatherburn, especially when it comes to a comparative analysis with the cost of traditional HIV testing interventions in sexual health, primary care and antenatal services.

Nevertheless, the service was found to be "highly acceptable" to users. In particular, the one-hour rapid service and the convenience of the location and/or opening times were considered to be a very welcome additional option to establish HIV status.

Although comparisons with standard sexual health clinics showed no evidence that community-based testing sites diagnose people any earlier in their disease history, these sites do expand choice and increase capacity, concluded Mr Weatherburn, and will continue to do so as long as they are funded and do not replace pre-existing HIV testing services.

Comparisons between community- and clinic-based testing

Data collection is ongoing for comparisons between three community-based screening sites and their sexual health clinic counterparts.

Specific data were provided in this presentation comparing the 278 gay men who used the THT FasTest site in central Brighton with 191 gay men who accessed HIV antibody testing at the city's sexual health clinic, the Claude Nichol Centre at Brighton and Sussex University Hospital, about a mile away.

Although there were no significant differences regarding risk behaviour, the men using the THT site were significantly younger (33 vs. 34 years; p<0.016) and were less likely to have previously taken an HIV test (14.7% vs. 23.7%; p<0.018) than the men using the sexual health clinic.

Although the men who used THT's testing site were more likely to expect a positive result (6.8% vs. 2.7%), only 9/280 (3.2%) received a positive result compared with 17/187 (9.1%) at the sexual health clinic (p<0.009).

Note

A full listing of sites that currently provide rapid HIV testing services is available at THT's FasTest website as well as the youchoose website, the latter aimed exclusively at gay men.