Abstract
Introduction
In the United Kingdom, rates of virological suppression on antiretroviral therapy (ART) are very high, but there remain a small but significant number of people on ART with detectable viraemia. The impact of socio-economic factors on virological suppression has been little studied.
Materials and Methods
We used data from ASTRA, a cross-sectional, questionnaire study of >3000 individuals from 8 clinics in the United Kingdom in 2011–2012, linked to clinical records to address this question. Included participants had received ART for >6 months with a recorded current viral load (VL) (latest at the time of questionnaire). Participants provided data on demographic factors: gender, sexual orientation, ethnicity and age; and socio-economic factors: UK birth/English reading ability, employment, housing, education and financial hardship. To assess non-adherence, participants were asked if in the past 3 months, they had missed ART for ≥2 days at a time. Virological suppression was defined as VL≤50 cps/mL. For each socio-economic factor, we calculated prevalence ratios using modified Poisson regression, first adjusting for demographic factors, then also for non-adherence.
Results
A total of 2445 people fulfilled the inclusion criteria (80% male, 69% MSM, median age: 46 years, median CD4 count: 556 cells/mm3); 10% (234/2445) had VL>50 cps/mL. After adjusting for demographic factors, non-fluent English, not being employed, not home owning, education below university level and increasing financial hardship were each associated with higher prevalence of VL>50 cps/mL. Additional adjustment for non-adherence largely attenuated each association, but did not fully explain them (see Table 1). After adjustment for non-adherence and demographic factors, younger age was also associated with VL>50 cps/mL: for each additional 10 years an individual was 0.80 (95% CI 0.70–0.92) times as likely to have VL>50 cps/mL (p=0.0019). Adjusted prevalence ratios for VL>50cps/mL were 0.91 (0.62–1.34) for women and 1.25 (0.85–1.84) for non-MSM men versus MSM, and 1.29 (0.92–1.80) for white versus non-white people.
Conclusions
Among people on ART in the United Kingdom, the proportion with detectable VL is low. Poorer socio-economic status is associated with increased probability of virological non-suppression. It is likely that much of this association is mediated through difficulties in taking ART. Emphasis should be put on aiding the adherence of people in these higher risk groups.
Table 1.
Association between socio-economic factors and having VL > 50 copies/mL
| VL > 50 copies/mL | Adjusted for demographic factorsa | Adjusted for demographic factors and non-adherenceb | |||||
|---|---|---|---|---|---|---|---|
| Socio-economic factors | N (%) | p | Prevalence Ratio (95% CI) | p | Prevalence Ratio (95% CI) | p | |
| Overall | 234/2445 (10%) | ||||||
| English reading ability | Born in the UK | 114/1337 (9%) | 0.0021~ | 1.00 | 0.0389 | 1.00 | 0.3058 |
| Fluent | 73/841 (9%) | 0.75 (0.54, 1.05) | 0.85 (0.62, 1.17) | ||||
| Not fluent | 34/185 (18%) | 1.28 (0.79, 2.05) | 1.18 (0.73, 1.89) | ||||
| Employed | Yes | 95/1316 (7%) | <.0001 | 1.00 | <.0001 | 1.00 | 0.0057 |
| No | 139/1129 (12%) | 1.80 (1.39, 2.34) | 1.44 (1.11, 1.87) | ||||
| Homeowner | Yes | 44/861 (5%) | <.0001 | 1.00 | <.0001 | 1.00 | 0.0007 |
| No | 181/1537 (12%) | 2.07 (1.48, 2.91) | 1.74 (1.23, 2.45) | ||||
| University | Yes | 72/986 (7%) | 0.0051 | 1.00 | 0.0011 | 1.00 | 0.0214 |
| No | 149/1390 (11%) | 1.55 (1.18, 2.04) | 1.36 (1.04, 1.78) | ||||
| Enough money for basic needs? | Always | 66/1050 (6%) | <.0001~ | 1.00 | 0.0001 | 1.00 | 0.0224 |
| Mostly | 66/626 (11%) | 1.68 (1.20, 2.34) | 1.46 (1.05, 2.03) | ||||
| Sometimes | 48/423 (11%) | 1.71 (1.18, 2.50) | 1.29 (0.88, 1.89) | ||||
| No | 45/298 (15%) | 2.32 (1.60, 3.37) | 1.77 (1.21, 2.59) |
Adjusted for age, gender, sexual orientation and ethnicity
adjusted for demographics and ART non-adherence – self-reported ever missed ≥2 days.
Test for trend.