Relative reduction of total (urogenital and/or anorectal) chlamydia prevalence of female STI clinic visitors 10 years after introducing universal routine doxycycline treatment or universal routine anorectal testing or both interventions combined compared with continuation of standard of care
| Universal routine doxycycline, % (IQR) | Universal routine anorectal testing, % (IQR) | Both interventions combined, % (IQR) | |
|---|---|---|---|
| Baseline | 4.3 (3.5–5.3) | 8.7 (7.6–9.7) | 9.3 (8.2–10.3) |
| Uncertainty analyses | |||
| Infection parameters | |||
| Anal infection duration doubled (2 years) | 4.3 (3.4–4.8) | 12.5 (11.9– 13.3) | 13.0 (11.9–13.8) |
| Anal infection duration halved (0.5 year) | 4.7 (3.8–5.3) | 6.7 (5.6–7.4) | 7.3 (6.3–8.0) |
| Behavioural parameters | |||
| Higher frequency of anal sex acts (once per week) | 4.3 (3.4–4.9) | 8.3 (7.6–9.1) | 8.8 (8.2–9.7) |
| Lower vaginal sex acts in pairs that also engage in anal sex (same amount of sex acts in both partnerships) | 4.5 (3.9–5.3) | 9.0 (8.1–10.0) | 9.6 (8.8–10.5) |
| Higher fraction of people with recent anal sex (30%) | 2.8 (2.3–3.1) | 5.2 (4.6–5.6) | 5.8 (5.3–6.1) |
| Treatment parameters | |||
| Lower azithromycin effectiveness for anorectal infection (56%) | 9.0 (7.2–11.6) | 13.4 (11.2–16.0) | 14.0 (11.8–16.5) |
| Lower doxycycline effectiveness for anorectal infection (90%) | 2.5 (2.1–2.5) | 6.7 (5.9–7.1) | 7.2 (6.5–7.7) |
| Higher azithromycin and doxycycline efficacy for urogenital infection (96.8% and 100%)10 | 4.6 (3.8–5.5) | 8.9 (7.8–9.7) | 9.5 (8.6–10.4) |
| Other scenarios | |||
| Azithromycin as the standard of care for anorectal infections4 | 7.0 (6.0–8.5) | 11.4 (10.1–12.9) | 12.1 (10.7–13.4) |
| Higher female testing uptake (from 14% to 40% per year) | 4.8 (4.1–5.7) | 9.4 (8.6–10.0) | 10.0 (9.3–10.5) |
| Other data source | |||
| Peters et al (South-African primary care facility data)8 | 3.2 (2.7–3.7) | 5.9 (4.4–7.3) | 7.3 (5.9–8.6) |
| Østergaard et al (Danish STI clinic data)7 | 4.4 (3.6–5.0) | 9.1 (7.6–9.9) | 9.8 (8.5–10.5) |