HIV Incidence Risk Index for MSM (HIRI-MSM)
Validated risk score identifying HIV-negative men who have sex with men (MSM) at highest risk for HIV acquisition who would benefit most from pre-exposure prophylaxis (PrEP). Derived from the EXPLORE cohort. Score 0–45; score ≥11 indicates high risk warranting PrEP discussion.
Score interpretation
HIRI-MSM <11 — lower HIV acquisition risk
→ HIV and STI testing every 6–12 months; safer sex counselling; condom promotion; advise on symptoms of acute HIV seroconversion; reassess risk annually or with change in behaviour
HIRI-MSM 11–20 — significant HIV risk; PrEP warranted
→ Offer HIV PrEP (tenofovir/emtricitabine daily or event-driven 2-1-1 regimen); confirm HIV-negative status before starting; baseline renal function, Hepatitis B serology; STI screen; 3-monthly HIV and STI testing on PrEP; condom use for STI prevention; assess adherence at every visit
HIRI-MSM ≥21 — high HIV acquisition risk
→ Strongly recommend PrEP; ensure HIV test negative; baseline: renal function (eGFR), Hep B status, Hep C antibody, STI screen, HbA1c if indicated; daily tenofovir/emtricitabine (or 2-1-1 for event-driven use); 3-monthly follow-up with HIV, STI, renal monitoring; PEP awareness if potential exposure; harm reduction for substance use
Interpretation bands for the HIRI-MSM. Apply clinical judgement and local guidance.
References
- Smith DK et al. Vital Signs: Estimated Percentages and Numbers of Adults with Indications for Preexposure Prophylaxis to Prevent HIV Acquisition — United States, 2015. MMWR. 2015;64(46):1291–1295.
- Menza TW et al. Predicting human immunodeficiency virus acquisition among men who have sex with men. Sex Transm Dis. 2009;36(9):547–555.
Related
Curated clinical cross-links plus same-class fallbacks.
- Propranolol (Migraine Prevention) · Beta-Blocker — Migraine Prophylaxis
- Aspirin (Low-Dose — Pre-eclampsia Prevention) · Antiplatelet — Pre-eclampsia Prophylaxis
- Palivizumab · RSV Prophylaxis — Monthly Monoclonal Antibody (High-Risk Infants)
- Thiamine (IV/IM — Pabrinex) · Vitamin B1 (Thiamine) — deficiency treatment / Wernicke's encephalopathy prevention
- Ketoconazole (Adrenal Indication) · Adrenal Steroidogenesis Inhibitor (Antifungal with Adrenal Suppressing Properties)
- Doxycycline 100mg Capsules (Sinusitis — Penicillin Allergy) · Tetracycline antibiotic
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.