Author, year of publication, country	Outcome	Outcome prevalence (%)	Intravaginal practice & prevalence (%)	Effect measure of association
Bui et. al, 2018 Cambodia	HPV infection (number of infecting HPV genotypes)	47.0	Intravaginal washing: 90 Intravaginal wiping: 29 Intravaginal insertion: 5.5	Ever performed intravaginal washing: IRR 0.59 [95% CI 0.41 – 0.85], P = 0.005 Often performed intravaginal washing shortly before vaginal sex in lifetime: IRR 0.92 [95% CI 0.85 – 1.01], P = 0.086 Often performed intravaginal washing shortly after vaginal sex in lifetime: IRR 0.88 [95% CI 0.81 – 0.97], P = 0.007 No significant associations for the solution used for intravaginal washing Ever performed intravaginal wiping: IRR 0.82 [95% CI 0.60 – 1.12], P = 0.208 No significant associations for performing intravaginal wiping before/after vaginal sex No significant associations for frequency of intravaginal wiping Ever performed intravaginal insertion: IRR 0.81 [95% CI 0.43 – 1.52]
Bui et. al, 2016 USA	HPV infection (number of infecting HPV DNA types)	48.6	Douching*: 23	Douched in past 6 months & higher number of HPV DNA types: RRR 1.56 [95% CI 1.28 – 1.90], P <0.001 Frequency of douching in the past 6 months (unadjusted analyses): <1 time/month (82 participants): RRR 1.49 [1.09 – 2.05], P=0.013 1 time/month (91 participants): RRR 1.54 [1.14 – 2.09], P=0.005 2-4 times/month (85 participants): RRR 1.63 [1.21 – 2.21], P=0.002 5 or more/month (7 participants): RRR 1.77 [0.71 – 4.42], P= 0.22
Ebrahim et. al, 2016 South Africa	HPV prevalence	76.3	Vaginal insertion practices: 32.1	Vaginal insertion practices & HPV infection: Crude OR: 2.12 (95% CI 1.02 – 4.41), P = 0.045 Adjusted OR: 1.98 [95% CI 0.88 – 4.48], P = 0.099
Esber et. al, 2016 (full publication) Malawi	High-risk HPV infection	22	Intravaginal cleansing: With soap & water: 47 With cotton, cloth or tissue: 94 Intravaginal insertion: 5	Cleansing with soap and water: PR 1.03 [95% CI 0.51 – 2.08] Cleansing with cotton, cloth or tissue: PR 0.73 [95% CI 0.25 – 2.08] Other products: PR 1.96 [95% CI 0.69 – 5.5] IVP frequency and hr-HPV: Any IVP: PR 0.98 [95% CI 0.52 – 1.85] Soap and water: PR 0.48 [95% CI 0.19 – 1.20]
Houlihan et. al, 2014 (full publication) Tanzania	HPV infection	8.4	Intravaginal cleansing: 20.9 Intravaginal insertion: 0.2	Intravaginal cleansing: aOR 2.19 [95% CI 1.09 – 4.39] Dose-response relationship between cleansing frequency and HPV DNA detection: aOR 1.54 [95% CI 1.17 – 2.03]
Lee et. al, 2014 South Korea	HPV infection	7.9	Douching: 92.5	Douching: Every other day or more: OR 0.32 [95% CI 0.13 – 0.77] 1 – 2 times/month: OR 1.79 [95% CI 0.13 – 24.38]
Moscicki et. al, 2013 USA	HPV16 DNA redetection on cervical sample	18.1 redetection within 8.5 years	Douching: Not reported	Association of douching with redetection of human papillomavirus Type 16 (HPV16) DNA Among Women who had evidence of HPV16 DNA infection and clearance: aOR 2.35 [95% CI 1.02 – 5.41]
Seay et. al, 2017 (full publication) Haiti	High-risk HPV infection	11	Douching: 97.1	Douching with pigeon pea infusion & high-risk HPV: aOR 5.01 [95% CI 1.56 – 16.05]
Shaw et. al, 2016 Brazil	HPV 1-year period prevalence; transient HPV infection, persistent HPV infection	39.3	Douching: Not reported	Douching frequent vs. infrequent & Subgenus 2 (carcinogenic) HPV: OR 1.29 [95% CI 0.83 – 2.00] Douching frequent vs. infrequent: OR 1.10 [95% CI 0.60 – 2.00] for transient infection, 1.12 [95% CI 0.62 – 2.01] for persistent infection No association for substance used (Natural/Medical/Unknown)
Sun et. al, 2005 Taiwan	HPV prevalence	68.5	Douching: 64.7	Frequent vaginal douching: OR 1.48 [95% CI 1.12 – 1.97] With tap water OR 1.426 [95% CI 1.08 – 1.89] With normal saline or detergent OR 2.230 [95% CI 1.08 – 4.61] Vaginal douche after sexual intercourse: aOR 1.48 [95% CI 1.12 – 1.97]
Tarkowski et. al, 2004 USA	HPV infection	64	Douching: 41.3	Douching during the last 90 days: aOR 2.1 [95% CI 1.2 – 3.6] Douching frequency during the last 90 days 0: OR 1.6 [95% CI 0.9 – 3.1] 1 or 2: OR 2.6 [95% CI 1.4 – 5.0] 3 or more: OR 5.2 [95% CI 2.4 – 11.2]