Univariable and multivariable generalised estimating equations analyses of factors associated with the detection rate of anorectal gonorrhoea
| Number of anorectal swabs tested positive for gonorrhoea (%) | Number of anorectal swabs tested negative for gonorrhoea (%) | ORs (95% CI) | P value | Adjusted ORs (95% CI)* | P value | |
| Patients’ characteristics | ||||||
| Age (years) | ||||||
| ≤31 | 161 (12.5) | 1127 (87.5) | 1.6 (1.3 to 2.0) | <0.001 | 1.5 (1.2 to 2.0) | 0.001 |
| >31 | 89 (8.1) | 1015 (91.9) | 1 | Ref | 1 | Ref |
| Condom use in last 12 months | ||||||
| Always | 33 (6.1) | 507 (93.9) | 1 | Ref | 1 | Ref |
| Not always | 217 (11.7) | 1635 (88.3) | 2.0 (1.4 to 3.0) | <0.001 | 1.8 (1.1 to 2.8) | 0.011 |
| No. of partners in last 12 months | ||||||
| ≤5 | 117 (9.1) | 1173 (90.9) | 1 | Ref | 1 | Ref |
| >5 | 133 (12.1) | 969 (87.9) | 1.4 (1.1 to 1.7) | 0.006 | 2.0 (1.4 to 2.8) | <0.001 |
| Self-reported drug use | ||||||
| Never | 153 (9.0) | 1541 (91.0) | 1 | Ref | 1 | Ref |
| Ever | 97 (13.9) | 601 (86.1) | 1.6 (1.3 to 2.0) | <0.001 | 1.5 (1.1 to 2.0) | 0.019 |
| HIV status | ||||||
| Negative | 211 (9.6) | 1977 (90.4) | 1 | Ref | 1 | Ref |
| Positive | 39 (19.1) | 165 (80.9) | 2.2 (1.5 to 3.2) | <0.001 | 2.0 (1.3 to 2.9) | 0.001 |
| Contact of gonorrhoea | ||||||
| No | 219 (9.6) | 2069 (90.4) | 1 | Ref | 1 | Ref |
| Yes | 31 (29.8) | 73 (70.2) | 4.0 (2.3 to 7.0) | <0.001 | 2.9 (1.8 to 4.7) | <0.001 |
| Presence of proctitis | ||||||
| No | 208 (9.3) | 2039 (90.7) | 1 | Ref | 1 | Ref |
| Yes | 42 (29.0) | 103 (71.0) | 4.0 (2.9 to 5.5) | <0.001 | 3.3 (2.3 to 4.8) | <0.001 |
| Oropharyngeal gonorrhoea† | ||||||
| Negative | 153 (7.1) | 2003 (92.9) | 1 | Ref | 1 | Ref |
| Positive | 90 (46.2) | 105 (53.8) | 11.2 (8.3 to 15.2) | <0.001 | 9.4 (6.6 to 13.4) | <0.001 |
| Urethral chlamydia‡ | ||||||
| Negative | 202 (9.2) | 1987 (90.8) | 1 | Ref | 1 | Ref |
| Positive | 27 (22.1) | 95 (77.9) | 2.8 (1.8 to 4.4) | <0.001 | 2.5 (1.5 to 4.1) | <0.001 |
| Clinicians’ sampling technique | – | – | ||||
| Distance of swab inserted from the anal verge (cm) | – | – | 0.9 (0.8 to 1.0) | 0.124 | 0.9 (0.8 to 1.1) | 0.377 |
| Frequency of patient self-collected swabs | – | – | 1.0 (1.0 to 1.0) | 0.705 | 1.0 (1.0 to 1.0) | 0.068 |
| Frequency of clinician-collected swabs without proctoscope | – | – | 1.0 (1.0 to 1.0) | 0.522 | 1.0 (1.0 to 1.1) | 0.054 |
| Frequency of asking patients to relax the anal sphincter | – | – | 1.0 (1.0 to 1.0) | 0.072 | 1.0 (1.0 to 1.0) | 0.825 |
| Frequency of rotating the swab within the anal canal | – | – | 1.0 (1.0 to 1.0) | 0.211 | 1.0 (1.0 to 1.0) | 0.015 |
| Frequency of moistening swab before insertion | – | – | 1.0 (1.0 to 1.0) | 0.002 | 1.0 (1.0 to 1.0) | 0.104 |
*Adjusted for patients' characteristics and all other sampling techniques.
†41 oropharyngeal gonorrhoea tests were not performed.
‡81 urethral chlamydia tests were not performed.