Table 2

Characteristics of 150 men who have sex with men in the syndemic-based intervention (syn.bas.in) study at the STI outpatient clinic in Amsterdam, 2017–2018

InterventionControlP value
Self-reported help-seeking behaviour
 mITT analysis30/74 (41%)22/76 (29%)0.136
 PP analysis29/69 (42%)20/72 (28%)0.076
Confirmed help-seeking behaviour*
 mITT analysis20/72 (28%)16/72 (22%)0.441
 PP analysis19/67 (28%)14/68 (21%)0.294
STI rates (n/100 person-years)
 Chlamydia any site47.3 (33.7 to 66.4)46.3 (33.1 to 64.6)0.926
 Pharyngeal4.9 (1.9 to 13.2)1.2 (0.2 to 8.5)0.204
 Urethral13.5 (7.1 to 25.6)21.5 (12.7 to 36.2)0.269
 Anorectal33.3 (21.0 to 52.8)30.3 (19.2 to 47.9)0.777
 Of which LGV3.7 (1.2 to 11.5)6.0 (2.5 to 14.3)0.515
 Gonorrhoea any site59.2 (44.6 to 78.6)52.4 (39.0 to 70.5)0.559
 Pharyngeal23.4 (15.0 to 36.8)20.2 (12.6 to 32.6)0.662
 Urethral9.9 (5.0 to 20.4)11.9 (6.2 to 22.9)0.711
 Anorectal48.2 (34.8 to 66.8)44.1 (31.6 to 61.6)0.709
 Syphilis (recent, stadium 1 or 2)6.2 (2.6 to 14.8)13.1 (7.3 to 23.7)0.163
 HIV00/
 Hepatitis C01.2 (0.2 to 8.4)0.995
 Any bacterial STI105.1 (72.6 to 137.3)104.9 (83.9 to 131.2)0.991
  • *Unable to obtain six for whom informed consent was not obtained, two in the intervention group and four in the control group.

  • LGV, lymphogranuloma venereum; ; mITT, modified intention-to-treat; PP, per-protocol.