Table 2

Multivariable analysis of possible syphilis symptoms and their association with a diagnosis of infectious syphilis among MSM; Amsterdam Centre for Sexual Health, 2018–2019

CodingSymptoms/risk factorModel A*
aOR (95% CI)		βˆModel B†
aOR (95% CI)		βˆModel C‡
aOR (95% CI)		βˆ
1.mUlcer in the mouthNoRef
Yes3.2 (0.9 to 12.0)1.2
1.sUlcer on the skin§NoRef
Yes0.7 (0.1 to 4.4)−0.3
1.1.pPainless ulcer on the penisNoRef
Yes36.1 (25.2 to 51.6)3.6
1.1.1.aPainless ulcer at the anus with lymph nodes¶NoRefRefRef
Yes63.8 (4.1 to 991.8)4.263.6 (4.1 to 989.3)4.265.4 (4.4 to 981.1)4.2
1.1.1.pPainless ulcer on the penis with lymph nodesNoRefRef
Yes85.8 (36.6 to 201.0)4.585.7 (36.6 to 200.6)4.5
1.1.2.aPainless ulcer at the anus without lymph nodesNoRef
Yes1.4 (0.3 to 6.5)0.4
1.1.2.pPainless ulcer on the penis without lymph nodesNoRefRef
Yes29.1 (19.5 to 43.4)3.730.0 (20.2 to 44.7)3.4
1.2.pPainful ulcer on the penisNoRef
Yes21.7 (14.2 to 33.2)3.1
1.2.1.aPainful ulcer at the anus with lymph nodesNoRef
Yes1.5 (0.2 to 11.7)0.4
1.2.1.pPainful ulcer on the penis with lymph nodesNoRefRef
Yes11.5 (4.1 to 32.0)2.413.0 (4.9 to 34.4)2.6
1.2.2.aPainful ulcer at the anus without lymph nodesNoRefRefRef
Yes9.6 (4.9 to 18.6)2.39.6 (5.0 to 18.7)2.39.7 (5.0 to 18.8)2.3
1.2.2.pPainful ulcer on the penis without lymph nodesNoRefRef
Yes25.0 (15.6 to 39.9)3.224.7 (15.5 to 39.6)3.2
2.pasoRash on the palms of the hands or soles of the feetNoRef
Yes2.6 (0.8 to 8.1)
2.1Itching rash¶NoRefRefRef
Yes7.4 (3.4 to 16.3)2.08.1 (3.8 to 17.2)2.18.0 (3.7 to 17.0)2.1
2.2Non-itching rashNoRefRefRef
Yes54.3 (32.7 to 90.2)4.064.8 (40.4 to 103.7)4.264.8 (40.5 to 103.7)4.2
3.Notified for syphilisNoRefRefRef
Yes4.4 (3.3 to 5.7)1.54.4 (3.3 to 5.7)1.54.3 (3.3 to 5.7)1.5

  • β∧ is the regression coefficient of the logistic regression models (i.e. the log of the Odds Ratio).

  • *Model A is based on the symptoms of the expert-based algorithm: ulcer in the mouth, ulcer on the skin, painless ulcer at the anus with palpable regional lymph nodes, painless ulcer on the penis with palpable regional lymph nodes, painless ulcer at the anus without palpable regional lymph nodes, painless ulcer on the penis without palpable regional lymph nodes, painful ulcer at the anus with palpable regional lymph nodes, painful ulcer on the penis with palpable regional lymph nodes, painful ulcer at the anus without palpable regional lymph nodes, painful ulcer on the penis without palpable regional lymph nodes, rash on the palms of the hands or soles of the feet, itching rash, non-itching rash and a partner notification for syphilis.

  • †Model B is based on the symptoms and risk factor (a partner notification for syphilis) that were significantly associated with infectious syphilis: painless ulcer at the anus with palpable regional lymph nodes, painful ulcer at the anus without palpable regional lymph nodes, painless ulcer on the penis with palpable regional lymph nodes, painless ulcer on the penis without palpable regional lymph nodes, painful ulcer on the penis with palpable regional lymph nodes, painful ulcer on the penis without palpable regional lymph nodes, itching rash, non-itching rash and a partner notification for syphilis.

  • ‡Model C is based on model B, but simplified by including painless and painful ulcers (both regardless of lymph nodes): painless ulcer at the anus with palpable regional lymph nodes, painful ulcer at the anus without palpable regional lymph nodes, painless ulcer on the penis, painful ulcer on the penis, itching rash, non-itching rash and a partner notification for syphilis.

  • §Skin is defined as location other than anogenital (anus or penis) or mouth.

  • ¶Rash associated with syphilis: a maculopapular exanthema or erythematous exanthema.

  • aOR, adjusted OR; MSM, men who have sex with men.