Skip to main content

Advertisement

Table 3 Risk factors for a new diagnosis of syphilis among HIV-positive MSM, OHTN Cohort Study, 2006–2010

From: High incidence of diagnosis with syphilis co-infection among men who have sex with men in an HIV cohort in Ontario, Canada

  First syphilis diagnosis Re-diagnosis of syphilis (a) Any new syphilis diagnosis
Risk factor Rate per 100PY (95 % CI) Adjusted RR (95 % CI) Rate per 100PY (95 % CI) Adjusted RR (95 % CI) Rate per 100PY (95 % CI) Adjusted RR (95 % CI)
Time (1-year increase)   1.3 (1.1, 1.5)   1.4 (1.2, 1.6)   1.3 (1.1, 1.4)
Age
 <30 years 6.8 (4.2, 11.1) 4.5 (1.9, 10.3) 18.7 (10.9, 32.3) 3.7 (1.9, 7.2) 9.5 (6.6, 13.7) 3.0 (1.7, 5.4)
 30–49 years 2.2 (1.8, 2.7) 1.7 (1.0, 2.9) 9.8 (8.0, 12.0) 2.4 (1.6, 3.7) 3.7 (3.2, 4.3) 1.6 (1.1, 2.3)
 50+ years 1.1 (0.7, 1.7) 1.0 3.8 (2.7, 5.4) 1.0 1.9 (1.5, 2.5) 1.0
Race
 White 1.9 (1.6, 2.4) 1.0 7.4 (6.1, 9.0) 1.0 3.2 (2.8, 3.7) 1.0
 Black 2.3 (0.8, 6.0) 0.9 (0.3, 2.6) 7.8 (3.5, 17.3) 0.8 (0.4, 1.8) 3.9 (2.1, 7.3) 1.0 (0.5, 1.8)
 Indigenous 0.8 (0.3, 2.5) 0.2 (0.02, 1.3) 1.9 (0.3, 13.6) 0.4 (0.1, 2.8) 0.9 (0.4, 2.5) 0.25 (0.06, 0.97)
 Other/unknown 2.8 (1.9, 4.0) 1.1 (0.7, 1.8) 8.3 (5.8, 11.9) 0.9 (0.5, 1.4) 4.2 (3.2, 5.4) 0.9 (0.6, 1.3)
Education
 High school or less 0.9 (0.5, 1.6) 0.4 (0.2, 0.8) 5.7 (3.7, 8.8) 0.8 (0.4, 1.4) 1.9 (1.4, 2.7) (b)
 Trade school or college 2.7 (2.0, 3.6) 1.0 (0.6, 1.6) 8.9 (6.8, 11.8) 1.1 (0.7, 1.7) 4.2 (3.5, 5.2)  
 University 2.4 (1.8, 3.1) 1.0 7.5 (5.8, 9.7) 1.0 3.6 (3.0, 4.4)  
Annual personal income
 Less than $20,000 CDN 1.9 (1.4, 2.7) 1.1 (0.6, 2.0) 7.7 (5.8, 10.3) 0.8 (0.5, 1.4) 3.3 (2.7, 4.1) 1.2 (0.8, 1.8)
 $20,000–$59,999 CDN 2.3 (1.7, 3.0) 1.1 (0.7, 1.9) 6.7 (5.0, 8.9) 0.6 (0.4, 1.0) 3.3 (2.7, 4.1) 0.9 (0.6, 1.4)
 $60,000 CDN or more 1.9 (1.3, 2.9) 1.0 9.4 (6.8, 12.9) 1.0 3.7 (2.9, 4.8) 1.0
Region receiving HIV care
 Toronto 2.6 (2.2, 3.1) 4.0 (1.6, 10.3) 8.4 (7.0, 10.0) 2.9 (0.9, 9.0) 4.1 (3.6, 4.7) 4.7 (2.1, 10.6)
 Ottawa 1.1 (0.5, 2.6) 0.7, (0.1, 6.4) 3.1 (1.2, 8.3) 1.2 (0.3, 5.2) 1.5 (0.8, 2.9) 2.2 (0.7, 7.0)
 Elsewhere in Ontario 0.4 (0.2, 1.0) 1.0 3.1 (1.4, 6.9) 1.0 0.8 (0.4, 1.4) 1.0
Maximum viral load in year
 Detectable 2.9 (2.2, 3.7) 1.3 (0.8, 2.3) 8.8 (6.9, 11.1) 1.0 (0.6, 1.5) 4.4 (3.7, 5.3) 1.1 (0.8, 1.6)
 Undetectable 1.6 (1.2, 2.1) 1.0 7.0 (5.5, 8.8) 1.0 2.8 (2.3, 3.3) 1.0
Minimum CD4 in calendar year
 <350 cells/mm3 2.1 (1.5, 2.9)   8.4 (6.4, 11.1)   3.7 (3.0, 4.5)  
 350–499 cells/mm3 2.6 (1.9, 3.5)   9.0 (6.7, 12.2)   4.1 (3.3, 5.1)  
 500 cells/mm3 or greater 1.5 (1.0, 2.1)   6.4 (4.7, 8.7)   2.6 (2.0, 3.2)  
 Per 100 unit increase   0.93 (0.85, 1.01)   0.93 (0.85,1.0)   0.92 (0.86, 0.99)
On antiretroviral treatment
 Yes 1.7 (1.4, 2.4) 0.9 (0.5, 1.7) 7.0 (5.8, 8.5) 0.8 (0.5, 1.4) 2.9 (2.5, 3.4) 0.9 (0.6, 1.3)
 No 3.8 (2.7, 5.4) 1.0 9.6 (6.6, 13.7) 1.0 5.3 (4.1, 6.8) 1.0
Past syphilis diagnosis
 Yes      19.7 (14.8, 26.2) 3.5 (2.2, 5.8)
 No      2.8 (2.4, 3.2) 1.0
  1. PY Person years, CI Confidence interval, RR Rate ratio calculated using Poisson regression adjusted for all variables shown
  2. (a) Re-diagnosis defined as a four-fold rise in RPR titre. See text for details
  3. (b) In the analysis of any new syphilis diagnosis, there was a statistically significant interaction between education and history of past syphilis diagnosis (P = 0.04). Adjusted RRs (95 % CI) for education level among men with no past syphilis diagnosis were 0.42 (0.25, 0.73) for high school or less and 0.88 (0.62, 1.3) for trade school/college compared to men with university. Among men with a past syphilis diagnosis, the adjusted RRs were 1.4 (0.69, 8.4) for high school or less and 1.3 (0.71, 2.3) for trade school/college compared to men with university