Table 3.
GEE multinomial logistic regression: multivariate analysis of factors associated with being a MSM who engaged in chemsex (CX) and being an MSM who did not use drugs at all (non-DU) compared with MSM who used drugs but did not engage in chemsex (DU) (N = 2 493 participants, 19 375 follow-up visits)
| Univariate models | Multivariate model | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Non-DU* (vs. DU**) | CX*** (vs. DU) | No-DU (vs. DU) | CX (vs. DU) | ||||||
| OR [IC 95%] | p | OR [IC 95%] | p | aOR [IC 95%] | p | aOR [IC 95%] | p | ||
| Agea (years) | 1.04 [1.03;1.05] | < 0.001 | 1.04 [1.03;1.05] | < 0.001 | 1.03 [1.02;1.04] | < 0.001 | 1.02 [1.01;1.03] | < 0.001 | |
| Education level a | |||||||||
| Upper secondary school certificate or lower | ref | ref | ref | ref | |||||
| Tertiary education below Master’s degree | 0.78 [0.61;1.00] | 0.053 | 0.89 [0.68;1.15] | 0.365 | 0.81 [0.64;1.02] | 0.073 | 0.86 [0.67;1.11] | 0.240 | |
| Master’s degree or higher | 0.78 [0.61;1.00] | 0.046 | 0.72 [0.56;0.93] | 0.011 | 0.79 [0.62;0.99] | 0.042 | 0.70 [0.55;0.90] | 0.005 | |
| Perceived financial situation a | |||||||||
| Comfortable | |||||||||
| You get by | 1.09 [0.91;1.32] | 0.342 | 1.11 [0.90;1.36] | 0.351 | |||||
| It’s difficult to make ends meet | 0.86 [0.71;1.05] | 0.144 | 1.19 [0.96;1.47] | 0.109 | |||||
| Had already taken PrEP at enrolment a | 0.80 [0.68;0.93] | 0.003 | 1.27 [1.07;1.51] | 0.006 | 0.74 [0.64;0.86] | < 0.001 | 1.04 [0.87;1.23] | 0.664 | |
| Center for Epidemiologic Studies-Depression scale score b | 1.00 [0.99;1.01] | 0.934 | 1.01 [1.00;1.02] | 0.026 | 1.00 [1.00;1.01] | 0.854 | 1.01 [1.00;1.02] | 0.006 | |
| Rosenberg self-esteem scale b | 1.01 [1.00;1.02] | 0.218 | 0.99 [0.98;1.01] | 0.453 | |||||
| Feeling… b | |||||||||
| Very supported | 0.84 [0.73;0.96] | 0.011 | 0.75 [0.62;0.91] | 0.004 | |||||
| Quite supported | |||||||||
| Quite or very alone | 1.02 [0.94;1.15] | 0.660 | 1.14 [0.98;1.32] | 0.089 | |||||
| Lifetime care received from a professional for mental health problems b | 0.88 [0.76;1.02] | 0.095 | 0.91 [0.77;1.07] | 0.237 | |||||
| Alcohol Use Disorders Identification Test-Consumption score | 0.86 [0.84;0.88] | < 0.001 | 0.86 [0.84;0.89] | < 0.001 | 0.90 [0.88;0.92] | < 0.001 | 0.91 [0.88;0.93] | < 0.001 | |
| Cannabis use c | |||||||||
| Never | |||||||||
| Occasionally | 0.51 [0.46;0.57] | < 0.001 | 0.59 [0.50;0.70] | < 0.001 | 0.62 [0.55;0.69] | < 0.001 | 0.67 [0.57;0.78] | < 0.001 | |
| Regularly | 0.31 [0.26;0.37] | < 0.001 | 0.49 [0.39;0.60] | < 0.001 | 0.40 [0.34;0.48] | < 0.001 | 0.62 [0.50;0.76] | < 0.001 | |
| Poppers use c | |||||||||
| Never | |||||||||
| Occasionally | 0.60 [0.54;0.67] | < 0.001 | 1.14 [0.99;1.32] | 0.077 | 0.70 [0.63;0.78] | < 0.001 | 1.19 [1.03;1.37] | 0.021 | |
| Regularly | 0.48 [0.42;0.55] | < 0.001 | 1.16 [0.97;1.38] | 0.102 | 0.61 [0.53;0.70] | < 0.001 | 1.14 [0.96;1.37] | 0.141 | |
| Having a main partner | 1.04 [0.95;1.14] | 0.406 | 0.75 [0.66;0.86] | < 0.001 | 0.93 [0.85;1.02] | 0.104 | 0.74 [0.65;0.84] | < 0.001 | |
| Number of casual sex partners c | |||||||||
| < 5 | |||||||||
| Between 5 and 9 | 0.70 [0.63;0.77] | < 0.001 | 0.93 [0.81;1.08] | < 0.329 | 0.73 [0.66;0.81] | < 0.001 | 0.91 [0.78;1.06] | 0.241 | |
| Between 10 and 19 | 0.61 [0.55;0.68] | < 0.001 | 0.96 [0.83;1.11] | 0.577 | 0.64 [0.57;0.71] | < 0.001 | 0.90 [0.77;1.06] | 0.206 | |
| ≥ 20 | 0.55 [0.49;0.63] | < 0.001 | 1.14 [0.96;1.34] | 0.131 | 0.61 [0.54;0.69] | < 0.001 | 1.08 [0.91;1.27] | 0.390 | |
| Systematic use of condoms c | 0.97 [0.97;1.07] | 0.529 | 0.73 [0.63;0.85] | < 0.001 | 0.97 [0.87;1.09] | 0.642 | 0.76 [0.64;0.81] | 0.002 | |
| PrEP adherence | |||||||||
| Optimal | |||||||||
| Sub-optimal | 0.81 [0.73;0.89] | < 0.001 | 0.65 [0.57;0.74] | < 0.001 | 0.91 [0.83;1.00] | 0.058 | 0.70 [0.61;0.80] | < 0.001 | |
| No PrEP use (at or after baseline) | 0.89 [0.82;0.98] | 0.013 | 0.53 [0.47;0.60] | < 0.001 | 0.94 [0.86;1.03] | 0.192 | 0.65 [0.57;0.75] | < 0.001 | |
| Fisting or BDSM sexual practices d | 1.87 [1.49;2.34] | < 0.001 | 5.60 [4.26;7.36] | < 0.001 | 1.64 [1.34;2.01] | < 0.001 | 4.73 [3.69;6.05] | < 0.001 | |
| Satisfaction with current sex life b | |||||||||
| Not at all satisfied or not really satisfied | |||||||||
| Quite satisfied | 0.80 [0.71;0.89] | < 0.001 | 0.87 [0.76;1.01] | 0.063 | 0.87 [0.78;0.98] | 0.024 | 0.92 [0.79;1.07] | 0.291 | |
| Very satisfied | 0.76 [0.64;0.89] | < 0.001 | 0.85 [0.68;1.05] | 0.138 | 0.88 [0.75;1.03] | 0.112 | 0.95 [0.77;1.16] | 0.602 | |
| Having a risky sex life b | |||||||||
| Not at all or not really | |||||||||
| Yes, quite risky | 0.86 [0.78;0.95] | 0.003 | 1.07 [0.94;1.22] | 0.304 | 0.89 [0.81;0.98] | 0.017 | 1.07 [0.94;1.22] | 0.329 | |
| Yes, definitely risky | 0.86 [0.73;1.00] | 0.055 | 1.29 [1.06;1.57] | 0.011 | 0.92 [0.79;1.07] | 0.277 | 1.23 [1.01;1.49] | 0.038 | |
aBaseline data; bAnnual imputed data; c Previous 3 months. dDuring the most recent sexual intercourse
* MSM who used drugs but did not engage in chemsex
** MSM who did not use drugs
*** MSM who engaged in chemsex