Table 3.

Factors associated with PrEP adherence using mixed effect logistic model

	Univariable		Multivariable
			Model 1 (1,054 observations)		Model 2 (680 observations)
	OR (95% CI)	p‐value	aOR (95% CI)	p‐value	aOR (95% CI)	p‐value
Baseline characteristics
Age (ref ≤30)	1.02 (0.99 to 1.06)	0.214
In stable relationship	0.69 (0.47 to 1.02)	0.061
Education (Above college vs. college graduate or below)	1.57 (0.96 to 2.56)	0.074
Salary (≥1,000 USD vs. <1,000 USD)	1.07 (0.72 to 1.60)	0.728
PEP in the past year	1.64 (0.86 to 3.12)	0.130
Time‐varying variables a
Time (days) b			1.00 (1.00 to 1.00)	0.615	1.00 (1.00 to 1.02)	0.983
Anxiety (≥10 vs. <10) c	0.46(0.24 to 0.90)	0.023*	0.70 (0.30 to 1.67)	0.422	0.58 (0.18 to 1.88)	0.364
Depression (≥15 vs. <15) d	0.35 (0.14 to 0.87)	0.025*	0.58 (0.17 to 1.96)	0.379	0.55 (0.11 to 2.64)	0.453
Had STI	0.76 (0.46 to 1.26)	0.286
Number of anal sex partners in the past month (ref = 0)
1	1.41 (0.83 to 2.40)	0.206	1.40 (0.82 to 2.41)	0.222	1.49 (0.75 to 2.96)	0.258
2 to 5	1.84 (1.07 to 3.17)	0.027*	2.07 (1.18 to 3.62)	0.011*	2.02 (0.98 to 4.15)	0.056
>5	0.70 (0.34 to 1.41)	0.317	0.84 (0.40 to 1.77)	0.653	0.78 (0.30 to 2.06)	0.617
Number of CAS in the past 4 weeks (≥5 vs. <5) e	0.58 (0.32 to 1.05)	0.072
Alcohol use in the past month	0.92 (0.51 to 1.67)	0.782
Sexualized drug use in the past month f	0.50 (0.28 to 0.89)	0.018*	0.50 (0.27 to 0.94)	0.031*	0.62 (0.25 to 1.50)	0.286
PrEP dosing regimen (Event‐driven vs. daily)	0.58 (0.39 to 0.86)	0.007**	0.54 (0.36 to 0.81)	0.003**
Dosing regimens switch (ref= daily, no switch)
Event‐driven, no switch	0.61 (0.32 to −1.13)	0.116			0.56 (0.30 to 1.06)	0.071
Daily to event‐driven	0.31 (0.15 to 0.63)	0.001***			0.30 (0.15 to 0.63)	0.001***
Event‐driven to daily	0.47 (0.22 to 1.02)	0.056			0.52 (0.24 to 1.15)	0.105

Model 2 only included those participants who had data from more than one visit with 680 observations. The variables were the same as Model 1 except that Model 2 included dosing regimen switching rather than PrEP dosing regimen. AOR, adjusted odds ration; CAS, condomless anal sex; OR=odds ration; PEP, Post‐exposure Prophylaxis; STI, sexually transmitted infections.

^aAdjusted time since first self‐report PrEP initiation during the study period in univariate model

^btime: Since first self‐report PrEP initiation during the study period, unit: month

^cgeneralized anxiety disorder 7‐item (GAD‐7) scale score

^dpatient health questionnaire (PHQ‐9) scale score

^eCAS: condomless anal sex

^fdefined as use of methamphetamine or ecstasy or GHB/GBL or ketamine or mephedrone.

^*odds ratio significant at the p ≤ 0.05 level

^**odds ratio significant at the p ≤ 0.01 level

^***odds ratio significant at the p ≤ 0.001 level.