Study sample
A total of 1,016 participants completed at least one interview between 01 January 2016 and 31 December 2021 inclusive. We excluded 351 participants (35%) who reported ‘female’ sex at birth, and/or reported ‘female’ or ‘other’ gender. Of 665 men, 100 (15%) were excluded because of missing data on past-month injecting drug use. A further 40 (6%) were excluded because of missing data on sexual orientation and reporting zero male sexual partners since their last study visit (<12 months). The final study sample consisted of 525 men (Figure 1).
Demographic data
Of 525 included men, 48 (9%) reported gay, bisexual, or queer orientation and/or having had sex with men in the previous 12 months. Of these, 8 (17%) identified as gay and 28 (58%) as bisexual.
In our sample, GBMSM were significantly younger than non-GBMSM (38 years vs. 40 years, p=0.049). GBMSM and non-GBMSM were comparable across the remaining socio-demographic variables examined, with no significant differences identified (Table 1).
Table 1: Socio-demographics, HCV and HIV testing and self-report status among men who inject drugs in Melbourne, Australia, August 2016–August 2021, stratified by sexuality (N=525)
Characteristic
|
Total
N=525
N (%)
|
GBMSM
n=48
N (%)
|
Non- GBMSM
n=477
N (%)
|
P-value
|
Interview completion year
2016
2017
2018
2019
2020
2021
|
2 (0.4)
26 (5.0)
147 (28.0)
172 (32.8)
151 (28.8)
27 (5.14)
|
<5 (<5%)
5 (10.4)
14 (29.2)
10 (20.8)
15 (31.3)
<5 (<5%)
|
0 (0.0)
21 (4.4)
133 (27.9)
162 (34.0)
136 (28.5)
25 (5.2)
|
0.007++
|
Mean age at interview (years, SD), (n=524)
|
39.8 (8.2)
|
37.5 (8.4)
|
40 (8.1)
|
0.049*
|
Country of birth
Australia
Other
Missing
|
446 (85.0)
78 (14.9)
<5 (<5%)
|
42 (87.5)
5 (10.4)
<5 (<5%)
|
404 (84.7)
73 (15.3)
0 (0.0)
|
0.391+
|
Aboriginal or Torres Strait Islander identity
Yes
No
Missing
|
87 (16.6)
436 (83.1)
<5 (<5%)
|
11 (22.9)
37 (77.1)
0 (0.0)
|
76 (15.9)
399 (83.7)
<5 (<5%)
|
0.220+
|
Educational attainment
<Year 10
Year 10–12
Tertiary/diploma/trade
Other
Missing
|
159 (30.3)
217 (41.3)
104 (19.8)
42 (8.2)
<5 (<5%)
|
11 (22.9)
19 (39.6)
13 (27.1)
5 (10.4)
0 (0)
|
148 (31.0)
198 (41.5)
91 (19.1)
38 (8.0)
<5 (<5%)
|
0.439+
|
Average weekly income
<$400
$400–$999
>$1000
Missing
|
239 (45.5)
244 (46.5)
38 (7.2)
<5 (<5%)
|
15 (31.3)
28 (58.3)
5 (10.4)
0 (0)
|
224 (47.0)
216 (45.3)
33 (6.9)
<5 (<5%)
|
0.097+
|
Main source of income
Wage or Salary
Government pension or benefits
Other
Missing
|
42 (8.0)
437 (83.24)
40 (7.6)
6 (1.1)
|
5 (10.4)
38 (79.2)
5 (10.4)
0 (0.0)
|
37 (7.8)
399 (83.7)
35 (7.3)
6 (1.3)
|
0.516++
|
Living circumstances
Alone
With others
Missing
|
295 (56.2)
213 (40.6)
17 (3.3)
|
29 (60.4)
18 (37.5)
<5 (<5%)
|
266 (55.8)
195 (40.9)
16 (3.3)
|
0.596+
|
Housing stability
Stable
Unstable/Homeless
Missing
|
243 (46.3)
281 (53.5)
<5 (<5%)
|
23 (47.9)
25 (52.1)
0 (0.0)
|
220 (46.1)
257 (53.7)
<5 (<5%)
|
0.822+
|
HCV testeda during recall period (‘ever’ at baseline or ‘past 12 mo /since last seen’)
Yes
No
Missing
|
337 (64.2)
176 (33.52)
12 (2.3)
|
37 (77.1)
11 (22.9)
0 (0.0)
|
300 (62.9)
165 (34.6)
12 (2.5)
|
0.081+
|
HCV status (self-report), among those tested during reporting period (n=337)
Positive (Ab positvie/PCR positive)
Negative (Ab negative, PCR negative)
Exposed/negative (Ab positive/PCR negative)
Missing
|
102 (30.3)
71 (21.1)
137 (40.7)
27 (8.0)
|
11 (29.7)
10 (27.0)
11 (29.7)
5 (13.5)
|
91 (30.3)
61 (20.3)
126 (42.0)
22 (7.3)
|
0.389+
|
HIV tested during reporting period (“ever” or “past 12 months/since last seen”)
Yes
No
Missing
|
325 (61.9)
285 (35.2)
15 (2.9)
|
33 (68.8)
15 (31.3)
0 (0.0)
|
292 (61.2)
170 (35.6)
15 (3.4)
|
0.447+
|
Note: All cells of <5 have been suppressed. p‐values were derived using +Pearson's χ2 test or, alternatively, ++Fisher's exact test on non-missing data when expected cell counts were ≤5 for categorical variables, and *Welch’s t-test for continuous variables
a Any hepatitis C test
Abbreviations: Ab = antibody; HCV = hepatitis C virus; neg = negative; PCR = polymerase chain reaction
HCV and HIV testing
There was no significant difference in the distribution of GBMSM and non-GBMSM reporting HCV testing (77% vs 63%, respectively, p=0.081). Of those tested, similar percentages of GBMSM and non-GBMSM reported testing positive for HCV infection (antibody positive and PCR positive, 30% vs 30%, respectively), testing negative (antibody negative, PCR negative; 27% vs 20%, respectively), and past exposure to HCV but no active infection (antibody positive, PCR negative; 30% vs 42%, respectively).
There was no significant difference in the distribution of GBMSM and non-GBMSM reporting recent HIV testing (69% vs 61%, respectively, p=0.447). Among those tested, overall <5 participants returned a positive test result, with no significant differences between groups regarding HIV result (p=0.179, data not shown in Table 1).
Drug use
On average, participants were 18 years old when they first injected drugs (Table 2). For GBMSM, the earliest and latest age of initiation was 13 and 26 years, and 8 and 41 years among non-GBMSM (data not shown).
A significantly greater percentage of GBMSM compared to non-GBMSM reported meth/amphetamines as their drug of choice (31% vs 16%, respectively, p=0.022). A higher percentage of GBMSM compared to non-GBMSM, though not significantly different, also reported methamphetamine as their most injected drug (40% vs 26%, respectively, p=0.098).
Social injecting practices
There was no statistically significant difference between GBMSM and non-GBMSM groups in the distribution of knowing >50 other people who inject drugs (46% and 37% respectively, p=0.527). All GBMSM reported knowing at least one other person who injects drugs, while 1% of non-GBMSM reported knowing none.
Across both groups, the percentage of participants injecting with a greater number of people increased as the recall period increased, more so among GBMSM. In the past one month, 14 GBMSM (29%) reported always injecting alone, or injecting with 1–2 other people (compared to 99 (21%) and 164 (35%) of non-GBMSM, respectively)). Ten GBMSM (11%) reported injecting with 2–5 and ≥6 people (vs. 117 (25%) and 83 (17%) of non-GBMSM respectively, p=0.527). Over six months, similar proportions of GBMSM and non-GBMSM reported injecting alone (15% vs 14%), versus with 1–2 (31% vs 27 %), 3–5 (23% vs 25%), or ≥6 (31% both, p=0.963) people over the recall period.
There was no significant difference between groups for either giving or receiving injecting assistance. Across both groups, peer-to-peer injecting assistance was more commonly performed than received, with 35% of GBMSM and 42% of non-GBMSM reporting having assisted another person’s injection in the past month, compared to 13% of GBMSM and 15% of non-GBMSM reporting having received assistance. Past-month receptive syringe sharing was reported by 13% of GBMSM and 10% of non-GBMSM (p=0.625).
Healthcare access
Eighty-one per cent of GBMSM and 72% of non-GBMSM reported having received any drug treatment over the reporting period (p=0.163). NSPs were reported as the main source of injecting equipment by over 70% of men in both groups (p=0.876). Most GBMSM and non-GBMSM reported not having visited injecting-specific community health clinics for reasons other than to access the NSP in the past 12 months (77% vs 72%, respectively, p=0.401).
Table 2: Drug use patterns and social injecting among men who inject drugs by sexuality, in Melbourne, Australia, August 2016–August 2021 (N=525)
Characteristic
|
Total
N=525
N (%)
|
GBMSM
N=48
N (%)
|
Non-GBMSM
N=477
N (%)
|
P-value
|
Drug use factors
|
|
|
|
|
Age of injection initiation (years), Mean (SD)
|
18 (5)
|
17 (3)
|
18 (5)
|
0.267*
|
Main drug of choice
Heroina
Meth/amphetamines
Otherb
Missing
|
344 (65.5)
90 (17.14)
86 (16.4)
5 (0.95)
|
28 (58.3)
15 (31.3)
5 (10.4)
0 (0.0)
|
316 (66.3)
75 (15.7)
81 (17.16)
5 (1.1)
|
0.022+
|
Drug injected most in month prior to interview
Heroinc
Meth/amphetamines
Otherd
Missing
|
268 (70.1)
145 (27.6)
12 (2.3)
0 (0.0)
|
29 (60.4)
19 (39.6)
0 (0.0)
0 (0.0)
|
339 (71.1)
126 (26.4)
12 (2.5)
0 (0.0)
|
0.098+
|
Social injecting practices
|
|
|
|
|
Number of social contacts who inject
Zero
1–21
21–50
>50
Missing
|
6 (1.1)
149 (28.4)
159 (30.3)
200 (38.1)
11 (2.1)
|
0 (0.0)
12 (25.0)
14 (29.2)
22 (45.8)
0 (0.0)
|
6 (1.3)
137 (28.7)
145 (30.4)
178 (37.3)
11 (2.3)
|
0.811++
|
Number of people injected with in the past six months
Zero
1–2 person
3–5 people
>6 people
Missing
|
73 (13.9)
145 (27.6)
129 (24.6)
164 (31.2)
14 (2.7)
|
7 (14.6)
15 (31.3)
11 (22.9)
15 (31.3)
0 (0.0)
|
66 (13.8)
130 (27.3)
118 (24.7)
149 (31.2)
14 (2.9)
|
0.963+
|
Number of people injected with in past month
Zero
1-2 person
3-5 persons
>6 persons
Missing
|
113 (21.5)
178 (33.9)
127 (24.2)
93 (17.7)
14 (2.7)
|
14 (29.2)
14 (29.2)
10 (10.8)
10 (10.8)
0 (0.0)
|
99 (20.8)
164 (34.4)
117 (24.5)
83 (17.4)
14 (2.9)
|
0.527+
|
Provided injecting assistance in past month
No
Yes
Missing
|
301 (57.3)
217 (41.3)
7 (1.3)
|
29 (60.4)
17 (35.4)
<5 (<5%)
|
272 (57.0)
200 (41.9)
5 (1.1)
|
0.477+
|
Received injecting assistance in past month
No
Yes
Missing
|
443 (84.4)
75 (14.3)
7 (1.3)
|
40 (83.3)
6 (12.5)
<5 (<5%)
|
403 (84.5)
69 (14.5)
5 (1.1)
|
0.772+
|
Re-used another person’s needle/syringe in past month
No
Yes
Missing
|
463 (88.2)
54 (10.3)
8 (1.5)
|
42 (87.5)
6 (12.5)
0 (0.0)
|
421 (88.3)
48 (10.1)
8 (1.7)
|
0.625+
|
Healthcare access
|
|
|
|
|
Accessed any drug treatment during recall period
No
Yes
Missing
|
143 (27.2)
381 (72.6)
<5 (<5%)
|
9 (18.8)
39 (81.3)
0 (0.0)
|
134 (28.1)
342 (71.7)
<5 (<5%)
|
0.163+
|
Main source of needle/syringes in past month
NSP
Othere
Missing
|
399 (76.0)
82 (15.6)
44 (8.4)
|
37 (77.1)
8 (16.7)
<5 (<5%)
|
362 (75.9)
74 (15.5)
41 (8.6)
|
0.891+
|
Access of IDU-specific primary care clinic for reasons other than NSP in past 12-months
No
Yes
Missing
|
376 (71.6)
147 (28.0)
<5 (<5%)
|
37 (77.1)
11 (22.9)
0 (0.0)
|
339 (71.1)
136 (28.5)
<5 (<5%)
|
0.401+
|
Note: All cells of <5 have been suppressed. p‐values were derived using on +Pearson's χ2 test or, alternatively, ++Fisher's exact test on non-missing data when expected cell counts were ≤5 for categorical variables, and *Mann–Whitney U test (t-test) for continuous variables,
aCategory includes participants who specified equal preference for heroin and methamphetamine in freetext (n=1 non-GBMSM)
bCategory includes participants who specified cannabis, methadone, suboxone, ‘other’ opiates (e.g., codeine), benzodiazepines, cocaine, ecstasy/MDMA, hallucinogens, and those who specified in freetext fentanyl (n=2), dexamphetamine (n=1), homebake (n=1), synthetic cannabis (n=1) and ‘no drug’ (n=3) (all non-GBMSM)
cCategory includes participants who specified combined heroin and methamphetamine injecting in freetext (n=2 non-GBMSM), and combining heroin and unisom in freetext (n=1 GBMSM)
dCategory includes participants who specified cocaine, morphine, buprenorphine, suboxone, cannabis; or who selected ‘other’ drug most injected, specifying ‘homebake’ in freetext (n=1 non-GBMSM)
eCategory includes participants who specified partner/friend, dealer, chemist/pharmacy, syringe vending machine, mobile outreach NSP van, supervised injecting facility, other
Abbreviations: IDU = injecting drug use; NSP = needle-syringe program