Table 4.

Factors associated with hospital admission for an abscess or redness, swelling and tenderness, at an injection site in the previous 12 months in people who inject drugs

Characteristics	Yes	n	Total, N	P	aOR	(95% CI)
Abscess
Gender
Male	52%	41	79
Female	30%	10	33	0·036	†
Age (years)
<25	0%	0	5
25–29	30%	9	30
30–34	48%	15	31
⩾35	57%	27	47	0·019	†
Years since first injected
<5	17%	2	12		1·00
5–9	43%	13	30		7·15	(1·04–48·9)
10–14	39%	13	33		5·01	(0·75–33·4)
⩾15	59%	23	39	0·059	25·9	(3·54–189)
Injected crack preceding year
No	21%	7	33		1·00
Yes	55%	44	80	0·001	7·49	(2·50–22·5)
Shared N/S preceding year
No	40%	34	85		1·00
Yes	63%	17	27	<0·001	3·57	(1·25–10·2)
Anti-HBc test result
Positive	61%	19	31
Negative	39%	31	80	0·032	†
Anti-HCV test result
Positive	52%	42	81
Negative	29%	9	31	0·030	†
Redness, swelling and tenderness
Gender
Male	34%	36	105
Female	21%	11	53	0·079	†
Age (years)
<25	6·3%	1	16
25–29	37%	18	49
30–34	24%	10	42
⩾35	35%	18	51	0·077	†
Injected crack preceding year
No	20%	9	45
Yes	34%	39	114	0·079	†
Imprisonment
Never	13%	4	31
Yes, not preceding year	33%	29	89
Yes, preceding year	38%	15	39	0·052	†
Anti-HBc test result
Positive	43%	20	47
Negative	24%	27	112	0·020	†
Anti-HCV test result
Positive	37%	37	101		1·00
Negative	18%	10	57	0·012	0·38	(0·17–0·83)

aOR, Adjusted odds ratio; CI, confidence interval; N/S, needles or syringe.

^†Not included in the final model.