. Author manuscript; available in PMC: 2015 Aug 1.

Published in final edited form as: J Epidemiol Community Health. 2015 Mar 26;69(8):745–752. doi: 10.1136/jech-2014-205224

Table 4.

GEE modelling of outcome trends over time – by age group

Age at baseline < 25 years:
Outcome	HCV negative aOR^b (95% CI) p-value	HCV diagnosed aOR^b (95% CI) p-value	Interaction (time*HCV-disclosure group) p-value
Recent^a injection drug use	0.98 (0.95, 1.02) 0.261	0.98 (0.96, 1.00) 0.079	0.093
Recent syringe borrowing	0.94 (0.86, 0.99) 0.047	0.99 (0.94, 1.04) 0.612	0.087
Recent receptive sharing - other equipment	1.04 (0.98, 1.11) 0.169	1.00 (0.92, 1.09) 0.911	0.301
Recent alcohol use	0.99 (0.97, 1.01) 0.128	1.03 (1.01, 1.04) 0.015	0.009

Age at baseline >= 25 years:
Outcome	HCV negative aOR^b (95% CI) p-value	HCV diagnosed aOR^b (95% CI) p-value	Interaction (time*HCV-disclosure group) p-value
Recent^a injection drug use	0.94 (0.91, 0.96) <0.001	0.93 (0.90, 0.97) <0.001	0.087
Recent syringe borrowing	0.95 (0.88, 1.01) 0.072	0.95 (0.89, 0.99) 0.036	0.769
Recent receptive sharing - other equipment	0.97 (0.91, 1.05) 0.401	0.96 (0.92, 1.02) 0.109	0.606
Recent alcohol use	0.97 (0.91, 1.02) 0.142	1.00 (0.99, 1.02) 0.434	0.528

Recent=past month or past 3-months depending on cohort

aOR = adjusted odds ratio for every 3-month increment post-baseline, adjusted for site, age, sex and baseline outcome value