TABLE 2—
Time Trends in Sharing Needles and Injection Equipment Other Than Needles Across Seattle-Area Surveys of Injection Drug Users, With Multivariate Results: Seattle, WA, 1994–2013
| Needle Sharing |
Sharing Injection Equipment Other Than Needles |
||||||
| Year | Survey | % | No./Total No. | PRa (95% CI) | % | No./Total No. | PRb (95% CI) |
| 1994 | RAVENc | 42 | 210/503 | 1 (Ref) | 73 | 343/468 | 1 (Ref) |
| 1995 | RAVEN | 38 | 512/1335 | 0.87 (0.77, 0.98) | 78 | 984/1270 | 1.05 (0.99, 1.12) |
| 1996 | RAVEN | 48 | 313/648 | 1.07 (0.94, 1.21) | 81 | 514/633 | 1.10 (1.03, 1.17) |
| 1997 | RAVEN | 57 | 85/149 | 1.24 (1.05, 1.48) | 88 | 130/148 | 1.16 (1.07, 1.26) |
| 1998 | Kiwi | 55 | 37/67 | 1.29 (1.01, 1.65) | 74 | 51/69 | 1.01 (0.87, 1.18) |
| 1999 | Kiwi | 61 | 216/353 | 1.54 (1.35, 1.76) | 79 | 279/355 | 1.10 (1.02, 1.19) |
| 2000 | Kiwi | 57 | 62/109 | 1.48 (1.22, 1.80) | 77 | 85/111 | 1.11 (0.99, 1.24) |
| 2001 | Kiwi | 64 | 358/564 | 1.62 (1.44, 1.84) | 83 | 462/559 | 1.21 (1.13, 1.30) |
| 2002 | Kiwi | 60 | 345/580 | 1.51 (1.34, 1.72) | 83 | 457/548 | 1.20 (1.12, 1.28) |
| 2003 | . . . | . . . | . . . | . . . | . . . | . . . | . . . |
| 2004 | . . . | . . . | . . . | . . . | . . . | . . . | . . . |
| 2005 | NHBS | 44 | 163/371 | 1.09 (0.93, 1.28) | 75 | 279/371 | 1.05 (0.97, 1.14) |
| 2006 | . . . | . . . | . . . | . . . | . . . | . . . | . . . |
| 2007 | . . . | . . . | . . . | . . . | . . . | . . . | . . . |
| 2008 | . . . | . . . | . . . | . . . | . . . | . . . | . . . |
| 2009 | NHBS | 31 | 154/505 | 0.73 (0.62, 0.87) | 65 | 327/504 | 0.88 (0.81, 0.96) |
| 2009 | Needle exchange | 20 | 88/436 | 0.47 (0.38, 0.58) | 42 | 181/431 | 0.59 (0.37, 0.96) |
| 2010 | . . . | . . . | . . . | . . . | . . . | . . . | |
| 2011 | Needle exchange | 20 | 72/366 | 0.47 (0.37, 0.59) | 43 | 156/366 | 0.59 (0.52, 0.67) |
| 2012 | NHBS | 32 | 215/674 | 0.74 (0.63, 0.86) | 62 | 419/673 | 0.83 (0.77, 0.90) |
| 2013 | Needle exchange | 23 | 103/456 | 0.52 (0.43, 0.63) | 45 | 204/455 | 0.62 (0.55, 0.69) |
Note. CI = confidence interval; NHBS = National HIV Behavioral Surveillance system; PR = prevalence ratio; RAVEN = Risk Activity Variables, Epidemiology, and Network study.
Based on general estimating equation analyses including terms for age, race/ethnicity, gender, homelessness, injection frequency, drug most frequently injected, and combined men who have sex with men and amphetamine injector status. Education and area of residence were not significantly associated with needle sharing.
Based on general estimating equation analyses including terms for age, gender, education, homelessness, drug most frequently injected, and combined men who have sex with men and amphetamine injector status. Race/ethnicity and area of residence were not significantly associated with sharing injection equipment other than needles.
The referent period for both needle sharing and sharing injection equipment other than needles was 6 months in RAVEN and Kiwi, 12 months in NHBS, and 3 months in the needle-exchange surveys.