Table 1

Incidence of hepatitis C among injecting drug users in Dublin, by general and drug misuse characteristics

NumberSeroconvertorsPerson years at risk (PYAR)Incidence (per 100 PYAR)95% Confidence intervals*p Value†
*Confidence intervals for the incidence rate were calculated using the exact confidence limits for a Poisson count. †p Values were generated by comparing incidence rates using the z test. ‡Benzodiazepines were the principal drug injected in three cases. §Benzodiazepine misuse was determined on the basis of urine toxicology (Immunoassay EMIT test).
Total10067101.66651 to 84
    Male664463.07051 to 94
    Female342338.66038 to 890.54
Age ,(y)
    Under 21573959.46647 to 90
    ≥21432842.36644 to 960.98
    Unemployed886389.57054 to 90
    Working (or at school)12412.2339 to 840.13
Current sexual relationship
    No partner/non-injecting partner684570.56447 to 85
    Partner injects292026.97445 to 1150.57
    Unknown324.2485.8 to 172.0
Imprisoned before first test
    No553565.15437 to 75
    Yes362526.99360 to 1370.03
    Unknown979.77229 to 149
Time since onset of injecting (months)
    1 to 12674763.67454 to 98
    13 or more332037.75332 to 820.21
Principal drug injected
    Heroin724575.85943 to 79
    Other or combination282225.98553 to 1290.17
Daily drug expenditure
    Up to Ir£65764880.46044 to 79
    More than Ir£65241921.09054 to 1410.12
Route of opioid use‡ at first testing
    Not all injected18727.12610 to 56
    All injected675053.69369 to 1230.006
    Unknown151021.04823 to 88
Benzodiazepine misuse§
    No503355.36041 to 84
    Yes452940.37248 to 1030.46
    Unknown556.08327 to 194
Imprisoned between tests
    No774869.16951 to 92
    Yes151221.95528 to 960.46
    Unknown8710.76526 to 135
Addiction treatment between tests
    None or less than 3 months  treatment674256.27554 to 101
    More than 3 months312344.45233 to 780.16
    Unknown221.118222 to 657