Table 4

Cox proportional hazards models of predictors of death in prison among opioid-dependent prisoners in New South Wales, Australia, 2000–2012 (n=16 715)

PredictorTotal time in prisonFirst 4 weeks in prison
All-cause deathsUnnatural deathsAll-cause deathsUnnatural deaths
HR (95% CI)Adjusted HR (95% CI)HR (95% CI)Adjusted HR (95% CI)HR (95% CI)Adjusted HR (95% CI)HR (95% CI)Adjusted HR (95% CI)
Receipt of OST*0.25 (0.13 to 0.48)0.26 (0.13 to 0.5)0.15 (0.06 to 0.39)0.13 (0.05 to 0.35)0.07 (0.01 to 0.54)0.06 (0.01 to 0.48)0.08 (0.01 to 0.59)0.07 (0.01 to 0.53)
Male1.21 (0.48 to 3.04)0.94 (0.36 to 2.41)0.75 (0.29 to 1.96)0.57 (0.22 to 1.54)0.66 (0.22 to 2.04)0.54 (0.16 to 1.76)0.48 (0.15 to 1.57)0.34 (0.1 to 1.18)
Indigenous0.64 (0.34 to 1.18)0.84 (0.44 to 1.59)0.92 (0.44 to 1.9)1.02 (0.48 to 2.21)0.70 (0.24 to 1.98)0.71 (0.23 to 2.13)1.13 (0.37 to 3.46)0.98 (0.3 to 3.18)
Age at prison reception1.06 (1.03 to 1.1)1.05 (1.01 to 1.09)1.03 (0.98 to 1.07)1.02 (0.97 to 1.07)1.00 (0.93 to 1.07)0.98 (0.91 to 1.06)0.99 (0.91 to 1.07)0.99 (0.91 to 1.07)
No of prior incarcerations1.01 (0.91 to 1.12)1.09 (0.99 to 1.21)1.10 (0.97 to 1.24)1.13 (0.99 to 1.28)0.94 (0.79 to 1.12)0.96 (0.81 to 1.14)0.99 (0.78 to 1.24)1.01 (0.8 to 1.27)
Duration of prior incarcerations†0.98 (0.96 to 1)0.98 (0.96 to 1)1.01 (0.98 to 1.04)1.01 (0.98 to 1.04)0.98 (0.95 to 1.01)0.99 (0.95 to 1.02)1.02 (0.97 to 1.06)1.02 (0.97 to 1.07)
Any prior drug offences0.95 (0.53 to 1.7)0.97 (0.53 to 1.76)0.96 (0.46 to 2.01)0.92 (0.43 to 1.95)1.12 (0.36 to 3.51)1.21 (0.38 to 3.82)0.84 (0.25 to 2.78)0.91 (0.27 to 3.07)
Any prior property offences0.47 (0.25 to 0.92)0.76 (0.37 to 1.57)0.71 (0.29 to 1.75)0.81 (0.31 to 2.14)0.59 (0.13 to 2.69)0.70 (0.15 to 3.36)1.04 (0.13 to 8.39)1.15 (0.14 to 9.67)
Any prior violent offences0.53 (0.3 to 0.94)0.69 (0.37 to 1.26)0.65 (0.31 to 1.34)0.70 (0.32 to 1.5)0.49 (0.18 to 1.33)0.49 (0.18 to 1.37)0.64 (0.2 to 1.98)0.56 (0.17 to 1.83)
  • *Time-dependent variable.

  • †HR refers to change in hazard associated with 28-day increase in duration of prior incarcerations.

  • OST, opioid substitution treatment.