TY - JOUR
KW - Aging
KW - Crime/prevention & control/statistics & numerical data
KW - Criminals/legislation & jurisprudence
KW - Early Medical Intervention/methods
KW - Female
KW - Heroin Dependence/therapy
KW - Humans
KW - Incidence
KW - Norway/epidemiology
KW - Proportional Hazards Models
KW - Substance Abuse Treatment Centers
KW - Treatment Outcome
AU - J. Roislien
AU - T. Clausen
AU - J. M. Gran
AU - A. Bukten
A1 - 
AB - BACKGROUND: The reduction of crime is an important outcome of opioid maintenance treatment (OMT). Criminal intensity and treatment regimes vary among OMT patients, but this is rarely adjusted for in statistical analyses, which tend to focus on cohort incidence rates and rate ratios. The purpose of this work was to estimate the relationship between treatment and criminal convictions among OMT patients, adjusting for individual covariate information and timing of events, fitting time-to-event regression models of increasing complexity. METHODS: National criminal records were cross linked with treatment data on 3221 patients starting OMT in Norway 1997-2003. In addition to calculating cohort incidence rates, criminal convictions was modelled as a recurrent event dependent variable, and treatment a time-dependent covariate, in Cox proportional hazards, Aalen's additive hazards, and semi-parametric additive hazards regression models. Both fixed and dynamic covariates were included. RESULTS: During OMT, the number of days with criminal convictions for the cohort as a whole was 61% lower than when not in treatment. OMT was associated with reduced number of days with criminal convictions in all time-to-event regression models, but the hazard ratio (95% CI) was strongly attenuated when adjusting for covariates; from 0.40 (0.35, 0.45) in a univariate model to 0.79 (0.72, 0.87) in a fully adjusted model. The hazard was lower for females and decreasing with older age, while increasing with high numbers of criminal convictions prior to application to OMT (all p < 0.001). The strongest predictors were level of criminal activity prior to entering into OMT, and having a recent criminal conviction (both p < 0.001). The effect of several predictors was significantly time-varying with their effects diminishing over time. CONCLUSIONS: Analyzing complex observational data regarding to fixed factors only overlooks important temporal information, and naive cohort level incidence rates might result in biased estimates of the effect of interventions. Applying time-to-event regression models, properly adjusting for individual covariate information and timing of various events, allows for more precise and reliable effect estimates, as well as painting a more nuanced picture that can aid health care professionals and policy makers.
BT - BMC medical research methodology
C5 - Opioids & Substance Use
CY - England
DO - 10.1186/1471-2288-14-68
JF - BMC medical research methodology
N2 - BACKGROUND: The reduction of crime is an important outcome of opioid maintenance treatment (OMT). Criminal intensity and treatment regimes vary among OMT patients, but this is rarely adjusted for in statistical analyses, which tend to focus on cohort incidence rates and rate ratios. The purpose of this work was to estimate the relationship between treatment and criminal convictions among OMT patients, adjusting for individual covariate information and timing of events, fitting time-to-event regression models of increasing complexity. METHODS: National criminal records were cross linked with treatment data on 3221 patients starting OMT in Norway 1997-2003. In addition to calculating cohort incidence rates, criminal convictions was modelled as a recurrent event dependent variable, and treatment a time-dependent covariate, in Cox proportional hazards, Aalen's additive hazards, and semi-parametric additive hazards regression models. Both fixed and dynamic covariates were included. RESULTS: During OMT, the number of days with criminal convictions for the cohort as a whole was 61% lower than when not in treatment. OMT was associated with reduced number of days with criminal convictions in all time-to-event regression models, but the hazard ratio (95% CI) was strongly attenuated when adjusting for covariates; from 0.40 (0.35, 0.45) in a univariate model to 0.79 (0.72, 0.87) in a fully adjusted model. The hazard was lower for females and decreasing with older age, while increasing with high numbers of criminal convictions prior to application to OMT (all p < 0.001). The strongest predictors were level of criminal activity prior to entering into OMT, and having a recent criminal conviction (both p < 0.001). The effect of several predictors was significantly time-varying with their effects diminishing over time. CONCLUSIONS: Analyzing complex observational data regarding to fixed factors only overlooks important temporal information, and naive cohort level incidence rates might result in biased estimates of the effect of interventions. Applying time-to-event regression models, properly adjusting for individual covariate information and timing of various events, allows for more precise and reliable effect estimates, as well as painting a more nuanced picture that can aid health care professionals and policy makers.
PP - England
PY - 2014
SN - 1471-2288; 1471-2288
SP - 68
T1 - Accounting for individual differences and timing of events: estimating the effect of treatment on criminal convictions in heroin users
T2 - BMC medical research methodology
TI - Accounting for individual differences and timing of events: estimating the effect of treatment on criminal convictions in heroin users
U1 - Opioids & Substance Use
U2 - 24886472
U3 - 10.1186/1471-2288-14-68
VL - 14
VO - 1471-2288; 1471-2288
Y1 - 2014
ER -