| 
      Crude Overdose Mortality Rate (COMR): The OMRs derived from each study were categorized into the following regions: USA, Canada, Puerto Rico, Europe, and Asia.
    For each region the Crude Mortality Rate was calculated by using the following formula: Σ [(OMR) x N Total Deaths] / Σ N Total Deaths
    The 95% Confidence Interval (CI) for the mean crude mortality rate was calculated using an alpha value of .05.
        | Crude Overdose Mortality Rate  | USA
                (95% CI) | Canada
                (95% CI) | Europe
                (95% CI) | Puerto Rico (95% CI) | Asia
                (95% CI) | Mean
                (95% CI) |  
        | Pre-
                HAART | 1.36%
          (0.03-2.79) | 2.20%
          (n/a) | 7.26%
          (5.53-8.99) | n/a | 5.30%
          (n/a) | 4.03%
          (0.9-7.16) |  
        | Post-HAART | 18.96%
          (13.39-24.53) | 19.75%
          (11.91-27.59) | 13.63%
          (10.56-16.70) | 24.1%
          (n/a) | 19.5%
          (10.51-28.39) | 17.54%
          (12.42-22.66) |  |