Table 2 Number of automatic tr acks and manual interventions for each software and type of marker. Type of marker Software Automatic tr acks Manual interventions Percentage of manual interventions Odds ratio 95% CI Full black circle DVP COM 1286 1147 113 252 8.1 18.0 .40 * .32 – .51 Full white circle DVP COM 290 290 0 0 0 0 ≈ž -≈ž – ≈ž CI, confidence interval for odds ratio. * .05, significantly different from 1