Excessive substance use did not differ significantly between patients whose physicians were in the intervention group and those whose physicians were in the control group at any of the follow-up points ( odds ratio [ OR ] and 95 % confidence interval [ CI ] at 3 months : 0.9 [ 0.6-1 .4 ] ; at 6 mo : 1.0 [ 0.6-1 .6 ] ; and at 12 mo : 1.1 [ 0.7-1 .8 ] ) .