From baseline to the 24-month follow-up assessment , eight participants in brief CBT ( 13.8 % ) and 18 participants in treatment as usual ( 40.2 % ) made at least one suicide attempt ( hazard ratio = 0.38 , 95 % CI = 0.16-0 .87 , number needed to treat = 3.88 ) , suggesting that soldiers in brief CBT were approximately 60 % less likely to make a suicide attempt during follow-up than soldiers in treatment as usual .