group disability wratr wrata treatment mild 115 108 treatment mild 98 105 treatment mild 107 98 treatment moderate 100 105 treatment moderate 105 95 treatment moderate 95 98 treatment severe 89 78 treatment severe 100 85 treatment severe 90 95 control mild 90 92 control mild 85 95 control mild 80 81 control moderate 70 80 control moderate 85 68 control moderate 78 82 control severe 65 62 control severe 80 70 control severe 72 73