Table 2.

ROC Analysis Results

	Total Usage Time	Female Usage Time	Male Usage Time
Cut-Off*	20.5	17.5	20.5
Sensitivity	71.8%	63.6%	91.3%
Specificty	73,1%	78.9%	67.5%
PPV	49.4%	46.2%	54.0%
NPV	50.6%	53.8%	46.0%
AUC	0.779	0.794	0.819
Accuracy	72.4%	69.9%	76.2%

^*Usage times are shown as hy (hour x year); PPV: Positive predictive value; NPV: Negative predictive value; AUC: Area under the curve.