Table 2.

Walking speed thresholds (m/s) for moderate intensity based on ROC curve analyses

	Threshold (95% CIs), m/s	Sensitivity (%)	Specificity (%)	Accuracy (%)	AUC	PPV (%)	NPV (%)
Young	1.28 (1.07, 1.38)	54.2	81.2	60.0	0.69	91.4	32.5
Middle-aged	1.25 (1.13, 1.33)	73.8	88.9	77.2	0.90	95.7	50.0
Older-aged	1.23 (1.11, 1.33)	71.2	78.2	73.4	0.83	88.7	53.7
Whole sample	1.28 (1.13, 1.33)	58.1	88.7	65.7	0.82	93.9	41.4

Note: Young, middle- and older-aged represents participants 21–40, 41–60 and 61–85 years, respectively. Abbreviations: AUC, area under the curve; CI, confidence interval; mph, mile per hour; NPV, negative predictive value; PPV, positive predictive value; ROC, Receiver operating characteristic.