Table 3.
Cadence thresholds (steps/min) for moderate and vigorous intensity based on regression and ROC curve analyses
| Intensity METs | Measure | Regression thresholds | ROC thresholds | Heuristic thresholds | ||
|---|---|---|---|---|---|---|
| Value | 95% PI | Value | 99% CI | Value | ||
| 3 | Threshold (steps/min) | 102.2 | 45.9–111.2 | 95.5 | 91.5–105.5 | 100 |
| Se | 80.5 | – | 91.3 | – | 86.0 | |
| Sp | 92.5 | – | 86.2 | – | 89.6 | |
| PPV | 93.3 | – | 89.5 | – | 91.4 | |
| NPV | 78.7 | – | 88.5 | – | 83.3 | |
| AUC | – | – | 0.95 | 0.94–0.98 | – | |
| 4 | Threshold (steps/min) | 112.5 | 103.5–120.2 | 112.5 | 105.5–113.5 | 110 |
| Se | 89.0 | – | 89.0 | – | 93.5 | |
| Sp | 93.0 | – | 93.0 | – | 88.3 | |
| PPV | 86.0 | – | 86.0 | – | 79.6 | |
| NPV | 94.6 | – | 94.6 | – | 96.6 | |
| AUC | – | – | 0.97 | 0.96–0.99 | – | |
| 5 | Threshold (steps/min) | 120.2 | 112.5–127.8 | 116.5 | 114.5–120.5 | 120 |
| Se | 85.7 | – | 95.0 | – | 88.2 | |
| Sp | 93.7 | – | 89.2 | – | 92.7 | |
| PPV | 76.7 | – | 68.1 | – | 74.5 | |
| NPV | 96.5 | – | 98.7 | – | 97.0 | |
| AUC | – | – | 0.97 | 0.96–0.99 | – | |
| 6 | Threshold (steps/min) | 129.1 | 121.4–136.8 | 119.5 | 119.5–125.5 | 130 |
| Se | 64.1 | – | 98.4 | – | 64.1 | |
| Sp | 96.9 | – | 85.8 | – | 96.9 | |
| PPV | 70.7 | – | 44.7 | – | 70.7 | |
| NPV | 95.8 | – | 99.8 | – | 95.8 | |
| AUC | – | – | 0.97 | 0.95–0.99 | – | |
95% Prediction Intervals (PI). 99% Confidence Intervals (CI). AUC area under the curve, PPV Positive Predictive Value, NPV Negative Predictive Value, Se sensitivity, Sp specificity