Table 3.
Effect of temporal resolution on the reliability of estimates of breathing ratea.
| Breathing rate resolution | Device, mean (SD) | PSGb, mean (SD) | Biasc (SD; 95% CI) | LoAd (lower bound), (95% CI) | LoA (upper bound), (95% CI) | MDCe | MAEf (95% CI) | SADg (95% CI) | MAPEh (95% CI) | ICCi (95% CI) | |||||||||||
| 60 minutes | |||||||||||||||||||||
|
|
WSAj | 13.67 (1.51) | 14.58 (1.87) | −0.91 (1.28; −1.06 to −0.76) | −3.42 (−3.67 to −3.17) | 1.6 (1.34 to 1.85) | 2.51 | 1 (1.14 to 0.86) | 0.59 (0.47 to 0.71) | 6.48 (5.73 to 7.22) | 0.72 (0.65 to 0.77) | ||||||||||
|
|
Emfit | 14.18 (1.86) | 14.33 (1.85) | −0.14 (1.66; −0.44 to 0.15) | −3.39 (−3.9 to −2.89) | 3.11 (2.6 to 3.62) | 3.25 | 0.92 (1.16 to 0.67) | 0.5 (0.32 to 0.67) | 6.35 (4.68 to 8.02) | 0.6 (0.47 to 0.7) | ||||||||||
|
|
Somnofy | 13.89 (1.65) | 14.31 (1.8) | −0.42 (1.19; −0.65 to −0.19) | −2.76 (−3.16 to −2.36) | 1.92 (1.52 to 2.31) | 2.34 | 0.55 (0.77 to 0.33) | 0.32 (0.13 to 0.51) | 3.47 (2.27 to 4.67) | 0.76 (0.67 to 0.83) | ||||||||||
| 10 minutes | |||||||||||||||||||||
|
|
WSA | 13.67 (1.67) | 14.6 (2.2) | −0.93 (1.67; −1.01 to −0.86) | −4.21 (−4.34 to −4.08) | 2.34 (2.21, 2.47) | 3.28 | 1.14 (1.21 to 1.07) | 0.59 (0.54 to 0.63) | 7.29 (6.94 to 7.65) | 0.63 (0.61 to 0.66) | ||||||||||
|
|
Emfit | 14.16 (2.2) | 14.35 (2.17) | −0.18 (2.1; −0.33 to −0.04) | −4.31 (−4.56 to −4.06) | 3.94 (3.69 to 4.19) | 4.12 | 1.09 (1.22 to 0.96) | 0.5 (0.43 to 0.57) | 7.42 (6.6 to 8.25) | 0.54 (0.48 to 0.58) | ||||||||||
|
|
Somnofy | 13.87 (1.77) | 14.35 (2.05) | −0.48 (1.49; −0.59 to −0.36) | −3.41 (−3.6 to −3.21) | 2.45 (2.26 to 2.65) | 2.93 | 0.68 (0.79 to 0.57) | 0.36 (0.28 to 0.43) | 4.2 (3.64 to 4.76) | 0.69 (0.65 to 0.73) | ||||||||||
| 1 minute | |||||||||||||||||||||
|
|
WSA | 13.67 (2.04) | 14.61 (2.61) | −0.93 (2.32; −0.97 to −0.9) | −5.48 (−5.54 to −5.42) | 3.61 (3.56 to 3.67) | 4.55 | 1.51 (1.54 to 1.48) | 0.64 (0.63 to 0.66) | 9.85 (9.68 to 10.02) | 0.51 (0.5 to 0.52) | ||||||||||
|
|
Emfit | 14.17 (2.5) | 14.35 (2.57) | −0.18 (2.73; −0.24 to −0.12) | −5.54 (−5.65 to −5.44) | 5.18 (5.07 to 5.28) | 5.36 | 1.6 (1.65 to 1.56) | 0.63 (0.61 to 0.65) | 11.07 (10.74 to 11.4) | 0.42 (0.4 to 0.44) | ||||||||||
|
|
Somnofy | 13.87 (1.91) | 14.35 (2.43) | −0.47 (1.99; −0.52 to −0.43) | −4.38 (−4.46 to −4.3) | 3.43 (3.35 to 3.51) | 3.9 | 1.06 (1.1 to 1.01) | 0.48 (0.46 to 0.51) | 6.76 (6.54 to 6.99) | 0.58 (0.57 to 0.6) | ||||||||||
aMetrics of agreement for overall heart rate estimates from the devices against PSG electrocardiogram (ECG) estimates (beats per minute) at various temporal resolutions.
bPSG: polysomnography.
cBias is the difference in measurement between the device and PSG ECG (device–PSG ECG).
dLoA: limits of agreement.
eMDC: minimum detectable changes; smallest detectable change independent of measurement error (half of Bland-Altman agreement width).
fMAE: mean absolute error.
gSAD: standardized absolute difference; a directionless version of Cohen d.
hMAPE: mean absolute percentage error.
iICC: intraclass correlation coefficient; with two-way random effects (measures of measurement reliability).
jWSA: Withings sleep analyzer.