Table 5.

Bland–Altman ratios between the results generated by smartphone PPG and ECG.

Threshold	FPDT	rMSSD	pNN50	SDNN	Log HF	Log LF
SPQI > 0	Peak	0.694	0.888	0.443	0.232	0.268
	Valley	0.552	0.813	0.344	0.199 *	0.215
	M1D	0.539	0.833	0.312	0.186 *	0.181 *
	M2D	0.848	0.940	0.621	0.256	0.315
	Tangent	0.677	0.905	0.287	0.166 *	0.156 *
SPQI > 0.8	Peak	0.581	0.798	0.351	0.214	0.241
	Valley	0.451	0.660	0.262	0.164 *	0.165 *
	M1D	0.433	0.701	0.220	0.164 *	0.141 *
	M2D	0.653	0.808	0.455	0.233	0.291
	Tangent	0.469	0.708	0.177 *	0.134 *	0.105 *
SPQI > 0.95	Peak	0.514	0.737	0.283	0.180 *	0.217
	Valley	0.297	0.547	0.144 *	0.129 *	0.108 *
	M1D	0.367	0.615	0.179 *	0.150 *	0.136 *
	M2D	0.504	0.672	0.308	0.195 *	0.257
	Tangent	0.325	0.529	0.123 *	0.108 *	0.092 *
* acceptable or good agreement