Table 4.

Results of the usability measurements of the pulse oximeter and Spearman correlation between usability and prior health knowledge (N=147).

Measurement	Value		Correlation with health knowledge (r)		P value (unilateral)
	Mean (SD)	Range (minimum-maximum)
Effectiveness (errors)	0.99 (0.92)	0-6	−0.263		.001
Efficiency (seconds)	158.42 (75.75)	24.8-458.8	−0.062		.45
Satisfaction (SUSa score)	71.52 (17.29)	15-100	0.195		.02
Data recorded (rate of correct response)	0.65 (0.48)	0-1	0.018		.82

^aSUS: system usability scale.