Body Mass Index, Gender, and Ethnic Variations Alter the Clinical Implications of the Epworth Sleepiness Scale in Patients with Suspected Obstructive Sleep Apnea§

Table 1.: Demographic and Clinical Characteristics of the Participants

Group	Males	Females	P-Value
Number	1092	805
Age, years (± s.d.)	53 ± 15	55 ± 14	0.0020
Height, cm (± s.d.)	177 ± 8	161 ± 9	<0.0001
Weight, kg (± s.d.)	73 ± 18	63 ± 17	<0.0001
Body mass index, kg/m² (± s.d.)	35 ± 8	36 ± 9	0.0003
Neck circumference, cm (± s.d.)	17 ± 2	15 ± 3	<0.0001
Ethnicity, no.(%) Caucasian Hispanic Other^†	593 (54%) 471 (43%) 28 (3%)	401 (50%) 385 (48%) 18 (2%)	ns 0.045 ns
TST, minutes (± s.d.)	343 ± 79	346 ± 76	ns
Sleep efficiency, % (± s.d.)	77 ± 16	78 ± 17	ns
RDI, events/hour (± s.d.)	37 ± 30	23 ± 27	<0.0001
Lowest SaO₂, % (± s.d.)	77 ± 12	81 ± 10	<0.0001

^* s.d. = standard deviation; cm = centimeters; kg = kilograms; m = meters; no. = number; ESS = Epworth Sleepiness Scale score; AHI = apnea-hypopnea index, SaO₂ = oxyhemoglobin percentage, ns = not significant.

^† Other reported ethnicities: Black (n = 36), Asian (n = 4), American Indian (n = 2), Filipino (n = 1), Indian (n = 1), Lebanese (n = 1), and Portuguese (n = 1).