The Top End Sleepiness Scale (TESS): A New Tool to Assess Subjective Daytime Sleepiness Among Indigenous Australian Adults

Figures & data

Figure 1 (Continue).

Figure 1 Top End Sleepiness Scale.

Table 1 Demographic and Clinical Parameters of the Study Participants

Clinical Parameters	Participants (n=82)
Age (mean, 95% CI)	45.47 (42.9, 48.05)
18<35	17 (21%)
35<45	24 (29%)
45<55	24 (29%)
≥55	17 (21%)
Males	41 (50%)
BMI (Median, IQR) (n=81)	33.67 (30.86, 38.95)
Normal Weight (BMI<25)	2 (3%)
Overweight (BMI 25 < 30)	16 (20%)
Obese (BMI 30 < 35)	25 (31%)
Morbidly obese (BMI ≥35)	38 (47%)
Consumed alcohol on study date (n=79)	1 (1%)
Medical co-morbidities	59 (72%)
Hypertension (n=80)	31 (39%)
Diabetes (n=81)	28 (35%)
Heart disease (n=60)	11 (18%)
Completed TESS	82 (97%)
ESS (median (IQR))	8 (5, 12)
TESS (median (IQR))	5 (3, 7)
Total AHI (n=80)	30.9 (12.8, 55.45)
OSA (AHI ≥ 5) (n=80)	72 (90%)
Mild (AHI 5 < 15)	16 (22%)
Moderate (AHI 15 < 30)	15 (21%)
Severe (AHI ≥ 30)	41 (57%)

Abbreviations: CI, confidence interval; BMI, body mass index; IQR, interquartile range; TESS, Top End Sleepiness Scale; ESS, Epworth Sleepiness Scale; AHI, apnea-hypopnea index; OSA, obstructive sleep apnea.

Table 2 Median and Mean Top End Sleepiness Scale Scores by Demographic Breakdown

Clinical Parameters	TESS Median (IQR)*	TESS Mean (95% CI)*	Patients with OSA (n (%))
Age
18–35 (n=16)	5.5 (3.5, 10)	7.06 (4.35, 9.78)	14 (88%)
35–45 (n=24)	4.5 (1.5, 6)	4.21 (2.97, 5.45)	22 (92%)
45–55 (n=23)	6 (3, 10)	6.83 (5.22, 8.44)	21 (91%)
55+ (n=17)	3 (2, 6)	4.41 (2.39, 6.44)	15 (88%)
Sex
Female (n=41)	5 (3, 7)	5.29 (4.11, 6.47)	35 (85%)
Male (n=39)	5 (3, 9)	5.87 (4.47, 7.28)	37 (95%)
BMI
Normal weight (n=2)	7, 12	9.5	2 (100%)
Overweight (n=15)	4 (2, 6)	4.73 (2.8, 6.67)	12 (80%)
Obese (n=25)	5 (3, 7)	5.52 (3.71, 7.34)	20 (80%)
Obese II (n=37)	6 (3, 8)	5.9 (4.58, 7.20)	37 (100%)
Chronic disease
No (n=26)	5 (3, 7)	5.73 (4.28, 7.18)	24 (92%)
Yes (n=54)	5 (2, 8)	5.5 (4.34, 6.66)	48 (89%)

Note: *Median and mean scores calculated only for patients with AHI data.

Abbreviations: TESS, Top End Sleepiness Scale; IQR, interquartile range; CI, confidence interval; OSA, obstructive sleep apnea; BMI, body mass index.

Figure 2 Frequency plot of Top End Sleepiness Scale scores.

Abbreviation: TESS, Top End Sleepiness Scale.

Table 3 Breakdown of Scores for Individual Top End Sleepiness Scale Questions with Cronbach’s α and Split Half Reliability Value

Question Number	Median (IQR)	Mean (95% CI)	Cronbach’s α	Spearman Correlation
TESS-1 (n=64)	0 (0, 1)	0.55 (0.35, 0.74)	0.80
TESS-2 (n=65)	0 (0, 1)	0.58 (0.37, 0.8)	0.76
TESS-3 (n=65)	1 (0, 2)	1.4 (1.12, 1.68)	0.79
TESS-4 (n=65)	0 (0, 1)	0.78 (0.54, 1.03)	0.75
TESS-5 (n=65)	1 (0, 1)	0.89 (0.63, 1.16)	0.78
TESS-6 (n=65)	1 (1, 3)	1.55 (1.28, 1.82)	0.77
TESS Total (n=83)	5 (3, 7)	5.49 (4.62, 6.37)	0.81
Odd Half (n=64)	2 (1, 4)	2.86 (2.31, 3.41)		0.71
Even half (n=65)	3 (1, 4)	2.92 (2.34, 3.51)

Abbreviations: TESS, Top End Sleepiness Scale; IQR, interquartile range.

Table 4 Spearman Correlation Coefficient Between Questions Within Top End Sleepiness Scale and Top End Sleepiness Scale Total Score

Questions	TESS-1	TESS-2	TESS-3	TESS-4	TESS-5	TESS-6	TESS Total
TESS-1		0.40	0.26	0.26	0.23	0.38	0.54
TESS-2	0.001		0.41	0.48	0.42	0.33	0.66
TESS-3	0.040	0.001		0.49	0.40	0.42	0.74
TESS-4	0.036	<0.001	<0.001		0.48	0.40	0.71
TESS-5	0.066	0.001	0.001	<0.001		0.47	0.71
TESS-6	0.002	0.007	0.001	0.001	<0.001		0.75
TESS Total	<0.001	<0.001	<0.001	<0.001	<0.001	<0.001

Note: Right upper half reports Spearman correlation coefficient, while left lower half reports the respective p-values of the coefficient.

Abbreviation: TESS, Top End Sleepiness Scale.

Figure 3 Scatterplots showing the relationship between TESS (left) and ESS (right) scores and total AHI.

Abbreviations: TESS, Top End Sleepiness Scale; ESS, Epworth Sleepiness Scale; AHI, apnea-hypopnea index.

Figure 4 Area under the curve (AUC) receiver operator characteristic (ROC) for TESS and ESS tools sensitivity and 1-specificity overall (A) and for cut-offs TESS ≥3, TESS ≥8 and ESS ≥8 (B).

Abbreviations: TESS, Top End Sleepiness Scale; ESS, Epworth Sleepiness scale.

Table 5 Sensitivity, Specificity, Positive and Negative Predictive Values of Top End Sleepiness Scale in the Prediction of Obstructive Sleep Apnea (AHI ≥15), Severity, and by Sex Stratification

Parameters	Sensitivity	Specificity	Positive Predictive Value	Negative Predictive Value
TESS ≥3
AHI ≥15	84	38	76	50
Moderate OSA	67	18	18	67
Severe OSA	90	36	65	73
Sex
Male	85	50	90	38
Female	83	33	61	60
TESS ≥8
AHI ≥15	32	92	90	37
Moderate OSA	20	72	16	77
Severe OSA	37	87	79	51
Sex
Male	33	100	100	21
Female	30	89	78	50

Abbreviations: OSA, obstructive sleep apnea; TESS, Top End Sleepiness Scale.

Table 6 Sensitivity, Specificity, Positive and Negative Predictive Values of Top End Sleepiness Scale in the Prediction of Moderate to Severe Obstructive Sleep Apnea for Scores ≥3 and ≥8 Compared to Other Alternative Obstructive Sleep Apnea Specific Screening Questionnaires

Items	Berlin Questionnaire	STOP-BANG Cut-Off ≥3	STOP-BANG ≥4	OSA 50	TESS Cut-Off ≥3	TESS Cut-Off ≥8
Sensitivity	82	94	81	94	84	32
Specificity	39	32	51	31	38	92
PPV					76	90
NPV					50	37

Abbreviations: OSA, obstructive sleep apnea; TESS, Top End Sleepiness Scale; PPV, positive predictive value; NPV, negative predictive value.