Table 1 Characteristics in all participants (N=222)
N %
Gender
Male 149 67.1
Female 73 32.9
Adiposity
Obese 48 21.6
Non-obese 174 78.4
Adenoid hypertrophy 134 60.4
Tonsil hypertrophy 126 56.8
Tonsil size
Grade 1 14 6.3
Grade 2 82 36.9
Grade 3 82 36.9
Grade 4 44 19.8
Disease severity
AHI <1 106 47.7
AHI ≥ 1 116 52.3
Note: AHI = apnea /hypopnea index.
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Table 2 Demographic data and sleep studies in all participants (N=222)
Mean ±SD Min-Max Q1 Q2 Q3
Age, year 7.3 ± 3.7 1.4-17.8 4.7 6.5 9.4
Weight, kg 29.2 ± 16.2 10-93 18.0 22.9 34.7
Height, cm 122.2 ± 21.7 79-185 106.8 119.5 136.3
BMI, kg/m2 18.1 ± 3.9 11.4-31.2 15.3 16.8 20.4
BMI percentile 62.2 ± 30.7 2-99 37.8 64.7 92.3
AN ratio 0.69 ± 0.16 0.30-0.95 0.58 0.73 0.83
AHI, event/hour 5.4 ± 13.0 0-130.5 0.3 1.0 3.4
MeanSaO2, % 97.2 ± 2.2 70.0-99.4 97 97.7 98
MinSaO2, % 88.8 ± 2.2 50-97 86 91 93
Note: AHI = apnea /hypopnea index; AN ratio = adenoidal-nasopharyngeal ratio;
BMI = body mass index; SaO2 = oxygen saturation.
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Table 3 Objective and subjective measures in all participants (N=222)
N %
Objective measure
Tonsil hypertrophy 126 56.8 Adenoid hypertrophy 134 60.4
Obesity 48 21.6
Subjective measure
Snoring > 5 nights/week 144 64.9 Snoring > 3month 166 74.8
Diaphoresis 53 23.9
Awaken 71 32.0
Bedwetting 27 12.2
Nightmare 60 27.0
Breathing pause 62 27.9
Nasal speech 178 80.2
Mouth breathing 179 80.6
Weight gain 38 17.1
Low academic performance 39 17.6
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Table 4 Correlation between age (in year) and adenotonsillar size stratified by OSAS
Tonsil Adenoid
Subgroup ρ† P ρ† P
AHI＜1 -0.10 0.300 -0.56 < 0.001
AHI ≥1 -0.17 0.062 -0.55 < 0.001
† Spearman rank correlation
66
Table 5 Comparison of adenotonsillar size among age groups stratified by OSAS Toddler
67
Table 6 Comparisons of demographics between OSAS and non-OSAS children OSAS
(n = 116)
Non-OSAS (n = 106)
P
Gender 0.270
Male 74 (63.8) 75 (70.8)
Female 42 (36.2) 31 (29.2)
Age, year 7.6 ± 4.0 7.1 ± 3.2 0.355
Weight, kg 31.5 ± 18.9 26.8 ± 12.4 0.031*
Height, cm 123.0 ± 23.3 121.3 ± 19.9 0.543
BMI, kg/m2 18.9 ± 4.6 17.3 ± 2.8 0.002*
BMI percentile 64.9 ± 31.0 59.3 ± 30.3 0.175 AHI, event/hour 9.9 ± 16.8 0.4 ± 0.3 <0.001*
MeanSaO2, % 96.6 ± 2.8 97.7 ± 0.9 <0.001*
MinSaO2, % 86.1 ± 6.8 91.7 ± 3.4 <0.001*
Note: AHI = apnea /hypopnea index; BMI = body mass index; SaO2 = oxygen saturation
* indicates that the significant level was below 0.05.
68
Table 7 Clinical measures in detecting pediatric OSAS (AHI ≥1 as OSAS).
OSAS
Note: Data were analyzed using Chi-square test. CI = confidence internal; NPV = negative predictive value; OR = odds ratio; OSAS = obstructive sleep apnea syndrome;
PPV = positive predictive value. * indicates that the significant level was below 0.05.
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Table 8 Multiple logistic regression model of measures in detecting pediatric OSAS
B P OR (95% CI)
Tonsil hypertrophy 1.98 <0.001* 7.2 (3.5–14.8)
Adenoid hypertrophy 0.69 0.047* 2.0 (1.0–3.9)
Obesity 0.76 0.068 2.1 (0.9–4.8)
Snoring > 5 nights/week 0.33 0.382 1.4 (0.7–2.9)
Snoring > 3month 0.30 0.475 1.3 (0.6–3.1)
Awaken 0.75 0.043* 2.1 (1.0–4.4)
Breathing pause 1.74 <0.001* 5.7 (2.4–13.5)
Note: OSAS = obstructive sleep apnea syndrome; OR = odds ratio.
* indicates that the significant level was below 0.05.
70
Table 9 Collinearity diagnostics of the seven clinical measures in detecting pediatric OSAS
Tolerance Variance inflation factor
Tonsil hypertrophy 0.89 1.13
Adenoid hypertrophy 0.85 1.17
Obesity 0.96 1.04
Snoring >5 nights/week 0.77 1.29
Snoring >3month 0.81 1.24
Awaken 0.98 1.02
Breathing pause 0.87 1.15
Note: OSAS = obstructive sleep apnea syndrome.
71
Table 10 Global model fit when adding each subjective measure on objective model in detecting pediatric OSAS
Note: Objective model = adenoid hypertrophy + tonsil hypertrophy + obesity.
OSAS = obstructive sleep apnea syndrome.
72
Table 11 Discrimination and calibration properties when adding each subjective measure on objective model in detecting pediatric OSAS
Model C-Inde x
△C-Index P Value for △ C-Index
Chi-Square for HL†
P Value of HL
Objective model 0.775 – – 2.0 0.848
+snoring frequency 0.788 0.013 0.191 3.9 0.793
+ snoring duration 0.786 0.011 0.163 4.2 0.753
+ awaken 0.790 0.015 0.185 6.5 0.480
+ breathing pause 0.822 0.047 0.001 0.73 0.994
Note: † HL = Hosmer–Lemeshow statistic using deciles of risk for OSAS probabilities.
Objective model = adenoid hypertrophy + tonsil hypertrophy + obesity.
OSAS = obstructive sleep apnea syndrome.
73
Table 12 Integrated discrimination improvement of each subjective measure on objective model in detecting pediatric OSAS
Model Predicted
†
Compare to objective model; IDI = integrated discrimination improvement.74
Table 13 Reclassification table for predicted pediatric OSAS risk using objective measures with and without adding “snoring frequency”
Number of subjects Reclassified Net
Correctly
Subjects without OSAS (n = 106)
Predicted OSAS risk
Note: OSAS = obstructive sleep apnea syndrome.
75
Table 14 Reclassification table for predicted pediatric OSAS risk using objective measures with and without adding “snoring duration”
Number of subjects Reclassified Net
Correctly
Subjects without OSAS (n = 106)
Predicted OSAS risk
Note: OSAS = obstructive sleep apnea syndrome.
76
Table 15 Reclassification table for predicted pediatric OSAS risk using objective measures with and without adding “breathing pause”
Number of subjects Reclassified Net
Correctly
Subjects without OSAS (n = 106)
Predicted OSAS risk
Note: OSAS = obstructive sleep apnea syndrome.
77
Table 16 Reclassification table for predicted pediatric OSAS risk using objective measures with and without adding “awaken”
Number of subjects Reclassified Net
Correctly
Subjects without OSAS (n = 106)
Predicted OSAS risk
Note: OSAS = obstructive sleep apnea syndrome.
78
Table 17 Global model fit comparing subjective model, objective model, and combined model in detecting pediatric OSAS
Model Likelihood Note: OSAS = obstructive sleep apnea syndrome.
Objective model = adenoid hypertrophy + tonsil hypertrophy + obesity.
Subjective model = snoring frequency + snoring duration + breathing pause + awaken.
79
Table 18 Discrimination and calibration properties comparing subjective model, objective model, and combined model in detecting pediatric OSAS
Model C-Index Chi-Square
for HL†
P Value of HL
Objective model 0.78 2.01 0.848
Subjective model 0.72 4.42 0.730
Combined model 0.84 6.19 0.626
Note: † HL = Hosmer–Lemeshow statistic using deciles of risk for OSAS probabilities.
Objective model = adenoid hypertrophy + tonsil hypertrophy + obesity.
Subjective model = snoring frequency + snoring duration + breathing pause + awaken.
OSAS = obstructive sleep apnea syndrome.
80
Table 19 Comparison of discrimination properties of pediatric OSASA among different models
Contrast △AUC SE 95% CI of △AUC P
Objective vs. Subjective 0.0531 0.0444 -0.0340 to 0.140 0.2321 Objective vs. Combined 0.0610 0.0207 0.0205 to 0.101 0.0032*
Subjective vs. Combined 0.114 0.0289 0.0574 to 0.171 0.0001*
Note: AUC = area under the ROC curve; SE = standard error; CI = confidence interval.
* indicates that the significant level was below 0.05.
81
Table 20 Integrated discrimination improvement of subjective model on objective model and objective model on subjective model in detecting pediatric OSAS Model Predicted
†
Compare to objective model;IDI = integrated discrimination improvement.
82
Table 21 Reclassification table for predicted pediatric OSAS risk using subjective measures with and without adding objective measures
No. of subjects Reclassified Net
Correctly
with "objective measures"
Subjects with OSAS (n = 116)
Subjects without OSAS (n = 106)
Predicted OSAS risk
Note: OSAS = obstructive sleep apnea syndrome.
83
Table 22 Reclassification table for predicted pediatric OSAS risk using objective measures with and without adding subjective measures
No. of subjects Reclassified Net
Correctly
with "subjective measures"
Subjects with OSAS (n = 116)
Subjects without OSAS (n = 106)
Predicted OSAS risk
Note: OSAS = obstructive sleep apnea syndrome.
84
Table 23 Validation statistics of the combined model
Leave-one-out Bootstrap K-fold
100
iterations
200 iterations
500 iterations
K=3 K=5 K=10
C-index 0.801 0.812 0.817 0.817 0.805 0.802 0.804