76 / 232
demonstrated a positive moderate agreement (
r
= 0.36,
P
\
.0001) between the AHI and the C-P score (
Figure 1A
).
This analysis includes 5 patients with an AHI
.
70; if these
subjects are excluded from the study population, there is
still a positive moderate agreement (
r
= 0.32,
P
= .0004).
Correlation analysis for AHI for patients who underwent
DISE by the senior author demonstrated a positive moderate
agreement (n = 58,
r
= 0.33,
P
= .01), as did correlation
analysis for the remaining 7 surgeons (n = 69,
r
= 0.37,
P
=
.002).
Using the same methodology, we found a negative weak
agreement between the lowest oxygen saturation and the C-
P score (
r
=
2
0.26,
P
= .004;
Figure 1B
). Five patients
were included in this analysis with a lowest oxygen satura-
tion
\
65%, and excluding these subjects from the study
population failed to demonstrate any agreement between C-
P score and lowest oxygen saturation (
r
= 0.16,
P
= .08).
Correlation analysis for O
2
nadir for patients who underwent
DISE by the senior author demonstrated a similar negative
moderate agreement (n = 58,
r
=
2
0.3,
P
= .03); however,
correlation analysis for the remaining 7 surgeons did not
identify a significant correlation (n = 64,
r
=
2
0.2,
P
= .1).
Multivariate linear regression analysis—controlling for
age at endoscopy, presence of a syndrome, and history of
adenotonsillectomy—demonstrated a statistically significant
association between the C-P score and both preprocedural
AHI and oxygen nadir. This analysis revealed that a 2.6-
point increase in AHI corresponds to a 1-point increase in the
C-P score (95% confidence interval: 1.4-3.8,
P
\
.001). A simi-
lar, 1.1% decrease in oxygen nadir corresponds to a 1-point
increase in the C-P score (95% confidence interval: –1.7 to
2
0.5,
P
\
.001). These results indicate that the severity of ana-
tomic obstruction in pediatric OSA, as defined with a systematic
scoring system for DISE, correlates with both AHI and the
lowest oxygen saturation on preprocedural PSG when known
covariates are accounted for.
Discussion
The present data extend the previously published relation-
ship between C-P score and PSG severity to a larger, multi-
institutional prospective series of patients who underwent
DISE. We hypothesized that the severity of anatomic
obstruction would correlate with the severity of OSA as
defined by the PSG. For this study, we chose to include all
children who presented to our institutions with a PSG and
met the criteria for undergoing DISE, regardless of age,
severity of OSA, and medical complexity. We found a sta-
tistically significant positive correlation between the C-P
score and the AHI, as well as a statistically significant nega-
tive correlation between the C-P score and the lowest
oxygen saturation. Our analysis found a much stronger rela-
tionship between C-P score and AHI than between C-P
score and lowest oxygen saturation, as evidenced by the fact
that a few patients with very low oxygen saturations had a
significant influence over this correlation. These data pro-
vide initial evidence supporting our hypothesis that the
severity of anatomic obstruction in children with OSA, as
measured with DISE, correlates with PSG parameters. Such
data are important clinically, as DISE is becoming a widely
utilized tool for the identification of airway obstruction in
children with OSA. The evidence supporting DISE-directed
surgery in the management of pediatric OSA is limited, and
an organized approach toward studying this procedure, such
as the one provided by the C-P scoring system, is critical to
determining the proper role of DISE in the treatment of
OSA.
To our knowledge, this study represents the first to
examine the relationship between anatomic obstruction in
OSA, as measured by DISE, and preprocedural PSG para-
meters in children. A number of studies have examined
whether DISE findings are correlated with PSG severity in
adult populations. Most recently, Dedhia and Weaver
reviewed a case series of 65 adult patients who underwent
DISE, and they scored the anatomic obstruction using the
VOTE system (velum, oropharynx, tongue, epiglottis).
7
In
this study, the authors failed to detect a significant associa-
tion between the level of anatomic obstruction on DISE and
the pre-DISE PSG parameters. Furthermore, this study
failed to detect any significant associations between the
severity of anatomic obstruction on DISE and Epworth
Sleepiness Scale scores or quality of life as measured by the
SNORE25 instrument. This study calls into question the
external validity and clinical usefulness of DISE scoring
systems for adult OSA patients.
A
B
0
20
40
60
80
100
120
0
2
4
6
8
10
12
14
Apnea Hypopnea Index (event/hr)
Chan-Parikh Score
40
50
60
70
80
90
100
0
2
4
6
8
10
12
14
O
2
Nadir (%)
Chan-Parikh Score
Figure 1.
Correlation analysis: (A) apnea-hypopnea index and
Chan-Parikh score (
r
= 0.36,
P
\
.0001) and (B) O
2
nadir and
Chan-Parikh score (
r
=
2
0.26,
P
= .004).
Otolaryngology–Head and Neck Surgery 155(4)
54