Ww. Flemons et al., LIKELIHOOD RATIOS FOR A SLEEP-APNEA CLINICAL-PREDICTION RULE, American journal of respiratory and critical care medicine, 150(5), 1994, pp. 1279-1285
Citations number
25
Categorie Soggetti
Emergency Medicine & Critical Care","Respiratory System
Nocturnal polysomnography, the standard diagnostic test for sleep apne
a, is an expensive and limited resource. In order to help identify the
urgency of need for treatment, we determined which clinical features
were most useful for establishing an accurate estimate of the probabil
ity that a patient had sleep apnea. Of 263 physician-referred patients
, 200 were eligible for the study and 180 (90%) completed it. All pati
ents had their histories recorded with a standard questionnaire, and u
nderwent anthropomorphic measurements and nocturnal polysomnography. S
leep apnea was defined as more than 10 episodes of apnea or hypopnea p
er hour of sleep. Multiple linear and logistic regression models predi
ctive of sleep apnea were compared with physicians' subjective impress
ions and previously reported models. Likelihood ratios were calculated
for several levels of a sleep apnea clinical score produced by one of
the linear models. Predictors of sleep apnea in the final model (R(2)
= 0.34) included neck circumference, hypertension, habitual snoring,
and bed partner reports of nocturnal gasping/choking respirations This
model was superior to physician impression, slightly inferior to more
detailed linear and logistic models, and comparable to previously rep
orted models. A sleep apnea clinical score of less than 5 had a likeli
hood ratio of 0.25 (95% CI: 0.15 to 0.42) and a corresponding posttest
probability of 17%, while a score of greater than 15 had a likelihood
ratio of 5.17 (95% CI: 2.54 to 10.51) and posttest probability of 81%
. These likelihood ratios can simply and accurately determine the prob
ability of whether a patient has sleep apnea.