Sleep disordered breathing and daytime sleepiness are associated with poor academic performance in teenagers. A study using the Pediatric Daytime Sleepiness Scale (PDSS)

Abstract

Study objectives: Inadequate sleep and sleep disordered breathing (SDB) can impair learning skills. Questionnaires used to evaluate sleepiness in adults are usually inadequate for adolescents. We conducted a study to evaluate the performance of a Spanish version of the Pediatric Daytime Sleepiness Scale (PDSS) and to assess the impact of sleepiness and SDB on academic performance.

Design: A cross-sectional survey of students from 7 schools in 4 cities of Argentina.

Measurements: A questionnaire with a Spanish version of the PDSS was used. Questions on the occurrence of snoring and witnessed apneas were answered by the parents. Mathematics and language grades were used as indicators of academic performance.

Participants: The sample included 2,884 students (50% males; age: 13.3 +/- 1.5 years)

Results: Response rate was 85%; 678 cases were excluded due to missing data. Half the students slept <9 h per night on weekdays. The mean PDSS value was 15.74 +/- 5.93. Parental reporting of snoring occurred in 511 subjects (23%); snoring was occasional in 14% and frequent in 9%. Apneas were witnessed in 237 cases (11%), being frequent in 4% and occasional in 7%. Frequent snorers had higher mean PDSS scores than occasional or nonsnorers (18 +/- 5, 15.7 +/- 6 and 15.5 +/- 6, respectively; P < 0.001). Reported snoring or apneas and the PDSS were significant univariate predictors of failure and remained significant in multivariate logistic regression analysis after adjusting for age, sex, body mass index, specific school attended, and sleep habits.

Conclusions: Insufficient hours of sleep were prevalent in this population. The Spanish version of the PDSS was a reliable tool in middle-school-aged children. Reports of snoring or witnessed apneas and daytime sleepiness as measured by PDSS were independent predictors of poor academic performance.

Figure 1

Sleep hours during weekdays and weekends, excluding daytime naps. (*)Excludes weekend and weeknight naps. Pearson's χ² P < 0.01.

Figure 2

Relative frequency histogram of PDSS. The estimated Gaussian distribution curve has been superimposed.

Figure 3

Average mathematic and literature grades (means ± SD) according to the PDSS in non-snorers (•), occasional snorers (○) and frequent snorers (▾). Two-way ANOVA found significant main effects of the PDSS (P< 0.001) and snoring (P<0.001). For each quartile, average grade was compared between snorers, occasional and frequent snorers (One-way ANOVA, * P<0.05, ** P<0.01).