Relationship between poor quality sleep, excessive daytime sleepiness and low academic performance in medical students

Figures & data

Table 1 Comparison between the two groups of the study population: “female students” and “male students”

Variable	Group “female students” (n=323)	Group “male students” (n=134)	P-value
Age (years)*	20 (19; 21)	21 (20; 22)	0.03
BMI (kg/m^2)*	21.2 (19.6; 23.1)	21.8 (20.4; 23.5)	0.02
Psychological distress** (K6 score >13)	277 (85.8%)	118 (88.1%)	0.51
Excessive daytime sleepiness** (ESS score ≥11)	139 (43%)	27 (20.1%)	<0.001
Poor sleep** (PSQI score >5)	190 (58.8%)	76 (56.7%)	0.68
General average mark/20*** (academic performance)	12.83±2.3	12.53±2.14	0.19

Notes:

* Expressed as median (IQR);

** expressed as frequency(%);

*** expressed as mean±SD. Bold values are statistically significant.

Abbreviations: BMI, body mass index; K6, Kessler Psychological Distress Scale; ESS, Epworth Sleepiness Scale; PSQI, Pittsburgh Sleep Quality Index; IQR, interquartile range.

Figure 1 Histograms showing the distribution of Epworth Sleepiness Scale and PSQI Score in the study population.

Abbreviation: PSQI, Pittsburgh Sleep Quality Index.

Table 2 Comparison between the two groups of the study population: “students in first or second medical year” and “students from the third to the fifth medical year”

Variable	Students in first or second medical year (n=207)	Students from the third to the fifth medical year (n=250)	P-value
Psychological distress (K6 score >13)	174 (84.1%)	220 (88%)	0.22
Excessive daytime sleepiness (ESS score ≥11)	83(40.1%)	83 (33.2%)	0.12
Poor sleep (PSQI score >5)	107 (51.7%)	159 (63.6%)	0.01

Note: Bold value is statistically significant.

Abbreviations: K6, Kessler Psychological Distress Scale; ESS, Epworth Sleepiness Scale; PSQI, Pittsburgh Sleep Quality Index.

Table 3 Univariate linear regression model for factors associated with the academic performance of the study population

Parameter	Univariate analysis
	Regression coefficient (ß)	95% CI	P-value
Age (years)	−0.23	−0.36 to −0.11	<0.001
Sex	−0.3	0.15 to 0.76	0.19
K6 score	0.04	0.005 to 0.07	0.024
ESS score	−0.03	−0.08 to 0.02	0.23
PSQI score	−0.09	−0.17 to −0.03	0.004

Note: Bold values are statistically significant.

Abbreviations: CI, confidence interval; K6, Kessler Psychological Distress Scale; ESS, Epworth Sleepiness Scale; PSQI, Pittsburgh Sleep Quality Index.

Table 4 Multiple linear regression analysis showing adjusted factors of academic performance among the study population

Parameter	Multivariate analysis
	Regression coefficient (ß)	95% CI	P-value
Age (years)	−0.22	−0.35 to −0.09	<0.001
Sex	0.36	−0.09 to 0.83	0.12
K6 score	0.03	−0.001 to 0.06	0.05
ESS score	−0.04	−0.09 to 0.011	0.13
PSQI score	−0.07	−0.14 to −0.002	0.04

Note: Bold values are statistically significant.

Abbreviations: CI, confidence interval; K6, Kessler Psychological Distress Scale; ESS, Epworth Sleepiness Scale; PSQI, Pittsburgh Sleep Quality Index.