Table 2.

Agreement between Categorical Designations (Kappa Coefficient) and Continuous Measures (Correlations) of Self-Reported and Actigraphy-Assessed Sleep Outcomes (n=477)

Sleep Outcome	Weighted Kappa† (95% CI)		P-Value
Sleep duration‡	0.1951 (0.1315 – 0.2587)		0.0001
Sleep onset latency§	0.2186 (0.0339 – 0.1522)		0.0001
Sleep efficiency¶	0.0054 (−0.0333 – 0.0440)		0.79
Sleep Outcome	Actigraphy Mean (SD)	Self-Report Mean (SD)	Pearson’s R
Sleep duration (minutes)	433.41 (72.14)	394.09 (85.17)	0.24*
Sleep onset latency (minutes)	26.55 (27.11)	39.35 (39.05)	0.27*
Sleep efficiency (%)	94.17% (5.79)	82.76% (15.08)	0.05

^†Weighted Kappa coefficients reported due to ordinal categories

^‡Sleep duration categories: <360 minutes; 360–419 minutes; 420–479 minutes; 480–540 minutes; >540 minutes

^§Sleep onset latency categories: <15 minutes; 15–20 minutes; 21–30 minutes; >30 minutes

^¶Sleep efficiency categories: <80%; 80–84%; 85–90%; >90%

^*P < 0.05 for Pearson’s R test