TABLE 4.

Correlations Between Rotator Cuff Tear Characteristics and PSQI Score^a

Characteristic	Correlation (r)	Significance (P)
Retraction	–0.01b	.84
Anterior-posterior dimension	0.00b	.99
Atrophy	0.13c	.06
Goutallier grade	0.07c	.29
Level of retraction	–0.04c	.60
No. of torn tendons	0.01c	.91
Humeral head rise	0.11d	.10

^aP < .05. PSQI, Pittsburgh Sleep Quality Index.

^bPearson correlation coefficient (both variables are continuous).

^cSpearman rank-order correlation coefficient (one variable is continuous, and the other is ordinal [ranked]).

^dPoint biserial correlation coefficient (one variable is dichotomous [nominal: yes or no], and the other is continuous).