Table 5.

Reliability analysis showing the test-retest effect sizes and intra-class correlation coefficient (ICC) and internal consistency

	Test re-test reliability (n = 93)					Correlation,	Internal consistency a
BCTOS item	Test		Re-test		Effect size	ICC [95% CI]		Cronbach’s α
	Mean	SD	Mean	SD	Cohen’s d	Test re-test, n = 93	Item-subscale totalabn = 101	n = 101
Cosmetic subscalea	1.95	0.69	1.88	0.61	0.112	0.89 [0.84–0.93]		0.89
1 Breast texture (hardening)	2.06	0.92	2.03	0.83	0.034	0.82 [0.74–0.87]	0.79 [0.69–0.85]
2 Nipple appearance	1.93	1.08	1.86	1.05	0.074	0.85 [0.78–0.90]	0.60 [0.45–0.72]
3 Breast elevation/position	1.86	1.00	1.81	0.92	0.053	0.76 [0.66–0.84]	0.65 [0.52–0.75]
4 Scar tissue	2.12	0.94	2.09	0.86	0.034	0.82 [0.74–0.88]	0.60 [0.45–0.71]
5 Breast swelling	1.62	0.91	1.50	0.79	0.132	0.83 [0.75–0.89]	0.62 [0.39–0.76]
6 Fit of bra	1.84	0.93	1.71	0.90	0.130	0.76 [0.66–0.84]	0.75 [0.65–0.83]
7 Breast sensitivity	2.15	0.99	2.05	0.94	0.099	0.72 [0.60–0.80]	0.70 [0.56–0.79]
8 Overall skin appearance	1.85	0.88	1.70	0.78	0.172	0.79 [0.69–0.86]	0.77 [0.67–0.84]
9 Breast tenderness	2.11	0.97	2.07	0.93	0.043	0.79 [0.71–0.86]	0.63 [0.49–0.74]
Functional subscalea	1.46	0.73	1.43	0.67	0.032	0.90 [0.86–0.93]		0.90
10 Arm heaviness	1.49	0.87	1.51	0.85	0.024	0.84 [0.78–0.89]	0.92 [0.88–0.95]
11 Shoulder discomfort	1.49	0.93	1.48	0.87	0.011	0.83 [0.75–0.88]	0.84 [0.77–0.89]
12 Arm discomfort	1.60	0.89	1.55	0.87	0.058	0.86 [0.80–0.90]	0.91 [0.86–0.94]
13 Arm swelling	1.24	0.58	1.19	0.47	0.090	0.87 [0.81–0.91]	0.78 [0.69–0.85]
All itemsa	1.80	0.62	1.74	0.56	0.105	0.91 [0.87–0.94]		0.90

^aanalysis performed for the new BCTOS-13 ^banalysis performed on test