Table 2.

Internal consistency of four breast lymphoedema questionnaires

Breast questionnaire questions	McDonald’s Omega (ω) (95%CI)	Pooled imputed ω (range)	⍺ of total scale ⍺ if item removed	Median (IQR) [range]
BLYSS (n = 158)	0.91 (0.87–0.93)	0.90 (0.89–0.90)	0.91
Q1 Swelling	0.89		0.89	1 (0–1) [0–4]
Q2 Pain	0.89		0.89	1 (0–1) [0–4]
Q3 Heaviness	0.89		0.89	0 (0–1) [0–3]
Q4 Unpleasant sensation	0.89		0.89	1 (0–1) [0–3]
Q5 Hardness	0.91		0.91	1 (0–1) [0–4]
Q6 Discomfort wearing a bra	0.89		0.89	0.5 (0–1) [0–4]
Q7 Indentations from the bra	0.89		0.89	0 (0–1) [0–4]
EORTC-BR23 Breast symptoms subscale (n = 163)	0.73 (0.65–0.80)	0.73 (0.72–0.74)	0.72
Q50 Pain	0.67		0.59	2 (1–2) [1–4]
Q51 Swelling	0.70		0.67	1 (1–2) [1–4]
Q52 Oversensitive	0.64		0.61	2 (1–2) [1–4]
Q53 Skin problems	0.73		0.73	1 (1–2) [1–4]
LSIDS-T Intensity Soft tissue subscale (n = 161)	0.84 (0.77–0.89)	0.85 (0.84–0.86)	0.85
Q1 Heaviness	0.		0.80	0 (0–1) [ 0–5]
Q2 Tightness	0.		0.81	0 (0–2) [0–5]
Q3 Pain	0.		0.82	0 (0–2) [0–5]
Q4 Achiness	0.		0.83	0 (0–1) [0–4]
Q5 Swelling	0.		0.83	1 (0–1) [0–4]
Q6 Hardness	0.		0.84	0 (0–2) [0–5]
BOB (n = 164)	0.91 (0.88–0.93)	No missing	0.83
Q1 Frequency of breast bother	0.90		0.77	3 (1–4) [0–4]
Q2 Average breast bother in past week	0.88		0.79	1 (1–2) [0–3]
Q3 Worst breast bother in past week	0.87		0.78	1 (0–2) [0–4]
Q4 Breast bother VAS	0.88		0.87	2.6 (0.5-5) [0–10]

ω: McDonald’s Omega ⍺: Cronbach’s alpha (internal consistency), IQR: interquartile range, VAS: visual analogue scale, BLYSS: Breast Lymphoedema Symptoms Severity, EORTC-BR23: European Organization for Research and Treatment of Cancer Breast Cancer-Specific Quality of Life Questionnaire - Breast and Arm symptom sub-scales, LSIDS-T: Lymphedema Symptom Intensity and Distress -Trunk - Soft tissue subscale, BOB: Breast Oedema Bother scale