None N = 418		Mild N = 1346		Moderate N = 1070		Severe N = 356
	N	%	N	%	N	%	N	%
a. Characteristics of the subgroups—self-reported severity of arm swelling (N = 3190)
Country
Denmark	334	79.9	1165	86.6	990	92.5	337	94.7
USA	84	20.1	181	13.4	80	7.5	19	5.3
Age groups (years)
≤ 49	33	7.9	153	11.4	93	8.7	31	11.5
50–59	86	20.6	379	28.1	274	25.6	109	30.6
60–69	161	38.5	429	31.9	345	32.2	97	27.3
≥ 70	138	33.0	385	28.6	358	33.5	109	30.6
BMI (kg/m2)
Under/normal weight (< 25)	180	43.1	558	41.5	377	35.2	98	27.5
Overweight (25–29)	143	34.2	461	34.2	378	35.3	115	32.3
Obese (≥30)	94	22.5	325	24.1	310	29.0	140	39.3
Missing	1	0.2	2	0.2	5	0.5	3	0.9
Ethnicity
Caucasian	370	88.5	1195	88.8	914	85.4	303	85.1
Other	48	11.5	151	11.2	156	14.6	53	14.9
Time since lymphedema diagnosis
≤ 4	123	29.4	475	35.3	310	29.0	82	23.0
5–9	142	34.0	489	36.3	402	37.5	135	38.0
≥ 10	153	36.6	382	28.4	358	33.5	139	39.0
Lymphedema laterality
Unilateral	413	98.8	1322	98.2	1044	97.6	345	96.9
Bilateral	5	1.2	24	1.8	26	2.4	11	3.1

	None N = 335		Minor N = 2108		Major N = 779
	N	%	N	%	N	%
b. Characteristics of the subgroups—based on having a problem with the arm(s) as a result of breast cancer and/or its treatment (N = 3222)
Country
Denmark	302	90.1	1865	88.5	691	88.7
USA	33	9.9	243	11.5	88	11.3
Age groups (years)
≤ 49	21	6.3	211	10.0	90	11.6
50–59	57	17.0	564	26.8	233	29.9
60–69	105	31.3	695	33.0	237	30.4
≥ 70	152	45.4	638	30.2	219	28.1
BMI (kg/m2)
Under/normal weight (< 25)	152	45.4	834	39.6	240	30.8
Overweight (25–29)	114	34.0	734	34.8	259	33.3
Obese (≥30)	67	20.0	534	25.3	276	35.4
Missing	2	0.6	6	0.3	4	0.5
Ethnicity
Caucasian	292	87.2	1844	87.5	670	86.0
Other	43	12.8	264	12.5	109	14.0
Time since lymphedema diagnosis
≤ 4	94	28.1	683	32.4	221	28.4
5-9	132	39.4	774	36.7	277	35.6
≥ 10	109	32.5	651	30.9	281	36.0
Lymphedema laterality
Unilateral	330	98.5	2080	98.7	746	95.8
Bilateral	5	1.5	28	1.3	33	4.2

	No sleeve N = 940		Sleeve N = 2282
	N	%	N	%
c. Characteristics of the subgroups—based on whether participant wore a compression sleeve in the past 12 months (N = 3222)
Country
Denmark	807	85.9	2051	89.9
USA	133	14.1	231	10.1
Age groups (years)
≤ 49	83	8.8	239	10.5
50–59	226	24.0	628	27.5
60–69	319	34.0	718	31.5
≥ 70	312	33.2	697	30.5
BMI (kg/m2)
Under/normal weight (< 25)	350	37.2	876	38.4
Overweight (25–29)	328	34.9	779	34.1
Obese (≥ 30)	260	27.7	617	27.1
Missing	2	0.2	10	0.4
Ethnicity
Caucasian	811	86.3	1995	87.4
Other	129	13.7	287	12.6
Time since lymphedema diagnosis
≤ 4	217	23.1	781	34.2
5–9	350	37.2	833	36.5
≥ 10	373	39.7	668	29.3
Lymphedema laterality
Unilateral	913	97.1	2243	98.3
Bilateral	27	2.9	39	1.7