Table 1

Baseline characteristics of the study population stratified by levels of loneliness.

Characteristic	No loneliness		Lonely once in a while		Lonely often
Characteristic	n	%	n	%	n	%
Total	367 890	79	76 393	16	21 007	5
Age (years)
<18	9573	65	4045	28	1071	7
18–29	41 562	67	15 943	26	4333	7
30–39	48 394	79	10 038	16	2507	4
40–49	68 380	82	11 691	14	3183	4
50–59	72 268	82	11 995	14	3340	4
60–69	72 299	84	10 900	13	2684	3
70+	55 414	78	11 781	17	3889	5
Sex
Male	171 744	81	31 588	15	8729	4
Female	196 146	77	44 805	18	12 278	5
Marital status
Married	230 739	87	28 178	11	5279	2
Never married	88 079	69	30 762	24	8982	7
Divorced	30 711	70	9628	22	3444	8
Widow	18 361	62	7825	27	3302	11
Cohabitation
Living with others	290 133	85	42 646	13	8192	2
Living alone	77 757	63	33 747	27	12 815	10
Country of origin
Danish	349 031	80	69 381	16	18 315	4
Western	9540	72	2717	21	932	7
Non-Western	9319	61	4295	28	1760	11
Educational level
Elementary school	85 365	73	24 086	21	8159	7
Upper secondary education	25 285	73	7511	22	1901	6
Vocational education	131 262	82	23 417	15	5894	4
Short-cycle higher education	17 702	83	2895	14	648	3
Medium-cycle higher education	68 723	83	11 578	14	2405	3
Long-cycle higher education	33 163	85	4915	13	1024	3
Unknown	6390	68	1991	21	976	10
Smoking status
Non-smokers	173 136	80	35 270	16	8521	4
Former smokers	113 828	82	20 514	15	5316	4
Occasional smokers	14 105	75	3804	20	1001	5
Daily smokers	62 529	75	15 588	19	5673	7
Unknown	4292	72	1217	20	496	8
Physical activity
Physically active	98 052	81	18 943	16	4666	4
Physically inactive	252 185	79	52 378	16	14 477	5
Unknown	17 653	72	5072	21	1864	8
Weekly alcohol consumption
No consumption	68 069	73	18 866	20	6983	7
Low/moderate consumption	257 600	82	46 608	15	10 417	3
High consumption	30 540	77	7166	18	2235	6
Unknown	11 681	70	3753	22	1372	8
Dietary habits (salad)
Every day/several time a day	24 492	79	4960	16	1497	5
Occasionally	288 019	80	56 722	16	13 609	4
Never/rarely	53 193	73	14 139	19	5621	8
Unknown	2186	72	572	19	280	9
Body mass index (kg/m²)
Underweight <18.5	7628	69	2483	23	879	8
Normal weight ≥18.5–24.9	177 763	79	37 500	17	9335	4
Overweight ≥25–29.9	127 475	81	23 517	15	6371	4
Obese ≥30–39.9	45 439	77	10 100	17	3221	6
Severe obesity ≥40	2967	67	951	22	481	11
Unknown	6618	72	1842	20	720	8
At least one mental disorder
No	331 610	81	62 901	15	14 826	4
Yes	36 280	65	13 492	24	6181	11
Nervous disorders
No	363 627	80	74 197	16	19 628	4
Yes	4263	54	2196	28	1379	18
Affective disorders
No	336 905	81	64 821	16	15 789	4
Yes	30 985	65	11 572	24	5218	11
Schizophrenia and other psychosis
No	367 206	79	75 868	16	20 567	4
Yes	684	42	525	32	440	27
Mental and behavioral disorders due to psychoactive substance use
No	362 685	79	74 384	16	19 873	4
Yes	5205	62	2009	24	1134	14