Table 2 Baseline characteristics of 1,843 patients who called the OHS-PC with SOB, stratified by uncanny feeling (yes/no)

Patient characteristics

 Mean age in years (SD)

53.4 (21.6)

55.6 (21.1)

52.2 (21.7)

0.002

 Male sex

817 (44.3%)

286 (47.0%)

531 (43.0%)

0.100

 Female sex

1,026 (55.7%)

322 (53.0%)

704 (57.0%)

0.100

Call characteristics

 Call duration in min:sec (SD) (n = 1,829)^a

12:52 (51:36)

14:53 (1:11:35)

11:52 (37:58)

0.238

 Someone else called on behalf of patient (n = 1,840)^a

939 (51.0%)

328 (54.0%)

611 (49.6%)

0.074

 GP participated in triage (n = 1,841)^a

876 (47.6%)

297 (48.9%)

579 (46.9%)

0.417

Medical history

 Cardiovascular disease (n = 916)^a

308 (33.6%)

113 (37.5%)

195 (31.7%)

0.079

 Respiratory disease (n = 1,005)^a

471 (46.9%)

160 (48.2%)

311 (46.2%)

0.554

 Thrombo-embolic diseases (n = 656)^a

24 (3.7%)

12 (5.9%)

12 (2.7%)

0.043

Use of medication

 Cardiovascular medication use

269 (14.6%)

96 (15.8%)

173 (14.0%)

0.308

 Respiratory medication use

462 (25.1%)

139 (22.9%)

323 (26.2%)

0.125

 Antithrombotic therapy

82 (4.4%)

32 (5.3%)

50 (4.0%)

0.234

Symptoms mentioned during the call

 Ankle oedema (n = 95)^a

54 (56.8%)

25 (55.6%)

29 (58.0%)

0.810

 Autonomic nervous system related symptoms^b (n = 1,364)^a

693 (50.8%)

255 (54.3%)

438 (49.0%)

0.065

 Chest pain (n = 845)^a

499 (59.1%)

184 (58.4%)

315 (59.4%)

0.770

 Coughing (n = 1,302)^a

883 (67.8%)

266 (65.2%)

617 (69.0%)

0.171

 Coughing blood (n = 1,073)^a

48 (4.5%)

22 (6.2%)

26 (3.6%)

0.059

 Coughing sputum (n = 641)^a

216 (33.7%)

68 (32.1%)

148 (34.5%)

0.541

 Fever (n = 1,261)

346 (27.4%)

126 (30.8%)

220 (25.8%)

0.063

 Immobilisation (n = 85)^a

58 (68.2%)

27 (77.1%)

31 (62.0%)

0.162

 Malaise (n = 676)^a

533 (78.8%)

254 (86.1%)

279 (73.2%)

 < 0.001

 Musculoskeletal pain (n = 209)^a

168 (80.4%)

63 (76.8%)

105 (82.7%)

0.299

 Palpitations (n = 155)^a

99 (63.9%)

49 (68.1%)

50 (60.2%)

0.312

 Shortness of breath (n = 1,816)^a

1,757 (96.8%)

582 (96.8%)

1,175 (96.7%)

0.882

 Swollen calf (n = 41)^a

5 (12.2%)

3 (13.0%)

2 (11.1%)

1.000

 Tingling sensations (n = 103)^a

69 (67.0%)

26 (57.8%)

43 (74.1%)

0.080

Chest pain characteristics

 Chest pain association with respiration (n = 169)^a

136 (80.5%)

46 (71.9%)

90 (85.7%)

0.028

 Pain onset < 12 h (n = 291)^a

163 (56.0%)

76 (58.5%)

87 (54.0%)

0.450

 Pain duration > 15 min (n = 250)^a

239 (95.6%)

116 (93.5%)

123 (97.6%)

0.135

 Posture-specific chest pain (n = 35)^a

28 (80.0%)

13 (81.3%)

15 (78.9%)

1.000

 Radiation of pain (n = 219)^a

128 (58.4%)

51 (56.0%)

77 (60.2%)

0.543

 Severe pain (score > 7 on VAS) (n = 100)^a

27 (27.0%)

7 (23.3%)

20 (28.6%)

0.633

Shortness of breath characteristics

 SOB on exertion (n = 706)^a

612 (86.7%)

214 (86.6%)

398 (86.7%)

0.979

 SOB at rest (n = 1,550)^a

1,491 (96.2%)

516 (97.2%)

975 (95.7%)

0.145

 Stridor (n = 1,141)^a

38 (3.3%)

17 (4.8%)

21 (2.7%)

0.059

 Unable to speak full sentences (n = 1,514)^a

223 (14.7%)

92 (18.4%)

131 (12.9%)

0.004

 Wheezing (n = 1,205)^a

179 (14.9%)

46 (12.1%)

133 (16.1%)

0.069