Characteristics of the study population
| Characteristics | Total | Subjective swallowing symptoms | No swallowing symptoms |
| Subjects | 571 | 186 (33%) | 385 (67%) |
| Sex | |||
| Female | 335 | 112 (33%) | 223 (67%) |
| Male | 236 | 74 (31%) | 162 (69%) |
| Age years | 68.6±7.6 | 68.9±7.8 | 68.4±7.6 |
| GOLD spirometric stage | |||
| Stage 1, FEV1 ≥80% predicted | 57 | 22 (39%) | 35 (61%) |
| Stage 2, FEV1 50–<80% predicted | 314 | 96 (31%) | 218 (69%) |
| Stage 3, FEV1 30–<50% predicted | 155 | 56 (36%) | 99 (64%) |
| Stage 4, FEV1 <30% predicted | 45 | 12 (27%) | 33 (73%) |
| GOLD 2017 | |||
| Group A | 188 | 40 (21%) | 148 (79%) |
| Group B | 244 | 98 (40%) | 146 (60%) |
| Group C | 29 | 3 (10%) | 26 (90%) |
| Group D | 110 | 45 (41%) | 65 (59%) |
| Spirometry | |||
| FEV1 % predicted | 56.6±17.8 | 57.0±18.3 | 56.3±17.6 |
| FEV1 L | 2.9±0.91 | 2.81±0.85 | 3.0±0.93 |
| Smoking status | |||
| Current smoker | 165 | 42 (26%) | 123 (74%) |
| Former smoker | 395 | 140 (35%) | 255 (65%) |
| Never-smoker | 9 | 2 (22%) | 7 (78%) |
| Weight | |||
| Stable | 377 | 108 (29%) | 269 (71%) |
| Weight gain | 111 | 43 (39%) | 68 (61%) |
| Weight loss | 80 | 34 (42%) | 46 (58%) |
| BMI kg·m−2 | 26.8±5.1 | 28.1±5.6 | 26.2±4.6 |
| Underweight, BMI <18.5 kg·m−2 | 25 | 6 (24%) | 19 (76%) |
| Normal weight, BMI 18.5–24.9 kg·m−2 | 199 | 54 (27%) | 145 (73%) |
| Overweight, BMI 25–29.9 kg·m−2 | 207 | 61 (29%) | 146 (71%) |
| Obese, BMI ≥30 kg·m−2 | 137 | 65 (47%) | 72 (53%) |
| Comorbidities | |||
| Stroke/TIA | 50 | 20 (40%) | 30 (60%) |
| Obstructive sleep apnoea | 60 | 27 (45%) | 33 (55%) |
| Rheumatoid arthritis | 65 | 24 (37%) | 41 (63%) |
| Asthma | 189 | 72 (38%) | 117 (62%) |
| Chronic bronchitis | 193 | 80 (41%) | 113 (59%) |
| Heart disease | 114 | 49 (43%) | 65 (57%) |
| Symptom burden | |||
| Dyspnoea, mMRC score ≥2 | 252 | 116 (46%) | 136 (54%) |
| Health-related QoL, CAT score ≥10 | 354 | 143 (40%) | 210 (60%) |
| Exacerbations | |||
| ≤1 during previous year | 432 | 138 (32%) | 294 (68%) |
| >1 or hospital admission | 139 | 48 (35%) | 91 (65%) |
Data are presented as mean±sd unless otherwise stated. GOLD: Global initiative for Obstructive Lung Disease; FEV1: forced expiratory volume in 1 s; BMI: body mass index;
TIA: transient ischaemic attack; mMRC: modified Medical Research Council; QoL: quality of life; CAT: COPD Assessment Test.