First author [ref.] | Total sample size | Sample size of patients with chronic cough | Type of care/sample type | Age (years) | Female (%) | Never smoker (%) | Current smoker (%) | Former smoker (%) | Smoking pack history (pack-years) | Causes of chronic cough (%) | Duration of chronic cough |
Adams [24] | 3960 | 812 | Other; general population | NR | NR | NR | NR | NR | NR | 13.5 (asthma), 7.3 (CB),1.3 (emphysema) | NR |
Baiardini [8]# | 166 | 166 | Secondary/tertiary | 53.9 | 56.0 | 34.3 | 39.8 | 25.9 | NR | NR | 25 months (sd: 9 months) |
Birring [7]¶ | 104 | 104 | Secondary/tertiary | 57.0 | 62.5 | NR | NR | NR | NR | 100 (UCC) | 65 months (range: 2.6–650 months) |
Campi [25] | 1204 | 1204 | Secondary/tertiary | 61.0 | 70.4 | 61.1 | 8.6 | 29.0 | NR | 1.74 (COPD) | 39 months |
Chamberlain [26] | 1120 | 1120 | Other; general population | 51.0 | 67.0 | NR | 16.5 | NR | NR | 11.88 (asthma), 7.14 (GORD), 3.57 (PND), 8.75 (bronchitis), 4.38 (COPD), 3.84 (viral infection), 2.41 (cough hypersensitivity syndrome), 0.89 (laryngitis), 1.96 (allergy), other | 26–65 months (range: 2 months to 10+ years) |
Chan [27] | 55 | 18 | NR | 53.0 | 32.7 | 100.0 | 0.0 | 0.0 | NR | 100 (sleep disordered breathing, no known respiratory cause of cough) | 67% (≤8 weeks), 33% (>8 weeks) |
Cheng [28] | 176 | NR | Secondary/tertiary | 64.3 | 56.8 | NR | 2.8 | 59.7 | 8.17 | 15.91 (ACEi), 76.70 (GORD), 11.93 (chronic sinus disease), 28.98 (chronic heart disease), 19.32 (non-ILD chronic lung disease) | 36.5 months |
Çolak [29] | 14 740 | 554 | Other; general population | 58.2 | 54.5 | 45.6 | 10.4 | 43.1 | 14.87 | 12.64 (asthma), 87.36 (other) | NR |
Çolak [30] | 14 669 | 554 | Other; general population | 58.2 | 55.1 | 46.0 | 10.5 | 43.5 | NR | 2.53 (asthma), 0.18 (bronchiectasis), 2.89 (GORD), 1.26 (UACS) | NR |
Cornford [31] | 30 | 30 | Primary | 48.0 | NR | NR | NR | NR | NR | NR | NR |
Crawford [32]+ | 41 | NR | NR | NR | NR | NR | NR | NR | NR | 100 (CB) | NR |
Decalmer [33] | 62 | 62 | Secondary/tertiary | 54.9 | 62.9 | NR | 0.0 | 37.1 | NR | 53.23 (GORD), 12.9 (PND), 9.68 (asthma), 3.23 (EB), 3.23 (bronchiectasis), 3.23 (tracheopathia osteochondroplastica) | 71.5 months (range: 13–390 months) |
Everett [34] | 373 | 373 | Primary/secondary/tertiary | 65.3 | 73.0 | NR | 2.1 | 40.8 | 8 | 24 (asthma), 66 (no respiratory diagnosis other than cough) | 84.5 months (range: 0.63–949 months) |
Everett [35] | 47 | 47 | Secondary/tertiary | 54.3 | 55.3 | NR | NR | NR | NR | 100 (GORD) | NR |
Faruqi [36] | 86 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
Faruqi [37] | 25 | 25 | Secondary/tertiary | 54.0 | 60.0 | 0.0 | NR | NR | NR | NR | 130 months |
Ford [38] | 3883 | 481 | Primary | 40–49 | 56.1 | NR | 21.7 | NR | NR | NR | NR |
French [39] | 80 | 80 | Secondary/tertiary | 58.5 | 68.8 | 97.5 | NR | NR | NR | 86.3 (GORD), 72.5 (UACS), 27.5 (asthma), 5.0 (drug induced), 3.8 (bronchiectasis), 3.8 (postinfectious), 2.5 (NAEB), 2.5 (COPD), 2.5 (laryngeal sensory neuropathy), 1.3 (CHF), 1.3 (bronchiolitis), 1.3 (infiltrate), 1.3 (suppurative airway infection), 1.3 (vocal cord dysfunction), 1.3 (ILD) | 86 months (sd: 123.7 months) |
French [40] | 39 | 39 | Secondary/tertiary | 54.0 | 82.1 | NR | NR | NR | NR | 40 (PND), 36 (GORD) 15 (asthma), 3 (bronchiectasis), 3 (pertussis), 3 (other) | 56 months (sd: 63 months) |
Fujimura [41] | 1000 | 232 | Other; general population | 55.3 | 38.2 | 41.6 | 22.2 | 36.1 | 566 | 10.1 (cold), 18.5 (asthma), 7.6 (CB), 6.7 (CVA), 5.9 (GORD), sinusitis, 6.7 (pulmonary emphysema), pneumonia, atopic cough, lung cancer, COPD, 17.6 (CB), 15.1 (unknown) | 3.8 weeks |
Hilton [42] | 100 | 100 | Secondary/tertiary | 60.0 | 71.0 | NR | 0.0 | NR | NR | NR | 91 (IQR: 52–195 months) |
Hsu [14] | 47 | 14 | Secondary/tertiary | 49.1 | 57.1 | NR | NR | NR | NR | 14.29 (GORD), 21.43 (PND due to paranasal sinusitis or rhinosinusitis), 4 (responsive to inhaled steroid therapy, no wheeze or shortness of breath), 5 (UCC) | 81.65 months (sd: 79.3 months) |
Hulme [43] | 14 | 14 | Secondary/tertiary | 58.9 | 85.7 | NR | NR | NR | NR | 100 (CRC) | 82.94 months (sd: 61.49 months) |
Kang [44] | 447 | 447 | Secondary/tertiary | 55.1 | 67.1 | 73.6 | 8.3 | 18.1 | NR | 8.72 (UCC) | 46% (2–6 months), 14.09% (6–12 months), 21.72% (1–5 years), 18.19% (>5 years) |
Kelsall [45] | 62 | 62 | Secondary/tertiary | 56.8 | 69.4 | NR | 0.0 | NR | NR | 32.26 (GORD), 37.10 (rhinosinusitis), 6.45 (asthma), 8.06 (EB), 6.45 (bronchiectasis), 29.03 (UCC) | 42.9 months (IQR: 6–130 months) |
Kelsall [46] | 70 | 70 | Secondary/tertiary | 55.0 | 72.9 | 100.0 | 0.0 | 0 (stopped <6 months) | NR | 100 (UCC) | 62.4 months (IQR: 32.5–131.3 months) |
Koo [10]§ | 401 | 401 | Secondary/tertiary | 48.4 | 61.1 | NR | NR | NR | NR | 0 (ILD), 0 (COPD), 0 (asthma), 0 (severe bronchiectasis), 0 (lung cancer) | NR |
Koskela [47] | 3697 | 976 | Other; general population | 47.8 | 82.6 | NR | 6.9 | 31.4 | 6.38 | NR | 57% (>13 months), 26% (>65 months) |
Koskela [48] | 3695 | 975 | Other; general population | 47.8 | 82.6 | NR | 31.4 | NR | NR | 10.25 (asthma), 15.66 (chronic rhinosinusitis), 12.59 (GORD) | 13.85% (2–12 months), 86.15% (3–8 weeks) |
Kuznair [49] | 136 | 136 | Secondary/tertiary | 63.0 | 65.4 | 63.2 | 3.7 | 33.1 | NR | 64.71 (rhinitis or sinusitis), 36.03 (GORD), 16.18 (asthma), 6.62 (bronchitis), 6.62 (ILD), 5.88 (postinfectious), 4.41 (bronchiectasis), 1.47 (ACEi), 6.62 (others) | 18 months (IQR: 6–48 months) |
Lai [50] | 1162 | 1162 | Secondary/tertiary | 42.6 | 55.4 | 100.0 | 0.0 | 0.0 | NR | 22.29 (EB), 19.10 (CVA), 12.48 (GORD), 7.31 (UACS), 38.81 (other) | 27.07 months |
Lan [51] | 164 | 118 | Secondary/tertiary | 69.0 | 47.0 | 41.5 | 9.2 | 49.4 | 25.07 | 61.02 (GORD), 16.95 (ACEi), 12.71 (asthma), 12.71 (UACS), 9.32 (infection) | 89.7 months (sd: 123.5 months) |
Landt [52] | 41 545 | 2381 | Other; general population | 59.9 | 55.4 | 45.8 | 11.5 | 42.5 | 13.55 | 50.22 (COPD), 49.78 (other) | NR |
Lätti [53] | 3673 | 957 | Other; general population | 47.8 | 82.6 | NR | 6.9 | 31.4 | 6.41 | 15.51 (chronic rhinosinusitis), 11.69 (asthma), 12.59 (GORD) | 5.42% (<3 weeks), 3.43% (3–8 weeks), 7.27% (>8 weeks) |
Lee [54] | 49 | 28 | Secondary/tertiary | 54.8 | 55.1 | NR | 0.0 | NR | NR | 21 (asthma), 14 (GORD), 7 (postinfectious disease), 4 (rhinitis), 4 (EB), 4 (OSA), 4 (bronchiectasis), 43 (UCC) | 41.5 months |
Lee [55] | 100 | 100 | Secondary/tertiary | 54.0 | 57.0 | 80.0 | 5.0 | 15.0 | NR | 24 (asthma), 7 (EB), 9 (rhinitis), 3 (GORD), 29 (UCC), 7 (postviral cough), 6 (sarcoidosis), 8 (ILD), 2 (OSA), 2 (bronchiectasis), 1 (CB), 1 (ACEi), 1 (postinfective) | 40 months |
Lee [56] | 32 | 17 | Secondary/tertiary | 51.3 | 59.4 | 100.0 | 0.0 | 0.0 | NR | 24 (asthma), 24 (GORD), 6 (EB), 6 (post-infectious), 6 (bronchiectasis), 35 (UCC) | 34 months (range: 24–85 months) |
Ma [57] | 200 | 110 | Secondary/tertiary | 47.0 | 62.0 | 100.0 | 0.0 | 0.0 | NR | 9.09 (UACS), 49.09 (CVA), 5.45 (GORD), 9.09 (NAEB), 8.18 (post virus cough), 9.09 (two causes), 10 (other) | 9 months (range: 2–360 months) |
Mello [58] | 88 | 88 | Secondary/tertiary | 53.1 | 72.7 | 99.4 | NR | NR | NR | 40 (GORD), 38 (PND), 14 (asthma), 4 (bronchiectasis), 4 (other) | 85.8 months (sd: 127.4 months) |
Morice [59]§ | 255 | 185 | Secondary/tertiary | 60.8 | 63.1 | NR | NR | NR | NR | NR | NR |
Murry [60] | 16 | 16 | NR | 29–69 | NR | NR | NR | NR | NR | 100 (GORD, laryngopharyngeal reflux, and concurrent paradoxical vocal fold movement) | 8.4 months (sd: 5.3 months) |
Ojoo [61] | 112 | 112 | Secondary/tertiary | 56.2 | 65.2 | 53.6 | 5.4 | 41.1 | NR | 29.35 (reflux related cough), 21.74 (asthma), 11.96 (rhinitis), 4.35 (post-infective), 11.96 (multiple causes), 7.61 (UCC), 13.04 (other) | 39 months (range: 3.25–832 months) |
Ozge [62] | 165 | NR | Secondary/tertiary | 43.3 | 58.2 | 41.2 | 38.2 | 20.6 | NR | 25.6 (asthma), 18 (PND), 21 (sinusitis), 35.6 (CB) | 46.5 months (sd: 9.6 months) |
Sato [63] | 129 | 129 | Secondary/tertiary | 68.5 | 40.9 | NR | 7.8 | NR | 23.0 | 54.26 (idiopathic interstitial pneumonias), 37.98 (connective tissue disease-associated ILD), 7.75 (chronic hypersensitivity pneumonitis) | NR |
Shariat [64] | 360 | 263 | Secondary/tertiary | 39.4 | 100.0 | NR | NR | NR | NR | NR | 260 months of chest symptoms (range: 6.5–793 months) |
Shembel [65] | 365 | 345 | Secondary/tertiary | 53.7 | 84.7 | NR | NR | NR | NR | 100 (UACS) | NR |
Sinha [66] | 223 | NR | NR | NR | NR | NR | NR | NR | NR | NR | NR |
Smith [67] | 26 | 26 | Secondary/tertiary | 68.7 | NR | NR | 0.0 | NR | 42.4 | 100 (COPD) | 117 months (range: 26–936 months) |
Song [68] | 857 | 37 | Other; general population | 76.8 | 57.0 | 62.2 | 12.2 | 25.5 | NR | 16.2 (asthma), 13.5 (allergic rhinitis), 2.8 (GORD) | NR |
Ternesten-Hasseus [69] | 121 | 62 | Secondary/tertiary | 53.6 | 64.5 | 61.3 | 0.0 | 38.7 | NR | 100 (UCC) | 137.8 months (sd: 130 months) |
Van de Kerkhove [70] | 51 | 51 | Secondary/tertiary | NA | 80.4 | NR | NR | NR | NR | 100 (UCC) | 48 months (IQR: 2–192 months) |
Vazquez [71] | 1422 | 552 | NR | 54.8 | 76.6 | NR | 61.7 | NR | 37.59 | 100 (COPD) | 28.13% (3 months to 2 years), 10.69% (>2 years) |
Vernon [16] | 22 | 22 | Secondary/tertiary | 66.1 | 72.7 | NR | NR | NR | NR | 31.82 (GORD), 22.73 (asthma), 18.18 (bronchitis), 18.18 (PND), irritant exposure, post-infectious cough, mild COPD | 100% (>8 weeks), 81.8% (>52 weeks) |
Vernon [15] | 39 | 24 | Primary | 44.1 | 71.8 | NR | 0.0 | NR | NR | 20.83 (asthma), 20.83 (GORD), 8.33 (irritable larynx), 12.5 (irritant exposure), 25 (PND), 8.33 (other), 50 (unknown) | 38.46% (3 weeks to 2 months), 17.95% (2–6 months), 10.26% (6–12 months), 30.77% (>1 year) |
Vertigan [72]§ | 38 | 11 | Secondary/tertiary | 56.1 | 77.0 | NR | 11.0 | NR | NR | 49 (reflux), 29 (asthma), 17 (rhinitis) | NR |
Vertigan [73] | 171 | 111 | Secondary/tertiary | 53.3 | 76.6 | NR | NR | NR | NR | 50.45 (CRC), 49.55 (CRC/paradoxical vocal fold movement) | NR |
Vertigan [74] | 171 | 111 | Secondary/tertiary | 56.4 | 76.6 | NR | 3.5 | NR | NR | 55 (GORD), 18 (asthma), 49 (PND), 35 (allergies) | NR |
Vertigan [75] | 53 | 53 | Secondary/tertiary | 60.0 | 66.0 | 100.0 | 0.0 | 0.0 | NR | 100 (CRC) | 59 months |
Won [76] | 478 | 478 | Secondary/tertiary | 55.1 | 68.4 | 74.7 | 7.7 | 17.7 | NR | 12.97 (UCC), 87.03 (chronic cough with unspecified underlying condition) | 44% (8–24 weeks), 13.8% (24–48 weeks), 21.6% (52–269 weeks), 20.6% (>260 weeks) |
Xu [77] | 87 | 87 | Secondary/tertiary | 45.1 | 55.2 | NR | NR | NR | NR | 100 (GORD) | 8.28 months (sd: 30.83 months) |
Zhan [11]¶ | 237 | 237 | Secondary/tertiary | 40.4 | 54.0 | NR | NR | NR | NR | NR | 43 months (sd: 77.3 months) |
NR: not reported; CB: chronic bronchitis; UCC: unexplained chronic cough; GORD: gastro-oesophageal reflux disease; PND: post-nasal drip; ACEi: angiotensin-converting-enzyme inhibitor use; ILD: interstitial lung disease; UACS: upper airway cough syndrome; EB: eosinophilic bronchitis; NA: not applicable; NAEB: non-asthmatic eosinophilic bronchitis; CHF: chronic heart failure; CVA: cough-variant asthma; CRC: chronic refractory cough; OSA: obstructive sleep apnoea. #: item generation and reduction sample; ¶: item reduction and validation sample; +: item generation sample; §: validation sample.