Table 1.
Clinical characteristics of latent classes in the Royal Brompton cohort
| Class | P value | Adjusted P value | |||
|---|---|---|---|---|---|
| 1 | 2 | 3 | |||
| N = 14 | N = 38 | N = 33 | |||
| Female Sex | 9 (64.3%) | 22 (57.9%) | 23 (69.7%) | 0.571 | 0.670 |
| Age (years) | 72.4 (±10.0) | 61.5 (±11.1) | 66.8 (±9.1) | 0.003 | 0.037 |
| Smoking | 0.411 | 0.575 | |||
| Never smoker | 6 (42.9%) | 18 (47.4%) | 17 (51.5%) | ||
| Ex-smoker | 5 (35.7%) | 16 (42.1%) | 15 (45.5%) | ||
| Current smoker | 3 (21.4%) | 4 (10.5%) | 1 (3.0%) | ||
| White - British Ethnicity | 12 (85.7%) | 30 (78.9%) | 28 (84.8%) | 0.747 | 0.747 |
| Diagnosis | 0.006 | 0.039 | |||
| Bronchiectasis | 5 (35.7%) | 13 (34.2%) | 25 (75.8%) | ||
| COPD | 5 (35.7%) | 11 (28.9%) | 4 (12.1%) | ||
| Other | 0 (0.0%) | 6 (15.8%) | 2 (6.1%) | ||
| No underlying disease | 4 (28.6%) | 8 (21.1%) | 2 (6.1%) | ||
| Systemic corticosteroids | 4 (28.6%) | 7 (18.4%) | 5 (15.2%) | 0.574 | 0.670 |
| Oral antibiotic prophylaxis | 2 (14.3%) | 9 (23.7%) | 11 (33.3%) | 0.404 | 0.575 |
| Nebulised antibiotic prophylaxis | 1 (7.1%) | 2 (5.3%) | 4 (12.1%) | 0.677 | 0.702 |
| Chronic Pseudomonas infection | 0 (0.0%) | 3 (7.9%) | 7 (21.2%) | 0.088 | 0.176 |
| Semi-invasive Aspergillosis | 2 (14.3%) | 1 (2.6%) | 0 | 0.069 | 0.155 |
| NTM species | 0.612 | 0.685 | |||
| M. abscessus | 4 (28.6%) | 4 (10.5%) | 6 (18.2%) | ||
| M. avium complex | 7 (50.0%) | 18 (47.4%) | 19 (57.6%) | ||
| M. kansasii | 1 (7.1%) | 4 (10.5%) | 4 (12.1%) | ||
| M. xenopi | 1 (7.1%) | 8 (21.1%) | 2 (6.1%) | ||
| Other species | 1 (7.1%) | 4 (10.5%) | 2 (6.1%) | ||
| Sputum smear positive | 1 (7.1%) | 3 (7.9%) | 5 (15.2%) | 0.639 | 0.688 |
| Currently receiving NTM treatment | 6 (42.9%) | 8 (21.1%) | 4 (12.1%) | 0.072 | 0.155 |
| Ever received NTM treatment | 11 (78.6%) | 15 (39.5%) | 11 (33.3%) | 0.015 | 0.060 |
| Duration of NTM disease (years) | 3.4 (±3.2) | 1.6 (±2.6) | 4.3 (±4.7) | 0.01 | 0.047 |
| Age at diagnosis (years) | 69.6 (±9.9) | 60.0 (±11.5) | 62.5 (±10.6) | 0.035 | 0.098 |
| BMI (kg/m2) | 18.3 (±3.2) | 22.6 (±4.3) | 22.3 (±3.4) | 0.004 | 0.037 |
| SGRQ total score | 51.3 (±24.6) | 42.1 (±26.1) | 48.1 (±21.6) | 0.443 | 0.591 |
| MRC dyspnoea score | 2.9 (±1.4) | 2.4 (±1.5) | 2.6 (±1.1) | 0.513 | 0.653 |
| FEV1 (% predicted) | 58.7 (±13.3) | 69.5 (±27.6) | 53.9 (±20.1) | 0.024 | 0.081 |
| FVC (% predicted) | 83.1 (±27.0) | 97.7 (±20.8) | 85.8 (±16.8) | 0.026 | 0.081 |
| TLCOc (% predicted) | 47.9 (±24.1) | 62.2 (±26.0) | 59.2 (±18.2) | 0.25 | 0.389 |
| Haemoglobin (g/dL) | 12.7 (±1.7) | 13.7 (±1.6) | 13.7 (±1.1) | 0.049 | 0.125 |
| Neutrophil count (× 109/L) | 7.0 (±2.9) | 5.3 (±3.0) | 6.1 (±3.1) | 0.186 | 0.326 |
| Lymphocyte count (× 109/L) | 1.4 (±0.5) | 1.6 (±0.6) | 1.8 (±0.7) | 0.242 | 0.389 |
| Serum albumin (g/L) | 36.0 (±6.3) | 40.2 (±3.7) | 38.2 (±3.9) | 0.007 | 0.039 |
| CRP (mg/L) | 37.2 (±51.1) | 7.1 (±13.7) | 10.0 (±13.5) | < 0.001 | 0.017 |
| Platelet count (× 109/L) | 298 (±126) | 244 (±62) | 255 (±86) | 0.126 | 0.235 |
Continuous variables are given as mean ± standard deviation and compared using ANOVA, categorical values are given as number and percentage and compared using Fisher’s exact test
COPD chronic obstructive pulmonary disease, BMI body mass index, SGRQ St George’s Respiratory Questionnaire, MRC Medical Research Council dyspnoea scale, FEV1 forced expiratory volume in 1 s, FVC forced vital capacity, TLCOc corrected transfer factor for carbon monoxide, CRP C-reactive protein
Values shown in bold indicate P < 0.05