Table 3.
Cluster analysis reproducing four clinical phenotypes
| Reproduction cluster 1 | Reproduction cluster 2 | Reproduction cluster 3 | Reproduction cluster 4 | |
|---|---|---|---|---|
| Number | 37 | 14 | 32 | 39 |
| Variables used in clustering* | ||||
| Age in years | 64 [57–71]** | 55 [48–61] | 65 [58–71.5] | 63 [57–68] |
| Smoked PY | 40 [25–53] | 50 [30–66] | 22 [5–35] | 42 [30–57] |
| FEV1% pred | 39 [30–52] | 56 [51–79] | 68 [62–80] | 59 [49–72] |
| BMI kg/m2 | 21 [19–25] | 26 [21–35] | 28 [25–31] | 29 [24–35] |
| mMRC dyspnoea score | 2 [1–3] | 3.5 [1–4] | 1 [0.5–1.5] | 1 [0–1] |
| CCQ total score | 2.5 [2–3.2] | 3.3 [2.8–4.3] | 1.9 [1.3–2.7] | 1.2 [0.7–2.4] |
| BDI-PC total score | 1 [1–4] | 9.5 [7–11] | 1 [0–2.5] | 1 [0–2] |
| Exacerbations p/y | 1 [1–3] | 1 [1–3] | 2 [1–3] | 0 [0–1] |
| Other patient and disease characteristics | ||||
| Male/female % | 46/54 | 71/29 | 47/53 | 59/41 |
| FVC% pred | 87 [72–101] | 89 [77–105] | 99 [91–115] | 93 [75–108] |
| GOLD stage % | ||||
| 1 | 0 | 21 | 25 | 10 |
| 2 | 35 | 64 | 66 | 64 |
| 3 | 46 | 7 | 9 | 26 |
| 4 | 19 | 7 | 0 | 0 |
| BOD score | 4 [4–5] | 5 [1–5] | 2 [1–2] | 2 [1–3] |
| Steps per day | 5283 [3165–7116] | 3032 [2277–3936] | 5037 3416–6797] | 5041 [3371–8371] |
| NCSI quality of life | 19 [11–31] | 57 [41–63] | 14 [6–24] | 12 [6–23] |
| NCSI satisfaction relationship | 3 [2–5] | 6 [4–7] | 2 [2–3] | 3 [2–4] |
| NCSI activities of daily living | 22 [12–30] | 18 [9–28] | 17 [5–29] | 12 [3–18] |
| NCSI shortness of breath | 12 [10–17] | 16 [12–20] | 10 [8–15] | 10 [7–13] |
| NCSI fatigue | 42 [37–47] | 49 [38–55] | 39 [32–50] | 38 [29–45] |
| Main corresponding ABCD groups | ||||
| A | 8 (21) | 3 (21) | 6 (19) | 30 (77) |
| B | 11 (30) | 5 (36) | 5 (16) | 9 (23) |
| C | 7 (19) | 1 (7) | 18 (56) | 0 (0) |
| D | 11 (30) | 5 (36) | 3 (9) | 0 (0) |
*Hierarchical clustering is performed based on PCA of eight variables: age, packyears, FEV1% pred, BMI, mMRC, CCQ, BDI-PC, exacerbation per year
**Data are presented as N (%) or median [25–75 interquartile], unless otherwise stated. PY packyears, FEV1% pred Forced Expiratory Volume in 1 s percentage predicted, FVC Forced Vital Capacity, BMI Body Mass Index, MMRC Modified Medical Research Council, CCQ Clinical COPD Questionnaire, BDI-PC Beck Depression Inventory for primary care. Definition of group A: mMRC < 2 and exacerbations < 2, group B: mMRC > = 2 and exacerbations < 2, group C: mMRC < 2 and exacerbations > = 2, group D: mMRC > = 2 and exacerbations > = 2