Table 1.
Descriptive statistics for derivation dataset
| Variable | Missing data (n = 835 404), n (%)a | Non-myeloma (n= 834 909), n (%)a | Myeloma (n= 495), n (%)a |
|---|---|---|---|
| Demographics | |||
| Female | 0 (0.0) | 492 039 (58.9) | 227 (45.9) |
| Mean age, years (SD) | 0 (0.0) | 63.7 (13.8) | 70.9 (10.5) |
| Mean BMI (SD) | 541 782 (64.9) | 28.5 (6.2) | 26.5 (4.6) |
|
| |||
| Symptoms | |||
| Back pain | 0 (0.0) | 78 291 (9.4) | 94 (19.0) |
| Chest pain | 0 (0.0) | 53 256 (6.4) | 56 (11.3) |
| Bone pain | 0 (0.0) | 12 933 (1.5) | 12 (2.4) |
| Rib pain | 0 (0.0) | 3809 (0.5) | 8 (1.6) |
| Joint pain | 0 (0.0) | 35 348 (4.2) | 19 (3.8) |
| Shortness of breath | 0 (0.0) | 66 047 (7.9) | 53 (10.7) |
| Chest infections | 0 (0.0) | 54 198 (6.5) | 40 (8.1) |
| Fatigue | 0 (0.0) | 66 903 (8.0) | 34 (6.9) |
| Nosebleeds | 0 (0.0) | 7022 (0.8) | 14 (2.8) |
| Bruising | 0 (0.0) | 8682 (1.0) | 5 (1.0) |
| Fracture | 0 (0.0) | 13 361 (1.6) | 12 (2.4) |
| Weight loss | 0 (0.0) | 10 985 (1.3) | 12 (2.4) |
| Nausea | 0 (0.0) | 25 126 (3.0) | 21 (4.2) |
|
| |||
| Blood tests | |||
| 2nd FBC test (index) | |||
| Mean haemoglobin (SD) | 50 292 (6.0) | 13.5 (1.6) | 12.0 (1.9) |
| Mean white cell count (SD) | 62 843 (7.5) | 7.3 (5.2) | 6.5 (3.6) |
| Mean platelets (SD) | 67 222 (8.0) | 265.4 (80.2) | 247.4 (80.6) |
| Mean MCV (SD) | 72 537 (8.7) | 90.6 (5.9) | 93.5 (6.1) |
|
| |||
| Difference in FBC parameters (2nd – 1st) | |||
| Mean haemoglobin diff (SD) | 87 941 (10.5) | 0.01 (1.0) | −0.25 (1.1) |
| Mean white cell count diff (SD) | 101 091 (12.1) | −0.04 (5.3) | 0.13 (2.3) |
| Mean platelets diff (SD) | 107 485 (12.9) | −1.8 (54.9) | −2.9 (61.1) |
| Mean MCV diff (SD) | 114 841 (13.7) | 0.19 (3.1) | −0.06 (2.4) |
|
| |||
| Other tests | |||
| Mean calcium (SD) | 634 969 (76.0) | 2.3 (0.12) | 2.4 (0.18) |
| Mean creatinine (SD) | 453 831 (54.3) | 89.3 (30.2) | 99.9 (44.9) |
| Mean ESR (SD) | 621 155 (74.4) | 18.6 (19.5) | 55.3 (41.7) |
| CRP, median (IQR) | 679 841 (81.4) | 5 (2 to 10) | 5 (2.5 to 17) |
| Mean PV (SD) | 798 298 (95.6) | 1.71 (0.16) | 1.96 (0.73) |
|
| |||
| Blood tests (normal/abnormal)b | |||
| FBC (index test) | |||
| Anaemia | 50 292 (6.0) | 120 247/784 649 (15.3) | 269/463 (58.1) |
| Leukopenia | 62 843 (7.5) | 22 424/772 119 (2.9) | 59/442 (13.3) |
| Low platelets | 67 222 (8.0) | 25 165/767 738 (3.3) | 44/444 (9.9) |
| High MCV | 72 537 (8.7) | 52 385/762 443 (6.9) | 85/424 (20.0) |
|
| |||
| Other testsb | |||
| Abnormal calcium | 634 969 (76.0) | 4056/200 263 (2.0) | 14/172 (8.1) |
| High creatinine | 453 831 (54.3) | 56 106/381 341 (14.7) | 63/232 (27.2) |
| High ESR | 621 155 (74.4) | 89 735/214 088 (41.9) | 129/161 (80.1) |
| High CRP | 679 841 (81.4) | 51 000/155 452 (32.8) | 47/111 (42.3) |
| High PV | 798 298 (95.6) | 14 080/37 084 (38.0) | 15/22 (68.2) |
a
Unless otherwise stated.
b
Percentages reported for patients with complete data. Denominator displayed to indicate where missing data applies. BMI = body mass index. CRP = C-reactive protein. ESR = erythrocyte sedimentation rate. FBC = full blood count. IQR = interquartile range. MCV = mean corpuscular volume. PV = plasma viscosity. SD = standard deviation.