Table 2.
Patients with complete and incomplete follow-up data stratified for CKD onset; values are numbers (%) unless indicated otherwise
| Parameters | No CKD | CKD | |||||
|---|---|---|---|---|---|---|---|
| Patients with complete follow-up | Patients with incomplete follow-up | ||||||
| Missing | Missing | Missing | |||||
| Included patients | 156,615 | None | 172,361 | None | 6038 | None | |
| Died before developing CKD | 719 (0.5) | None | 6941 (4) | None | / | None | |
| Follow-up (mean, SD) | 5.6 (0.2) | None | 5.4 (0.7) | None | 2.6 (1.7) | None | |
| Age (mean, SD) | 42.1 (16.7) | None | 42.7 (17.3) | None | 70.3 (12.5) | None | |
| Female sex | 82,883 (52.9) | None | 89,389 (51.9) | None | 3452 (57.2) | None | |
| Townsend index (mean, SD)e | 1.6 (3.5) | 2900 (1.9) | 1.6 (3.4) | 3244 (1.9) | 1.4 (3.4) | 47 (0.8) | |
| Ethnicity | Not recorded | 55,586 (35.6) | Not applicabled | 61,220 (35.6) | Not applicabled | 2014 (33.4) | Not applicabled |
| White | 90,443 (57.8) | 99,243 (57.7) | 3889 (64.5) | ||||
| Other | 10,586 (6.8) | 11,898 (6.9) | 135 (2.2) | ||||
| Smokinge | Non-smoker | 66,769 (48.8) | 19,901 (12.7) | 72,137 (48.4) | 23,296 (13.5) | 2167 (37.7) | 292 (4.8) |
| Ex-smoker | 29,980 (21.9) | 33,097 (22.2) | 2475 (43.1) | ||||
| Light smoker (1–9 cg/day) | 11,072 (8.1) | 12,128 (8.1) | 344 (6) | ||||
| Moderate smoker (10–19 cg/day) | 16,951 (12.4) | 18,472 (12.4) | 413 (7.2) | ||||
| Heavy smoker (≥ 20 cg/day) | 11,942 (8.7) | 13,231 (8.9) | 347 (6) | ||||
| BMI, kg/m2 (mean, SD)e | 26.6 (6) | 33,717 (21.5) | 28 (6.1) | 38,628 (22.4) | 28.4 (6) | 518 (8.6) | |
| Diastolic blood pressure, mmHg (mean, SD)e | 76.9 (9.8) | 75,616 (48.3) | 78.9 (10.2) | 85,075 (49.4) | 75.8 (10.2) | 1164 (19.3) | |
| Systolic blood pressure, mmHg (mean, SD)e | 128.2 (15.8) | 75,602 (48.3) | 130.5 (16.7) | 85,058 (49.3) | 136.3 (16.7) | 1166 (19.3) | |
| eGFR, mL/min/1.73 m2 (mean, SD) | 83.7 (9.4) | 118,912 (75.9) | 82.5 (9.4) | 131,103 (76.1) | 69.4 (11.3) | 1828 (30.3) | |
| Hb, g/dLe | 13.9 (1.6) | 110,723 (70.7) | 13.8 (1.6) | 122,430 (71) | 13.4 (1.7) | 2530 (41.9) | |
| Proteinuriaa,b | 751 (0.5) | 149,234 (95.3) | 18 (0.2) | 164,097 (95.2) | 236 (3.9) | 4665 (77.3) | |
| Quantitative albuminuriab,c | 129 (0.1) | 152,266 (97.2) | 4 (0) | 167,482 (97.2) | 62 (1) | 5167 (85.6) | |
| HDL cholesterol levelb, mg/dL (mean, SD) | 25.9 (7.9) | 122,477 (78.2) | 26.7 (7.9) | 135,066 (78.4) | 25.7 (7.8) | 2413 (40) | |
BMI, body mass index; cg, cigarettes; CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; HDL, high-density lipoprotein; MDRD, modification of diet in renal disease; SD, standard deviation
aAlbumin:creatinine ratio >30 mg/mmol or albumin concentration >200 mg/L, or diagnostic code
bVariable excluded as predictor from external validation due to >70 % missing values
cAlbumin:creatinine ratio >30 mg/mmol
dPatients without recorded ethnicity were considered as white (see Methodssection)
eMultiple imputation applied to missing values