Skip to main content

Table 1 Baseline patient demographics and clinical histories of chronic kidney disease patients, stratified by serum potassium category

From: Serum potassium as a predictor of adverse clinical outcomes in patients with chronic kidney disease: new risk equations using the UK clinical practice research datalink

Variable

All

Serum potassium at baseline (mmol/L)a

< 3.5

3.5 to < 4.0

4.0 to < 4.5

4.5 to < 5.0

5.0 to < 5.5

5.5 to < 6.0

≥6.0

Number of patients

191,964

3635

17,662

50,065

48,543

18,454

4250

1026

Follow-up time (years), mean (SD)

4.96 (2.76)

4.65 (3.06)

5.17 (2.86)

5.14 (2.80)

5.02 (2.79)

4.83 (2.81)

4.62 (2.85)

4.25 (2.94)

Patient demographics, mean (SD)b

 Age (years)

72.48 (12.26)

73.46 (13.08)

72.45 (12.59)

71.63 (12.39)

72.03 (12.12)

72.53 (11.80)

72.67 (11.87)

71.97 (13.48)

 Male, n (%)

75,611 (39.39%)

1145 (31.50%)

6365 (36.04%)

19,000 (37.95%)

19,958 (41.11%)

8118 (43.99%)

1987 (46.75%)

480 (46.78%)

 Current smoker, n (%)

27,078 (16.1%)

530 (16.20%)

2511 (15.50%)

7047 (15.31%)

7577 (16.87%)

2987 (17.48%)

762 (19.35%)

192 (20.3%)

 Body mass index (kg/m2)

28.53 (5.89)

27.80 (6.50)

28.32 (5.92)

28.44 (5.75)

28.69 (5.90)

28.71 (6.05)

28.38 (6.14)

28.41 (7.13)

 Systolic blood pressure (mmHg)

139.77 (19.96)

138.87 (21.95)

140.33 (20.24)

140.07 (20.05)

139.82 (19.92)

139.61 (20.09)

139.86 (21.05)

138.42 (23.69)

 eGFR (mL/min/1.73m2)

50.96 (8.43)

49.93 (8.84)

51.59 (7.63)

51.88 (7.54)

51.14 (8.15)

49.63 (9.45)

47.00 (11.47)

42.17 (14.48)

 Serum potassium (mmol/L)

4.47 (0.53)

3.20 (0.24)

3.76 (0.13)

4.22 (0.14)

4.68 (0.14)

5.15 (0.14)

5.64 (0.13)

6.36 (0.51)

 Serum phosphorus (mmol/L)

1.14 (0.94)

1.06 (0.24)

1.08 (0.21)

1.13 (1.32)

1.14 (0.21)

1.17 (0.24)

1.23 (0.30)

1.32 (0.39)

Clinical history at baseline, n (%)c

 History of diabetes

28,089 (14.63%)

330 (9.08%)

1778 (10.07%)

5658 (11.30%)

7437 (15.32%)

3719 (20.15%)

1025 (24.12%)

284 (27.68%)

 History of myocardial infarction

6277 (3.27%)

74 (2.04%)

419 (2.37%)

1433 (2.86%)

1661 (3.42%)

802 (4.35%)

192 (4.52%)

46 (4.48%)

 History of stroke

12,087 (6.30%)

251 (6.91%)

1114 (6.31%)

2969 (5.93%)

2875 (5.92%)

1198 (6.49%)

272 (6.40%)

73 (7.12%)

 History of arrhythmia

14,835 (7.73%)

313 (8.61%)

1416 (8.02%)

3812 (7.61%)

3767 (7.76%)

1482 (8.03%)

327 (7.69%)

83 (8.09%)

 History of peripheral vascular disease

4620 (2.41%)

76 (2.09%)

374 (2.12%)

1057 (2.11%)

1174 (2.42%)

507 (2.75%)

148 (3.48%)

40 (3.90%)

 History of chronic pulmonary disease

18,401 (9.59%)

381 (10.48%)

1727 (9.78%)

5003 (9.99%)

4805 (9.90%)

1911 (10.36%)

414 (9.74%)

95 (9.26%)

 History of malignancy

17,658 (9.20%)

443 (12.19%)

1700 (9.63%)

4658 (9.3%)

4497 (9.26%)

1814 (9.83%)

404 (9.51%)

122 (11.89%)

 History of metastatic tumour

4296 (2.24%)

121 (3.33%)

466 (2.64%)

1243 (2.48%)

1082 (2.23%)

421 (2.28%)

108 (2.54%)

31 (3.02%)

 History of rheumatic disease

6377 (3.32%)

155 (4.26%)

784 (4.44%)

1884 (3.76%)

1538 (3.17%)

538 (2.92%)

119 (2.80%)

30 (2.92%)

 History of peptic ulcer

1649 (0.86%)

30 (0.83%)

126 (0.71%)

410 (0.82%)

405 (0.83%)

178 (0.96%)

34 (0.80%)

7 (0.68%)

 History of dementia

4749 (2.47%)

179 (4.92%)

561 (3.18%)

1235 (2.47%)

1009 (2.08%)

360 (1.95%)

80 (1.88%)

35 (3.41%)

Medication use at baseline, n (%)d

 ACE inhibitors

67,886 (35.36%)

1116 (30.70%)

5912 (33.47%)

17,604 (35.16%)

18,859 (38.85%)

7970 (43.19%)

1926 (45.32%)

467 (45.52%)

 ARBs

26,517 (13.81%)

482 (13.26%)

2465 (13.96%)

6952 (13.89%)

6850 (14.11%)

2926 (15.86%)

682 (16.05%)

151 (14.72%)

 Renin inhibitors

68 (0.04%)

0 (0.00%)

10 (0.06%)

15 (0.03%)

17 (0.04%)

9 (0.05%)

0 (0.00%)

0 (0.00%)

 MRAs

4911 (2.56%)

200 (5.50%)

445 (2.52%)

1106 (2.21%)

1330 (2.74%)

744 (4.03%)

281 (6.61%)

103 (10.04%)

 Any RAASi therapye

92,267 (48.06%)

1630 (44.84%)

8235 (46.63%)

23,931 (47.80%)

25,102 (51.71%)

10,567 (57.26%)

2566 (60.38%)

613 (59.75%)

 CCBs (DHP)

45,640 (23.78%)

1227 (33.76%)

5106 (28.91%)

12,191 (24.35%)

11,294 (23.27%)

4362 (23.64%)

1117 (26.28%)

290 (28.27%)

 CCBs (non-DHP)

7568 (3.94%)

148 (4.07%)

798 (4.52%)

2093 (4.18%)

1885 (3.88%)

745 (4.04%)

184 (4.33%)

31 (3.02%)

 NSAIDs

26,739 (13.93%)

466 (12.82%)

2453 (13.89%)

7277 (14.54%)

7424 (15.29%)

2993 (16.22%)

695 (16.35%)

159 (15.50%)

 Diuretics

77,143 (40.19%)

2842 (78.18%)

10,850 (61.43%)

21,548 (43.04%)

16,819 (34.65%)

6182 (33.5%)

1478 (34.78%)

407 (39.67%)

 Beta blockers

48,570 (25.3%)

994 (27.35%)

4608 (26.09%)

12,655 (25.28%)

12,898 (26.57%)

5277 (28.60%)

1280 (30.12%)

326 (31.77%)

 Statins

82,815 (43.14%)

1456 (40.06%)

7479 (42.35%)

21,479 (42.90%)

22,269 (45.87%)

9210 (49.91%)

2103 (49.48%)

481 (46.88%)

 Bronchodilators

21,771 (11.34%)

493 (13.56%)

2059 (11.66%)

5843 (11.67%)

5879 (12.11%)

2435 (13.19%)

581 (13.67%)

123 (11.99%)

  1. ACE angiotensin converting enzyme, ARBs angiotensin receptor blockers, CCBs calcium channel blockers, DHP, dihydropyridine, eGFR estimated glomerular filtration rate, MRAs mineralocorticoid receptor antagonist, NSAIDs, nonsteroidal anti-inflammatory drugs, RAASi renin-angiotensin-aldosterone system inhibitor, SD standard deviation aStratified baseline characteristics include only those patients with an observed serum potassium measurement recorded within + 3 months of the index date bBaseline clinical measurements defined as the first measurement recorded within + 3 months of the index date cDefined as clinical history over five years (60 months) prior to the index date dDefined as medication prescribed within ±3 months of the index date eRAASi therapy was comprised of ACE inhibitors, ARBs, renin inhibitors and MRAs