Table 1

 Characteristics of acute kidney injury cases and matched controls. Values are numbers (percentages) unless stated otherwise

CharacteristicsCases (n=2215)Controls (n=21 993)
Mean (SD) age (years)*76.9 (10.9)76.9 (10.7)
Male sex*1133 (51.2)11 226 (51.0)
Mean (SD) duration of follow-up (years)*5.9 (3.4)5.9 (3.4)
Body mass index:
 <18.548 (2.2)346 (1.6)
 18.5-24423 (19.1)4662 (21.2)
 25-29468 (21.1)5563 (25.3)
 ≥30467 (21.1)3548 (16.1)
 Unknown809 (36.5)7874 (35.8)
Excessive alcohol use302 (13.6)1882 (8.6)
Smoking status:
 Ever1288 (58.1)11 207 (51.0)
 Never848 (38.3)9962 (45.3)
 Unknown79 (3.6)824 (3.7)
At least one hospital admission†805 (36.3)2174 (9.9)
Mean (SD) No of hospital admissions‡6.3 (6.1)2.9 (4.3)
Diabetes726 (32.8)3905 (17.8)
Indication for use:
 Hypertension1145 (51.7)12 684 (57.7)
 Congestive heart failure130 (5.9)512 (2.3)
 Coronary artery disease37 (1.7)339 (1.5)
 Two or more155 (7.0)782 (3.6)
 Unknown748 (33.8)7676 (34.9)
Rhythm disorders456 (20.6)2728 (12.4)
Valvular disease5 (0.2)28 (0.1)
Other cardiovascular disease17 (0.8)44 (0.2)
Blood pressure (mm Hg):
 140≤systolic<160 or 90≤diastolic<100751 (33.9)7705 (35.0)
 160≤systolic<180 or 100≤diastolic<110318 (14.4)2924 (13.3)
 Systolic≥180 or diastolic≥110114 (5.1)805 (3.7)
 Unknown1032 (46.6)10 559 (48.0)
Other antihypertensive drugs:
 Calcium channel blockers712 (32.1)7340 (33.4)
 β blockers701 (31.7)6366 (29.0)
Anti-arrhythmics199 (9.0)1515 (6.9)
Digoxin304 (13.7)1407 (6.4)
Clopidogrel150 (6.8)921 (4.2)
Statins1039 (46.9)8951 (40.7)
Antibiotics1448 (65.4)9291 (42.2)
Immunosuppressive agents123 (5.6)509 (2.3)
Paracetamol1234 (55.7)8905 (40.5)
Corticosteroids427 (19.3)2993 (13.6)

*Matching variables (along with year of cohort entry).

†Within current time window before index date.

‡From Hospital Episode Statistics database.