Table 1

Baseline characteristics
N = 123499
Demographics
Age, years, median (IQR) 75 (70–81)
Women, n (%) 67207 (54.4)
Income quintile, n (%)
One (lowest) 24803 (20.1)
Two 24607 (19.9)
Three (middle) 25016 (20.3)
Four 23112 (18.7)
Five (highest) 24837 (20.1)
Rural Location, n (%) 25707 (20.8)
Comorbidities, n (%)
Coronary artery disease 49027 (39.7)
Diabetes mellitus£ 28759 (23.3)
Heart failure 20259 (16.4)
Peripheral vascular disease 2730 (2.2)
Stroke/Transient ischemic attack 4812 (3.9)
Medication use in prior 6 months, n (%)
Angiotensin-converting enzyme inhibitors 49635 (40.2)
Angiotensin-receptor blockers 28438 (23.0)
Beta blockers 47051 (38.1)
Calcium channel blockers 40600 (32.9)
Loop diuretics 22860 (18.5)
NSAIDs(excluding aspirin) 26478 (21.4)
Warfarin 14967 (12.1)
Potassium sparing diuretics 9948 (8.1)
Statins 65168 (52.8)
Thiazide diuretics 27448 (22.2)
Baseline Laboratory Measurements*
Serum creatinine μmol/L, median (IQR) 84 (70–102)
eGFR category ŦmL/min per 1.73m2, n (%)
≥60mL 78584 (63.6)
45-59 25904 (21.0)
30-44 13749 (11.1)
15-29 4624 (3.7)
<15 638 (0.5)
Serum sodium mmol/L, median, (IQR) 140 (138–142)
Serum potassium mmol/L, median (IQR) 4.2 (3.9-4.6)
Proteinuria (dipstick value) g/L
Category, n (%)
Negative 23792 (19.3)
0.3 1509 (1.2)
1.0 962 (0.8)
≥3.0 220 (0.2)

Abbreviations: IQR, interquartile range; NSAIDs, non-steroidal anti-inflammatory drugs; eGFR, estimated glomerular filtration rate.

Coronary artery disease includes receipt of coronary artery bypass graft surgery, percutaneous coronary intervention and diagnoses of angina.

£ Assessed by diabetic medication use in previous 6 months.

* All patients had a serum creatinine measurement. A total of 109,743 (88.9%), and 111,304 (90.1%) patients had a serum sodium and potassium measurement in the year prior to cohort entry, respectively while 26,483(21.4%) patients had a urine dipstick protein value. The most recent values prior to the prescription date were used.

ŦeGFR was calculated using the CKD-Epi equation.

CKD-Epi equation:141 x min([serum creatinine in umol/L /88 · 4 ]/κ, 1)α x max([serum creatinine in umol/L / 88 · 4]/κ, 1)-1·209 x 0 · 993Age x 1 · 018 [if female] x 1 · 159 [if African American] κ = 0 · 7 for females and 0 · 9 for males, α = −0 · 329 for females and −0 · 411 for males, min = the minimum of Scr/κ or 1, max = the maximum of Scr/κ or 1.Racial information was not available in our data sources and all patients were assumed not to be of non African-Canadian race. This was a reasonable assumption; as of 2006, African-Canadians represented <7% of the Ontario population. Source:http:// http://www12.statcan.ca/census-recensement/2006/dp-pd/hlt/97-562/index.cfm?Lang=E webcite.

Fleet et al.

Fleet et al. BMC Nephrology 2013 14:81   doi:10.1186/1471-2369-14-81

Open Data