Table 5.

Likelihood of discontinuing renin-angiotensin-aldosterone system blocker among users

VariableSerum K+ LevelOmnibus P Value
<3.5 mEq/L3.5–3.9 mEq/L4.0–4.4 mEq/L4.5–4.9 mEq/L5.0–5.4 mEq/L5.5–5.9 mEq/L≥6.0 mEq/L
eGFR<30 ml/min per 1.73 m2
 Patient-years24168620101670624351
 Stops, n4417658789363629086
 Crude rate/100 patient-years186.51104.6194.7587.8890.08119.29168.09
 Adjusted IRRa (95% CI)2.07 (1.52 to 2.81)1.19 (1.01 to 1.41)1.10 (0.99 to 1.22)Ref1.00 (0.90 to 1.11)1.31 (1.15 to 1.49)1.81 (1.45 to 2.26)<0.001
eGFR 30–39 ml/min per 1.73 m2
 Patient-years4848518772488140936760
 Stops, n483541146144089430363
 Crude rate/100 patient-years99.4673.0261.0757.8963.4382.46103.90
 Adjusted IRRa (95% CI)1.69 (1.26 to 2.26)1.28 (1.14 to 1.44)1.07 (0.99 to 1.16)Ref1.08 (0.99 to 1.17)1.38 (1.22 to 1.57)1.71 (1.33 to 2.20)<0.001
eGFR 40–49 ml/min per 1.73 m2
 Patient-years101107139004544202736947
 Stops, n7256319162190105826953
 Crude rate/100 patient-years71.0652.5849.1248.1952.1973.04113.10
 Adjusted IRRa (95% CI)1.50 (1.19 to 1.91)1.13 (1.03 to 1.25)1.05 (0.98 to 1.11)Ref1.06 (0.99 to 1.15)1.45 (1.28 to 1.65)2.21 (1.68 to 2.90)<0.001
eGFR 50–59 ml/min per 1.73 m2
 Patient-years129144151035171191131328
 Stops, n787122254233990220323
 Crude rate/100 patient-years60.4849.4044.1745.2447.2164.9683.37
 Adjusted IRRa (95% CI)1.37 (1.09 to 1.72)1.13 (1.03 to 1.23)1.00 (0.94 to 1.06)Ref1.03 (0.95 to 1.11)1.39 (1.20 to 1.61)1.70 (1.13 to 2.56)<0.001
  • Reference group is 4.5–4.9 mEq/L. P value interaction between eGFR category and K=0.66. K+, potassium; IRR, incidence rate ratio; 95% CI, 95% confidence interval; Ref, reference.

  • a IRRs were adjusted for age, sex, race, diabetes, congestive heart failure, coronary artery disease, cerebral vascular accident, β-blocker use, and nondihydropyridine calcium channel blocker use, loop diuretic use, and thiazide diuretic use. Associations were estimated using mixed-effects Poisson models, with random intercept terms representing individual patients and fixed-effects terms as described.