Table 2.
Relative Risks of Serious Hyperkalemia-Associated Adverse Outcomes among Patients with Diabetes Who Are New Users of ACEi, ARB and/or Spironolactone Therapy
| Serious Hyperkalemia outcome (serum potassium ≥6.0 mmol/l or ICD9 code 276.7 plus an emergency department visit or hospitalization) | All patients | Patients with ≥1 screening potassium monitoring | Patients without screening potassium monitoring | Unadjusted relative risk (95% CI) a | Adjusted relative risk (95% CI) b | |||
|---|---|---|---|---|---|---|---|---|
| Number of outcomes | Incidence rate (per 1,000 person-years) | Number of outcomes | Incidence rate (per 1,000 person-years) | Number of outcomes | Incidence rate (per 1,000 person-years) | |||
| Entire study cohort | ||||||||
| All patients (n = 27,361) | 184 | 10.2 | 154 | 10.7 | 30 | 8.3 | 1.29 (0.87, 1.90) | 0.50 (0.37, 0.66) |
| Drug subcohorts | ||||||||
| ACEi or ARB alone or in combination (n = 26,794) | 155 | 8.8 | 131 | 9.3 | 24 | 6.7 | 1.38 (0.90, 2.14) | 0.46 (0.34, 0.63) |
| Spironolactone alone or in combination (n = 561) | 29 | 96.0 | 23 | 83.5 | 6 | 220.2 | 0.38 (0.15, 0.93) | 0.26 (0.11, 0.60) |
| Subcohorts of patients without chronic kidney diseasec or heart failure diagnosis | ||||||||
| No chronic kidney disease and no heart failure, ACEi or ARB alone or in combination (n = 23,539) | 39 | 2.5 | 32 | 2.7 | 7 | 2.1 | 1.28 (0.57, 2.91) | 1.08 (0.48, 2.40) |
| No chronic kidney disease and no heart failure, spironolactone (n = 266) | 7 | 55.8 | 4 | 37.1 | 3 | 170.6 | 0.22 (0.05, 0.97) | 0.16 (0.04, 0.67) |
| Subcohorts of patients with chronic kidney diseasec | ||||||||
| Chronic kidney disease stage 3 or 4; ACEi or ARB alone or in combination (n = 1,482) | 44 | 41.3 | 34 | 34.6 | 10 | 121.7 | 0.28 (0.14, 0.57) | 0.19 (0.11, 0.36) |
| Chronic kidney disease stage 3 or 4, spironolactone (n = 42) | 4 | 179.0 | 4 | 187.5 | 0 | 0 | -- | -- |
| Subcohorts of patients with heart failure diagnosis | ||||||||
| Heart failure, ACEi or ARB alone or in combination (n = 1,232) | 31 | 36.3 | 27 | 35.7 | 4 | 41.1 | 0.87 (0.30, 2.48) | 1.04 (0.32, 3.40) |
| Heart failure, spironolactone (n = 142) | 6 | 67.8 | 5 | 60.6 | 1 | 170.2 | 0.35 (0.04, 3.05) | 0.40 (0.06, 2.82) |
| Subcohorts of patients with chronic kidney diseasec and heart failure diagnosis | ||||||||
| Chronic Kidney disease stage 3 or 4 and heart failure, ACEi or ARB alone or in combination (n = 541) | 41 | 115.1 | 38 | 112.0 | 3 | 176.7 | 0.63 (0.20, 2.05) | 0.46 (0.16, 1.36) |
| Chronic kidney disease stage 3 or 4 and heart failure, spironolactone (n = 112) | 12 | 180.0 | 10 | 156.5 | 2 | 722.1 | 0.22 (0.05, 0.99) | 0.26 (0.01, 4.79) |
aComparing patients with monitoring to patients without monitoring based on Poisson regression accounting for person time
bComparing patients with monitoring to patients without monitoring based on Poisson regression accounting for person time and weighting with the inverse of propensity scores. For variables included in the propensity score models, please see the Methods section
cChronic kidney disease was determined from any of the following: an ICD9 code indicating chronic kidney disease, at least two eGFR ≤59 ml/min/1.73 m2, estimated from the Modification of Diet in Renal Disease (MDRD) equation and measured at least 91 days apart, at least two creatinine clearance rates ≤59 ml/min estimated from the Cockcroft-Gault equation and measured at least 91 days apart, or at least two serum creatinine concentrations >1.5 mg/dl