Table 2.

Outcomes assessed using database codes

OutcomeNo. Events (%)Odds Ratio (95% CI)P Value
Levetiracetam Users (n=3980)Nonusers (n=7960)
30 d after prescription
 AKIa13 (0.33)21 (0.26)1.24 (0.62 to 2.47)0.55
180 d after prescriptiona
 AKIa23 (1.15)65 (1.63)0.70 (0.43 to 1.13)0.15
 Rhabdomyolysisa10 (0.50)14 (0.35)1.43 (0.64 to 3.22)0.39
 Nephrologist consultation36 (1.80)62 (1.55)1.17 (0.77 to 1.77)0.47
 Acute dialysisb0 (0.00)≤5 (≤0.06)
 Acute interstitial nephritisb≤5 (≤0.12)≤5 (≤0.06)
 Kidney biopsyb≤5 (≤0.12)≤5 (≤0.06)
  • 95% CI, 95% confidence interval; —, not applicable.

  • a The number of events (and the proportion of patients who experienced an event) for both outcomes were assessed using hospital diagnosis codes. This underestimates the true event rate because these codes have high specificity but low sensitivity.

  • b To comply with Institute for Clinical Evaluative Sciences privacy regulations to minimize the chance of identifying a study patient, numbers of patients were suppressed in the case of 1–5 patients (reported as ≤5).