Table 2. Variation in oral anticoagulant propensity between general practice clinics
Observed variation (p90/p10)Random variation (p90/p10)Excess variation (observed/random)
1.08/0.90 = 1.201.07/0.92 = 1.161.20/1.16 = 1.03
  • p10 = 10th percentile. p90 = 90th percentile