Table 1

Comparison of two adverse event classification systems and the ‘reconciled’ version taken forward in this study

Forster et al13 (patients experiencing adverse events after discharge)Brennan et al24 (patients experiencing adverse events in hospital)Reconciled
Health OutcomeProportion with the outcomeHealth statesProportion in each stateHealth statesProportion in each state
Permanent disability*0.03Permanent disability >50%0.026Permanent disability >50%0.02
Permanent disability ≤50%0.039Permanent disability ≤50%0.03
Readmission0.21Moderate impairment, recovery >6 months0.028Moderate impairment, recovery >6 months0.10
A & E visit0.11Moderate impairment, recovery 1–6 months0.137Moderate impairment, recovery 1–6 months0.30
Physician visit0.14
No extra use of health service0.51Minimal impairment, recovery <1 month†0.634Minimal impairment, recovery <1 month0.50
  • *These patients were also assumed to be readmitted to hospital (the observed readmission in the study was 24%).

  • †Brennan et al included an ‘unclassified’ category for 6.5% of adverse events—we have subsumed this into the ‘minimal impairment’ category.