Table 2

 Incorrect coding by diagnosis group

E-codeDiagnosis groupTotal% correct (95% CI)% Correct to 4 digit level, 5th digit incorrect% Correct to 3 digit level, 4th digit incorrect% Correct to group level, 2nd or 3rd digit incorrect% Incorrect at group level
820–829Lower limb fracture26397 (95–99)0110
810–819Upper limb fracture22896 (93–98)2100
996–999Complications22294 (90–96)0123
850–854Intracranial17593 (88–96)0062
960–979Poisoning10892 (85–96)0243
870–897Open wounds20493 (88–95)1321
800–805Skull, neck/trunk fractures14498 (94–99)0101
Other diagnoses32693 (90–96)1105
Total167095 (93–96)1122