Probability of admission – further data sources and issues Colin Cryer IPRU, Univ of Otago, NZ Presented at the ICE on Injury Statistics Meeting, 7-8 September 2006, Washington DC

7 September Colin Cryer, IPRU, Univ of Otago, NZ Other data sources CountryDetail Coding by Contact Italy Diag coded to ICD-9-CM in 60 hospitals in Lazio (incl. Rome). RTIs and home. Includes up to 4 diagnoses. Clinicians + coding aid (GIPSE) Paolo Georgi Rossi Greece >500,000 cases with diagnosis coded to ICD-9; around 250,000 to ICD-10 Professional coders Eleni Petridou

7 September Colin Cryer, IPRU, Univ of Otago, NZ Issue: Coding frame Several different coding frames used for diagnosis: eg. ICD-9, ICD-9-CM, ICD-10 Several different coding frames used for diagnosis: eg. ICD-9, ICD-9-CM, ICD-10 Options Options Restrict study to just one of these (eg. ICD-10) Restrict study to just one of these (eg. ICD-10) Include all Include all If all, is ICD-9 to ICD-10 translation good enough for comparison? If all, is ICD-9 to ICD-10 translation good enough for comparison? To resolve To resolve

7 September Colin Cryer, IPRU, Univ of Otago, NZ Issue: Specificity of codes What specificity of ICD diagnosis code should be used to estimate probability of admission? What specificity of ICD diagnosis code should be used to estimate probability of admission? Issue Issue Too specific many diagnosis codes with too few cases Too specific many diagnosis codes with too few cases Less specific diagnoses with high Pr(Adm) may be hidden in heterogeneous groups. Less specific diagnoses with high Pr(Adm) may be hidden in heterogeneous groups.

7 September Colin Cryer, IPRU, Univ of Otago, NZ Issue: Accuracy of coding Correspondence of ED and hospital discharge diagnosis codes (Source: Farchi, 7 th World Conference) Correspondence of ED and hospital discharge diagnosis codes (Source: Farchi, 7 th World Conference) 62.2% of linked cases, diagnosis concordant* 62.2% of linked cases, diagnosis concordant* Higher concordance in older people, and less urgent care Higher concordance in older people, and less urgent care Over 80% concordance for: Over 80% concordance for: Fracture (upper and lower extremities, head and neck, spine, torso), lower extremity crushes/ amputation. Fracture (upper and lower extremities, head and neck, spine, torso), lower extremity crushes/ amputation. *At the Barell matrix cell level

7 September Colin Cryer, IPRU, Univ of Otago, NZ Preliminary results Probability of Admission – Barell matrix Lazio, Italy – Farchi S, Rossi PG, Camilloni L, Chini F (personal correspondence) Source: EIS home and road

7 September Colin Cryer, IPRU, Univ of Otago, NZ Probability of Admission – Barell matrix – high Lazio, Italy – Farchi S, Rossi PG, Camilloni L, Chini F (personal correspondence) Source: EIS 2000 – home and road

7 September Colin Cryer, IPRU, Univ of Otago, NZ Probability of Admission – Barell matrix – single cell Lazio, Italy – Farchi S, Rossi PG, Camilloni L, Chini F (personal correspondence) ICD-9-CM codes with less than 50 ED attendances were excluded Source: EIS 2000 – home and road