Facilitating Cross-National Comparisons of Indicators for Patient ...

DELSA/ELSA/WD/HTP(2008)126. In this manual it is assumed that countries using definition B for assignment of principaldiagnosis are able to identify the case-related admission diagnosis (ADx) in their data sets. In this casepatients with admission diagnosis corresponding to the numerator definition of the indicator should beexcluded (see left-sided flow chart “PDx algorithm” on p.14). Furthermore it shall be avoided thatcountries using definition B for assignment of principal diagnosis miss numerator cases by assigningspecific complications as principal diagnosis. If a diagnosis type indicator is in use data can be properlyrearranged (see right-sided flow chart at Figure 1: PDx Algorithm).Secondary diagnosis27. Patient safety indicators are largely constructed from secondary diagnoses. The calculation of thenumerator builds on secondary diagnosis for most of the indicators. The indicator definitions refer toconditions aroused post admission. To make sure that all participating countries use the same definition ofsecondary diagnosis it is presented here:Definition of Secondary Diagnosis (SDx) 828. Comorbid conditions are those conditions for which the patient received treatment and consumedhospital resources in addition to those conditions considered to be the principal, main or dischargediagnosis.34. Pre-admission conditions without any necessary treatment during the hospital stay do not meetthe definition. Pre-admission comorbidities with in-hospital treatment meet the definition of the secondarydiagnosis. Countries using diagnosis type indicators have the possibility to distinguish between pre- andpost-admission comorbidities. If they perform additional exclusions of numerator cases their calculatedrates might be lower than in countries where additional criteria for secondary diagnosis documentation arenot in use.Use of codes for external causes of morbidity and mortality (“E-codes”)35. Several indicators (e.g. Complications of Anaesthesia) build on diagnoses codes from ChapterXX (20) of the ICD-10 or the corresponding supplement of the ICD-9 respectively. The WHO designatesthose codes for additional documentation of external causes of morbidity. The availability of these codes incountry modifications of the ICD may vary. Furthermore their use is optional in some countries.Depending on the extent of available e-codes in country modifications indicator rates may vary betweencountries.Exclusions of MDC36. In countries using DRG for hospital reimbursement each case is assigned to a MDC (MajorDiagnostic Category) by the grouper software. The MDC assignment relies exclusively on the principaldiagnosis of the case (definition A above).The calculation of several indicators (Table 3) requires theexclusion of certain MDCs to ensure that whole populations with high risk for a condition are not counted.For example, MDC 9 (diseases of skin, subcutaneous tissue, and breast) is excluded from the calculation ofindicator Decubitus Ulcer. Lists of ICD-10-WHO codes referring to certain MDCs are provided in theAnnex 2 - Code List M 5 for countries using ICD-10 without DRG reimbursement or if the MDCassignment of data is impossible.5. Code lists and neonate identification are adapted from (InEK, 2006 and Commonwealth of Australia,1998).13