[Assessing the balance of quality indicator sets of external quality assurance according to SGB V section 136]

The value and usefulness of the results of indicator-based performance measurement in healthcare for different purposes do not only depend on the methodological quality of the individual indicators but also on the composition of the indicator sets. So far, the balance of the currently used indicator sets of the German mandatory national performance measurement system for hospitals has not been systematically analyzed.

Due to the lack of a methodological gold standard for the assessment of balance and orientation of indicator sets we adapted the OECD concept of quality dimensions and defined four categories: 1) "Achieving primary goals of treatment", 2) "Avoiding adverse events", 3) "Indication" and 4) "Patient-centeredness". We defined rules for the assignment to the categories and analyzed the distribution of the 239 indicators from 29 medical areas in relation to these categories.

63 indicators (26.4 %) were assigned to the category "Achieving primary goals of treatment", 153 (64.0 %) to the category "Avoiding adverse events", 18 (7.5 %) to the category "Indication", one indicator (0.4 %) to the category "Patient-centeredness". Four indicators (1.7 %) addressed documentation quality. 12 of the 29 indicator sets only covered one OECD quality dimension by at least one indicator.

The current indicator sets seem to be unbalanced with a strong focus on the category "Avoiding adverse events". As regards the goal of monitoring compliance with minimal safety standards and performing improvement interventions, the direction of the indicator sets seems to be appropriate. With respect to other goals, such as for example the identification of "excellence", further development efforts are required. One relevant reason for the dominant focus on the category "Avoiding adverse events" seems to be that data sources for a follow-up and for the inclusion of the patient perspective have not been available until recently. There is a strong demand for the consequent use of these data sources to optimize the interpretability and value of the current performance measurement. The methodological approach presented may offer useful information to assess the value of indicator sets for different purposes although further development and research is necessary.