Wirksamkeitsanalyse externer Qualitätssicherungsmaßnahmen anhand von Veränderungen in Qualitätskennzahlen einzelner Krankenhäuser

Judging the effectiveness of external quality assurance programmes by comparing current performance with unadjusted regional or national crude averages is misleading because the influence of the actual size of the populations under consideration as well as the variance of performance between hospitals is underestimated. Not only do these artefacts lead to a general overestimation of changes in regional averages. They also may lead to a ranking confounded by regional size. An assessment at unit level circumvents these difficulties. The differential grading of degree of departure of a unit's performance from national targets available from funnel plots allows, in addition, for the discrimination between effects due to the monitoring institution and achievements attributable to the hospital under surveillance. A central role is played by the scoring system adopted for evaluating incremental changes of performance indicator values in successive years. The following proposal is intended to both assist the assessment of effectiveness of quality assurance programmes and identify areas requiring urgent improvement. Bavarian quality assurance data (BAQ 1995) are used to illustrate the method.