Improving managed competition by homogenizing the Dutch DBC

Summary BACKGROUND: In 2009, 12 percent of the annual gross domestic product was spent on health care in the Netherlands, which is more than most other OECD countries. Governmental budgets in the Netherlands had to be cut and cost containment in health care was inevitable. To create awareness of cost of treatment, the Diagnosis Treatment Combinations (DBC) system was introduced. To control costs, all health care players need to know which patients and their treatments are most expensive. Therefore, it is important that patients are classified by adequate classification variables which reflect differences between patient groups to predict high treatment costs. This study will examine whether it is necessary to increase the homogeneity of patient groups in DBCs and which (current) classification variables are able to create homogeneity of patient groups in DBCs to decrease cost variation. METHODS: In this study, patient level data of 2008 from the Dutch DBC database of inguinal hernia repair, appendectomy and cholecystectomy within the medical specialty Surgery were used for analyses. For each clinical pathway, the most relevant DBC codes and classification variables were selected. Classification variables concerned both care activities and patient core variables. Ordinary Least Squares (OLS) regression was used to examine the ability of DBC codes and classification variables to explain cost variation between patients. RESULTS: Although the predictive ability of appendectomy and cholecystectomy was very low, current DBC codes explained 30 percent of cost variation for inguinal hernia repair. Except for inguinal hernia repair, patient characteristics seemed to have a low predictive ability. However, age has a significant impact on cost variation and this is valid for all clinical pathways. As expected, care activities explained much cost variation. Although classification variables in general had a significant impact for inguinal hernia repair, care activities were most important for all clinical pathways particularly physiotherapy, CT scans, echoes, review ECG, daycare hours, laboratory- and microbiological services, open – and laparoscopic procedure, inpatient- and outpatient visit, pathological examination and emergency care visit. CONCLUSIONS: The choice of a grouping algorithm is essential to increase homogeneity and consequently result in efficiency gains for hospitals. Together with care activities, age can serve as additional classification variable to increase homogeneity of patient groups. Although these results cannot be used to represent all Dutch patients and other important determinants should be taken into account, these results may help the decision-making process of improving the grouping algorithm of the new DOT (DBC towards transparency) system. Furthermore, these study results might have valuable implications for the relationships within the triangle in Dutch health care.