Is it time to rebalance the case mix? A portfolio analysis of direct catheterization laboratory costs over a 5-year period.
BACKGROUND
Cardiac catheterization laboratories (CLL) have continued to function as profit centers for hospitals. Due to a high percentage of material and labor costs, they are natural targets for process improvement. Our study applied a contribution margin (CBM) concept to evaluate costs and cost dynamics over a 5-year period.


METHODS
We retrospectively analyzed all procedures performed at a tertiary heart center between 2007 and 2011. Total variable costs, including labor time, material, and maintenance-expenses, were allocated at a global as well as a procedural level. CBM and CBM ratios were calculated by integration of individual DRG revenues.


RESULTS
Annual case volume increased from 1288 to 1545. In parallel, overall profitability improved as indicated by a 2% increase in CBM ratio and a higher CBM generated per hour of CLL working time (4325 vs. 5892 €, p < 0.001). Coronary angiography generated higher average CBMs per hour than coronary or electrophysiological interventions (5831 vs. 3458 vs. 1495 €; p < 0.001). The latter are characterized by relatively high per case material expenditures. On a procedural level, DRG-specific trends as a steady improvement of examination time or an increase in material costs were detectable.


CONCLUSIONS
The CBM concept allows a comprehensive analysis of CLL costs and cost dynamics. From a health service providers view, its range of application includes global profitability analysis, portfolio evaluation, and a detailed cost analysis of specific service lines. From a healthcare payers perspective, it may help to monitor hospital activities and to provide a solid data basis in cases where inappropriate developments are suspected. The calculation principle is simple which may increase user acceptance and thus the motivation of team members.
Department of Cardiology, Johanniter-Hospital Duisburg Rheinhausen, Germany, Kreuzacker 1-7, 47228, Duisburg, Germany. gunnar.plehn@rub.de.|Ruhr-University of Bochum, Universitätsstrasse 150, 44801, Bochum, Germany. gunnar.plehn@rub.de.
Gunnar
G
Plehn
Department of Cardiology, Catholic Hospital Oberhausen, Wilhelmstrasse 34, 46145, Oberhausen, Germany.
Thomas
T
Butz
Ruhr-University of Bochum, Universitätsstrasse 150, 44801, Bochum, Germany.|Department of Cardiology, Cologne-Merheim-Hospital, Ostmerheimer Strasse 200, 51109, Cologne, Germany.
Petra
P
Maagh
Department of Radiology, University Hospital Bergmannsheil Bochum, Bürkle de la Camp-Platz 1, 44789, Bochum, Germany.
Ahmet
A
Oernek
Ruhr-University of Bochum, Universitätsstrasse 150, 44801, Bochum, Germany.|Department of Cardiology, Cologne-Merheim-Hospital, Ostmerheimer Strasse 200, 51109, Cologne, Germany.
Axel
A
Meissner
Schumpeter School of Business and Economics, University of Wuppertal, Gaussstrasse 20, 42119, Wuppertal, Germany.
Natalie
N
Plehn
D006328:Cardiac Catheterization / Q000191:economics* / Q000706:statistics & numerical data; D017023:Coronary Angiography / Q000191:economics / Q000706:statistics & numerical data; D003362:Cost-Benefit Analysis; D003365:Costs and Cost Analysis; D005858:Germany; D006801:Humans; D012189:Retrospective Studies; D062606:Tertiary Care Centers / Q000191:economics* / Q000706:statistics & numerical data
Cardiac catheterization laboratory; Contribution margin; Cost analysis; Procedural portfolio analysis