Effect of patient's age on the profitability of inpatient cardiac catheterization: a contribution margin analysis of frequently performed procedures over a 5-year period.

Background: Due to a continuing age shift in the German society hospital providers are concerned about the additional costs associated with the treatment of elderly patients. It is not clear if cardiac catheterization in aged patients leads to higher resource utilization and if DRG-revenues do compensate for this factor.

Methods: Procedure-related and administrative data of all patients who underwent cardiac catheterization at a tertiary heart center between 2007 and 2011 were collected and analyzed. Then a profitability analysis was performed by comparing the case related variable costs with the Diagnosis-related group (DRG) per case revenues. A particular emphasis was placed on a comparative analysis of identical clusters of procedures.

Results: The most frequently performed catheterization procedure (n = 1800) was associated with significantly higher material expenditure in very old patients (178 ± 48 €) than in old (171 ± 28; p = 0.001) and young patients (172 ± 39; p = 0.046). Furthermore, radiation time and the length of hospital stay were increased in very old patients (3.5 ± 3.8 min and 6.2 ± 4.8 days) compared to old (2.7 ± 2.8 min and 4.6 ± 3.8 days; p < 0.001) and young patients (2.5 ± 2.5 min and 4.5 ± 3.9 days; p < 0.001). Due to higher DRG revenues very old patients achieved higher absolute contribution margins (2065 ± 1033 €) than old (1804 ± 1902 €; p < 0.001) and young patients (1771 ± 902 €; p < 0.001). However, the contribution margins per day were significantly smaller (440 ± 226 €) than those in old (488 ± 234 €; p = 0.001) and young patients (484 ± 206 €; p = 0.001).

Conclusions: Catheterization of very old patients is related to lower contribution margins per day despite higher material and time expenditures. Since efforts to reduce the length of hospital stay of these patients are limited, this may result in a competitive disadvantage of hospitals which are more affected by the demographic change.