Adverse reactions to contrast media: factors that determine the cost of treatment

The purpose of this study was to determine the cost of treating adverse reactions to contrast material that occur in patients with different clinical characteristics, the characteristics of patients who have adverse reactions that are expensive (> $500) to treat, and the types of adverse reactions that are expensive to treat. The cost of patient care associated with treating complications of medical procedures is an important consideration when evaluating the cost effectiveness of medical practices. Information about the cost of treating complications can be useful in guiding the development and application of new and safer strategies for patient care.

We performed an economic analysis of data collected in a clinical trial comparing the safety of low- vs high-osmolality radiologic contrast media in 1004 patients who underwent either cardiac angiography or contrast-enhanced body CT; 193 (19%) of these patients had at least one adverse reaction. By means of bivariate and multivariate analyses, we examined the association between the cost of treating adverse reactions to contrast material and the baseline characteristics (age, sex, race, radiologic procedure, contrast medium, preexisting disease) of patients and clinical features (type and/or number of different types) of these reactions.

The mean cost per patient to the hospital of treating adverse reactions to contrast material among the 193 patients who sustained a reaction was $459 (range, $0-39,057). The mean cost varied with the type and number of reactions, ranging from $32 (+/- $13) for treatment of increased systolic blood pressure to $15,360 (+/- $7994) for treatment of thromboembolism. Bivariate and multivariate analyses showed the variables associated with higher cost of treating reactions: cardiac angiography vs body CT (mean cost, $476 vs $198), a history vs no history of unstable angina (mean cost, $930 vs $208), a history vs no history of renal insufficiency (mean cost, $2064 vs $152), two adverse reactions (mean cost, $221) or three or more reactions (mean cost, $3585) vs one reaction (mean cost, $161), and a thromboembolic reaction (mean cost, $15,360). These variables explained 38% of the variation in the costs of treating adverse reactions to contrast material (p < .0001).

Costs of treating adverse reactions to contrast material vary, both overall and by type and extent of reaction. Cardiac angiography, a history of unstable angina or renal insufficiency, multiple (two or more types of) adverse reactions, and thromboembolism are major factors that contribute to the cost of such treatment. Future strategies of patient care should be directed at reducing the risk of adverse reactions to contrast material for patients with these characteristics and at reducing the cost of treating these particularly expensive adverse reactions.