Five-Year Evolution of Drug Prescribing in a University Adult Intensive Care Unit

Abstract

Healthcare costs are steadily increasing. In Switzerland, in 2007, they amounted to 10.8% of gross domestic product, of which 45.6% related to hospital care (including drug-related costs) and 10.3% to drugs.[1] Very few data exist regarding evolution of drug costs in hospitals, as they are included in the hospital financing system.[2] In our university hospital, the 32-bed adult intensive care unit (AICU) amounts to 0.3% of hospital beds but 3% of hospital costs. In 2008, drug costs amounted to 4.8% of hospital costs but 11% of AICU costs. Intensive care physicians (ICPs) prescribe most usual drugs, but specialists clinicians (SCs) are allowed to prescribe specific expensive drugs in their specific field. We assessed the 5-year evolution of AICU drug prescription both in quantities and costs, by type of prescriber.Patients' characteristics and AICU activity were extracted from the 2004-2008 annual reports, and drug data were taken from the pharmacy database on a quarterly basis.First, global evolution of both quantities and costs of all drugs used in AICU was retrieved and split by the first level of the Anatomical Therapeutic Chemical (ATC) international system.[3] Then, within each ATC code, drugs with high consumption or high costs (yearly nominal values), or important variations over time in both quantities and costs, were singled out. Drugs with quarterly costs lower than 3000 Swiss francs (CHF) [[euro]2100, $US2300, 2008 values] were ignored. Finally, the share of both quantities and costs of drugs prescribed by SCs and ICPs were compared.Lastly, to account for annual inflation (0.6 to 1.2%) and increase in activity as measured by the number of admitted patients (2.2 to 7.3%), an adjusted daily cost of drug treatment was computed for each year of follow-up.Over the 5-year period, the number of AICU admissions increased by 10.8% (2226 to 2466), AICU days by 7.3% (9921 to 10 645), average length of stay by 5% (4.53 to 4.76 days), and occupancy rate by 8.0% (87% to 94%), while patients' severity did not significantly change. Over the same period, drug quantities increased by 36% (235 807 to 312 700 unit doses) and costs by 34% (CHF3 205 408 to CHF4 298 402), in a non-steady, non-parallel way (figure 1 displays the quarterly evolution of both drug quantities and costs).Fig. 1 Five-year evolution in drug quantities (solid line) and costs (dotted line), quarterly distribution. CHF = Swiss francs. [Figure omitted.]Four ATC classes amounted to 80% of both quantities and costs, with ATC code B (blood and haematopoietic organs) amounting to 63% of quantities and 41% of costs.In this class, the leading group in quantities and costs was B05 (blood substitutes and perfusion solutions). A peak in costs for B01 (anti-thrombotics), not mirrored in a peak in quantity, was noticeable in 2008, due to the temporary unavailability of danaparoid (B01AB09), replaced by argatroban (B01AE03), which was six times more expensive.Intravenous solutions (B05B) showed a major increase in costs of parenteral nutrition solutions, not mirrored in a corresponding increase in quantities, whereas the reverse was stated for intravenous electrolyte solutions. This transient increase was due to a shift towards prescribing more expensive solutions, which was reverted afterwards.A striking evolution was noted in antibiotics (ATC J01 CR05), when a generic for piperacillin tazobactam became available, resulting in important savings.Altogether, 48 drugs were identified which fulfilled the initial criteria of high quantity or costs or wide variations in quantities or costs. The detailed list is displayed in Annex 1 (Supplemental Digital Content, http://links.adisonline.com/APZ/A58).Prescription by the SCs amounted to an average of 1% in quantity, but 19% in costs. The rate of increase in both quantities and costs was seven times larger for ICPs than for SCs (figure 2 displays the quarterly evolution in drug prescription costs). …