THE COST OF INFECTION IN SURGICAL PATIENTS - A CASE-CONTROL STUDY

To determine the excess hospital cost attributable to hospital acquired infection in a UK hospital 67 surgical patients with hospital acquired infection (HAI) were matched with uninfected controls on the primary features of the first operative procedure and primary diagnosis, and on the secondary features of sex, age and surgical service. Costs were calculated from the hospital's unit costs for pathology, radiology and for the cost of one day's extra stay. The mean cost of one day of antibiotic therapy was also measured. In infected patients there was a significant increase in the length of hospital stay of 8·2 days with a mean extra cost per patient of £1041 (P < 0·001). Microbiology, haematology, chemical pathology and radiology requests were all significantly increased with a mean extra cost per infected patient of £10·4, £7·8, £9·6, and £3·3, respectively. Antibiotic therapy contributed significantly to the extra costs (£44 per infected patient). The mean extra cost per patient was highest in orthopaedic patients (£2646) and least in gynaecology patients (£404). For the infections with significantly increased cost, multiple infections carried the greatest (£3362), and urinary tract infections the least (£467) cost. Hospital length of stay was the greatest contributor to the cost and accounted for 95% of the extra cost in orthopaedics, 94% in gynaecology and 92% in general surgery and urology. Antibiotic therapy was the second most significant contributor to cost and, with the exception of urinary tract infection and infections in gynaecology, was at least five times more per patient than requests for microbiology, haematology, chemical pathology or radiology. © 1993.