The effect of intravenous-to-oral switch guidelines on the use of parenteral antimicrobials in medical wards.

The effect of an intravenous (i.v.)-to-oral switch policy on antibiotic prescribing in general medical wards was examined. Three audits, each of 2 months' duration, were carried out to examine the duration of i.v. therapy and length of patient stay. The first audit (S1) was performed before the introduction of switch guidelines, the second (S2) after guidelines had been placed in patient case-notes and the third (S3) after the guidelines had been introduced into the drug charts. The duration of i.v. therapy was significantly shorter in the S3 group (mean = 3.7 days) than in the S2 or S1 groups (mean 4.4 and 4.35 days, respectively) (P < 0.05). There was no significant difference in the length of patient stay between the three audit periods but the stay was significantly shorter in 81 switched patients (mean duration = 8.9 days) than in matched controls (mean duration = 12.6 days) (P = 0.01). Fewer patients with respiratory infection were treated for > 24 h with i.v. antimicrobials in the S3 audit period (75/549) than in the S2 (85/372) and S1 audits (83/326) (P < 0.01). The introduction of switch guidelines to drug charts reduces the length of i.v. therapy. Switched patients spend less time in hospital than their matched controls.