The 'morning dip' in antimicrobial appropriateness: circumstances determining appropriateness of antimicrobial prescribing.

Objectives: Quality of care has been shown to vary depending on the time of day or day of the week and depending on caregivers' gender and experience. We aimed to study how these factors influence quality of antimicrobial prescribing.

Methods: Prospective point-prevalence surveys were performed to determine the association between the above-mentioned prescription factors and antimicrobial appropriateness. Surveys included cases of patients admitted to a tertiary care hospital with a prescribed systemic antimicrobial drug and its prescribers. The main outcome was appropriateness of antimicrobial prescriptions. A post hoc qualitative survey among hospital physicians asked physicians to reflect on the results.

Results: The study included 351 antimicrobial prescriptions by 150 physicians prescribed for 276 patients. Appropriateness of antimicrobial prescribing in the morning was significantly lower compared with the afternoon and evening/night [43% versus 68% versus 70%, crude OR afternoon versus morning = 3.00 (95% CI = 1.60-5.48), crude OR evening/night versus morning = 3.40 (95% CI = 1.64-6.69)]. First-year residents performed significantly worse than their more experienced colleagues [51% versus 69%, crude OR = 2.09 (95% CI = 1.26-3.38)]. Infectious disease expert consultation improved appropriateness [54% versus 81%, crude OR = 3.71 (95% CI = 2.05-6.23)]. No significant effects for gender or office hours versus non-office hours were found. Post hoc survey results suggest creating room to improve prescribing circumstances during mornings and for inexperienced physicians.

Conclusions: Antimicrobial prescribing was less appropriate in the mornings and when prescribed by inexperienced physicians. Appropriateness may be increased by improving prescribing circumstances.