Branch-Elliman W, et al. - Through a multicenter, national retrospective cohort study including 79,058 subjects who underwent surgical procedures in the Veterans Affairs health care system, the researchers characterized the correlation of type and term of prophylaxis with surgical site infection (SSI), acute kidney injury (AKI), and Clostridium difficile infection. SSI had no correlation with a term of prophylaxis, following stratification by type of surgery and adjustment for age, sex, race, diabetes, smoking, American Society of Anesthesiologists score greater than 2, methicillin-resistant Staphylococcus aureus colonization, mupirocin, type of prophylaxis, and facility factors. With every new day of prophylaxis, an increase in the adjusted odds of AKI was noted. A similar duration-dependent relationship was exhibited by the risk of postoperative C difficile infection. The unadjusted numbers required to harm for AKI were 9, 6, and 4, and 2000, 90, and 50 for C difficile infection following 24 to less than 48 hours, 48 to less than 72 hours, and 72 hours or more of postoperative prophylaxis, respectively. Vancomycin receipt was also observed to be an important risk factor for AKI. Progressing term of antimicrobial prophylaxis had a correlation with higher odds of AKI and C difficile infection in a duration-dependent fashion, however, the extended-term did not result into additional SSI decrease. These conclusions reflected the notion that each day matters and inferred that to limit the duration of prophylaxis, stewardship efforts had the ability to decrease adverse events without increasing SSI.