Combining Procalcitonin and Rapid Multiplex Respiratory Virus Testing for Antibiotic Stewardship in Older Adult Patients With Severe Acute Respiratory Infection.

This was an observational study with a historical control group, not a randomized trial, so differences may reflect unmeasured factors. The comparison cohort did not receive procalcitonin testing, so the study cannot tell whether the respiratory panel, the procalcitonin test, the nurse communication, or the stewardship reminders drove the outcomes. The study nurse enrolled patients only on weekday working hours, and the authors noted possible selection bias, though they did not find outcome differences by time shift. Postdischarge follow-up for the historical cohort was unavailable, so oral antibiotic duration could not be compared. The tested group was small, and stopping antibiotics alone involved only 7 of 169 patients versus 10 of 507 controls, so that outcome was not meaningful. After adjustment, length of stay and mortality were not different, so the unadjusted shorter stay should not be treated as a firm outcome effect. Respiratory virus incidence may have differed between the two study seasons. All tested patients were hospitalized and had severe illness, so results may not apply to milder respiratory illness or other settings.

Do not conclude that the rapid respiratory panel alone caused shorter antibiotic courses. The tested patients also received procalcitonin testing and nurse-led result communication and stewardship reminders, and the study cannot separate the effect of any single part.