Schuetz 2009.

Methods	Randomised clinical trial, multicentre, 6 sites in Switzerland
Participants	Inclusion criteria: Clinical diagnosis of CAP, ECOPD, bronchitis with X‐ray confirmation Exclusion criteria: People with active intravenous drug use, severe immunosuppression other than corticosteroid use, life‐threatening medical comorbidity leading to possible imminent death, hospital‐acquired pneumonia (development of pneumonia 48 hours after hospital admission or if they were hospitalised within 14 days before presentation), and chronic infection necessitating antibiotic treatment Included in this analysis: 1359 out of 1381 randomised participants; 22 post randomisation exclusions due to withdrawal of consent
Interventions	Guiding antibiotic decisions in emergency department patients with different ARIs with repeated measurements Algorithm used in this study: Initiation or continuation of ABs was strongly discouraged if PCT was less than 0.1 µg/L and discouraged if levels were 0.25 µg/L or lower. Initiation or continuation of ABs was strongly encouraged if PCT was higher than 0.5 µg/L and encouraged if levels were higher than 0.25 µg/L. If ABs were withheld, hospitalised patients were clinically re‐evaluated and PCT measurement was repeated after 6 to 24 hours.
Outcomes	composite of overall adverse outcomes including death from any cause, ICU admission for any reason, disease‐specific complications, and recurrence of LRTI in need of ABs any of above outcomes length of stay side effects from antibiotics
Notes	Funding: This work was supported in part by grant SNF 3200BO‐116177/1 from the Swiss National Science Foundation and contributions from santésuisse and the Gottfried and Julia Bangerter‐Rhyner‐Foundation, the University Hospital Basel, the Medical University Clinic Liestal, the Medical Clinic Buergerspital Solothurn, the Cantonal Hospitals Muensterlingen, Aarau and Lucerne, respectively, the Swiss Society for Internal Medicine, and the Department of Endocrinology, Diabetology and Clinical Nutrition, University Hospital Basel. B·R·A·H·M·S Inc, the major manufacturer of the PCT assay, provided all assay‐related material, Kryptor machines if not already available onsite, and kits and maintenance required for 10,000 measurements related to the study. Follow‐up: Fixed follow‐up period after 30 days and 180 days Registration: ISRCTN95122877
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Independent statistician created randomisation scheme.
Allocation concealment (selection bias)	Low risk	Central randomisation using a study web site
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Open‐label trial where physicians knew to which group participants had been assigned and where PCT levels were only communicated in the intervention arm
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Interviews by blinded medical students, data safety monitoring board
Incomplete outcome data (attrition bias) All outcomes	Low risk	Follow‐up for mortality: 1358/1359 (100%)
Selective reporting (reporting bias)	Low risk	Outcomes match previously published protocol.
Other bias	Low risk	91% adherence to PCT algorithm in PCT group