Long 2011

Methods	Randomised clinical trial, single‐centre, emergency department outpatients in China
Participants	Inclusion criteria: CAP with X‐ray confirmation in an outpatient setting Exclusion criteria: pregnancy, commencement of antibiotic therapy ≥ 48 h before enrolment, systemic immune deficiency, withholding of life‐support and active tuberculosis Included in this analysis: 156 out of 172 randomised patients: 16 post randomisation exclusions (6 lost to follow‐up, 7 withdrew consent, 3 with final diagnosis other than CAP)
Interventions	Guiding antibiotic decisions in CAP patients with repeated levels Algorithm used in this study: a procalcitonin level of less than 0.1 µg/L suggested the absence of bacterial infection and the initiation or continuation of ABs was strongly discouraged. A procalcitonin level between 0.1 and 0.25 µg/L indicated that bacterial infection was unlikely and the initiation or continuation of ABs was discouraged. A procalcitonin level of 0.25 µg/L or greater was considered to indicate a possible bacterial infection and the initiation or continuation of AB therapy was encouraged. Re‐evaluation of the clinical status and measurement of procalcitonin levels was recommended after 6 to 12 h in all patients from whom ABs were withheld
Outcomes	Antibiotic use Mortality ICU admission
Notes	Funding: the study was sponsored by a grant from the Shanghai Fifth People′s Hospital Science Foundation (09YRCPY11) Follow‐up: fixed period of 4 weeks Registration: NA
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Odd and even patient ID numbers
Allocation concealment (selection bias)	High risk	Odd and even patient ID numbers
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Open‐label trial where physicians knew in which group patients were and where procalcitonin levels were only communicated in the intervention arm
Blinding of outcome assessment (detection bias) All outcomes	High risk	Non‐blinded study members
Incomplete outcome data (attrition bias) All outcomes	Low risk	Follow‐up for mortality: 156 (156) (100%)
Selective reporting (reporting bias)	Low risk	No selective reporting (oral verification with first author)
Other bias	Unclear risk	Adherence to procalcitonin protocol not reported/assessed