Summary of findings for the main comparison.

Summary of findings: prophylactic antibiotics before long‐term CVC insertion

Antibiotics compared with no antibiotics prior to long‐term CVC insertion to prevent catheter‐related infections
Patient or population: adults with a newly inserted long‐term CVC who were at risk of neutropenia due to chemotherapy or disease Settings: inpatient and outpatient Intervention: intravenous antibiotics (vancomycin, teicoplanin or ceftazidime) Comparison: placebo or no antibiotics
Outcomes	Illustrative comparative risks* (95% CI)		Relative effect (95% CI)	No of Participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Control	Antibiotics
Catheter‐related sepsis	200 per 1000	144 per 1000 (66 to 316)	RR 0.72 (0.33 to 1.58)	360 (5)	⊕⊕⊕⊝ moderate	The difference between the comparison groups was not significant (P = 0.41). We downgraded this evidence to moderate due to the substantial heterogeneity (I² = 52%) between studies.
*The basis for the assumed risk is the mean control group risk across studies. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: Confidence interval; RR: Risk ratio
GRADE Working Group grades of evidence High quality: Further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: We are very uncertain about the estimate.