Study	Reason for exclusion
Bystricka 2004	Study protocol
Davidson 1986	Comparison of different dressing types not frequencies
Dickerson 1989	Letter to the editor (comment on a study comparing two types of dressings)
Hagerstrom 1994	Conference abstract related to dressing methods ‐ unrelated to timing
Ishizuka 2011	The wards involved were randomly allocated, not the patients
Lucas 1996	Comparison of different dressing types not frequencies
Powell 1985	Co‐interventions (frequency of administration set replacement) were different between different arms of the study
Samsoondar 1985	Co‐interventions (frequency of administration set replacement) were different between different arms of the study Quasi‐randomisation
Young 1988	Co‐interventions (frequency of administration set replacement) were different between different arms of the study
Zitella 2003	Systematic literature review of central venous catheter site care for blood and marrow transplant recipients