Table 1 Search criteria

Date of publication

1 January 2002–22 October 2019

Before 1 January 2002

After October 2019

Location or context

Hospitals (e.g. ICU, medical wards, surgical units, inpatient units, entire facility) in high-income countries

All other settings; low-/middle-income countries

Intervention

Various forms of HH interventions

Outcome

Measurements of observed improvement in HHC

Studies that do not measure improvement in HHC

Study design

Experimental: randomized-controlled trial (RCT) and non-RCT

Experimental or quasi-experimental: pre-and-post intervention design with a control group; pre- and-post intervention design without a control group

Any other publications (e.g. outbreak reports, editorials)

Target population

Nursing staff; nursing student

Any other HCW