Abstract: We included 13 studies: one cluster randomised controlled trial (CRCT) and 12 ITS studies, involving 40 hospitals, 51 intensive care units (ICUs), 27 wards, and more than 3504 patients and 1406 healthcare professionals. Six of the included studies targeted adherence to guidelines to prevent central line-associated blood stream infections (CLABSIs); another six studies targeted adherence to guidelines to prevent ventilator-associated pneumonia (VAP), and one study focused on interventions to improve urinary catheter practices. We judged all included studies to be at moderate or high risk of bias. The largest median effect on rates of VAP was found at nine months follow-up with a decrease of 7.36 (-10.82 to 3.14) cases per 1000 ventilator days (five studies and 15 sites). The one included cluster randomised controlled trial (CRCT) observed, improved urinary catheter practices five weeks after the intervention (absolute difference 12.2 percentage points), however, the statistical significance of this is unknown given a unit of analysis error. It is worth noting that N = 6 interventions that did result in significantly decreased infection rates involved more than one active intervention, which in some cases, was repeatedly administered over time, and further, that one intervention involving specialised oral care personnel showed the largest step change (-22.9 cases per 1000 ventilator days (standard error (SE) 4.0), and also the largest slope change (-6.45 cases per 1000 ventilator days (SE 1.42, P = 0.002)) among the included studies. We attempted to combine the results for studies targeting the same indwelling medical device (central line catheters or mechanical ventilators) and reporting the same outcomes (CLABSI and VAP rate) in two separate meta-analyses, but due to very high statistical heterogeneity among included studies (I2 up to 97%), we did not retain these analyses. Six of the included studies reported post-intervention adherence scores ranging from 14% to 98%. The effect on rates of infection were mixed and the effect sizes were small, with the largest median effect for the change in level (interquartile range (IQR)) for the six CLABSI studies being observed at three months follow-up was a decrease of 0.6 (-2.74 to 0.28) cases per 1000 central line days (six studies and 36 sites). This change was not sustained over longer follow-up times. The low to very low quality of the evidence of studies included in this review provides insufficient evidence to determine with certainty which interventions are most effective in changing professional behaviour and in what contexts. However, interventions that may be worth further study are educational interventions involving more than one active element and that are repeatedly administered over time, and interventions employing specialised personnel, who are focused on an aspect of care that is supported by evidence e.g. dentists/dental auxiliaries performing oral care for VAP prevention.

Plain-language summary: We identified 13 studies: one cluster randomised controlled trial (CRCT) and 12 interrupted time series (ITS) studies, involving 40 hospitals, 51 intensive care units (ICUs), 27 wards and more than 1406 healthcare professionals and 3504 patients, which assessed the impact of different interventions to reduce the occurrence of device-related infections for inclusion in this review. We judged all studies to be at moderate to high risk of bias. The effect sizes were small with the largest median effect for studies addressing central line associated blood stream infections (CLABSIs) occurring immediately after the implementation of an intervention to improve adherence to guidelines, in the majority of studies this change was not sustained over longer follow-up times. The median effect for studies aiming to reduce ventilator-associated pneumonia (VAP) was somewhat greater and was sustained up to 12 months follow-up. The results of six studies that reported adherence/non-adherence with infection control recommendations showed very varying adherence scores ranging from 14% to 98%. The low to very low quality of the evidence of the studies included in this review provides insufficient evidence to determine with certainty which interventions are most effective in changing professional behaviour and in what contexts. However, interventions that may be worth further study are educational interventions consisting of more than one active element and that are repeatedly administered over time, and interventions employing dedicated personnel, who are focused on a certain aspect of care that is supported by evidence e.g. dentists/dental auxiliaries providing oral care. If healthcare organisations and policy makers wish to improve professional adherence to guidelines for the prevention of device-related infections, funding of well designed studies to generate high quality evidence is needed to guide policy.