What is the aim of this review?
Healthcare workers use needles, syringes and other devices for collecting patients' bood and to inject drugs that are in liquid form. Sometimes healthcare workers come into contact with the sharp end of these devices by accident. Such instances are called needlestick injuries (NSI) and they may expose healthcare workers to the risk of serious infections such as hepatitis or human immunodeficiency virus (HIV). Safety features such as shields or retractable needles can help prevent these injuries. We searched in multiple databases for randomised (RCTs) and non-randomised studies (NRS) that had evaluated these features.
Key messages
The evidence on safety devices preventing NSI is of low quality and inconsistent. The lack of a strong and consistent helpful effect could be due to bias. This does not mean that these devices are not effective. The risk of blood contamination may be greater.
More high-quality experimental studies with groups of healthcare workers are needed to compare the effects and cost-effectiveness of various types of safety devices on NSIs, especially in countries where both NSIs and blood-borne infections are common.
What was studied in the review?
We included eight RCTs and 16 NRS. These studies evaluated the safety of blood collection systems, intravenous (IV) systems, injection systems, multiple devices, sharps containers and legislation. We estimated that one to five NSIs occur per 1000 workers every year without intervention. The risk of bias was high in 20 out of 24 studies.
What are the main results of the review?
For safe blood collection systems, one RCT found very low quality evidence showing no considerable effect and one NRS produced very low quality evidence showing a large reduction in NSI. Another NRS used an outdated cap shield.
For safe IV devices, there was very low-quality evidence that NSIs decreased in two NRS but not in one RCT and one other NRS. However, four other RCT studies produced moderate quality evidence that the devices which had to be switched on increased the number of blood splashes. In two RCT studies where the safety feature automatically switched on produced low quality evidence showing no change in amount of blood splashes. Another RCT study found low quality evidence showing a decrease in the number of blood leakage events with these devices.
For safe injection devices, there was very low quality evidence that these reduced the NSI rate in one RCT and in one NRS. However, another NRS found low quality evidence no difference in NSI rate between active and passive safe injection devices.
For the introduction of several safety devices at once, there was very low quality evidence of inconsistent effects from three NRS. .One NRS showed a decrease in NSI rate but the other two studies showed no difference.
For the use of safety containers, there was very low quality evidence of inconsistent effects from three NRS. . One NRS showed a decrease in NSI but the other two studies showed inconsistent results.
For the introduction of legislation on safety-engineered devices, there was low to moderate quality evidence produced by two NRS studies showing a reduction in NSIs.
How up-to-date is this review?
We searched for studies up until 11 November 2016.
For safe blood collection systems, we found very low quality evidence of inconsistent effects on NSIs. For safe passive intravenous systems, we found very low quality evidence of a decrease in NSI and a reduction in the incidence of blood leakage events but moderate quality evidence that active systems may increase exposure to blood. For safe injection needles, the introduction of multiple safety devices or the introduction of sharps containers the evidence was inconsistent or there was no clear evidence of a benefit. There was low to moderate quality evidence that introduction of legislation probably reduces NSI rates.
More high-quality cluster-randomised controlled studies that include cost-effectiveness measures are needed, especially in countries where both NSIs and blood-borne infections are highly prevalent.
Percutaneous exposure injuries from devices used for blood collection or for injections expose healthcare workers to the risk of blood borne infections such as hepatitis B and C, and human immunodeficiency virus (HIV). Safety features such as shields or retractable needles can possibly contribute to the prevention of these injuries and it is important to evaluate their effectiveness.
To determine the benefits and harms of safety medical devices aiming to prevent percutaneous exposure injuries caused by needles in healthcare personnel versus no intervention or alternative interventions.
We searched CENTRAL, MEDLINE, EMBASE, NHSEED, Science Citation Index Expanded, CINAHL, Nioshtic, CISdoc and PsycINFO (until 11 November 2016).
We included randomised controlled trials (RCT), controlled before and after studies (CBA) and interrupted time-series (ITS) designs of the effect of safety engineered medical devices on percutaneous exposure injuries in healthcare staff.
Two of the authors independently assessed study eligibility and risk of bias and extracted data. We synthesized study results with a fixed-effect or random-effects model meta-analysis where appropriate.
We included six RCTs with 1838 participants, two cluster-RCTs with 795 participants and 73,454 patient days, five CBAs with approximately 22,000 participants and eleven ITS with an average of 13.8 data points. These studies evaluated safe modifications of blood collection systems, intravenous (IV) systems, injection systems, multiple devices, sharps containers and legislation on the implementation of safe devices. We estimated the needlestick injury (NSI) rate in the control groups to be about one to five NSIs per 1000 person-years. There were only two studies from low- or middle-income countries. The risk of bias was high in 20 of 24 studies.
Safe blood collection systems:
We found one RCT that found a safety engineered blood gas syringe having no considerable effect on NSIs (Relative Risk (RR) 0.2, 95% Confidence Interval (95% CI) 0.01 to 4.14, 550 patients, very low quality evidence). In one ITS study, safe blood collection systems decreased NSIs immediately after the introduction (effect size (ES) -6.9, 95% CI -9.5 to -4.2) but there was no further decrease over time (ES -1.2, 95% CI -2.5 to 0.1, very low quality evidence). Another ITS study evaluated an outdated recapping shield, which we did not consider further.
Safe Intravenous systems
There was very low quality evidence in two ITS studies that NSIs were reduced with the introduction of safe IV devices, whereas one RCT and one CBA study provided very low quality evidence of no effect. However, there was moderate quality evidence produced by four other RCT studies that these devices increased the number of blood splashes when the safety system had to be engaged actively (relative risk (RR) 1.6, 95% CI 1.08 to 2.36). In contrast there was low quality evidence produced by two RCTs of passive systems that showed no effect on blood splashes. Yet another RCT produced low quality evidence that a different safe active IV system also decreased the incidence of blood leakages.
Safe injection devices
There was very low quality evidence provided by one RCT and one CBA study showing that introduction of safe injection devices did not considerably change the NSI rate. One ITS study produced low quality evidence showing that the introduction of safe passive injection systems had no effect on NSI rate when compared to safe active injection systems.
Multiple safe devices
There was very low quality evidence from one CBA study and two ITS studies. According to the CBA study, the introduction of multiple safe devices resulted in a decrease in NSI,whereas the two ITS studies found no change.
Safety containers
One CBA study produced very low quality evidence showing that the introduction of safety containers decreased NSI. However, two ITS studies evaluating the same intervention found inconsistent results.
Legislation
There was low to moderate quality evidence in two ITS studies that introduction of legislation on the use of safety-engineered devices reduced the rate of NSIs among healthcare workers. There was also low quality evidence which showed a decrease in the trend over time for NSI rates.
Twenty out of 24 studies had a high risk of bias and the lack of evidence of a beneficial effect could be due to both confounding and bias. This does not mean that these devices are not effective.