What is the aim of this review?

The aim of this Cochrane review was to find out if system-wide interventions increased the use of measures to prevent blood clots (thromboprophylaxis), and decreased the incidence of blood clots (venous thromboembolism) in hospitalized adult medical and surgical patients at risk for this problem.

Key messages

Providing system-wide interventions, particularly alerts, to doctors and other healthcare professionals probably improves the use of thromboprophylaxis or appropriate thromboprophylaxis, and decreases the number of symptomatic blood clots (clots showing symptoms) at three months. However, the certainty of the evidence was rated as moderate or low, thus more high-quality studies examining the effectiveness of system-wide interventions are needed to confirm the findings of this review.

What was studied in this review?

Blood clots that occur in the leg veins (deep vein thrombosis) or in the lung circulation (pulmonary embolism) are together known as venous thromboembolism (VTE). VTE is a potential complication for patients who have been hospitalized for medical or surgical reasons. These complications lengthen hospital stay and are a leading cause of death and long-term disability. Risk factors for VTE include hospitalization for surgical or medical illness, cancer, trauma or immobilization, medications, such as oral contraceptives or hormone replacement therapy, and pregnancy or postpartum. Other risk factors are older age, obesity, previous blood clots, and family history of blood clots.

Thromboprophylaxis involves the administration of small doses of anticoagulant (i.e. blood thinning) medications, such as heparin, low molecular weight heparin, or oral blood thinners, or the application of physical measures, such as graduated compression stockings or sequential compression devices. In the USA, thromboprophylaxis has been ranked as the number one strategy to improve patient safety in hospitals, and interventions to improve the implementation of thromboprophylaxis were recently ranked as a top-10 patient safety strategy that demanded action.

While thromboprophylaxis is safe and can prevent VTE in various patient groups at risk for these complications, it remains underused or inappropriately used. We looked at two different ways to measure thromboprophylaxis use: received prophylaxis (did the patient receive any thromboprophylaxis?), and received appropriate prophylaxis (did the patient receive prophylaxis that was appropriate for them?). We considered prophylaxis to be appropriate if the study authors did.

What are the main results of this review?

We did a systematic review of randomized controlled trials (trials in which people are randomly put into one of two or more treatment groups) that tested various system-wide interventions, which aimed to increase the use of thromboprophylaxis in hospitalized patients. Our search found 13 relevant studies; two could not be pooled with the others because they did not report data in which we were interested. We included 11 studies, with a total of 33,207 participants, in our analyses. Our review showed that interventions using alerts seemed to be the most reliable way to increase the use of thromboprophylaxis.

Combined data showed that:

– Computer or human alerts increased the number of participants who received thromboprophylaxis by 21% (three studies, 5057 participants, low-certainty evidence).
– Alerts increased the number of participants who received appropriate thromboprophylaxis by 16% (three studies, 1820 participants, moderate-certainty evidence).
– Alerts decreased the relative rate of symptomatic VTE at three months by 36% (three studies, 5353 participants, low-certainty evidence).
– Multifaceted interventions were associated with only a modest 4% increase in the prescription of thromboprophylaxis (five studies, 9198 participants, moderate-certainty evidence).
– While not directly compared to each other, alerts, whether computer or human alerts, appeared to be more effective than multifaceted interventions.
– While not directly compared to each other, computer alerts may have been more effective than human alerts for increasing appropriate thromboprophylaxis and reducing symptomatic VTE.

How up to date is the review?

We searched for studies that had been published up to 7 January 2017.