The value of SSI surveillance

At the recent ASP National HCAI Symposium, Dr Peter Jenks highlighted the importance of surveillance in reducing surgical site infection (SSI). The director of infection prevention and control, for Plymouth Hospitals NHS Trust (PHNT), revealed that the greatest reductions in SSIs at the Trust have been seen in those surgical procedures for which surveillance has been established for some time – most notably cardiac and vascular surgery. Providing an overview of the Trust’s improvement journey, he gave an insight into the work of the Surgical Site Infection Surveillance Service at Plymouth and the significant results achieved, which resulted in the presentation of a national patient safety award in 2011. At the time of winning the award, the Trust’s SSI rate for coronary bypass graft was 2.1%, compared to a national rate of 5.2%, and 0.8% for vascular surgery, compared to a national rate of 3.5%.1 However, ten years ago, the Trust recognised the need to improve its performance on MRSA infection rates and, in particular, to minimise the risk of serious complications, such as deep sternal wound infections, following cardiac procedures. This type of surgical site infection carries a high risk of high mortality and morbidity – often resulting in prolonged hospital stay, use of antibiotics and repeat surgery. Around 50% of deep sternal wound infections were found to be due to MRSA. The Trust went on to embark on an intensive programme of work to reduce SSI on the cardiac surgery unit.

The Plymouth improvement journey

The first step in delivering improvement was to build a case for establishing a dedicated Surgical Site Infection Surveillance Service. Commenting on the key factors for tackling healthcareassociated infections (HCAIs), Dr Jenks explained: “In the current climate, finances have risen to top of the agenda and we are all struggling to hold on to the resources that we have got or want to bring in. Surveillance helps to demonstrate that the interventions you have implemented are working, as well as supporting the business case for interventions that you want to introduce. “Surveillance is about monitoring the distribution of infections, but it is also key that this is fed back to clinical staff, so that they can act on the information and do something about it. The information is also needed to guide interventions in a targeted fashion. Various studies have shown that surveillance, combined with feedback to staff, reduces infection rates by around a third.” He pointed out that surveillance is crucial for targeting performance, which is important for both patients and commissioners. Ultimately, patients want to know their local hospital infection rates so they can establish the level of risk of contracting an HCAI at a particular organisation, while surveillance is key to demonstrating the cost effectiveness of interventions. “There are many reasons why we should be looking at SSI. It is the third most common hospital-acquired infection; it has a big impact on finances and is preventable – there is clear guidance from NICE, which is evidence based, that can be implemented locally and impact on infection rates,” Dr Jenks commented. “It is also important to demonstrate that what you do not only reduces infection rates but also saves your hospital money,” he continued. “To be effective, you need to have the resources (i.e. people to collect the data, along with a system that will collate and analyse the information); clinicians need to be on board and not feel threatened; and there needs to be financial engagement.” When the Trust’s Surgical Site Infection Surveillance Service was first established, resources were initially limited (there was just one person allocated to surveillance). A decision was made to focus attention on collecting data from the cardiac unit and feed this back to the cardiac surgery directorate to identify where improvements needed to be made. A number of interventions had a significant impact. The management revisited the whole care pathway for cardiac surgery, optimising everything from an infection prevention and control perspective. MRSA screening was also introduced, which had a major impact on the Trust’s sternal wound infection rate. Changes were also made to perioperative antimicrobial prophylaxis which resulted in further decreases. While the surveillance resource may have been small, the feeding back of data to drive clinical engagement and direct interventions was highly successful. “The evidence showed that there was no reason why this could not be used for other surgical procedures to achieve a similar impact,” commented Dr Jenks. Dr Jenks pointed out that the results of a study by Wilson et al (2006) supported the initial findings at Plymouth. The study, carried out by researchers at University College London Hospitals, London, demonstrated that employing a team dedicated to surgical wound surveillance is both effective and reduces costs. Surveillance included post-discharge follow-up at 2-3 months, while feedback was provided to surgeons. The researchers concluded that wound surveillance was associated with a reduction in rates of wound infection within four years. Furthermore, the cost reduction as a result of fewer infections exceeded the cost of surveillance after two years.2 Drawing on the available evidence and its initial findings, the Plymouth team were able to build a business case for expanding its surveillance resources further, stating that it would reduce infection rates by around 30%. A dedicated surveillance team was appointed to monitor SSIs for all major surgical procedures. This was backed by the board and, today, there are four full-time members of staff performing surveillance, with four analysts overseeing the data collection. There is also input from the infection prevention and control team and the director of infection prevention and control. Patients are now sent home with a questionnaire (returned after 28 days), and there is also additional telephone follow up with primary care. “This has doubled the infection rates – obviously the better that you perform post discharge surveillance the more infections you will find. You really cannot tackle the whole pathway in preventing SSIs unless you are conducting post discharge surveillance,” said Dr Jenks, adding: “It is also extremely important that the data is reliable. It is sensitive data; once you start sending surgeons their annual infection rates, it can create tension – you need to be confident it is accurate, otherwise it can undermine the whole programme.” The Plymouth team uses ICNet surveillance software to collect the data, analyse it and generate reports. This helps to facilitate clinical engagement, according to Dr Jenks. “During our early implementation, we were lucky in that the surgeons were driving improvement and wanted the data – they found it beneficial in that it enabled them to try things that would otherwise have been difficult to implement. We have found that anonymous feedback is the best approach. Although a few surgeons may still feel threatened, overall clinical engagement is crucial to the success of a programme,” he continued. For the period April 2010-March 2012, some 14,300 procedures were surveyed, with 733 cases of SSI identified. The total infection rate for all procedures was around 5%; 60% were identified following discharge from hospital, while the most common organism was staphylococci. Very few were due to MRSA (2%) while the rates of MSSA were relatively high. Therefore, the Trust has introduced targeted screening and decolonisation of MSSA in a number of high-risk surgical procedures. Plymouth is able to detect trends and identify problems with specific organisms very early. Dr Jenks also pointed out that it is important to establish whether strains are related. “We see very few cases of hospitalacquired MRSA and ‘typing’ has been very helpful in identifying the origins of strains. The team has also been able to identify instances where staff have been the source of a cluster of infections and some staff screening exercises have been undertaken. “Previously we were focused on MRSA, but we are now adopting the techniques used to reduce rates for MRSA on other organisms – such as GRE, for which there has been an increase in the past few years. Patients who are infected have now gone up the ‘pecking order’ in terms of isolation; we are reinforcing good clinical practice and have also introduced enhanced environmental decontamination,” Dr Jenks explained.