Behind the scenes at SGH, antibiotic stewards fight resistance daily — using clinical judgment, collaboration, and A.I. to keep patients safe.

Every morning at Singapore General Hospital (SGH), a quiet battle begins. It's not fought in operating theatres or emergency departments, but at computer screens where a dedicated team works to protect something we often take for granted: antibiotics that actually work. 

Out of all the patients currently warded in the hospital, about half are on antibiotics. The job of the antibiotic stewards? They review a list of such patients every day to make sure each antibiotic prescription is necessary, appropriate, and safe. 

It's a role most people have never heard of, yet it stands at the frontline of one of healthcare's most pressing challenges: antibiotic resistance. 

When medicine stops working 

Antibiotics are designed to kill bacteria, but they're not selective sharpshooters. When we take them, not all the bad bacteria are killed off. Bacteria that can survive antibiotics remain and continue to grow replacing antibiotic-susceptible bacteria. When they cause a new infection, the original antibiotic no longer works. 

We then need stronger antibiotics to fight them, and the cycle repeats itself. Each time this happens, harmful bacteria become increasingly resistant, and we're left with fewer effective treatment options. 

This is the crisis Sarah Tang and her team are working to prevent. By ensuring antibiotics are prescribed only when necessary, they're protecting the effectiveness of our antibiotics today and safeguarding treatment options for tomorrow. 

The daily detective work 

With just a team of 10 to 12 stewards covering the entire hospital, they must prioritise carefully. 

"There's no way our stewards can review everyone on antibiotics, so the stewards focus on antibiotics that are more likely to be misused or cause resistance if not used properly," Sarah explains. The work is highly labour-intensive. Every case undergoes a thorough clinical review by a steward. "Our stewards review the whole case: the patient's history, lab results, clinical documentation, everything. For our complex SGH patients, it takes an average of 20 to 25 minutes per patient just to get a thorough understanding of the case." 

If the team identifies room for improvement, perhaps a culture result shows a narrower-spectrum antibiotic would work, they intervene. They might recommend to the doctor to change the antibiotics, adjust the dose, stop treatment, or do more tests.  

Why getting antibiotics right is so hard 

The challenge is that many conditions mimic bacterial infections. Pneumonia-like symptoms might be a viral infection, asthma or heart failure. With so many possibilities, it's genuinely difficult to pinpoint the exact cause at the time of consultation. 

Even when doctors order thorough examinations and tests, results typically take two to three days to come back. During this waiting period, doctors face a dilemma: they can't leave potentially serious bacterial infections untreated. 

"So, they'll prescribe antibiotics first, then wait for the results," Sarah explains. "If the tests show it's not a bacterial infection after all, they'll stop the antibiotics, but by then, the patient has already been on them for three days." 

Beyond medical considerations, certain patients, the elderly, the frail, or those with complex medical histories, are at higher risk, and doctors may prescribe antibiotics ‘just in case’. 

Social pressures also play a role. "Sometimes patients insist on antibiotics," Sarah notes.  

This is why antibiotic stewardship is fundamentally about changing behaviour. "We're not just reviewing prescriptions, we're working to shift how antibiotics are prescribed and used across the hospital," Sarah explains. 

The antibiotic stewards join ward rounds with doctors to discuss their recommendations in person. "This is where our stewards work collaboratively with doctors to optimise the patient's treatment." 

Sarah emphasises that managing infections isn't always just about antibiotics. "Sometimes surgery might be a better solution than continuing antibiotics indefinitely. Or perhaps changing a urinary catheter that's causing infection is more effective than prescribing more antibiotics. Our stewards take a multidisciplinary approach to ensure patients recover from infections whilst using antibiotics for the right purpose." 

When human effort is not enough 

Over time, the team realised that manual review alone was not sustainable. 

“The workforce is shrinking, healthcare needs are growing, and staff are increasingly hard to recruit,” Sarah explains. 

Enters Artificial Intelligence and machine learning. And SGH has a crucial advantage: years of accumulated stewardship data. 

"Throughout our many years of doing manual reviews, we had built up this extensive database. That database became incredibly valuable. It gave us the dataset we needed to train an A.I. solution," says Sarah, who is from the Research and Innovation arm of SGH’s Antibiotics Stewardship team.  

AI2D: Confidence amidst uncertainty 

One of the Research and Innovation team's most recent innovations is AI2D (Augmented Intelligence in Infectious Diseases), an A.I. system developed to tackle a specific problem: uncertainty about whether a bacterial infection is actually present. 

"When doctors face this uncertainty, they're more likely to prescribe antibiotics, just to be safe. We identified this as a major problem area, so we needed to design a solution," explains Sarah. 

She co-led the development of AI2D with SGH Infectious Diseases, SGH Future Health System (Artificial Intelligence & Automation unit), Synapxe and DXC Technology to support safer antibiotic decisions. 

AI2D identifies cases where a bacterial infection is unlikely. This helps doctors feel more confident. "It gives them the assurance they need to stop antibiotics when they're not necessary," Sarah says. 

Dr Piotr Chlebicki, Senior Consultant in Infectious Diseases, explains the challenge doctors face. "To decide on antibiotics, doctors traditionally have to piece together information from multiple sources: clinical notes, chest X-rays, blood tests, and culture results. We then determine: Is this a bacterial infection? Is the patient at risk of antibiotic-resistant bacteria? Based on these answers, we choose the right antibiotic, along with the correct dose and duration." 

With so many data points, it's easy to miss something or overlook a detail. This is where AI2D comes in. 

"AI2D acts as a safety net, reviewing all available information and offering suggestions," Dr Chlebicki explains. "The final decision still rests with the doctor, but AI2D provides an extra layer of confidence and support." 

The hidden challenge: Managing people, not just algorithms 

When we think of building an A.I. system, the mind often jumps to algorithms and data. But according to Dr Andrea Kwa, Deputy Director of the Research and Innovation arm, who co-led the AI2D project, the toughest part wasn't the coding—it was the people. 

"It's never the technical work that's most difficult, it's people management within the team," Dr Andrea shares. The project required collaboration between clinicians, IT specialists, and external vendors, each with their own priorities and packed schedules. Add to that the layers of administrative approvals for IT security and electronic medical record integration, and the complexity skyrocketed. 

So how did the team overcome this? Through persistence, communication, and compromise. 

"We had to agree to disagree," Dr Andrea explains. "Also, the updates have to be frequent because these people will also want to know that what they are helping you with is something that is fruitful. And that they are not wasting their time." 

Clear project management practices also helped them navigate the inevitable roadblocks. 

Says Sarah, "The Artificial Intelligence & Automation (AIA) unit in SGH played a pivotal role in the early stages of the AI2D project by providing project management and operational support." 

In the end, this collaborative approach paid off. Despite the hurdles, AI2D was developed in just 18 months, a remarkable feat for a project involving so many moving parts. 

The team is now looking into ways to make AI2D available to other hospitals in Singapore. They're also considering expanding to other types of infections. "We started with lung infections. Urinary tract infections are the next most common, so that could be our next focus area," shares co-lead Dr Andrea. 

Changing how stewards work - and think 

Today, AI2D transforms daily stewardship. 

Now, they run all cases through AI2D first as a triage tool at the start of each day. The system identifies which cases need review and which don't. 

"Out of all the cases, only about 30% actually need intervention," Sarah explains. "So, we now focus on reviewing these 30%.” But the impact goes beyond time savings.  

"It's made me rethink my own judgment on certain cases," Sarah admits. "There were cases that I might think 'the antibiotic seems okay, let's leave it.' But when AI2D tells me that bacterial infection is unlikely and antibiotics could actually be stopped, I'm prompted to have that conversation with the doctor." 

"It's converted cases I wouldn't have intervened on into cases that actually benefit from intervention," she says. "This AI tool pushes boundaries. Instead of intervening on 30% of cases like before, we're now intervening on 40% - stopping antibiotics for even more patients than we would have identified through human evaluation alone." 

The invisible shield 

The steward’s work extends far beyond daily case reviews. "Our stewards also conduct hospital-wide surveillance, engage in research, and train other stewardship teams. SGH is actually a central training site for those wanting to learn antibiotic stewardship, including teams from overseas," shares Sarah. 

Our stewards also develop antibiotics treatment guidelines and tools like the ABxSG mobile app, which houses guidelines, to help doctors better use antibiotics. They also run Antibiotic Awareness events for staff and the public to spread the message about using antibiotics wisely. 

As our stewards wrap up another day of interventions, and collaborations, the impact of their work ripple outward, benefitting patients and doctors.  And ensuring that somewhere in the future, antibiotics remain effective weapons against infections that might otherwise become untreatable. 

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