You go to hospital for treatment and to get better. But sometimes, you get something much less welcome: an infection.
Pneumonia, an infection of the lungs, is one of the most common and deadly infections people develop in hospital. Around 50,000 patients contract pneumonia in Australian hospitals every year. Around 1,900 of them die from it.
It's rarely monitored and rarely reported. And to date, few studies have looked at how it can be prevented.
But our new trial , published today in The Lancet Infectious Diseases, shows a surprisingly simple action can make a major difference: brushing patients' teeth.
We found this can reduce the chance of getting this type of pneumonia, called non-ventilator hospital-acquired pneumonia, by 60%.
What is this type of pneumonia?
Non-ventilator hospital-acquired pneumonia occurs in patients who aren't on a ventilator, usually outside of intensive care settings.
Patients are infected when bacteria from the mouth or throat are breathed into the lungs.
Patients who develop this type of pneumonia stay in hospital between ten and 48 days longer , and are around eight times more likely to die during their admission.
A simple intervention made a big difference
We studied 8,870 patients across three Australian hospitals to see whether improving oral care - which included tooth-brushing - could reduce this type of pneumonia.
Usually, when patients go to hospital, they don't pack a toothbrush - especially in emergencies.
In busy hospital wards, oral care isn't always given the attention it needs , nor are oral care products always readily available. Patients don't always get reminders to brush their teeth and many patients need help with their oral care.
The intervention in our study was deliberately simple . We:
gave patients in hospital a toothbrush and toothpaste in a bag when they were admitted
educated patients and hospital staff about the importance of tooth-brushing. The toothbrush also had a written prompt on it - "Brush away pneumonia"
assisted patients who needed help with tooth-brushing
audited how oral care was being delivered and gave feedback to hospital wards.
We introduced the intervention into one ward at a time over 12 months at each hospital. This gradual roll-out is known as a stepped-wedge cluster randomised trial. It can test new health interventions when it's too difficult to randomise individuals without revealing who is receiving the intervention and who isn't.
We found that this relatively simple intervention increased the proportion of people who cleaned their teeth from 16% to 62%.
This increasing oral care led to a 60% reduction in the risk of acquiring pneumonia, from the equivalent of eight infections per month on a typical ward of 30 patients, to less than four infections per month.
This is the largest trial of its kind and the first completed across multiple hospitals.
Why does brushing teeth help?
The mouth is home to billions of bacteria. Oral hygiene often deteriorates when people are unwell, sedated, immobile, or taking certain medications.
When this happens, bacteria build up on the teeth, gums and tongue. If these bacteria are breathed in - even in tiny amounts - they can cause pneumonia.
Daily tooth-brushing reduces this bacteria . It's a simple mechanical action with a powerful protective effect.
Yet in busy hospitals, oral care is often overlooked. Patients may not know just how important oral care is. Staff are often busy with competing priorities and oral care can be de-prioritised. There is also a general lack of understanding about the importance of oral care .
Patients can help protect themselves
One of the most important messages from our research is patients aren't powerless. While health-care staff such as nurses play a crucial role, patients who are able to brush their own teeth can meaningfully reduce their own risk.
If you or a loved one is admitted to hospital, you can:
- bring your own toothbrush and toothpaste
- brush your teeth twice a day if you're able
- ask staff for help if you can't
- remind staff if oral care has been missed.
These small actions can reduce the risk of a serious, life-threatening infection.
What happens next?
Pneumonia is costly - in lives, hospital days and the financial cost of care. But because non-ventilator hospital-acquired pneumonia isn't routinely reported, it's often invisible.
Our research challenges the assumption that hospital-acquired pneumonia is an unavoidable complication when you go to hospital.
It also highlights the need for hospitals to monitor non-ventilator hospital-acquired infections, in the same way they monitor falls, pressure injuries and other preventable harms.
Finally, our study strengthens the case for including oral care in national infection-prevention guidelines and nursing practice.
Oral care isn't glamorous, expensive or technologically advanced - but it works. Sometimes, the simplest interventions are the most powerful.
Brett Mitchell receives funding from the Medical Research Future Fund which helped fund the reported study. Brett also receives funding from the National Health and Medical Research Council through an Investigator grant. He is affiliated with Avondale University and the Hunter Medical Research Institute. Brett is Editor-in-Chief of Infection, Disease and Health.
Allen Cheng receives funding from the National Health and Medical Research Council and the Australian Government for research studies and surveillance systems. He is a member of the Infection Prevention and Control Advisory Committee for the Australian Commission for Safety and Quality in Healthcare - the views expressed in this article may not reflect the views of the committee.
Nicole White receives funding from the Medical Research Future Fund which helped fund the reported study. She is a member of the Statistical Society of Australia and holds editorial roles with the Infection, Disease and Health journal and Significance magazine.
Philip Russo is an NHMRC Early Career Research Fellow at Monash University and Director of Nursing Research at Cabrini Health.
Peta Ellen Tehan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
