Improving oral care reduces the incidence of non-ventilator hospital-acquired pneumonia (NV-HAP) among hospitalised patients compared with usual care, an Australian study has found.
The results of the Hospital Acquired Pneumonia Prevention (HAPPEN) trial, published in The Lancet Infectious Diseases [link here], reinforce the importance of providing oral care to hospitalised patients.
“The results contribute to a stronger evidence base for future NV-HAP prevention guidelines and initiatives, and they offer insights to inform clinical practice and local policy development,” it said.
The study comprised 8,870 adult patients admitted to one of nine wards, mostly general medicine and stroke units, across three participating hospitals in NSW and Victoria. Patients had a median age of 76 years, were about half male, and had a median hospital stay of six days.
The intervention consisted of provision of oral care products and assistance if required, patient and staff education, and an EMR audit of oral care and feedback. The control periods offered usual care.
The study found the primary outcome of NV-HAP was confirmed in 1·0% of patients under control conditions compared to 0·7% under intervention conditions.
After accounting for time at risk and background time trends, exposure to the intervention was associated with a cumulative hazard ratio of 0·40 (95% CI 0·19–0·82) for NV-HAP, it said.
Identified pathogens were all bacterial or fungal including mixed growth, Candida albicans and Aspergillus spp.
In secondary outcomes of upper or lower respiratory tract infections and infections of eye, ear, nose, throat, or mouth, exposure to the intervention resulted in cumulative hazard ratios of 1·64 and 1.08, respectively.
The investigators, including infectious diseases physician Professor Allen Cheng from Monash Health, hypothesised that primary routes of viral transmission, such as inhalation or direct deposition of infectious aerosols, might not be mitigated by oral care.
This might explain why improvements in oral hygiene did not reduce respiratory tract infections which were found to be mostly viral.
They said their results were consistent with others evaluating the effectiveness of oral care in older patients in residential aged care settings.
“In future work, we will update the resources used in our study and make these available open source. Cost-effectiveness evaluations and qualitative work exploring the patients’ and clinicians’ experience of the trial are planned.”
Perspective
A comment article in the journal [link here] said HAPPEN was the “largest and most rigorous NV-HAP prevention study to date and provides the best evidence thus far that better oral care can lower NV-HAP rates.”
“Large-scale randomised trials are rare in infection control despite the frequency and morbidity of nosocomial infections; the authors are to be congratulated for pulling off this remarkable study.”
However, it said the stepped-wedge design of the study effectively meant most control months were during the winter when NV-HAP rates were highest while most intervention months occurred after winter.
“The authors did not adjust for seasonality or respiratory viral activity so there is some risk that the observed decrease in NV-HAP rates was due to the passing of winter rather than enhanced oral care.”
As well, the authors said that the enhanced oral care was only one component of a multi-faceted behaviour and organisational initiative.
“As such, the reduction in NV-HAP might reflect increased clinical vigilance, improved general care processes, and changes in documentation in addition to reducing oral bioburden.”
Despite other limitations, including possible ascertainment bias, they reiterated their opinion that the pragmatic trial provides encouraging evidence that better oral care could prevent NV-HAP and represents an important advance in the field.
The HAPPEN trial was funded through the MRFF.