An interventional study of Interpretive comment on laboratory report in Gastroenteritis Acute and Diagnostic Communication, sponsored by Medical Research Institute of New Zealand. Recruiting at 4 sites in New Zealand. Open to participants aged 6 Months and older. Per ClinicalTrials.gov, last updated 2026-07-14.
Sponsored by Medical Research Institute of New Zealand · Not applicable, Interventional, and Diagnostic
Bacterial gastroenteritis is a common condition seen in Aotearoa New Zealand, which is typically diagnosed by PCR testing on a stool sample. Most causes of bacterial gastroenteritis (e.g. Campylobacter spp, Salmonella spp, Yersinia spp) cause a self-limiting illness and antibiotic therapy is not required. Indeed, guidelines available for community healthcare providers in Aotearoa (e.g. Community HealthPathways, recently released national antimicrobial guidelines Te Whata Kura) recommend against antibiotic therapy for the vast majority of cases.
A recent internal analysis at Awanui Laboratories of community faecal pathogen PCR testing revealed that antibiotic prescribing was very common after a positive result (ranging between 20-40% for the various individual pathogens), which suggests many community healthcare providers may not be following the recommended approach for the management of these infections. Given how common infectious gastroenteritis is in Aotearoa, and the volume of tests performed (approximately 100,000 through the Awanui network per year), this prescribing behaviour may represent a large volume of unnecessary antibiotic use in our communities, with resultant potential harmful effects at the individual patient level and population level via side effects, disruption to the faecal microbiome, and impacts on antimicrobial resistance (AMR).
In previous work we have demonstrated that interpretive comments, when added to laboratory reports, can have a significant positive effect on prescriber behaviour (https://doi.org/10.1093/jac/dkad384), but this has not been examined in relation to faecal pathogen testing.
This is a cluster randomised crossover trial, where four laboratories within the Awanui Labs network in Aotearoa New Zealand will act as the clusters. Each laboratory will be assigned four intervention levels, which will be implemented in random order over the course of the 12 month study period (i.e. 3 months per intervention).
The intervention will consist of interpretive comments that are appended to laboratory reports where a stool sample has been submitted for faecal bacterial pathogen detection (predominantly tested via multiplex PCR methodology) and one of the target organisms has been detected. The target organisms are Campylobacter spp, Shigella spp/Entero-invasive Escherichia coli, Salmonella spp, Yersinia spp, and Aeromonas spp.
There will be four different intervention levels: 1. a comment that reminds requesters that most acute bacterial gastroenteritis does not require antibiotic treatment, as per local guidelines; 2. the same comment as 1 is used, plus an additional comment is added reminding requesters of the negative effects of antibiotic over use at the population level (i.e. AMR); 3. the same comment as 1 is used, plus an additional comment is added reminding requesters of the negative effects of antibiotic overuse at the individual patient level e.g. harms due to side effects; 4. is a the control group, where no comment is appended.
The four levels will be auto added by each lab, each for a three month period, in the random order allocated at the beginning of the study.
Outcome measures will relate to antibiotic use in the time period following the laboratory report, plus unplanned hospitalisation out to 30 days post report.
This is the only study on the registry with Medical Research Institute of New Zealand as lead sponsor.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Interpretive comment with advice to follow local guidelines
Other: Interpretive comment on laboratory report
Interpretive comment with advice to follow local guidelines PLUS comment about population level harms of antibiotic overuse (i.e. AMR)
Other: Interpretive comment on laboratory report
Interpretive comment with advice to follow local guidelines PLUS comment about individual patient harms of antibiotic overuse (e.g. side effects)
Other: Interpretive comment on laboratory report
No comment added to lab report
Interpretive commend added to laboratory report - contents of comment will depend on associated arm
Specific antibacterial dispensing
Antibacterial dispensing within 5 days of laboratory report for agents that are more specific for the treatment of bacterial gastroenteritis: amoxicillin, azithromycin, ciprofloxacin, doxycycline, erythromycin, co-trimoxazole
Time frame: Within 5 days of lab report
Any antibacterial dispensing
Antimicrobial dispensing within 5 days of laboratory report for any antibacterial agent
Time frame: Within 5 days of lab report
Antibacterial dispensing within 30 days
Antimicrobial dispensing within 30 days of laboratory report 1. For any antibacterial agent 2. Limited to these agents that are more specific for the treatment of bacterial AG: amoxicillin, azithromycin, ciprofloxacin, doxycycline, erythromycin, co-trimoxazole
Time frame: Within 30 days of lab report
Unplanned hospital admission
Unplanned hospital admission within 5 and 30 days of laboratory report
Time frame: Within 5 and 30 days of lab report.
Plan to share: No
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