Our Research Methods
The CANHelp Working Group links community leaders with health officials and researchers from the University of Alberta. Together, they decide on which research questions to ask, and the best methods to address those questions.
Community participation in the research process and knowledge exchange with community members is an underlying principle of this project, which incorporates standards of the Institute of Aboriginal People’s Health of the Canadian Institutes of Health Research and the Association of Canadian Universities for Northern Studies.
To link the research team with the community, planning committees are established for each community project. During planning workshops, researchers inform planning committee members about research goals and limitations, relevant scientific information and, in particular, which kinds of data are required to address particular scientific questions. The committee provides input on design issues such as which age groups to target for participation, how to recruit participants, which kind of samples (e.g., blood or stool) to collect, and study implementation details. Community input is also sought for making study information documents and research questionnaires meaningful to the community. As information is generated by the research, activities are developed to inform the community of the results and help them understand how to use this information.
Each individual who enrolls as a participant in the project is given information outlining each procedure and project component, and asked to sign a document stating they agree to participate. Parents give their children’s consent, and children who are able to read and write are also asked to give assent.
Surveys on Clinical History, Relevant Symptoms, and Epidemiologic Risk Factors
Participants are interviewed using a health questionnaire with questions on previous diagnoses of H. pylori infection and related diseases, previous treatment for H. pylori and the outcome of previous treatment, frequency of symptoms of stomach discomfort, and other indications for H. pylori testing or endoscopy. Relevant information is also taken from participants’ medical records. Participants are also interviewed about social and environmental factors that may affect their health. Risk factors of interest include family size and structure, educational attainment, occupation, housing quality, residential crowding, water source, sewage disposal facility, hygienic practices, contact with animals, food preparation practices, and diet.
Participant Registry Form (Participant Registry 2012-11-08)
Health Questionnaire Survey_Health_generic 2012-11-08
Participant Questionnaire Survey_Participant _generic 2012-11-08
Household Questionnaire Survey_Household_generic
H. pylori Testing
The 13C-urea breath test is the best non-invasive method for detecting H. pylori infection and is used as the main screening method for detecting this infection in study participants. This test is widely regarded as the most accurate non-invasive test and is uniformly recommended for diagnosis of H. pylori infection in children and adults by experts. The urea breath test detects the presence of urease secreted by H. pylori in the stomach, using infrared spectroscopy to measure the 13C/12C ratio in breath samples collected before and after administration of 13C-labled urea. The standard test protocol is to collect a baseline breath sample, administer a standard age-dependent dose of labeled 13C-urea in citric acid or fruit juice, and collect another breath sample 30 minutes after ingestion of the 13C-urea. Because 13C is a stable isotope, the labeled urea can be used safely in pregnant women and humans of all ages. Breath samples are shipped to Edmonton for analysis.
Endoscopy allows doctors to examine the health of the stomach lining and collect biopsies to send to a laboratory for further analysis (pathology and microbiology). Equipment to perform upper gastrointestinal endoscopies is rented from Olympus. Gastroenterologists perform the endoscopies using thin gastroscopes with local sedation to numb the throat.
A pathologist examines slides made from slices of stomach biopsies to see if H. pylori organisms, inflammation or other abnormalities are present. The pathologist assigns a score to indicate the presence and severity of H. pylori density, neutrophil activity, chronic inflammation, glandular atrophy, mucus depletion of the surface epithelium and regenerative activity in the gland necks. Gastric mucosal tissue is classified as normal, non-atrophic gastritis, non-metaplastic multifocal atrophic gastritis, intestinal metaplasia, dysplasia, or gastric cancer.
The microbiology lab tests stomach biopsies using culture techniques to see if H. pylori will grow. When H. pylori organisms are grown from the biopsies, the organisms are tested for antibiotic susceptibility and genotypes. Antibiotic susceptibility testing targets antibiotics used commonly to eliminate H. pylori (clarithromycin; metronidazole; amoxicillin; and tetracycline), as well as those used when primary treatment fails (ciprofloxacin, furazolidone, and rifampicin). H. pylori genotypes of interest are classified by proteins suspected to play a role in the severity of disease outcomes: CagA; VacA; BabA; and IceA.
Establishing Indications for Treatment and Evaluating Effective Treatments
Anyone who tests positive for H. pylori infection is a candidate for treatment, and individuals with diagnosed H. pylori-associated diseases, dyspeptic symptoms or family history of gastric cancer are particularly targeted. Candidate treatment regimens were developed using information from antibiotic susceptibility testing, systematic reviews of H. pyloritreatment trials, and published results of trials conducted in similar populations.
Beginning with Aklavik data on the prevalence of H. pylori infection in association with symptoms and diagnosed diseases, willingness to receive care, local perceptions and cultural values, and treatment effectiveness, analyses will estimate the cost-effectiveness of test and treat strategies given specific clinical presentations, based on health system costs. These analyses will also determine whether H. pylori screening that targets high-risk groups of asymptomatic persons should be considered. The calculations will be done in a way that allows for variation in the inputs across communities and across time. The tools for modifying these calculations will be provided to the community and health officials in a form they can use with a variety of inputs to generate new outputs based on changing information in the future (e.g., changes in the costs of tests or treatments). These tools will then be used with data from additional communities to expand the information on which policies can be based. The research team will recommend H. pylorimanagement strategies to health authorities given the information in hand as the research progresses. Ultimately, as more communities are studied, the research team will recommend to territorial health authorities that any policy changes related to H. pylori management be implemented one community at a time, with some communities assigned differing start times, to permit valid assessment of the effectiveness of the policy changes. This will permit comparison of data on health care costs for H. pylori-associated diseases before and after policy changes.