Research Scenarios

Research question: The research question is “What are the causes of the transmission of Buruli ulcer”? Thus, the research aims at investigating the causes of the transmission of the infection, which is caused by the bacterium Mycobacterium ulcerans.

Study design: The study design chosen for this research is a case controlled study. This is because a case-control analysis is intended to assist in evaluating whether an exposure is connected with an outcome (i.e., illness, or concern condition). In theory, the analysis of case-control may be easily defined; first, identifying the cases (a group identified to have the outcome) and the controls (a group identified to be free from the outcome). Then going back in time and figure out the participants of each category have exposure(s), contrasting the level of exposure in the case category to the control group. By nature, the case-control analysis is retrospective as it begins with the result and then tracks back to the examination of exposures.  When participants are enrolled in their corresponding groups, the result of each subject is already identified to the investigator. That is what renders case-control experiments ‘retrospective’ and not the reality that the researcher typically takes use of formerly collected evidence (Tenny & Hoffman, 2019). Thus, for this research this study design will be appropriate.

Sampling methods: For this research, two groups of participants will be recruited. Two groups of participants will be recruited. The control group will consist of participants without any signs and symptoms of buruli cancer and the case patients will be recruited from a Public Hospital at Melbourne. The Public Hospital record will be scanned thoroughly to get information about patients with buruli ulcer. The case patient is an individual with a clinical lesion and a positive M. ulcerans PCR or a positive culture result (usually both). Each of the group’s data and information will be collected and analysed to evaluate and determine the common risk factors that might have triggered the infection. Other information like occupational history, social history, Lifestyle factors and demographic factors will be taken into consideration in order to understand and interpret the factors behind the transmission of the disease. Information will be collected with the help of a questionnaire which will be distributed to both of the groups and analysed to get the results.

Data collection: Questionnaires and interview surveys will be conducted to collect the data. Each of the groups will be given questionnaires and asked several questions which will be analysed to interpret the common transmission factors. Case-patients and control participants will receive a standardized questionnaire containing questions regarding their medical history; their natural environment and behaviour; and their exposure to soil, animals and insects. Case-patients may be required to restrict their answer to the 12-month period previous to their BU diagnosis. The environmental actions and behaviours, such as styles of clothes worn, precautions taken to defend against insect bites, forms of skin damage care, areas of their bodies most often attacked by insects, household pets and natural fauna with which they had daily interaction, and varieties of soil items to which they had been subjected in the previous year, will be investigated.

Data analysis: Case-patient ages and control subjects will be measured using a 2-sample t test. Fisher exact test, Chi-square analysis and logistic regression will be used to calculate the odds ratio (OR) and 95 per cent conviction interval (CI) for BU after correction for age and place of residence.   Multivariate models will be calculated by adding a backward elimination methodology to the logistic regression when controlling for age and city of residence. In all mathematical models, p values < 0.05 will be called statistically significant.

Strength- Case control trials are useful with unusual diseases or diseases with a long time of delay between diagnosis and disease manifestation. They are time-consuming and less costly; they are helpful when exposure details are expensive or difficult to obtain (Melamed & Robinson, 2019).

Limitation- While case-control studies are an important method of examining unusual events, there are major limitations inherent in this design. As with other observational studies, associations measured in case-control studies may or may not be causal relationships. Generally with observational research, while methodological approaches exist to account for confusion, some significant confounders may be unspecified for unusual outcomes which are often studied in case-control research (Pandis, 2014).

References

Melamed, A., & Robinson, J. N. (2019). Case–control studies can be useful but have many limitations: Study design: case?control studies. BJOG: An International Journal of Obstetrics & Gynaecology, 126(1), 23-23. doi: 10.1111/1471-0528.15200

Pandis, N. (2014). Case-control studies: Part 1. American Journal of Orthodontics and Dentofacial Orthopedics, 146(2), 266-267. doi: 10.1016/j.ajodo.2014.06.005

Tenny, S., & Hoffman, M. R. (2019). Case Control Studies. Retrieved 13 May 2020, from https://www.ncbi.nlm.nih.gov/books/NBK448143/