Study design/ survey,questionnaires

• Descriptive studies provide information on the frequency of an outcome or level of exposure, but do not analyse an association between the outcome and exposure
• Descriptive studies may be undertaken to assess whether the burden of an outcome is of public health importance
• Descriptive studies are used to identify health issues for further study
• Analytical studies measure the association between an exposure and outcome, with the aim of inferring causality
• Types of analytical studies include cross-sectional studies, cohort studies, case-control studies, and intervention studies
• Cross-sectional studies compare the prevalence of outcome with exposure status at one time-point from a random sample of individuals
• Cross-sectional studies are rapid and less costly than other studies
• Cross-sectional studies may be best for common or chronic outcomes
• Cross-sectional studies provide preliminary evidence of an individual-level association
• Cohort studies track two or more groups forward from exposure to outcome
• Cohort studies are less useful for examination of rare events or those that take a long time to develop
• Cohort studies are ideal for inferring causality, as the exposure is recorded prior to the outcome
• Cohort studies require a well-defined population
• Case-control studies select individuals based on their outcome status and analyse whether they differ in relation to previous exposure
• Case-control studies are best for studying rare outcomes or outbreak investigations
• Case-control studies provide an odds ratio, derived from the proportion of individuals exposed in each of the case and control groups
• Intervention studies allocate a protective exposure and compare outcomes between those exposed and unexposed
• Intervention studies are the gold standard for inferring causality
• Intervention studies can only be used for protective exposures, which include the removal of exposure to a risk factor
• Intervention studies may combine several study designs
• Objectives of the lecture:

  • Conceive and initiate a Public Health research
  • Understand basic concepts of research design
  • Design a good questionnaire
  • Write a good research proposal
  • Conduct a research
  • Present research findings scientifically
• Introduction:

  • Research is a scientific and systematic search for pertinent information on a specific topic
  • Implies searching for knowledge to make issues clearer
• Why conduct research:

  • Gain familiarity with a phenomenon or achieve new insight
  • Portray accurately the characteristics of an individual, situation, or group
  • Determine the frequency of occurrences
  • Test hypotheses of relationships between variables
  • Contribute to the body of knowledge
• Objectives of Writing a Proposal:

  • Persuade the supervisor to support and approve the project
  • Obtain a grant
  • Demonstrate the study is academically sound
• General contents of a proposal:

  • Project title
  • Introduction with background information, problem statement, objectives, scope, research questions, and hypothesis
  • Literature review
  • Methodology
  • Work plan & budget
  • Plan for dissemination of findings
  • References
  • Appendices
• Developing the Project Title:

  • Identify a Public health problem of interest
  • Title should reflect the focus and scope of the project
  • Relevance, priority, feasibility, acceptability to patients, community, and workers
  • Pay attention to the number of words
• Introduction –Background information:

  • Brief overview of the topic globally, nationally, regionally, and locally
  • Provide context and justify the need for the study
• Statement of the Problem:

  • Convince the reader of the relevance of the study
  • Provide background data for understanding different aspects of the problem
  • Describe who is affected, incidence, prevalence, complications, and public health implications
  • Briefly mention solutions tried in the past
• Rationale and Justification:

  • Describe past solutions, why further research is necessary
  • Provide evidence of a lack of information on the problem
  • Explain the expected information from the project and how it will be used
• Formulation of Research Objectives:

  • Aims, goals, general objectives describe the purpose of the study
  • Specific objectives are building blocks towards the aims, must be SMART
  • Provide context for specific objectives and inform methodology
• Statement of hypothesis:

  • Hypothesis is a supposition tested by data collection
  • Null hypothesis states no difference/association between variables
  • Alternative hypothesis states a difference/association
• Literature Review:

  • Describe work done on the topic
  • Cite relevant global, regional, and local literatures
  • Identify gaps in knowledge and flaws in previous studies
• Source of Literature:

  • Library textbooks, journals, reports, internet sources
  • Use keywords for searching and various techniques like Boolean Logic, Phrase searching, Truncation, and Controlled vocabulary
• Methodology:

  • Description of study area, study design, study population, sample size calculation, sampling methods
  • Data collection methods (qualitative and quantitative), data collection tools, training of research assistants, data processing & analysis plan
• Study/survey design:

  • Observational (Descriptive, Analytical, Experimental, Quasi-experimental)
• Descriptive Studies:

  • Describe disease distribution in terms of person, place & time
  • Assist in developing hypotheses about disease determinants
  • Include no intervention, case reports, case series, and cross-sectional studies
• Cross-sectional studies:

  • Happen at one time, provide a snapshot of factors and diseases
  • Administer questionnaires, collect information on risk factors
  • Advantages include providing prevalence quickly and generating hypotheses
• Case-Control Studies:

  • Compare affected (cases) and unaffected (controls) groups
  • Obtain past exposure information to analyze significant differences in exposure
• Cohort Studies:

  • Compare people exposed to an agent over time with controls
  • Analyze differences in exposure to suspected agents
• Cohort Studies:

  • A group of people exposed to a suspected aetiological agent are compared with matched controls who have not been exposed
  • Subjects are selected based on exposure or non-exposure
  • Incidence rate of the disease among the exposed is compared to the non-exposed