<aside> 💡 Measuring Health 1

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1. Describe the role of epidemiology in providing evidence for medicine

   • Study of distribution and determinants of health and disease within a specific population and its application in public health control
     • Distribution
       • Incidence
       • Prevalence
     • Determinants
       • Biopsychosocial factors influence on health
       • Exposures/risk factors
     • Application for providing evidence for medicine (public health control):
       • Data used for preventive and promotive measures
       • Examples
         • Pathological incidence frequency over time
           • Evidence for prevention programs
         • Frequency of screenings
           • Evidence for implementing screening programs
         • Frequency of people who do not complete healthcare plan
           • Evidence for education programs
         • Association between diseases and factors
           • Evidence for education and clinical plans
       • Types of epidemiological studies
         • Infectious disease control
           • Evidence for disease control
         • Promotion of good health/contributors of poor health
           • Evidence for public health campaigns
         • Screening and disease prevention
           • Evidence for disease prevalence and incidence
           • Used for preventative and health promotion campaigns
         • Clinical care standards/Treatments
           • Evidence for improving modifying, or getting rid of clinical standards
         • Analytic studies
           • Evidence to confirm or reject association between exposure and disease
           • Used for preventative and health promotion campaigns

2. Describe how the following studies are structured, including how study subjects are allocated to groups descriptive study, case-control, cohort, randomised controlled trial (RCT).

   • Descriptive study

     • Describe patterns of disease occurrence in relation to person, place, and time
     • Generate hypothesis but unable to confirm/disapprove it or establish causality
     • Sampling just snapshot of prevalence at the time
     • Since disease/exposure cannot be measured simultaneously, cannot test hypothesis
     • No comparison group
     • Non-directional (temporal relationship between disease/exposure cannot be determined)
     • Types of Descriptive studies:
       • Case study
         • Research into development of disease in one patient
         • Generates an association between exposure/disease (hypothesis), but cannot test
       • Case series
         • Research into development of disease in multiple similar case studies
         • Generates an association between exposure/disease (hypothesis), but cannot test
         • Development of rare pneumonia in Homosexual men alerted world of HIV
       • Cross sectional survey
         • Status of a disease within a population assessed at the same time
         • Cannot generate hypothesis because only samples point in time
         • Association between disease and exposure cannot be made
         • Prevalence and not incidence

   • Case control study

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     • Comparing 2 groups of participants based on outcome of interests
       • Looks back from a disease (D+/D-) to an exposure (E+/E+)
       • Outcome of interest
         • Exposure (E+/E+)
       • Hence always retrospective
     • Disease present = cases
     • Disease absent = control
     • Observational (not interventional) study
     • Good for:
       • Studying rare OUTCOMES
       • Cohort studies would mean studying large number of exposures before outcome comes along
     • Example:
       • Doll and hill
         • 700 men/women with lung cancer
         • 700 men/women hospitalized not for lung cancer
         • Average number of cigarettes smoked per day for last 10 years before onset of illness
         • Patients with lung cancer more likely to be smokers

   • Cohort study

     • Cohort = sample of people with similar exposure (E+/E-) to see if disease develops (D+/D)
     • Outcome of interest
       • Disease (D+/D-)
     • Study over time (longitudinal)
       • Retrospective cohort
         • Group of people (cohort) already shares common disease (outcome)
           • Study looks back (existing data); determine common exposure factors
         • Observational study
         • Looks for outcome
       • Prospective cohort
     • Observational (not interventional) study
     • Example:

   • Randomised controlled trial (RCT)

3. Describe a confounder/confounding factor/variable, and describe bias and random error.

4. Define a control group and describe its use.

5. Describe how researchers make a ‘control’ group -matching & restriction

6. Describe randomisation and its benefits.

7. Explain blinding and double blinding and their purpose

8. Identify health statistics as being prevalence or incidence and calculate and interpret incidence and prevalence

9. Explain the reasons for and effects on data of age-standardization.