MSc Public Health
\nEpidemiology in Public Health
\n(PUB002-6\/STI009-6)
\nRevision Session
\nSession \u2013 11
\n22-23, SEM1
\nEpidemiology Exam
\n\u2022 Assignment \u2013 Exam
\n\u2022 100% of the marks
\n\u2022 ALL examinations will be taken online through
\nWISEFLOW
\nhttps:\/\/breo.beds.ac.uk\/bbcswebdav\/pid-6385772-dtcontent-rid-32879053_1\/xid-32879053_1
\n\u2022 Exam date \u2013 students are required to check the exam
\ndata\/time at the UoB exam office.
\nhttps:\/\/breo.beds.ac.uk\/ultra\/organizations\/_52351_1\/cl\/outl
\nine > December 2022 SEM1 Examination Timetable
\nhttps:\/\/breo.beds.ac.uk\/ultra\/organizations\/_52351_1\/cl\/outline
\n2
\n\u2022 Timetable and updated guidance on BREO via the
\nExams information for Students organisation
\nExam date:
\nThursday 15 December 2022, 9.00am
\n(online, remote)
\nExpectations (from Unit Handbook)
\nShould be able to demonstrate knowledge of:
\n\u2022 the nature and uses of epidemiology
\n\u2022 the epidemiological approach to defining and measuring the occurrence of
\nhealth related states in populations
\n\u2022 the strengths and limitations of epidemiological study designs
\n\u2022 the epidemiological approach to causation
\n\u2022 the contribution of epidemiology to the prevention of disease, the promotion of
\nhealth and the development of health policy
\n\u2022 the contribution of epidemiology to good public health\/healthcare practice
\nand
\n\u2022 the role of epidemiology in evaluating the effectiveness and efficiency of
\nhealth care.
\nEpidemiology is the study of the distribution and determinants of health-related states or events (including diseases and other health conditions) in specified populations, and the application of this study to the control of health problems.<\/p>\n
The epidemiological approach involves the use of statistical and analytical methods to describe and measure the occurrence of health-related states in populations. This includes the study of patterns of disease, the identification of risk factors for disease, and the evaluation of the effectiveness of interventions designed to prevent or treat disease.<\/p>\n
One of the strengths of epidemiological study designs is that they can be used to study large populations over time, allowing for the identification of trends and patterns in disease occurrence. Epidemiological studies can also be used to identify risk factors for disease, which can help to inform the development of interventions to prevent or mitigate the impact of those diseases.<\/p>\n
However, epidemiological studies have limitations as well. For example, they may not be able to establish a causal relationship between a risk factor and a disease, as other factors may also be contributing to the observed relationship. Additionally, epidemiological studies may be subject to bias and confounding, which can affect the validity of the results.<\/p>\n
Despite these limitations, epidemiology plays a critical role in the prevention of disease, the promotion of health, and the development of health policy. By identifying risk factors for disease and evaluating the effectiveness of interventions, epidemiology can help to inform the development of strategies to prevent or control the impact of diseases on populations. Epidemiology is also important for evaluating the effectiveness and efficiency of healthcare practices, helping to ensure that resources are used effectively to improve the health of populations.
\nIn addition, the student will be expected to have gained a variety of skills,
\nincluding an ability to:
\n\u2022 outline appropriate study designs to answer specific questions concerning
\ndisease causation, natural history, prognosis, prevention, and the evaluation
\nof therapy and other interventions to prevent and control disease.
\nEpidemiology Exam
\n\u2022 Epidemiology
\n\uf0a7 Short answer questions
\n\uf0a7 Multiple choice questions
\n\uf0a7 Calculation and interpretation
\n\uf0a7 Essay (type) question
\n3
\nGeneral advice
\n\u2022 This is a CLOSED-BOOK exam. You are expected to work on
\nyour own to complete this exam, not using other people or any
\nmaterials for your assistance. Marks will NOT be given for
\nrepetition of standard material from notes or books or websites.
\n\u2022 Read the exam paper carefully \u2013 making sure that you
\nunderstand instructions. All questions do not necessarily carry
\nequal marks.
\n\u2022 Give precise, specific answers that demonstrate the depth of
\nyour knowledge of the area being examined by the question,
\nrather than vague and general comments.
\n\u2022 General advice \u2013 try to be concise and accurate.
\nPossible short questions
\n\u2013 Prevalence
\n\u2013 Incidence
\n\u2013 Advantages\/disadvantages of
\nroutine data
\n\u2013 Population at risk
\n\u2013 Crude mortality rate
\n\u2013 Age standardisation rates
\n\u2013 Prevention and types
\n\u2013 Confounding factor
\n\u2013 Cross-sectional study
\n\u2013 Ecological fallacy
\n\u2013 Sensitivity
\n\u2013 Specificity
\n\u2013 Selection of control group in a
\ncase-control study
\n\u2013 Advantages\/disadvantages of
\ncase-control study
\n\u2013 Advantages\/disadvantages of
\ncohort study
\n\u2013 Selection bias
\n\u2013 Observer bias
\n\u2013 Recall bias
\n\u2013 Attrition bias
\n\u2013 Matching
\n\u2013 Population screening
\n\u2013 Criteria of a disease suitable
\nfor screening
\n\u2013 Criteria for the assessment of
\ncausality
\n\u2013 Confounding
\n\u2013 Controlling for confounding
\neffect in the design and in the
\nanalysis
\nRisk, Rate and Odds
\nRisk
\n1. Defined population
\n2. Defined period of time
\n3. Number of new cases
\nRate
\n1. Number of new cases
\n2. The person time (cumulative Person-time)
\nOdds
\n1. Number of events happening
\n2. Number of events not happening
\n4
\nRisk and odds
\nRisk:
\n\u2022 24 people drank coffee
\n\u2022 6 developed a headache
\n\u2022 Risk of headache?
\nOdds:
\n\u2022 24 people drank coffee
\n\u2022 6 developed a headache
\n\u2022 Odds of headache?
\nRisk
\n\u2022 24 people drank coffee
\n\u2022 6 developed a headache
\nRisk = no. of participants WITH event of interest
\ntotal no. of participants
\n= 6 headaches\/24 people
\n= 6\/24 = \u00bc= 0.25 = 25%
\nInterpretation: The risk of having a headache was one in four, or 25%
\nOdds
\n\u2022 24 people drank coffee
\n\u2022 6 developed a headache
\nOdds = no. of participants WITH event of interest
\nno. of participants WITHOUT event of interest
\n= 6 headaches\/18 without headaches
\n= 6\/18 = 1\/3 = 0.33 = 33% (1:3)
\nInterpretation: The odds of having a headache were one in third of the odds of not
\nhaving a headache OR one person had a headache for every three that didn\u2019t OR the
\nodds of having a headache were 3 to 1 against
\nOdds-Ratio and Risk-Ratio
\n\u2022 Odds-Ratio is the ratio of odds
\n\uf0a7 An odds is the probability of failure over probability of
\nsuccess.
\n\u2022 Risk-ratio is the ratio of risks
\n\uf0a7 A risk is simply the probability of failure
\n\u2022 An odds-ratio or risk-ratio of 1 indicates no
\ndifference between the groups (e.g. disease\/riskoutcome)
\n\u2022 Odds-ratio more difficult to interpret than risk-ratios
\n\u2022 Risk ratios are more sensitive to base event rate;
\nodds-ratios are not
\n(Lipsey and Wilson, 2000)
\n5
\nComparing two groups
\nTask: Calculate the effect measures and interpret
\nthem:
\n\uf0a7 Risk-ratio (RR) [relative risk]
\n\uf0a7 Odds ratio (OR), if it\u2019s a case-control study.
\n\uf0a7 Risk difference (RD) [absolute risk reduction]<\/p>\n
Type\tHeadache\tNo headache\tTotal
\nCaffeine\t17\t51\t68
\nDecaf\t9\t55\t64
\nTotal\t26\t106\t132
\nComparing two groups
\nCalculate the effect measures
\nRisk-ratio (RR) [relative risk]
\n= (risk of event with intervention)\/(risk of event with
\ncontrol)
\n= (17\/68)\/(9\/64) = 0.25\/0.14 = 1.79
\n[Where RR =1, there is no difference between the groups]
\n\u2022 Interpretation: the risk of having a headache with treatment
\nwas 179% of the risk in the control group OR intervention
\nincreased the risk of headache by 79%<\/p>\n
Headache\tNo headache\tTotal
\nCaffeine (Inter.)\t17\t51\t68
\nDecaf (contrl)\t9\t55\t64
\nTotal\t26\t106\t132
\nComparing two groups
\n\u2022 Odds ratio (OR)
\n\u2022 OR = (17\u00d755)\/(9\u00d751) = 935\/459 = 2.037 = 2.04
\n[Where OR =1, there is no difference between the groups]
\n\u2022 Interpretation: Intervention doubled the odds of headache OR
\nintervention increased the odds to 204% of the odds in the
\ncontrol group OR intervention increased the odds of headache
\nby 104%<\/p>\n
Headache\tNo
\nheadache\tTotal
\nCaffeine\t17\t51\t68
\nDecaf\t9\t55\t64
\nTotal\t26\t106\t132
\n6
\nComparing two groups
\nCalculate the effect measures
\n\u2022 Risk difference (RD) [absolute risk reduction]
\n\u2022 RD= Risk-ratio (RR) [relative risk]
\n\u2022 = (17\/68)-(9\/64) = 0.25-0.14 = 0.11
\n[Where RD =0, there is no difference between the groups]
\n\u2022 Interpretation: intervention increased the risk of headache by
\n11%<\/p>\n
Headache\tNo
\nheadache\tTotal
\nCaffeine\t17\t51\t68
\nDecaf\t9\t55\t64
\nTotal\t26\t106\t132
\nPrevention
\nChoice of study designs
\n\u2022 Investigation of rare disease\u2026\u2026\u2026..
\n\u2022 Investigation of rare cause\u2026\u2026\u2026..
\n\u2022 Measure of incidence\u2026\u2026..
\n\u2022 Measure of prevalence\u2026\u2026..
\n7
\nChoice of study designs
\nMeasure of prevalence\u2026\u2026.. Cross-sectional
\nUseful 2 x 2 table for calculating rates, odds,
\nprevalence, relative risks, odds ratios
\n8
\nFinal tips:
\n1. Revise \u2013 weekly teaching notes\/slides
\n2. Also look at these texts:
\nBasic epidemiology, Bonita, Beaglehole and Kjellstr\u00f6m (WHO)
\nhttps:\/\/apps.who.int\/iris\/bitstream\/handle\/10665\/43541\/9241547073_eng.pdf;jsessionid=986D1CBB27D8AEFDCD290F9BDC105
\n4A7?sequence=1
\nGordis Epidemiology
\nEpidemiology for the Unintended
\nhttps:\/\/www.bmj.com\/about-bmj\/resources-readers\/publications\/epidemiology-uninitiated<\/p>\n","protected":false},"excerpt":{"rendered":"
MSc Public Health Epidemiology in Public Health (PUB002-6\/STI009-6) Revision Session Session \u2013 11 22-23, SEM1 Epidemiology Exam \u2022 Assignment \u2013 Exam \u2022 100% of the marks \u2022 ALL examinations will be taken online through WISEFLOW https:\/\/breo.beds.ac.uk\/bbcswebdav\/pid-6385772-dtcontent-rid-32879053_1\/xid-32879053_1 \u2022 Exam date \u2013 students are required to check the exam data\/time at the UoB exam office. https:\/\/breo.beds.ac.uk\/ultra\/organizations\/_52351_1\/cl\/outl ine […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,36,15,22,18,23,45,44,26,24,29,43,37],"tags":[56,51,50,49,48,55,54,47,46,53,52],"class_list":["post-234","post","type-post","status-publish","format-standard","hentry","category-ace-homework-tutors","category-ace-my-assignment","category-ace-my-homework","category-ace-tutors","category-cheapest-homework-help-online","category-help-with-homework-assignments","category-homework-for-you","category-homework-ace-tutors-assignment-help","category-homework-answers","category-homework-solving-website","category-homework-tutors","category-online-homework-help","category-essay-ace","tag-assessment-assignment-help","tag-assignment-help","tag-assignment-writing-help","tag-dissertation-help","tag-dissertation-writing-service","tag-healthcare-assignment-help","tag-nursing-essay","tag-research-essay-help","tag-research-paper-writing-service","tag-write-my-essay-for-me","tag-write-my-essay-online"],"_links":{"self":[{"href":"https:\/\/www.colapapers.com\/essays\/wp-json\/wp\/v2\/posts\/234","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.colapapers.com\/essays\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.colapapers.com\/essays\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.colapapers.com\/essays\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.colapapers.com\/essays\/wp-json\/wp\/v2\/comments?post=234"}],"version-history":[{"count":0,"href":"https:\/\/www.colapapers.com\/essays\/wp-json\/wp\/v2\/posts\/234\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.colapapers.com\/essays\/wp-json\/wp\/v2\/media?parent=234"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.colapapers.com\/essays\/wp-json\/wp\/v2\/categories?post=234"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.colapapers.com\/essays\/wp-json\/wp\/v2\/tags?post=234"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}