Presentation on theme: "Dr. IZZELDIN EL-JACK, M.D Consultant Public Health DHA"— Presentation transcript:
1 Dr. IZZELDIN EL-JACK, M.D Consultant Public Health DHA A Guide To The oral ExamDr. IZZELDIN EL-JACK, M.D Consultant Public HealthDHA
2 Oral Exam Setting General advices Face to face Comfortable position Be a good listenerUnderstand the questionThink before you speakOrganize what you say, short pause permissibleGood start is essential (1st impression is the last)Say what you know, do not bluff or guessRationalize and defend your answerShow good manners & do not argue with the examiner
3 ICD International Classification for Disease Viral hepatitis A => ICD – ;ICD –10B15Malaria => ICD – 9 084; ICD-10 B50-B54
4 EpidemiologyThe study of distribution, determinants and disease frequency in human populationDescriptive EpidemiologyAnalytical EpidemiologyDistribution: time, place, personDeterminants of health: hereditary, environmental, lifestyle, socio-economic, family and serviced welfare servicesFrequency: prevalence , incidence
5 ScreeningIs the presumptive identification of unrecognized disease or disability by rapid application of tests, examination, or other proceduresScreening criteriaDiseaseTest
6 Reliability - Errors: - Repeatability The ability of the test to provide consistent results- Errors:Observer error( intra-observer error): observer him self( inter-observer error) : different observersInstrumental errorBiological error: pt himself: not fasting, smoking before doing BP check
7 Validity Sensitivity Specificity The ability of the test to correctly identify those individuals who actually have the disease and those who do notSensitivityThe ability of the test to identify correctly those who have the diseaseSpecificityThe ability of the test to identify correctly those who do not have the disease
8 Validity Positive Predictive Value Negative Predictive Value The likelihood that a person with a positive test has the diseaseNegative Predictive ValueThe likelihood that a person with a negative test has not got the diseaseLikely hood ratio+ = sensitivity / 1- specificity_ = 1- sensitivity / specificity
9 SurveillanceThe ongoing and systematic collection, analysis, and interpretation of health data in the process of describing and monitoring a health event. The information is used for planning, implementing and evaluating public health interventions and programs.
10 Sources of disease surveillance data Individual case reportsLaboratory reportsAccident & Emergency (A&E) recordsHospital discharges summariesCase investigations revealing additional casesDeath certificatesSurveys
11 Purposes of Surveillance Monitor disease trends so that planning can be adjusted to meet new situations.Identify,investigate and help control outbreaks or epidemics.Identify specific population groups at high risk of illness or death from priority health events.Evaluate the impact of preventive and curative control activities on the incidence and prevalence of priority diseases in the community.Confirm current priorities among disease control activities.
12 HealthIt is the over-all Physical, Mental and Social well-being of a person.WHO definitionIs state of complete physical, mental, and social well being and not merely the absence of disease.in order to lead socially and economically productive live.
13 Dimensions of health Physical Mental Social Others From the definition (scope of health):PhysicalMentalSocialOthers
14 Determinants of health الاشياء المؤثرة على الصحةHeredity: genetic : what we born withEnvironmental: newborn: malaria biteLife style: smoking, dietSocio economic conditionsHealth and family welfare services
15 Indicators of health Tools to measure health Mortality Morbidity and disabilityNutritionalEnvironmental: municipalityPsycho-socialHealth servicesUtilization :of servicesHealth policies: budget provided by government , and their interest in heath
16 Why indicators are important Compare between countriesPlan for servicesPlan for control and preventionIndentify measures of health problemTo allocate resourcesEvaluation of the problem
17 Health careMultitude of services rendered to individuals, families or communities by the agents of the health services for the purpose of promoting, maintaining, monitoring or restoring health.Largely a government function.Medical care is a subset of health care
18 Health careGroup of services provided to individual, family, community by the agent of health services (PHC, community doctors, municipality..) for the purpose of:promoting, maintaining, monitoring or restoring(those who have disease)health.
19 DefinitionsDisease (Morbidity): pathologyIt is a departure from state of well-being to unhealthy state…when one organ go unwellThe inability of the human body to meet internal or external stresses with adequate reactionIllness:Subjective..sense of feeling unwellSickness:Social dysfunction: he can’t come today because he is sick, he took sick off
20 Disability Risk Factors Any temporary or long term reduction of an individual activity as a result of acute or chronic condition ;CVA consider temporarily as pt might recover after rehabilitationRisk FactorsFactors favoring development of disease often are present early in life outdating the appearance of disease by many yearse.g.: person obese (risk factor) now, after 10 years will develop DM
21 Concept Of Disease Sickness refers to state of social dysfunction. Disease = without ease (uneasiness-discomfort):when something is wrong with the bodily function.Illness :Individual’s perceptions and behavior in response to the disease.(a subjective state of the person who feels aware of not being well)Sickness refers to state of social dysfunction.
22 Concept of Epidemic Epidemic Vs outbreak The occurrence of a number of cases of a disease (or condition) in excess of a number expected in a given time and place.In some instances a single case will constitute such an unusual occurrencee.g UAE is free of malaria: 0 cases, so one case consider epidemicThe cases are present in the country in certain percentage, but when it exceed this percentage expected, so here we call it epidemicAnd to know if the number is exceed normal: we go back to surveillance we did about this disease
23 1.Common source epidemic Epidemic curve1.Common source epidemicPoint source: e.g people invited to dinner, all ate same food, all get food poison, all report to hospital at the same time.Continuous source: one same sourcelike the story of water source in London.OR shawarma cook has salmonella , every day he will transmit the disease to some one, continuously from same source.2.Propagated epidemic: not same sourcepeople got dystenry, they treated, but one of them partially recovered, we to al ain, transmit the disease to other group, this group treated, but one transmitted to other group and so on.Slow epidemicInvestigation of outbreak
24 Investigation of outbreak Verification of diagnosis: confirm DxConfirm the existence of an out break: No. exceed expectedDefining the population at risk: case definitionRapid search for all cases and their characteristicsEvaluation of ecological factors: cause of the problemFormulation of hypothesis: dystentry from water source in khawaneejTesting hypothesis: Data analysis: odds ratio, epidemic curveControl and prevention: actionFinal report: recommendation
25 Steps by Ameera Confirm the Dx Make sure it is an out break Make case definition and search for the casesPut the hypothesis: the cause is ….Test the hypothesis: collect the data and analyze, odds ration, epidemic curveDevelop and implement control and preventionReport.
26 Endemic e.g. TB in India - Hyper-endemic - Holo-endemic Continuous presence of a disease or infectious agent within a given geographical areae.g. TB in India- Hyper-endemic Expresses a persistence intense Transmission- Holo-endemic A high level of infection beginning early in life which affect most population.
27 Control Vs Eradication It is reduction of the disease transmission to an acceptable minimum, or to a level not be considered a major public health problemEradication:Complete elimination of a disease, or complete cessation of transmission and infectious agent
28 Communicable disease every communicable d. is infectious A disease capable of being transmitted from an infected person or species to a susceptible host, either directly or indirectly.Carrier carry disease without symptoms : HIVA person or animal that harbors a specific infectious agent in the absence of clinical disease and serve as a potential source of infection.ContactA person or animal that has associated with an infected person or animal that might provide an opportunity to acquire the infection.Infectious disease: disease caused by infectious agent
29 DisinfectionKilling of infectious agents outside the body by direct exposure to chemical or physical agents.High level disinfections refers to the inactivation of all microorganisms except some bacterial spores.e.g. what we do at home: cleaningConcurrent disinfectionImmediate disinfections and disposal of discharges and infective matter all through the course of a disease.
30 Concept of communicability Infectivity:Ability of the infective agent to enter, survive, and multiply in the hostHe has the disease but not showing S&SPathogenicity: cause destruction of organsThe property of an organism that determines the extent to which overt disease is produced in an infected population i.e the power of an organism to cause diseaseVirulence:The degree of pathogenicity, it is the disease-evoking power of the organism in a given host
31 Measures of Morbidity1. Incidence: new cases, need immediate action, it measure risk2. Prevalence : existing cases: new & old: used to plan for future, measure magnitude of disease
32 3. Attack rate: for primary cases Index case: first person report health services (went to hospital)Primary cases: people who first exposed directly to the source of infection4. Secondary attack rateSecondary cases :who got the disease but didn’t expose to the source of infection, bur from the primary casesWhy we calculate the 2ndy Attack rate:To know the infectivity(communicabilty) of the disease .i.e. if it is infectious or not.
33 Measures of MortalityCrude death rates : all death in dubai, it is not accurate , can’t be used for comparison, to make it better we have standardized itSpecific death ratesStandardized ratesCase fatality rates: اكثر فتكاProportionate mortality ratio :اكثر تسببا في الوفاة e.g.We have 10 diseases causes death, breast cancer PMR is the highestFetal and maternal mortality rate
34 DisasterAn event that overwhelmed the affected community and that really requires outside assistance.Emergency: same but require inside assistance only
35 Define treatment and control groups. What’s the Design?Define treatment and control groups.Administer exposure to treatment group, but not controls.Follow through time and compare rate of disease in treatment group with rate of disease in control group.Epidemiologist is involved during the entire time from exposure and disease. First descriptor (Randomized Trial) Second descriptor (Randomized Trial) Third descriptor (Randomized Trial) Fourth descriptor (Randomized Trial) “Randomized Trial”Next SlideRandomized Trial
36 Select a healthy study sample. What’s the Design?Select a healthy study sample.Observe who is exposed and who is not exposed.Follow through time and compare rate of disease in exposed group to rate of disease in unexposed group.Epidemiologist is involved during the entire time from exposure and disease. First descriptor (Cohort Study or Randomized Trial to prevent disease) Second descriptor (Cohort Study) Third descriptor (Cohort Study) Fourth descriptor (Cohort Study) “Cohort Study”Next SlideCohort Study
37 Ask both groups about their exposures in the past. What’s the Design?Select a group of people with disease and a similar group of people without the disease.Ask both groups about their exposures in the past.Compare proportion of exposure in diseased group to proportion of exposure in non-diseased group.Epidemiologist is involved after disease has occurred and relies on subjects’ memories to gather information about exposure. First descriptor (Case-Control Study) Second descriptor (Case-Control Study) Third descriptor (Case-Control Study) Fourth descriptor (Case-Control Study) “Case-Control Study”Next SlideCase-Control Study
38 Cross-Sectional Study What’s the Design?Select a study sample.Ask each person about both exposure and disease at that point in time.Disease rate in exposed group is compared to disease rate in unexposed group. First descriptor (Cross-Sectional Study) Second descriptor (Cross-Sectional Study) Third descriptor (Cross-Sectional Study) “Cross-Sectional Study”Next SlideEpidemiologist gathers data only at that one point in time.Cross-Sectional Study