to Community Medicine Course 31505201 Prevention and Control of Diseases Levels of Prevention By Hatim Jaber MD MPH JBCM PhD 27 11 2017 1 Post midterm Week 8 Unit 6 ID: 740509
Download Presentation The PPT/PDF document "Faculty of Medicine Introduction" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Faculty of Medicine Introduction to Community Medicine Course (31505201) Prevention and Control of Diseases Levels of Prevention
By Hatim JaberMD MPH JBCM PhD27 - 11- 2017
1Slide2
Post midtermWeek 8 Unit 6: Demography and DataWeek 9 Midterm assessment (Exams.)15-11-2017Week 10 Unit 8 Introduction to Epidemiology.Week 11 Unit 9: Prevention and Control of Diseases Causation Week 12 Unit 10: Health Education and CommunicationWeek 13 Unit 11: Public Health Surveillance and ScreeningWeek 14 Unit 12: Health Administration and healthcare
managementWeek 15 Unit 13: Revision and Health ResearchWeek 16 Final assessment (Exams.)Slide3Slide4Slide5
5Slide6
Presentation outlineTimeHealth promotion08:00 to 08:15Prevention and Control principles08:15 to 08:30
Levels of Prevention- concepts08:30 to 08:45Uses and characteristics of different levels
08:45 to 09:00
Control of
diseases
09:00 to 09:15
6Slide7
“Prevention is better then cure”7Slide8
Disease Prevention OverviewPrevention is a cornerstone concept in public healthIf it cannot be prevented, try to reduce its impactOften tailored to a specific disease or riskPrevention may occur at individual or population levels8Slide9
Health-to-Death ContinuumThink about various levels of healthiness, sickness, and deathActivities to reduce disease and increase health by where they are initiated on the continuum9Slide10
Relationship between Continuum and Health Promotion & Disease PreventionHealth Promotion – optimize overall health. LEFT sideDisease Prevention – reduce occurrence and impact of specific diseases. RIGHT side10Slide11Slide12
12Slide13
(I) PreventionThe goals of medicine are to promote health, to preserve health, to restore health when it is impaired, and to minimize suffering and distress.These goals are embodied in the word "prevention" 13Slide14
Prevention; Definition and ConceptActions aimed at eradicating, eliminating or minimizing the impact of disease and disability, or if none of these are feasible, retarding the progress of the disease and disability.The concept of prevention is best defined in the context of levels, traditionally called primary, secondary and tertiary prevention. A fourth level, called primordial prevention, was later added.14Slide15
Determinants of PreventionSuccessful prevention depends upon: a knowledge of causation, dynamics of transmission, identification of risk factors and risk groups, availability of prophylactic or early detection and treatment measures, an organization for applying these measures to appropriate persons or groups, and continuous evaluation of and development of procedures applied 15Slide16
Preventable Causes of DiseaseBEINGS Biological factors and Behavioral FactorsEnvironmental factorsImmunologic factorsNutritional factorsGenetic factors
Services, Social factors, and Spiritual factors[JF Jekel, Epidemiology, Biostatistics, and Preventive Medicine, 1996]
16Slide17
Leavell’s Levels of PreventionStage of diseaseLevel of preventionType of responsePre-disease
Primary PreventionHealth promotion and Specific protection
Latent Disease
Secondary prevention
Pre-symptomatic
Diagnosis and treatment
Symptomatic Disease
Tertiary prevention
Disability limitation for
early symptomatic disease
Rehabilitation for late
Symptomatic disease
A fourth level, called primordial prevention, was later added
.
17Slide18
Primordial preventionPri-mordial prevention consists of actions and measures that inhibit the emergence of risk factors in the form of environmental, economic, social, and behavioral conditions and cultural patterns of living etc.18Slide19
Primordial prevention (cont.)It is the prevention of the emergence or development of risk factors in countries or population groups in which they have not yet appeared For example, many adult health problems (e.g., obesity, hypertension) have their early origins in childhood, because this is the time when lifestyles are formed (for example, smoking, eating patterns, physical exercise). 19Slide20
Primordial prevention (cont.)In primordial prevention, efforts are directed towards discouraging children from adopting harmful lifestyles The main intervention in primordial prevention is through individual and mass education Primordial prevention, a new concept, is receiving special attention in the prevention of chronic diseases20Slide21
Primary preventionPrimary prevention can be defined as the action taken prior to the onset of disease, which removes the possibility that the disease will ever occur.It signifies intervention in the pre-pathogenesis phase of a disease or health problem.Primary prevention may be accomplished by measures of “Health promotion” and “specific protection”21Slide22
Primary prevention (cont.)It includes the concept of "positive health", a concept that encourages achievement and maintenance of "an acceptable level of health that will enable every individual to lead a socially and economically productive life". Primary prevention may be accomplished by measures designed to promote general health and well-being, and quality of life of people or by specific protective measures. 22Slide23
Primary PreventionGoal: Reduce number of new casesRationale: By reducing exposure rates and increasing resistance, can reduce number of new casesTarget population:Those who are most likely to be exposed and/or could increase their resistanceTypical activities:Remove or reduce source of the riskEducate and make aware of disease riskInclude behavioral changes to reduce exposureImprove general healthOutcome measure: incidence of exposure; incidence of disease
23Slide24
Primary preventionHealth promotionHealth educationEnvironmental modificationsNutritional interventionsLife style and behavioral changesSpecific protection Immunization and seroprophylaxisUse of specific nutrients or supplementationsProtection against occupational hazardsSafety of drugs and foodsControl of environmental hazards, e.g. air pollution
Achieved by24Slide25
Health promotionHealth promotion enables people to increase control over their own health. It covers a wide range of social and environmental interventions that are designed to benefit and protect individual people’s health and quality of life by addressing and preventing the root causes of ill health, not just focusing on treatment and cure.Slide26
Health promotion …….“is the process of enabling people to increase control over and to improve their health” (Ottawa Charter ’86)“involves the facilitation of skills in individuals and change in environments which impact positively on health” (Vic Health 2005)“is everyone’s business” (CEO DHCS 2004)26Slide27
Health promotionIt is not directed against any particular disease, but is intended to strengthen the host through a variety of approaches (interventions). The well-known interventions in this area are:health educationenvironmental modificationsnutritional interventionslifestyle and behavioral changes27Slide28
There are 3 key elements of health promotion:Slide29
There are 3 key elements of health promotionGood governance for health… requires policy makers across all government departments to make health a central line of government policy. Health literacy ….People need to acquire the knowledge, skills and information to make healthy choicesHealthy cities ….Strong leadership and commitment at the municipal level is essential to healthy urban planning and to build up preventive measures in communities and primary health care facilities.Slide30
30Slide31
31Slide32
Approaches for Primary PreventionThe WHO has recommended the following approaches for the primary prevention of chronic diseases where the risk factors are established:a. Population (mass) strategy b. High -risk strategy32Slide33
Population (mass) strategy“Population strategy" is directed at the whole population irrespective of individual risk levels. For example, studies have shown that even a small reduction in the average blood pressure or serum cholesterol of a population would produce a large reduction in the incidence of cardiovascular disease The population approach is directed towards socio-economic, behavioral and lifestyle changes 33Slide34
High -risk strategyThe high -risk strategy aims to bring preventive care to individuals at special risk. This requires detection of individuals at high risk by the optimum use of clinical methods.34Slide35
Example Infectious DiseaseDisease: Seasonal influenzaPrimary prevention: target population – everyone; all agesGoal – reduce number of cases of fluRationale – reduce exposures; bolster immune systemActions Education: cough and sneeze etiquette, hand washing, know risk groupsImmunization: vaccination to develop antibodiesInterventions at the individual level: vaccinate; good nutrition, sleep, and exercise to optimize health; good cough/sneeze etiquette; frequent hand washing; avoid others who are sickInterventions at the community/population level:Provide access to vaccinesUse Public Service Announcements (PSAs) to educate publicPrepare plans for schools, worksites, and hospitals/clinics for outbreak35Slide36
Secondary preventionIt is defined as “ action which halts the progress of a disease at its incipient stage and prevents complications.”The specific interventions are: early diagnosis (e.g. screening tests, and case finding programs….) and adequate treatment.36Slide37
Secondary preventionSecondary prevention attempts to: arrest the disease process, restore health by seeking out unrecognized disease and treating it before irreversible pathological changes take place, and reverse communicability of infectious diseases.It thus protects others in the community from acquiring the infection and thus provide at once secondary prevention for the infected ones and primary prevention for their potential contacts.37Slide38
Early diagnosis and treatmentWHO Expert Committee in 1973 defined early detection of health disorders as “ the detection of disturbances of homoeostatic and compensatory mechanism while biochemical, morphological and functional changes are still reversible.”The earlier the disease is diagnosed, and treated the better it is for prognosis of the case and in the prevention of the occurrence of other secondary cases.38Slide39
Secondary PreventionGoal: Reduce number of new cases; reduce number of severe casesRationale: By reducing number of exposures and early disease that progress to more severe disease, mortality and morbidity can be reducedTarget population:Those who have been exposed to the disease-causing agent or have early symptoms of the diseaseTypical activities:Screening for exposure and/or diseasePost-exposure prophylaxisEarly treatment to reduce impact of disease/reverse courseOutcome measure: incidence of disease39Slide40
Example Infectious DiseaseDisease: Seasonal influenzaSecondary prevention: target population – everyone who has been exposed to the virusGoal – reduce number and severity of cases of fluRationale – early treatment to reduce severity of diseaseActions Screening: identify those who are most likely exposed from those who are notEarly treatmentImmunization: vaccination to develop antibodiesInterventions at the individual level: Post flu symptoms and suggestions for self-careProvide antiviral within 48 hours of symptom onsetInterventions at the community/population level:Use quarantine or isolation measures; ban gatherings of large groups; travel restrictionsSend sick children home from school; enforce sick leave at work40Slide41
Tertiary preventionIt is used when the disease process has advanced beyond its early stages.It is defined as “all the measures available to reduce or limit impairments and disabilities, and to promote the patients’ adjustment to irremediable conditions.”Intervention that should be accomplished in the stage of tertiary prevention are disability limitation, and rehabilitation.41Slide42
Tertiary PreventionGoal: Reduce number of complications, deathsRationale: By reducing disease severity and increasing recovery, can reduce number of premature deaths or complicationsTarget population:Those who have disease and need treatmentTypical activities:Treatment tailored to the patientRehabilitation to promote recoveryOutcome measure: incidence of death and long-term disability42Slide43
Disability limitationdiseaseimpairmentdisabilityhandicap
43Slide44
ImpairmentImpairment is “any loss or abnormality of psychological, physiological or anatomical structure or function.”44Slide45
DisabilityDisability is “any restriction or lack of ability to perform an activity in the manner or within the range considered normal for the human being.”45Slide46
HandicapHandicap is termed as “a disadvantage for a given individual, resulting from an impairment or disability, that limits or prevents the fulfillment of a role in the community that is normal (depending on age, sex, and social and cultural factors) for that individual.”46Slide47
RehabilitationRehabilitation is “ the combined and coordinated use of medical, social, educational, and vocational measures for training and retraining the individual to the highest possible level of functional ability.”Rehabilitation
Medical
rehabilitation
Vocational
rehabilitation
Social
rehabilitation
Psychological
rehabilitation
47Slide48
Example Infectious DiseaseDisease: Seasonal influenzaTertiary prevention: target population – everyone who has influenzaGoal – reduce number and severity of flu-related complications and deathsRationale treatment and rehabilitation can reduce deaths and help return individual to a normal lifestyleActions Provide supportive care and early treatment of complicationsUse rehabilitation to increase recovery of normal lifestyle Interventions at the individual level: Tailor treatment to symptoms; monitor and treat complicationsInterventions at the community/population level:Ensure access to treatment (health insurance, local clinics available)Protect employees who are out sick from losing jobsResearch to find better treatments; monitor resistance patterns48Slide49
Levels of Prevention Table49Slide50
Strategy for Prevention
Assess
Exposure
Identify
Populations
at High
Disease Risk
(based on demography /
family history,
host factors..)
Conduct
Research on
Mechanisms
(including the study of
genetic susceptibility)
Apply
Population-Based
Intervention
Programs
Evaluate
Intervention
Programs
Modify Existing
Intervention
Programs
I
n
t
e
r
v
e
n
t
i
o
n
A
s
s
e
s
s
m
e
n
t
Epidemiology Division
50Slide51
SummaryDisease prevention aims to reduce avoidable morbidity and premature mortality by reducing exposure and disease severity, and facilitating recoveryDisease prevention efforts complement health promotion effortsThere are three levels of prevention. They vary in their target populations, rationales, goals, activities, and outcome measuresPharmacists can be involved in prevention at both the individual patient and community or population levels.51Slide52
(II) Control52Slide53
ControlConcept of control:The term disease control describes ongoing operations aimed at reducing:The incidence of diseaseThe duration of disease and consequently the risk of transmission The effects of infection, including both the physical and psychosocial complicationsThe financial burden to the community.53Slide54
Control activities focus on primary prevention or secondary prevention, but most programs combine both.controleliminationeradication
54Slide55
Disease EliminationBetween control and eradication, an intermediate goal has been described, called "regional elimination" The term "elimination" is used to describe interruption of transmission of disease, as for example, elimination of measles, polio and diphtheria from large geographic regions or areas Regional elimination is now seen as an important precursor of eradication55Slide56
Disease EradicationEradication literally means to "tear out by roots". It is the process of “Termination of all transmission of infection by extermination of the infectious agent through surveillance and containment”.Eradication is an absolute process, an "all or none" phenomenon, restricted to termination of an infection from the whole world. It implies that disease will no longer occur in a population. To-date, only one disease has been eradicated, that is smallpox.56Slide57
MonitoringMonitoring is "the performance and analysis of routine measurements aimed at detecting changes in the environment or health status of population" (Thus we have monitoring of air pollution, water quality, growth and nutritional status, etc). It also refers to on -going measurement of performance of a health service or a health professional, or of the extent to which patients comply with or adhere to advice from health professionals.57Slide58
Surveillance surveillance means to watch over with great attention, authority and often with suspicion According to another, surveillance is defined as "the continuous scrutiny (inspection) of the factors that determine the occurrence and distribution of disease and other conditions of ill-health" 58Slide59
Objectives of SurveillanceThe main objectives of surveillance are: (a) to provide information about new and changing trends in the health status of a population, e.g., morbidity, mortality, nutritional status or other indicators and environmental hazards, health practices and other factors that may affect health (b) to provide feed-back which may be expected to modify the policy and the system itself and lead to redefinition of objectives, and (c) provide timely warning of public health disasters so that interventions can be mobilized.59Slide60
Control of infectious diseases (the 4 “C”sControl
Cases
Contacts
Carriers
C
ommunity
Diagnosis
notification
isolation
disinfection
treatment
follow up
release
observation
detection
Epidemiological
Investigation &
containment
standard
strict
protective
60Slide61
Evaluation of controlEvaluation is the process by which results are compared with the intended objectives, or more simply the assessment of how well a program is performing. Evaluation should always be considered during the planning and implementation stages of a program or activity. Evaluation may be crucial in identifying the health benefits derived (impact on morbidity, mortality, sequel, patient satisfaction). Evaluation can be useful indentifying performance difficulties. Evaluation studies may also be carried out to generate information for other purposes, e.g., to attract attention to a problem, extension of control activities, training and patient management, etc. 61Slide62
To summarizeThe goals of medicine are to promote health, to preserve health, to restore health when it is impaired, and to minimize suffering and distress. These goals are embodied in the word "prevention" Successful prevention depends upon a knowledge of causation, dynamics of transmission, identification of risk factors and risk groups, availability of prophylactic or early detection and treatment measures, an organization for applying these measures to appropriate persons or groups, and continuous evaluation of and development of procedures applied The objective of preventive medicine is to intercept or oppose the "cause" and thereby the disease process. This epidemiological concept permits the inclusion of treatment as one of the modes of intervention62