AI in Public Health Lecture 1 PDF

AI in Public Health. Introduction Joacim Rocklöv, Prof. Marina Treskova, PhD Heidelberg Institute of Global Health & Interdisciplinary Centre for Scientific Computing Heidelbe...

AI in Public Health. Introduction Joacim Rocklöv, Prof. Marina Treskova, PhD Heidelberg Institute of Global Health & Interdisciplinary Centre for Scientific Computing Heidelberg University www.hei-planet.com 01/13/2025 Course outline Week 1 – introduction and basic concepts of Public Health and Epidemiology Introduction NCD Infectious diseases Study designs and Regression Causality and Intervention Week 2 – Topic and Method dives in Public Health and Epidemiology Systematic literature review, ethics and data protection Climate Change and Health CVD risk prediction using AI Integrated data analysis and outbreak prediction: avian flu Guest lecture: Wanda Markotter, Prof. Week 3 – Visual learning for Public Health Novel data streams for Public Health Visual learning & mosquito breading sites Early warning and ensemble approaches for outbreak prediction 01/13/2025 Course project and tutorials Project: The primary objective: build predictive algorithms that predict the removed case data for malaria cases in Mozambique. Work in groups of up to three students and utilize any predictors available within the dataset. Your predictions will be uploaded and integrated into an ensemble prediction exercise scheduled for January 30th. This exercise will evaluate how ensemble predictions perform relative to individual models. Tutorial: Tutorials linked to lectures are provided 01/13/2025  Lecture 1: Introduction to Public Health Marina Treskova, PhD Head of Research Group Eco-Epidemiology Heidelberg Institute of Global Health & Interdisciplinary Centre for Scientific Computing Heidelberg University www.hei-planet.com 01/13/2025 Outline Introducing Public Health Core concepts Approach and Key functions Determinants of Health Social, biological, and behavioral Global environmental changes and health Health systems, health economics, and policy Epidemiology 01/13/2025 Public Health Definition C.E.A. Winslow (1920) : Public health is the science and art of: 1.Preventing disease, 2.Prolonging life, and 3.Promoting health through organized efforts of society, including communities, governments, and health systems. It focuses on improving health outcomes for populations rather than individual care and is grounded in principles of equity, prevention, and evidence-based interventions. Levels: individual, organizational, community, and broader – state and international Mission by WHO: Public health aims to provide maximum benefit for the largest number of people – serving the greater good The principle of social justice in the core 01/13/2025 Why Public Health matters? Global perspective: PH improves health outcomes worldwide PH addresses health inequalities PH tackles global threats PH brings economic benefits by preventing diseases and healthcare costs Local perspective: Community health and well-being Disease prevention, e.g. outbreaks Environmental health Image Credit: VectorMine/Shutterstock.com PH communication and awareness campaigns 01/13/2025  Public Health successes Vaccination Programs Impact: Eradicated smallpox globally and significantly reduced polio, measles, and other Global Example: The Global Polio Eradication Initiative has reduced polio cases by over 99% since 1988. Local Example: Annual flu vaccination campaigns protect millions of people in vulnerable groups. Clean Water Initiatives Impact: Reduced waterborne diseases like cholera and diarrhea, especially in low-resource settings. Global Example: The WHO’s WASH (Water, Sanitation, and Hygiene) program Local Example: Municipal water treatment systems ensure safe drinking water in cities. Reduction in Tobacco Use Impact: Comprehensive tobacco control measures have decreased smoking rates and related diseases. Global Example: WHO Framework Convention on Tobacco Control (FCTC). Local Example: Smoke-free policies in restaurants and public spaces. Improved Maternal and Child Health Impact: Dramatic reductions in maternal and child mortality rates. Global Example: Millennium Development Goals (MDGs) Local Example: Prenatal care programs in underserved communities. HIV/AIDS Control Impact: HIV transmission slowed and improved life expectancy Global Example: The global PEPFAR program. Local Example: Community-based HIV awareness campaigns. 01/13/2025 Key concepts and components of Public Health Health outcome: result of a medical condition that directly affects the length or quality of a person’s life Health determinants: Factors that influence health outcomes, incl.: Biological factors: Genetics, age, sex. Social determinants: Education, income, housing, and social support. Environmental determinants: Air quality, water safety, climate. Behavioral factors: Diet, exercise, smoking. Clinical care: prevention, treatment, and management of illness and the preservation of mental and physical well-being through the services offered by medical and allied health professions Health promotion: enabling individuals and communities to increase control over and improve their health. 01/13/2025  Key concepts and components of Public Health (cntd.) Communicable Diseases: Definition: Diseases caused by infectious agents that can be transmitted from one individual to another, either directly or indirectly. Modes of Transmission: Direct Transmission: Person-to-person contact (e.g., touching, Indirect Transmission: Through contaminated surfaces, vectors), or the environment (e.g., waterborne pathogens). Examples? Non-Communicable Diseases (NCDs) Definition: Chronic diseases not caused by infectious agents Characteristics: Not transmissible between individuals. Often progress slowly over time. Strongly influenced by lifestyle and environmental factors. Examples? 01/13/2025 Determinants of Health Centers for Disease Control and Prevention. Social determinants of health. http://www.cdc.gov/socialdeterminants/FAQ.html. 01/13/2025  Health Impact Pyramid Frieden TR. Framework for public health action: the health impact pyramid. Am J Public Health 2010;100:590 –5. https://www.cdc.gov/training-publichealth101/media/pdfs/introduction-to-public-health.pdf 01/13/2025  Health Impact Pyramid Frieden TR. Framework for public health action: the health impact pyramid. Am J Public Health 2010;100:590 –5. https://www.cdc.gov/training-publichealth101/media/pdfs/introduction-to-public-health.pdf 01/13/2025 A Public Health Approach Identifying the problem: surveillance Determining the cause: risk factors of PROBLEM susceptibility, the problem Intervention and evaluation: what intervention works to solve the problem with a specific population Implementation: what are barriers to effective implementation and scale-up of interventions in RESPONSE real-world settings 01/13/2025 Essential Public Health Services (CDC) 10 interrelated services categorized under the three core functions of public health: Assessment, Policy Development, and Assurance. Assessment: Monitor health to identify and solve community health problems Regular collection, analysis, and sharing of health data. Diagnose and investigate health problems and hazards in the community Detecting and responding to health risks and outbreaks. Source: www.cdc.gov/stltpublichealth/publichealthservices/pdf/Ten_Essential Services_and_SDOH.pdf: 01/13/2025 Essential Public Health Services (CDC) Policy Development. Inform, Educate, and Empower people about health issues Providing accessible and accurate information to improve health literacy. Mobilize Community Partnerships to Identify and Solve Health Problems Collaborating with stakeholders to address health challenges. Develop Policies and Plans that Support Individual and Community Health Efforts Creating evidence-based policies and plans to improve health outcomes. Source: www.cdc.gov/stltpublichealth/publichealthservices/pdf/Ten_Essential Services_and_SDOH.pdf: 01/13/2025 Essential Public Health Services (CDC) Assurance Services. Enforce laws and regulations that protect health and ensure safety Ensuring compliance with laws to safeguard public health. Link people to needed personal health services and assure the provision of healthcare when otherwise unavailable Improving access to healthcare, especially for vulnerable populations. Assure a competent public and personal healthcare workforce Training and supporting a skilled workforce for public health and healthcare. Evaluate effectiveness, accessibility, and quality of personal and population-based health services Source: Continuous assessment of health services to www.cdc.gov/stltpublichealth/publichealthservices/pdf/Ten_Essential Services_and_SDOH.pdf: improve quality and outcomes. 01/13/2025 Major disciplines of Public Health (cntd.) Epidemiology: the study of the distribution and determinants of health-related states or events in populations and the application of this study to prevent and control health problems. Laboratories: methods and tools to support the detection, diagnosis, monitoring, prevention, and control of diseases that affect populations. Biostatistics: is the application of statistical methods and principles to biological, medical, and public health research. It involves the design, analysis, and interpretation of quantitative data related to health and disease in humans and other living organisms. Environmental health: focused on how the natural and built environments affect human health and well-being. It encompasses assessing, managing, and mitigating environmental factors that can harm or improve health. Social and behavioral sciences: application of behavioral and social sciences to public health practice: individual behavioral patterns, community and individual habits Health Economics: studies alternative uses of resources in the health services sector and with the efficient utilization of economic resources such as manpower, material and financial resources. 01/13/2025 Public health surveillance Public health surveillance is the systematic, ongoing collection, analysis, interpretation, and dissemination of health-related data for the planning, implementation, and evaluation of public health practices. It aims to monitor and understand the occurrence and spread of diseases, conditions, or other health-related events to guide public health actions and policies. 01/13/2025 Public health surveillance: importance Key reasons surveillance is vital: Assessment of current health status: e.g. the interpretation of mortality and morbidity status Monitoring health changes and trends: Increasing or decreasing trends in chronic conditions (e.g., diabetes, cancer). Seasonal patterns of infectious diseases (e.g., flu). Data for planning, evaluation and decision-making: programs, interventions, policies Monitoring childhood vaccination rates to ensure herd immunity. Supports advocacy efforts for funding and resource allocation. Scaling up interventions Identifying health disparities Early detection of diseases and outbreaks Sustaining public health preparedness: Strengthens the capacity to handle public health emergencies, such as pandemics or bioterrorism events. 01/13/2025 Public health surveillance: characteristics Surveillance should be: Useful Timely Representative Flexible Sensitive Strong predictive value Acceptable to The public Health care providers Cost-effective 01/13/2025 Public health surveillance: types Passive Surveillance Relies on routine reporting of health data by healthcare providers and laboratories. Example: Disease notification systems for reportable diseases. Active Surveillance Public health officials actively seek out data through direct outreach or investigation. Example: Conducting surveys during an outbreak to find additional cases. Sentinel Surveillance Monitors selected sites or populations for specific health events to detect trends. Example: Monitoring influenza trends through selected hospitals. Syndromic Surveillance Analyzes data based on symptoms rather than confirmed diagnoses, often for early detection of outbreaks. Example: Monitoring emergency room visits for flu-like symptoms. Laboratory-Based Surveillance Tracks data from laboratories to monitor infectious diseases or antimicrobial resistance (AMR). Example: Testing for foodborne pathogens. 01/13/2025 Driver-based surveillance Driver-based surveillance focuses on monitoring and analyzing the underlying factors or "drivers" contributing to the emergence, spread, and persistence of diseases or health conditions. These drivers may include social, environmental, economic, or biological factors that influence disease dynamics and population health. Focus on root causes: tracks determinants that influence health outcomes rather than just the diseases themselves. Proactive monitoring: to identify potential risks or vulnerabilities before they result in adverse health outcomes. Useful for predicting and preventing outbreaks or health crises. Multisectoral approach: integrates data from various sectors, such as health, environment, agriculture, and economics. 01/13/2025 Public health surveillance processes Data collection Gathering health-related information from various sources: hospitals, laboratories, surveys, environmental monitoring, and registries. Data analysis Types of data collected: Health outcomes (e.g., cases of diseases). Risk factors (e.g., smoking rates, water contamination). Interpretation Population characteristics (e.g., age, sex, location). Dissemination Action 01/13/2025 Public health surveillance processes Data collection Examining data to identify patterns, trends, and health threats. Data analysis Identify: What are the analyses for? Disease incidence and prevalence. Interpretation Geographic and temporal patterns. Correlation with potential risk factors. Who will analyze the data? Dissemination What methodology to use? How often to analyze the data? Action 01/13/2025 Public health surveillance processes Data collection Data analysis Based on the analyses: Make insights into the spread, severity, and Interpretation determinants of health events. Is this a true trend/change, or is it driven by other factors (e.g. reporting)? Dissemination Action 01/13/2025 Public health surveillance processes Data collection Data analysis Based on the analyses: Make insights into the spread, severity, and Interpretation determinants of health events. Is this a true trend/change, or is it driven by other factors (e.g. reporting)? Dissemination Action 01/13/2025 Public health surveillance processes Data collection Sharing analyzed data with stakeholders to inform decision-making. Prepare reports, dashboards, or alerts tailored Data analysis to the audience. Communicate findings through public health bulletins, presentations, or media. Interpretation Ensure timely dissemination for effective response. Target audiences: Dissemination Public health practitioners Clinicians and other health care providers Action Policy and other decision-makers Community organizations The general public 01/13/2025 Public health surveillance processes Data collection Data analysis Public health surveillance should always have a Interpretation link to action: Develop and implement interventions, such as vaccination campaigns or vector control Dissemination measures. Monitor the effectiveness of public health programs and refine them based on surveillance Action data. 01/13/2025 Epidemiology: Introduction to Fundamentals "The study of the occurrence and distribution of health-related events, states, and processes in specified populations, including the study of the determinants influencing” What we need to know about a disease in a population are who, where, and when: person, place, and time. Observational Epidemiology (non-experimental) Descriptive epidemiology: a study designed only to describe the distribution of exposure or outcome without seeking to explain the distribution by looking for associations. Analytical epidemiology: studies designed to examine associations, often to identify possible causes for an outcome. Interventional Epidemiology: studies designed to test a hypothesis by modifying an exposure within the study population 01/13/2025 Epidemiology: Introduction to Fundamentals (cntd.) Exposures and Outcomes: Exposure (aka risk factor or determinant) is any factor that may influence the outcome. The outcome is the disease, or event, or health-related state, that we are interested in. The outcome can be any health-related event or state - or it can be a risk factor for, or a precursor to, a disease. Risk factor: an aspect of personal behavior or lifestyle, an environmental exposure, or an inborn or inherited characteristic that, on the basis of epidemiological evidence, is known to be associated with the health-related condition(s) considered important to prevent. 01/13/2025 Epidemiology: major functions Field investigation – following the surveillance indication Observational and Analytic studies: to describe patterns of health and disease within populations to interpret these differences to test hypotheses and interpret Evaluation: to evaluate the effect of health-related interventions 01/13/2025 Epidemiology: cases and population A case definition is a set of standardized criteria used to identify cases. A set of diagnostic criteria that must be fulfilled in order to identify a case of a particular disease, health disorder or condition. The epidemiologic definition of a case is not necessarily the same as the ordinary clinical definition. Population: the population of individuals who potentially could become or could have become cases. Often the study population is called the population at risk because it represents the population at risk of developing the outcome of interest. A certain population may be a country, a state, a city, a community, or a neighborhood depending on the occurrence, determinants, distribution, and transmission of disease and related risks. 01/13/2025 Epidemiology: measures of occurrence Epidemiology quantifies disease frequency to understand and manage population health. Key measures include: Incidence: New cases over time. Prevalence: Total cases at a specific point or period. Why they matter: Incidence helps identify the risk of developing disease. Prevalence provides a snapshot of the burden of disease. 01/13/2025 Epidemiology: Incidence measures 1. Incidence Rate Formula: Incidence Rate=Number of new cases/Person-time at risk Example: If 5 new flu cases occur in 100 people who were observed for 6 months, that’s 5 cases in 50 person-years, giving an incidence rate of 0.1 per person-year. Focuses on speed of disease occurrence. Useful for dynamic populations. 2. Cumulative Incidence Formula: Cumulative Incidence=Number of new cases​/Total population at risk Measures risk over a specified period. Assumes a stable population. Example: Outbreak of flu: 10 cases in 100 people over a month → 10% cumulative incidence. 01/13/2025 Epidemiology: Prevalence measures 1. Point Prevalence Formula: Point Prevalence=Existing cases at a specific time/Total population at that time Example: 50 cases of diabetes in 1,000 people → 5% point prevalence. 2. Period Prevalence Formula: Period Prevalence=Cases during a period/Population during that period Example: 75 cases of flu in a school over winter break. Key Insights: Prevalence reflects disease burden. High prevalence: Indicates chronic diseases or ongoing transmission. 01/13/2025 Epidemiology: Morbidity and Mortality Morbidity: Refers to illness or health conditions in a population. Measures: Incidence, Prevalence, Disability-Adjusted Life Years (DALYs). Example: Diabetes prevalence, flu incidence. Mortality: Refers to deaths within a population. Measures: Crude death rate, Cause-specific mortality rate. Example: Infant mortality rate, deaths due to heart disease. Morbidity Mortality Measures non-fatal health outcomes Measures fatal health outcomes Tracks disease burden Tracks death causes and rates Example: Chronic illnesses Example: Cancer death rates 01/13/2025 Epidemiology: measures of effect Measures of effect quantify the relationship between exposure and disease or health outcomes. These measures are crucial for assessing the impact of risk factors, interventions, and public health policies. Key Measures: 1.Risk Ratio (Relative Risk) 2.Odds Ratio 3.Attributable Risk 4.Population Attributable Risk 01/13/2025 Epidemiology: Risk Ratio (Relative Risk) Risk ratio is commonly used in cohort studies to compare the risk of an outcome between an exposed group and an unexposed group. a: The number of individuals who are exposed to the risk factor and have the disease. b: The number of individuals who are exposed to the risk factor but do not have the disease. c: The number of individuals who are not exposed to the risk factor but have the disease. d: The number of individuals who are not exposed to the risk factor and do not have the disease. Interpretation: RR = 1: No effect (exposure doesn’t affect disease risk). RR > 1: Increased risk with exposure. RR < 1: Decreased risk with exposure (protective effect). Example: If the RR of lung cancer for smokers is 3, smokers have three times the risk of lung cancer compared to non-smokers. 01/13/2025 Epidemiology: Odds Ratio (OR) OR is a measure of association between exposure and outcome, especially in studies where you can't directly measure risk. The odds ratio of an outcome compares the odds of having a particular outcome in a population exposed to a suspected risk factor with the odds in a population not exposed. OR = odds of outcome in exposed individuals / odds of outcome in unexposed individuals Interpretation: OR = 1: No association between exposure and outcome. OR > 1: Positive association (increased odds of outcome with exposure). OR < 1: Negative association (decreased odds of outcome with exposure). Example: If OR = 2 for exposure to a chemical and cancer, the odds of cancer are twice as high for those exposed to the chemical compared to those not exposed. 01/13/2025 Epidemiology: Attributable Risk and Population Attributable Risk AR=Risk in exposed group−Risk in unexposed group Interpretation: Indicates how much of the risk in the exposed group can be attributed to the exposure. AR = 0: No risk attributed to exposure. Example: If 10% of lung cancer cases in smokers can be attributed to smoking, the AR for smoking would be 10%. Population Attributable Risk (PAR): PAR=Risk in total population−Risk in unexposed group Interpretation: Measures the proportion of disease in the entire population that can be attributed to a specific exposure. Example: If 30% of all lung cancer cases in a population are attributed to smoking, the PAR for smoking is 30%. 01/13/2025 Epidemiology: Understanding Survival Survival refers to the length of time an individual or group survives after being diagnosed with a disease or exposed to a risk factor. Survival Analysis involves estimating the time to an event, such as death, disease progression, or recovery. Survival Function (S(t)): Represents the probability of surviving beyond a certain time. It is a non-increasing function over time (always decreasing or staying the same). Hazard Function (h(t)): Represents the rate of occurrence of the event at a specific time point, given survival up to that time. 01/13/2025 Digital Transformation https://hr.un.org/sites/hr.un.org/files/hrportal_docs/presentation%20slides.pdf 01/13/2025 New in Data Sources https://hr.un.org/sites/hr.un.org/files/hrportal_docs/presentation%20slides.pdf 01/13/2025 THANK YOU! Questions? www.hei-planet.com