144: USP Environmental and Preventive Health Services 12/1/11
Get a sense of the health status in the U.S. Understand the multiple, interrelated social, environmental and biological factors that influence health and disease; Gain a basic overview of public health principles, terminology and prevention strategies; Be able to apply abstract principles and prevention strategies to concrete case studies and scenarios related to public health; Be conversant in public health policy questions and debates
So what's the good and bad re: the state of the nation's health? Are we in better shape than we were a hundred years ago?
Lo bueno (the good):
Improved life expectancy (mostly due to improved survival rates from infancy and childhood): 45 in 1900; 80 now Improved sanitation, nutrition and housing from the beginning of the 20th century Consequent drops in infectious disease rates: In 1900, children under age 5 accounted for 30.4 percent of deaths; now they account for only around 1% Discovery of penicillin, various vaccines and better medical treatment helped continue this trend
Medical advances improved our capacity to respond to trauma, extend life at the end-of-life, and increase neonatal survival rates Improvements in nutrition and food safety from the beginning of the 20th century (fortification of foods eliminated most vitamin-deficiency diseases; basic food safety, hand-washing, etc.) Improvements in occupational safety through policy/regulation & labor unions Improvements in overall and population-specific health due to economic leveling policies (education, employment, civil rights) from the 60s through around 1980 (when policies changed) Improved road safety and injury prevention Decreases in mortality rates for some diseases (breast cancer, CHD, etc.) Reduction in smoking rates
Lo malo (the bad):
Shamefully bad markers of health compared to other industrialized nations (Infant mortality rates, depression rates, obesity rates, teenage pregnancy and suicide rates, levels of violence as measured by murder rates, rape statistics, incarceration rates=higher than any other nation) Large health disparities (poorer you are, the sicker you are likely to be; and the U.S. has a very high GINI social inequality index + low social mobility)
This is bad not just for the poor, marginalized and underserved, but for the population as a whole
Unequal access to medical care
Changes in agriculture, food processing & globalized food market has created new problems and risks: nutrient depletion, new food borne threats (e.g., E. coli, "mad cow disease"), practices that leave a large ecological footprint, contribute to climate change Epidemic rates of overweight and obesity, Type 2 diabetes Smoking still an issue: 20-30% prevalence rates, depending on state, specific population New problems with antibiotic resistant strains of TB, and other bacterial infections (MRSA, Vancomyacin-resistant Enterococcus) New and mutating viral infections, like AIDS, SARS and influenza-still cause many deaths
Field of factors contributing to health Social determinants of health Ecological model to understand levels of health influence and intervention Epidemiological triangle Different types of epidemiological studies (cohort, case-control, experimental/intervention)
Gold standard against which compared?
Levels of prevention:
Primary Secondary Tertiary Educational Legislative Technological Legislative
Typology of prevention strategies
Can also use that epidemiological triangle or ecological model
What are some of the influences on health we have discussed?
What we eat Levels of (in)activity Levels of stress (economic and "everyday" stresses of a fast-paced life, but also stresses like racism, other forms of oppression, violence) Lifestyle factors like smoking, drug and alcohol use (esp. combined with driving, etc.) (unequal) access to clean water, good food, safe housing, walkable communities (built environment)
Having social support, community involvement, internal locus of control, sense of meaning and connection Globalization: far-reaching, highlyindustrialized global food system; quick spread of infectious diseases through migration, high-speed travel, etc. Re-emergence of infectious diseases, many with antibacterial resistance Poverty; social inequality; discrimination Barriers to health care access Exposure to toxins in food, the workplace and environment, etc.
Protective factors (e.g., good diet rich in whole grains, fruits and vegetables; familial and broader social support networks; community involvement, social capital) Risk factors (e.g., sedentary behavior, smoking, low SES, particular occupations, particular behaviors or exposures, etc.)
Constraints and barriers to good nutrition and weight maintenance at the:
Individual level (biological-based JONESING for sugar, salt and fats; inclination or disinclination to be active; time constraints, e.g., if working two jobs to make ends meet; psychological factors: changing behavior is very difficult for many reasons) Familial (family norms, as a child, what is served for meals and snacks, cultural traditions, SES)
Community (availability of safe places to run and play, garden, shop for healthy food, sit with neighbors; # of fast food restaurants, school policies, social norms, whether there are supportive community organizations, civic leadership opportunities, etc.) ...(and on down to...) Politics and policy level (farm and food policy, FDA, USDA, regulation of manufacturers, power of corporations to influence legislation and enforcement, etc.)
How would you apply abstract principles and prevention strategies to concrete public health problems, like:
CHD HIV/AIDS infectious diseases smoking What if there were an outbreak of an infectious disease-what would need to be done? Is the approach different from how we might best address chronic health problems? Is it similar to responses to emergencies or disasters? In what way?
How would you design an intervention?
Be conversant in current public health debates
Individual vs. social responsibility for health and prevention (what is within individual control? What arises out of and/or must be addressed by larger entities, like local communities, organizations, governments? Active vs. passive approaches to prevention efforts (what are some examples of each? What are the advantages and disadvantages of each?)
When it comes to issues like cleaning up and maintaining the environment, what can and should individual do? Is there a point at which involvement of govt. and other institutions is more effective? Is absolutely necessary?
What about an issue like obesity? Or smoking? (Is there a balance that needs to be struck? What is "good" for the individual? For society? What is reasonable/practical? Can/Should we legislate behavior?) There is often a moral debate (what SHOULD be done based on the values and goals of whatever group is talking), which ends up being in tension with evidence-based knowledge and practices (what works; what is most effective), e.g., sex-ed, needle-exchange
What was more effective as an anti-smoking campaign, changing social norms (e.g., though legislation, with smoking bans, etc.)? or getting individuals to change by warning them of the health consequences of smoking?
On to some reviews of guest lectures...
Incident & Command Structure (ICS) to manage crisis
Is ICS global? Need some organizing structure Response of victims to disasters is frequently unspecific "We need everything!" Need to push people to identify precisely what they need. After a disaster or emergency, there is a 3-4 month window to educate; after this time, it is off our radar screen Abroad: be aware that host nation might not see things the way the "helping" agency does; also, use local materials/resources (e.g., meds, antibiotics)
Operations (getting the work done; managing the clinic, etc.) Logistics (Supporting the operations work; "getting the stuff") Planning (situational awareness; how will we get through the next few days?) Financial/Admin (how will we pay for this entire mess?)
" A disaster is a serious disruption of the functioning of a society, causing widespread human, material or environmental losses which exceed the ability of the affected society to cope using only its own resources." Public health interface/effects?
Rubble, airborne particles > respiratory problems Power outages > food spoilage, systems breakdown Health care system overwhelmed Frequently accompanied by mass migrations
Early recognition of health problems Preventative strategies Rapid needs assessments in disasters Clear communications Quick but thoughtful action Mitigation actions for the future
Examples?
Distinguished btwn community services (e.g., filtering municipal water supply) vs personal services (e.g., screening for disease in asymptomatic population) U.S. Preventive Services Task Force: when to undertake large scale screenings (e.g., is there a clear benefit, is the test accurate and early, is it cost effective?) Talked about sensitivity and specificity (what do these mean and why do they matter?) Discussed her outreach program (model intervention)
What have the trends in quitting smoking been? What is the window for initiating smoking? time Average smoking takes off your life? Tobacco marketing strategies (see levels of marketing slide, e.g., ads targeted at teens, free cigarettes to troops) and are they effective? Efforts of the CA Tobacco Control Program to change adolescent norms? What works?
Increased Cigarette Price Mass Media Program Restrictions on Sales of Cigarettes Enforcement of Law Banning Sales to Minors Restrictions on Industry Marketing of Cigarettes.
Consumption of Tobacco Products in the United States: 1880-2000
Start of Cigarette Advertising Start of public health program
-68%
1st evidence that Smoking caused Lung Cancer
Source: Tobacco Situation and Outlook Report, U.S. Department of Agriculture, U.S. Census Note: Among persons >18 years old. Beginning in 1982, fine-cut chewing tobacco was reclassified as snuff.
Different Types of Marketing Focused on Tobacco Use
Number of known infections (1.4 million in US; over 22 million in Sub-Saharan Africa) One in every five people living with HIV is unaware that they have the disease. What are the implications of this (why does it matter?)? Had steady decrease in incidence until relatively recently, and then levels off with an uptick. Still 56k new cases/yr in the U.S. Why? Risk fatigue Are CDC recommendations working? What percentage of U.S. adults were tested for HIV in 2010?
Those who are unaware are responsible for over half of all new infections There is a 3-fold reduction in risk behavior when someone finds out they are HIV+ So, widespread testing is important (related to this, why didn't we have widespread testing and reporting from the outset? What is "HIV exceptionalism?" What are Dr. Little and her colleagues advocating now?
Routine (opt-out), universal, annual testing Plus Immediate antiretroviral therapy (ART)
According to models, can reduce new HIV cases by 95% in 10 years
And Pre-exposure Prophylaxis (PREP)
HIV does not spread randomly; it is predictable if we know people's social networks Single greatest predictor of HIV infection? Tremendous problems in poorer countries (cost of ART, infrastructure, stigma, high #s) Problems, even in the U.S.: of 100 ppl infected with HIV:
79% dx, 59% linked to care, 32% identified as needing ART, 24% on art, 19% adherent
-65% of women with new HIV infection are African-American -An African-American MSM has an almost 60% chance of becoming HIV infected by age 40
We've had knowledge about environmental and occupational health risks for a long time, and regulatory agencies, e.g., OSHA (Occupational Safety & Health Administration) for 40 years, so are our workers safe? What are some examples of workplace exposures (factors and modes of transmission), and their outcomes?
Assaults/Exposures "agent": Chemical, biological, ergonomic, psychosocial Modes of transmission: dermal, respiratory, ingestion, parenteral, transplacental Who is the host, i.e., who is at risk? Outcomes? Injuries, mental illness, substance abuse
Synergistic effects, e.g., smoking + asbestos exposure, each carries a 10 fold increase for lung cancer, but together?
What is the "healthy worker effect?"
Study of firefighters and diminished lung capacity
What are material data sheets, and do we have them for most workplace chemicals? Why or why not? How do we decide what level of harm is acceptable? What is the Precautionary Principle?
What kinds of screening did she discuss?
Carrier (asymptomatic; recessive disorders; one gene-one disease situations only)
Tay Sachs Sickle cell Cystic fibrosis
Prenatal (NOT diagnostic, rather, an assessment of risk profile)
Pre-implantation genetic screening (screen embryo prior to implantation in uterus) Presymptomatic (e.g., Alzheimers, Huntington's, breast cancer, colon cancer) Newborn (population-based)
PKU Cystic fibrosis Hearing
Cost-benefit analysis for screening; have to take into consideration:
Is there something we can do for the individual who tests positive? Is the condition severe? Cost Consequences of false positives and false negatives
How do we decide when to screen?
Condition severe High-risk population can be identified Screening test is inexpensive, specific, sensitive Be able to follow up (diagnostics) Be able to offer some kind of aid/assistance
A screening test is used to estimate an individual's risk of having a particular disease or disorder (e.g., a baby with a genetic disorder, like downs syndrome); it is NOT definitive (examples: 1st trimester screening, ultrasound) A diagnostic test indicates whether or not the individual (or baby) has a disease/disorder (e.g., amniocentesis, CVS)
What are sensitivity and specificity?
Sensitivity=how well the test "catches" or identifies those people who really have the condition or carry the gene); it won't catch all, i.e., there may be 100 carriers out there for a particular disease; if the test identifies 95/100 of those, that's the sensitivity, a 95% sensitivity =true positives/all carriers (so,...the proportion of people testing positive who HAVE the condition/gene)
Specificity=how accurately the test identifies those who are not carriers or don't have the condition; there may be 1000 people who do not have "the gene," but the test only identifies 900 of them; the other 100 get falsely identified as positive (even though they're not positive). This means the test has a 90% specificity rate =TN/all non-carriers (so, the proportion of people testing negative who really don't have the condition/gene)
The first trimester screen now uses a combination of the maternal age, the serum quadruple screen, the serum marker PAPP-A, and an ultrasound measurement of the back of the neck of the fetus. When used correctly, this first trimester screen has a detection rate of approximately 95% of all cases of Down syndrome, with a false-positive rate of 5%. So the series of tests combined have a 95% sensitivity
Positive predictive value (PPV)=how sure you can be that you really have a gene or condition if you get a positive test If a hundred people test positive, but only 80 of those people are "really" positive, are really carriers, for example, then the PPV=80% PPV=TP/all testing positive
Direct-to-consumer testing Concerns/constraints w/DTC?
"Just because we can do something, does it mean that we should?" (e.g., technology for nuclear bomb) "Technology is moving faster than our ability to understand its implications."
Who/what is involved in reproductive epi? What is a teratogen? Particular topics and studies she discussed:
FAS/D-what do we know? Is this a wellrecognized, well-addressed problem? Allergy/Asthma
Risk perception: asthma medication "Hypothesis-driven" what are we testing? What kind of an epidemiological study is this?
National Children's Study
What are the mortality trends since turn of 20th century, and what accounts for them? What factors favor the emergence of new infectious agents? (human actions and systems, medical advances, globalization) What are some emerging infections Dr. Reed discussed? Why are they resistant to our antibiotics?
Surveillance & response Applied research Infrastructure and training Prevention and control
Outbreak of some virulent viral strain of unknown etiology on UCSD campus What do we do? What do we want to know? We decide we want to try to tackle the unprecedented rise in childhood obesity What are some strategies and their justification?
A modest proposal: Moms and Mams
We are a local non-profit agency interested in addressing the problem of high cancer mortality rates in the African-American community
How do you think through an potential intervention? (do your epi hw: know the extent and distribution of your problem, get stats, meet w/players, consider costs and sustainability, identify multiple strategies and potential outcomes; identify benefits for different groups of participation) Think about how you reach people (especially racially/ethnically diverse groups of which you may not be a part)?
About 35 T/F 16 multiple choice 10 matching One essay (two options available) 400 possible points Thursday 12/8: 8-10am (two hours) Just bring a pen/pencil and your usual cheery morning disposition
Think about questions (for all your classes), in different categories of learning:
Knowledge (facts, definitions, theories) Comprehension (Demonstrative understanding of facts and ideas by organizing, comparing, translating, interpreting, giving descriptions, and stating main ideas) Synthesis (Compile information together in a different way by combining elements in a new pattern or proposing alternative solutions Analysis (Examine and break information into parts by identifying motives or causes. Make inferences and find evidence to support generalizations) Application (Using new knowledge. Solve problems to new situations by applying acquired knowledge, facts, techniques and rules in a different way) Evaluation (Present and defend opinions by making judgments about information, validity of ideas or quality of work based on a set of criteria)
Tuesday, December 6 11am-noon SSB 102 (Conference Room)
Also: Professor Lewis will hold office hours on Tuesday, 6th, 9:30-11:00am in SSB 342
Preguntas?
Good luck studying! You've been a great, interactive class-thank you for being so engaged!