Final Exam Review Social Analysis 76 January 12, 2007 Before we start…



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Final Exam Review

  • Social Analysis 76
  • January 12, 2007

Before we start…

  • This review is NOT comprehensive.
    • Study your lecture and section notes
    • Review your problem sets and solutions
    • Think about the readings
  • Some material will be reviewed quickly.
    • The test will focus more on post mid-term material
    • However, ALL course topics are covered on the exam
    • ALL material is fair game for exam questions.
  • Course material will be covered in a different order than was originally presented in the course – and will be covered in groupings, as topics were covered in section.
  • Please remember to complete your course evaluations
  • Good luck studying

Exam Format

  • Part 1: True/False(31.5 pts)
  • Part 2: Identifications (25.5 pts)
  • Part 3: Short answer- includes quantitative questions (53 pts)
  • Part 4: Short essay – choose 1 of 3 possible essays (10 pts)
  • Undergraduate exam:
  • January 18, 2007, 9:15am – 12:15pm, Lowell Lecture Hall
  • Extension school exam:
  • January 18, 2007, 6:00pm – 9:00pm, Emerson 105
  • (you may only bring a pen/pencil and calculator)
  • Read the directions for each section carefully. Be precise!

Section 1- Lectures1, 2, and 3

  • Section 1- Lectures1, 2, and 3
  • Section 10 – Lectures 22 and 23
  • Section 8 – Lectures 16, 17, and 18
  • Section 7 – Lectures 14 and 15
  • Section 5 – Lectures 10 and 11
  • Section 3 – Lectures 6 and 7
  • Section 9 – Lectures 19, 20, and 21
  • Section 6 – Lectures 12 and 13
  • Section 4 – Lectures 8 and 9
  • Section 2 – Lectures 4 and 5

Section 1- Lectures1, 2, and 3

  • Section 1- Lectures1, 2, and 3
    • 9/18 – Global health: main problems and solutions
    • 9/20 – The definition and quantification of health
    • 9/25 – How do we know about global health?
  • Section 10 – Lectures 22 and 23
    • 12/4 – Choosing the right interventions, cost-effectiveness
    • 12/6 – Quality of care, human resources, accountability and ethical concerns
  • Section 8 – Lectures 16, 17, and 18
  • Section 7 – Lectures 14 and 15
  • Section 5 – Lectures 10 and 11
  • Section 3 – Lectures 6 and 7
  • Section 9 – Lectures 19, 20, and 21
  • Section 6 – Lectures 12 and 13
  • Section 4 – Lectures 8 and 9
  • Section 2 – Lectures 4 and 5

Section 1: How do we know about health?

  • Mortality
  • Prevalence and incidence
  • Sensitivity and specificity
  • Domains of Health

Commonly Reported Probabilities of Death

  • 1q0
  • Infant mortality ‘rate’, the probability of death between birth and exact age 1.
  • 5q0
  • Child mortality, the probability of death between birth and exact age 5.
  • 45q15
  • Adult mortality, the probability of death between age 15 and exact age 60 conditional on being alive at age 15.
  • But remember that mortality is NOT the whole story. Morbidity must also be considered (think DALYs).
  • Length of the interval
  • Starting age

Prevalence and Incidence

  • Prevalence =
  • Number of individuals with disease
  • Population
      • Which is a proportion?
      • Which is a rate?
  • Incidence =
  • Number of NEW cases of disease
  • Person-time of observation

Answers

  • Prevalence is a proportion
  • Incidence is a rate

Example: Prevalence or Incidence?

  • Among men aged 55-69, 1% will have their first heart attack in the next year.
  • In 2000, 10% of women surveyed reported suffering from a migraine headache.
  • As of today, 12% of women have breast cancer.

Example: Prevalence or Incidence?

  • Among men aged 55-69, 1% will have their first heart attack in the next year. Answer: INCIDENCE
  • In 2000, 10% of women surveyed reported suffering from a migraine headache. Answer: PREVALENCE
  • As of today, 12% of women have breast cancer.
  • Answer: PREVALENCE

Practice Problem

  • In September 2006, 1,500 freshman students enrolled in a study looking at the number of back injuries associated with carrying heavy books during a school year. 100 of the students were found to have back problems at the initial examination. At the end of the first school year, 250 additional students reported back pain.
  • 1) What was the prevalence of back injuries among the students at the initial examination?
  • 2) What is the incidence rate of back injuries for the freshman year?

Answers

  • 1) What was the prevalence of back injuries among the students at the initial examination?
  • 100/1500 = .07
  • The prevalence of back injuries among the students at the beginning of the year is 7%.
  • 2) What is the incidence rate of back injuries for the freshman year?
  • Numerator (number of new cases) = 250
  • Denominator (pop at risk)
  • At beginning of year = 1500 – 100 = 1400
  • At end of year = 1400 – 250 = 1150
  • Average over year = (1400+1150)/2 = 1275
  • Incidence = 250/1275 = .20 (20,000/100,000 py)
  • The incidence of back injuries in the freshman year is 20,000 per 100,000 person years.

Sensitivity and Specificity of a Diagnostic Test

  • Sensitivity –
  • The proportion of those people with the disease that test positive (True Positives)
  • Specificity -
  • The proportion of those people without the disease that test negative (True Negatives)
  • Test
  • Positive
  • Negative
  • True disease status
  • Positive
  • A
  • B
  • Negative
  • C
  • D
  • Sensitivity = A / (A+B)
  • Specificity = D / (C+D)

Practice Problem

  • A newly developed diagnostic tool for determining anemia in children is 90% specific and 92% sensitive. Of the 965 children under-5 in a rural village in India, we know with certainty that 345 have the disease. Use the true prevalence to fill in the following 2 X 2 table with the values you would obtain if you applied the new diagnostic test in the village.
  • T+ T-
  • D+
  • D-
  • Test
  • True Disease Status
  • A + B =
  • Total children =
  • C + D =

Answers

  • A newly developed diagnostic tool for determining anemia in children is 90% specific and 92% sensitive. Of the 965 children under-5 in a rural village in India, we know with certainty that 345 have the disease. Use the true prevalence to fill in the following 2 X 2 table with the values you would obtain if you applied the new diagnostic test in the village.
  • T+ T-
  • D+
  • D-
  • Test
  • True Disease Status
  • A + B = 345
  • Total children = 965
  • 965 – 345 = 620
  • A/345 = .92
  • A = 317
  • 345 – 317 = B = 28
  • D/620 = .90
  • D = 558
  • 620 – 558 =
  • C = 62

Domains of Health

Section 10: Choosing and delivering health interventions

  • Cost-effectiveness
  • Human resources
  • Quality of care

Cost-Effectiveness Analysis

  • How can we make decisions about resource allocation when we know that finances are limited?
    • In general, most interventions that improve health cost money, so how do we chose among them?
    • Cost-Effectiveness Analysis (CEA) is an analytical tool to inform decision-making processes.
    • It is only one input into the decision-making process - also political, distributional and ethical considerations.
    • Two kinds: competing and non-competing choices problems.

Two Types of CEA Problems

  • Non-Competing Choice
    • How to best spend the budget you have?
    • You can make many choices (i.e. NOT mutually exclusive)
    • Ex: choosing among multiple public health programs for different diseases or problems
    • Calculate the Average CER
  • Goal:
    • Spend money on programs that will help maximize total gain in health benefits.
  • Competing Choice
    • How much are you willing to pay for the next unit?
    • You can only make one choice (i.e. MUTUALLY EXCLUSIVE alternatives)
    • Ex: choosing one life-saving surgery for disease X over another
    • Calculate the Incremental CER
  • Goal:
    • Find the treatment closest to a person’s willingness to pay for an additional unit of health.

Two Types of CEA Problems: Mechanics

  • Non-Competing Choice
  • Step 1: Calculate average C/E ratio.
  • Step 2: Rank interventions by increasing C/E ratios.
  • Competing Choice
  • Step 1: Arrange treatments by increasing costs.
  • Step 2: Check to see if interventions increase in health benefit. Eliminate dominated treatments (i.e those that cost more but give less health benefit).
  • Step 3: Calculate the ICER and eliminate dominated treatments; re-calculate ICER again as needed.

CEA Sample Problem 1

  • You are a public health officer responsible for disbursing your budget in a way that attempts to optimize total health benefit according to cost-effectiveness principle. The interventions listed below are what is available to you. If you are able to choose more than 1 health intervention and you have a budget of $100K, which do you choose to implement?
  • Time for some calculations…
  • Intervention QALY Gained Net Cost ($)
  • A 400 50,000
  • B 850 90,000
  • C 300 30,000
  • D 900 70,000
  • Intervention QALY Gained Net Cost ($) Average C/E Ratio
  • A 400 50,000 125.0
  • B 850 90,000 105.9
  • C 300 30,000 100.0
  • D 900 70,000 77.8
  • ARRANGE BY INCREASING C/E Ratio
  • Intervention QALY Gained Net Cost ($) Average C/E Ratio
  • D 900 70,000 77.8
  • C 300 30,000 100.0
  • B 850 90,000 105.9
  • A 400 50,000 125.0
  • With a budget of only $100,000 you would choose to implement interventions D and C. If you were given more money you would then implement B followed by A depending on how much your budget was increased.

A middle-aged male visits the doctor, complaining of chest pains. After a series of tests, the patient is diagnosed with a heart condition for which 4 known treatments are available. Each treatment costs a different price, and each is associated with different gains in health units. However, the patient can only choose one treatment option of the 4 available (i.e. they are mutually exclusive).

  • Treatment QALY Gained Net Cost ($)
  • A 425 50,000
  • B 800 90,000
  • C 400 30,000
  • D 850 70,000
  • CEA Sample Problem 2
  • Treatment QALY Gained Net Cost ($)
  • A 425 50,000
  • B 800 90,000
  • C 400 30,000
  • D 850 70,000
  • ARRANGE BY INCREASING COSTS and check that HEALTH BENEFITS ALSO INCREASE
  • Treatment QALY Gained Net Cost ($)
  • C 400 30,000
  • A 425 50,000
  • D 850 70,000
  • B 800 90,000
  • D costs less than B, but has more health benefit.
  • B is dominated by D, so we get rid of B.

CALCULATE THE INCREMENTAL COST-EFFECTIVENESS RATIO and check that the ICER goes from SMALLEST to BIGGEST, if not, a strategy is DOMINATED

  • Treatment QALY Gained Net Cost ($) ICER
  • C 400 30,000 75
  • A 425 50,000 800
  • D 850 70,000 47
  • A is dominated so remove it and re-calculate the ICER
  • Treatment QALY Gained Net Cost ($) ICER
  • C 400 30,000 75
  • D 850 70,000 89
  • Here we have two options left, so which do we choose? That depends on our patients threshold willingness to pay. If he will pay $75 or less per additional QALY gained, then he would choose C. If he is willing to pay $88 or less he would still choose C over D. However, if he is willing to pay $89/QALY or more then he will opt for D instead of C.

Human resource for Health

    • With efforts to scale up health programs such as ARVs for HIV, DOTS for tuberculosis and maternal mortality interventions, there is a widespread recognition that there is an absolute shortage of health workers in many low-income countries. But there are also problems with human resources for health in developed countries as well (e.g. rural areas with no doctors).
    • This is an area that has only recently received attention and the evidence base on short to medium-term solutions is poor.

Solutions to HR Shortages in Low-Income Countries

    • Import health workers – a common solution in better off Sub-Saharan African countries such as Botswana, Zimbabwe, Namibia or South Africa. Not feasible for all countries in need.
    • Redistribute existing health workers from urban to rural areas (easier said than done).
    • Lower the skills level required to deliver a health intervention – village doctors, village health workers, community participation.
    • Increase health worker retention rates.
    • Increase production of health workers – only effective in the long-term

Dealing with Geographic Inequality

    • Extensive experience in many countries with schemes to increase the number of health workers in rural areas or smaller metropolitan areas.
    • Build medical and nursing schools outside capital cities – Mexico, Iran.
    • Financial incentives – Thailand pays multiples of standard salaries for rural postings.
    • Quality of life interventions – housing, schooling, home leave.
    • Required service after medical school

Nurse/Doctor Migration Loss or Gain?

    • Highly politicized topic – clear evidence for Ghana, Zimbabwe and South Africa of emigration to UK, US, with vocal complaints by countries losing staff.
    • Commonwealth Ministers of Health call for convention; World Health Assembly resolutions.
    • BUT Philippines, South Korea, India, and Thailand see health workers as an export that brings back remittance income.

Quality: What is it?

    • Most of the literature on quality defines quality in terms of lists of desirable attributes for quality care: appropriateness, timeliness, effectiveness etc..
    • Two dimensions:
    • Technical quality of care—e.g. was a procedure done correctly, was a correct diagnosis made, etc.
    • Responsiveness—Interpersonal quality of care. Above and beyond the health gain from interacting with the health system, individuals are concerned with the nature of their interaction. Includes Respect of Persons (dignity, autonomy, confidentiality, communication) and Client Orientation (prompt attention, access to social support networks, quality of basic amenities, choice)

Measuring Quality: The Challenges

    • Risk adjustment – tertiary referral hospitals (often teaching hospitals) have higher risk patients with more comorbidity. Taking this into account is difficult or at least contentious.
    • Small numbers problems – assessing quality of an individual provider or even a small hospital is very difficult because there are too few events to monitor.
    • No direct measurement of health gain.

To Err is Human and Crossing the Quality Chasm IOM Reports

    • Release in the United States of the Institute of Medicine Report To Err is Human triggered enormous media and political response on patient safety.
    • The sub-component of variation in quality that is due to medical error has received intense intervention and policy engagement (Crossing the Quality Chasm).

Shifting From Blame to Systems

    • Patient safety movement is a paradigm shift from blaming the healthcare provider who makes a mistake to creating systems that prevent medical errors.
    • Analytical approach and ethos has been borrowed from airline safety field.
    • For example, if drug misdosing is a common error, systems should be created that minimize or stop misdosing at the time the medical order is written through to better labelling of products.

Section 1- Lectures1, 2, and 3

  • Section 1- Lectures1, 2, and 3
  • Section 10 – Lectures 22 and 23
  • Section 8 – Lectures 16, 17, and 18
    • 11/13 – Road traffic accidents, homicide, suicide and war
    • 11/15 – Environment of the poor
    • 11/17 – Tobacco and alcohol
  • Section 7 – Lectures 14 and 15
  • Section 5 – Lectures 10 and 11
  • Section 3 – Lectures 6 and 7
  • Section 9 – Lectures 19, 20, and 21
  • Section 6 – Lectures 12 and 13
  • Section 4 – Lectures 8 and 9
  • Section 2 – Lectures 4 and 5

Injuries: What to know

  • Who is affected?
  • What are the major risk factors?
  • What interventions are effective?

Road Traffic injuries

  • Who is affected?
    • Young adults
    • Males (80% of victims)
    • Motorcyclists, pedestrians and cyclists
  • What are the major risk factors?
    • Vehicle-pedestrian mixture
    • Speed, alcohol
    • Poor road or vehicle design

Road Traffic injuries

  • What are effective interventions?
    • There are many—see your class notes!
      • Decreasing exposure
      • Vehicle design
      • Road design
      • Enforcement of safety laws concerning speed, alcohol, seatbelt and helmet use
    • Education alone is not very effective
  • Global Distribution of Major Risk Factors

Attributable and Avoidable Burden

  • Attributable Burden –
  • Current burden of disease due to past exposure. Calculated with data on:
    • Exposure to the risk factor
    • Hazard (how dangerous is the risk factor)
    • Total burden of disease
  • Avoidable Burden –
  • Future burden of disease avoidable if current and future exposure levels are reduced.

Exposure  Disease?

  • Risk Factor
  • Anything that changes the probability of a health outcome (note: some diseases are risk factors, i.e. HepB, iron deficiency)
  • Relative Risk
  • Magnitude of association between exposure and disease. It indicates the likelihood of developing the disease in an exposed group relative to an unexposed group.

Calculating Relative Risk

  • RR = Probability of Disease in the Exposed
  • Probability of Disease in the Unexposed
  • E+ E-
  • D+
  • D-
  • A
  • B
  • C
  • D

Practice Problem: What is the relative risk of head injuries experienced in the following cohort of 100,000 Chinese high school students?

  • No Helmet Helmet Total
  • Injury 500 900 1400
  • No Injury 9,500 89,100 98,600
  • Total 10,000 90,000 100,000

For each risk factor covered in class, review:

  • Exposure: What is the exposure of interest?
  • Health Risks: Which diseases are caused by exposure to the risk factor?
  • Mitigation: What interventions reduce the health burden caused by the risk factor? Which interventions are less effective?

Example: Indoor Air Pollution

  • Exposure: Combustion of solid fuels (firewood, coal, other biofuels) in poorly ventilated homes
  • Health Risks:
    • Acute Respiratory Infections in children under 5
    • COPD among adults

Example: Indoor Air Pollution

  • Mitigation:
    • Behavioral change: keep children away from the fire
    • Improve ventilation in cooking areas
    • Improve stove quality (mixed effectiveness; women sometimes refuse to use them)
    • Shift to cleaner fuels, such as kerosene or LPG (where economically viable)

Tobacco: Unique mitigation method

  • As tobacco consumption has declined in the US and other Western markets, focus of marketing of tobacco has turned to developing countries.
  • In 1998, WHO began effort to create a binding global treaty on tobacco control: the Framework Convention for Tobacco Control.
  • After nearly 5 years of negotiations, the FCTC was passed by the World Health Assembly in May 2003 and entered into force in February 2005.
  • The FCTC includes provisions to impose restrictions or bans on advertising, sponsorship and promotion; establish new packaging and labelling of tobacco products, establish clean indoor air controls and strengthen legislation to clamp down on smuggling.

Section 1- Lectures1, 2, and 3

  • Section 1- Lectures1, 2, and 3
  • Section 10 – Lectures 22 and 23
  • Section 8 – Lectures 16, 17, and 18
  • Section 7 – Lectures 14 and 15
  • Section 5 – Lectures 10 and 11
  • Section 3 – Lectures 6 and 7
  • Section 9 – Lectures 19, 20, and 21
  • Section 6 – Lectures 12 and 13
  • Section 4 – Lectures 8 and 9
  • Section 2 – Lectures 4 and 5

Cancer: Biology

  • Cancer has many different diseases
    • Cancer is a general term for more than 100 diseases that are characterized by uncontrolled, abnormal growth of cells. Cancer cells can spread locally or through the bloodstream and lymphatic system to other parts of the body.
  • Etiology of Cancer is Complex
    • Molecular pathway that is disrupted may be different for cancers that appear to be the same.
    • At the same time cancers in different sites may share the same molecular or genetic origin.

Cancer: Epidemiology

  • There are 10 million new cases every year, from which there will be 7 million deaths
  • China has 20% of the world's total cancer cases (2.2 million), and the US accounts for the 14.5% of the world's total cancer cases (1.6 million cases)
  • Risks are determined by environmental exposures, diet and genetic susceptibility
  • Developing countries face higher risks of cancers in: stomach, liver, cervix, mouth, esophagus, prostate, While developed countries face higher risks of lung and colon C.
  • The most common cancer for men world wide is “Lung Cancer” and “Breast cancer” for women
  • If we aggregate men and women, “Lung Cancer” is the most common.

Epidemiology of Each Specific Cancer

  • Stomach Cancer
    • High incidence and mortality in East Asia
    • Major decline in stomach cancer incidence and morality in Western countries In past 50 years
    • Decline may be the result of refrigeration and the declining use of preservatives
    • H. pylori is a risk for stomach cancer and may account for 40 percent of stomach cancers worldwide
  • Liver Cancer
    • High incidence and mortality in Africa and East Asia
    • Major risk factor is chronic infection with Hepatitis B and Hepaitis C viruses
    • 85 percent of cases in developing countries are attributable to Hep B and Hep C infections.
  • Lung Cancer
    • Most common cancer and the largest cause of cancer mortality
    • Nearly all variation in lung cancer incidence can be attributed to tobacco smoking
    • Main strategy for tackling lunch cancer is to reduce tobacco consumption
    • If lifestyle change interventions are rarely successful, what are some other mechanism to reduce smoking?
  • Breast Cancer
    • Most common incident cancer in women
    • Incidence is recorded as higher and increasing in high income countries
    • Screening with mammography is believed to contribute to five-year survival
  • Cervical Cancer
    • Highest in poor developing countries
    • HPV is the main risk factor for cervical cancer
    • Most young women who are sexually active are infected with HPV (about 80 percent)

Estimating Cancer-Specific Survival

    • Absolute survival  The percentage of individuals diagnosed with cancer alive after 5 years
    • Relative survival  The percentage of individuals diagnosed with cancer alive after five years divided by the percentage of the age-sex matched general population alive after five years (most common method)
    • Cumulative Probability of Death The probability of death from cancer assuming there are no other causes of death

Prevention and Treatment

  • Prevention Effort
  • War on Cancer are initiated by National Cancer Institute, International Agency for Research on Cancer
  • Tobacco control efforts – Framework Convention on Tobacco Control by WHO
  • Cervical and breast cancer screening were included in discussions of the Cairo Reproductive Health agenda
  • Hepatitis B vaccination included in The Global Alliance for Vaccines and Immunization (GAVI)
  • Treatment Effort
  • Dramatic increase in understanding of cancer biology and genetics over the last 20 years.
  • Targeted therapy – imatinib (Gleevec) induces nearly complete and sustained remission in patients with early stage chronic myeloid leukemia.
  • Lots of promise for new generation treatments but they may be many years away.

2. CVD: Biology

  • King of Mortality but not so in GBD
    • In COM, Ischemic Heart Disease(#1), Cerebrovascular Disease(#2)
    • In GBD, Ischemic Heart Disease (#6) and Cerebrovascular Disease (#7)
    • It is the leading cause of mortality in both developed/developing countries.
  • Biology
    • Ischemic Heart Disease
      • Heart is deprived from oxygen (e.g. myocardial infarction)
    • Cerebrovascular Disease (a.k.a stroke)
      • Brain is deprived from oxygen
      • Two main form of stroke
        • Hemmorhagic: blood vessel in brain ruptures
        • Thrombotic: blood vessel occluded because of blood clot

CVD: Risk Factors and Prevention

  • Risk Factors
  • Increase risk
    • Saturated Fat
    • Transfatty acids
    • Dietary cholesterol
    • High sodium
    • Overweight/Obesity
    • High Alcohol Intake
    • Smoking
  • Decrease Risk
    • Fish and fish oils
    • Diet fiber
    • Fruits and Vegetables
    • Low to moderate alcohol intake
    • Regular Physical Activity
  • Prevention
  • strategies focus mostly on modifying these risk factors
  • Three main strategies to tackle global CVD:
  • Tobacco control
  • Diet and physical activity modification.
  • Direct interventions for known major risks: blood pressure and cholesterol

Intervention

  • Prevention: Targeting Blood Pressure and Choleserol
  • Stepwise reductions of salt content of processed foods with either legislation or voluntary agreements and food labelling
  • Health education through mass-media
  • Threshold based treatment
  • The Polypill
    • Statin, low-dose aspirin & blood pressure drugs
    • 65% reduction in heart attack & stroke risk
    • Very safe and tolerable
    • ~$20 a year
  • Treatment
  • Treatments developed over the last 35 years are effective in reducing the disability associated with angina pectoris and congestive heart failure. Emergency therapy of MI has also reduced the case-fatality rate.
  • Main treatment strategies:
    • Pharmacological management of angina, Cognitive Heart Failure
    • Pharmacological management of Blood Pressure, cholesterol, plus aspirin and/or beta-blockers
    • Revascularization of the heart muscle using angioplasty or coronary artery bypass graft
    • Emergency revascularization through thrombolytic agents (clot busters)

Section 1- Lectures1, 2, and 3

  • Section 1- Lectures1, 2, and 3
  • Section 10 – Lectures 22 and 23
  • Section 8 – Lectures 16, 17, and 18
  • Section 7 – Lectures 14 and 15
  • Section 5 – Lectures 10 and 11
    • 10/23 – Major Childhood Infectious Disease
    • 10/25 – Reproductive Health Challenges
  • Section 3 – Lectures 6 and 7
    • 10/11 – A framework for thinking about drivers in health
    • 10/13 – HIV/AIDS
  • Section 9 – Lectures 19, 20, and 21
  • Section 6 – Lectures 12 and 13
  • Section 4 – Lectures 8 and 9
  • Section 2 – Lectures 4 and 5

Child health: Diarrhea

  • Biology: 3 types of diarrhea (bloody, watery, and epidemic)
  • Prevention:
    • breastfeeding
    • water & sanitation
    • complementary feeding
    • zinc, vitamin A supplements
    • rotavirus vaccination
  • Treatment
    • Oral Rehydration Therapy (ORT): solution of sugar and salt
    • Shift in 1980s from prepackaged Oral Rehydration Salts (ORS) to home-made solutions of ORT

Child health: ARI

  • Biology: major burden is lower respiratory infection (i.e. pneumonia)
  • Prevention:
    • breastfeeding
    • complementary feeding
    • vaccination (Hemophilus influenza type B, conjugate pneumococcal)
    • zinc
  • Treatment:
    • antibiotics

Child health: IMCI

  • Integrated Management of Childhood Illness, WHO-led effort begun in 1992
  • Focus on 3 levels:
    • Caregivers (family and community health practices)
    • Health providers (standardized algorithms for diagnosis of diarrhea, malaria, and ARI)
    • Health system (planning, regulation, management)

Maternal and reproductive health

  • A problem of definition:
  • an aspect of a discipline (within demographics that focus on fertility and contraception)
  • a movement within women’s advancement, feminism (Reproductive rights, Cairo ‘94, Beijing ‘95, women’s decade)
  • a set of health conditions (maternal mortality, sexual problems)
  • a constellation of services (contraception, abortion, human sexuality, STD prevention and treatment, infertility)

Maternal causes (2% GBD)

  • Maternal causes
  • % of total maternal mortality
  • % of total burden of maternal disease
  • Hemorrhage
  • 25
  • 12
  • Sepsis
  • 15
  • 18
  • Unsafe abortion
  • 14
  • 17
  • Hypertensive disorders
  • 12
  • 5
  • Obstructed labor
  • 8
  • 22
  • Other
  • 26
  • 26

Perinatal causes (7% GBD)

  • Low Birth Weight (= <2500g) causes 2/3 perinatal conditions.
    • Small for gestational age (in developing countries due to malnutrition, malaria, anemia)
    • Pre-term (<37 weeks gestation)
  • Birth Asphysxia = lack of oxygen to fetus
  • Birth Trauma = damage during delivery

Measuring maternal health

  • Total Fertility Rate (TFR) = the number of children that would be born to each woman if she were to live through her child-bearing years, given current birth rates
  • Maternal mortality ratio = number of maternal deaths during a given time period per 100,000 live births during the same time period
  • = # of maternal deaths X 100,000
  • # live births
  • Maternal mortality rate = number of maternal deaths in a given time period per 100,000 women aged 15-49 (or woman-years of risk exposure) in the same time period
  • = # of maternal deaths X 100,000
  • # women aged 15-49
  • Lifetime maternal death risk = cumulative probability of death from a maternal cause between ages 15-50, often expressed in terms of odds

Drivers of health: causal pathways

Drivers of health: causal pathways

Causal factors

  • Causal factors
    • Distal causes
      • Societal factors (political, economic, cultural)
      • Health system
      • Physical environment
    • Proximal causes
      • Individual attributes (edu, income, prefs)
      • Behaviors and practices (behavioral risk factors)
    • Physiological/Pathophysiological causes (biological risk factors)
  • Health outcomes
  • (disease, injury, functional impairment, death)

Example of Causal Web

  • Poverty
  • Limited
  • Water
  • Extreme dehydration from exposure
  • to cholera
  • Death from cholera
  • Low-Income
  • Community
  • BMI, Cholesterol
  • Heart Disease
  • Diet, Physical Inactivity
  • Distal Proximal Physio./Pathophysio. Outcome

HIV disease

HIV transmission

  • Modes of transmission
  • sexual contact
  • blood contact (IV drug use, unsafe healthcare injections, unsafe blood transfusions)
  • mother to child transmission
  • Influencing factors: viral load, type of sex (anal, vaginal, oral); presence of ulcerative STIs, male circumcision

HIV prevention

  • Strategies
    • Decrease the number of sex acts
      • Abstinence, delay sex, decrease # of partners
    • Decrease the probability of transmission per sex act
      • Treat STDs, condom use, male circumcision
    • Decrease MTCT
  • Future: vaccines, microbicides

HIV treatment: ARVs/HAART

  • Impacts
    • dramatic effect on improving AIDS survival at individual level (P. Farmer’s patient),
    • decrease in probability of developing AIDS, decrease in probability of death in US, Europe (Egger, Lancet article)
  • Considerations
    • triple drug therapy does not cure the disease
    • a person must stay on the drugs even if they are asymptomatic - chronic lifetime intervention

Section 1- Lectures1, 2, and 3

  • Section 1- Lectures1, 2, and 3
  • Section 10 – Lectures 22 and 23
  • Section 8 – Lectures 16, 17, and 18
  • Section 7 – Lectures 14 and 15
  • Section 5 – Lectures 10 and 11
  • Section 3 – Lectures 6 and 7
  • Section 9 – Lectures 19, 20, and 21
    • 11/27 – The global obesity epidemic
    • 11/29 – Undernutrition and micro-nutrient deficiencies
    • 12/1 –Financing health systems, investments in health, and efficiency of health systems
  • Section 6 – Lectures 12 and 13
    • 10/30 – Epidemics, surveillance, response and eradication
    • 11/1 – Mental Health
  • Section 4 – Lectures 8 and 9
    • 10/16 – Tuberculosis
    • 10/18 – Malaria
  • Section 2 – Lectures 4 and 5
    • 9/27 – Global burden of diseases, injuries and risk factors
    • 10/2 – Inequalities in health
  • Trends in Measured Obesity
  • Changing US income-BMI relationship

Nutrition Transition

    • Shift to ‘Western’ high-fat, low fibre diet due to higher incomes and globalization of the food industry – focus on fat composition of caloric intake
    • Urbanization and decrease of physical activity associated with shift from manual labour to industry and service sectors combined with technology revolution decreasing physical activity within any occupation.

Snacking Theories

    • Main change in the energy balance is the rise of eating between meals which has been facilitated by food processing technologies (good tasting long lasting) and increased availability of snack foods sales points throughout society.
    • Some studies identify the main culprit at liquid carbohydrates (soft drinks and sweetened fruit juices) which have increased enormously in the last decades. Liquid carbohydrates may not trigger normal satiety mechanisms.

Culture of Food

    • In previous times, food accounted for 80% or more of household income. Food consumption was associated with elaborate rituals.
    • Patterns of food consumption have been changing dramatically: rise of eating out of the home, eating prepared food in the home, increased portion size (especially in the US), fast food restaurants as a global phenomenon.

Genes Environment Mismatch

    • Humans are the only higher primate that cooks their own food starting 1.6 million years ago. They likely ate one meal a day after hunting/gathering during the rest of the day. Humans also faced famines. Both probably led to a highly effective capacity to store excess energy as fat.
    • These thrifty genes in an environment of constant plenty lead to excess weight gain.

Population Strategies

    • Decrease availability of energy-dense snacks especially beverages to children in school.
    • Promote physical activity in schools, make the environment more conducive to physical activity, e.g. sidewalks.
    • Change national diet recommendations to reduce percent of free sugars; work with food industry to provide alternatives.
    • More aggressive state intervention to shift the national diet through taxes and regulatory mechanisms.
  • Summary OR: 0.72
  • Perinatal mortality: OR’s for each 1 g/dL Hb increase

Effect of Iron/Folic Acid (IFA) Supplementation on Adverse Events in Children 1-48 Months Old

  • Nepal (19,299 child-years IFA, 9,799 placebo) – no effect on deaths1
  • Zanzibar (16,950 child-years IFA, 8,574 placebo) – 12% increase in all hospitalizations/deaths, 16% in malaria, 33% in pneumonia2
  • 1Tielsch et al, submitted
  • 2Sazawal et al, submitted

Effects of Vitamin A on Infectious Disease Morbidity

  • Possible effect on diarrhea severity, but not all morbidity
  • No effect on pneumonia morbidity
  • Effect on measles complications
  • Major Trials of Vitamin A to Prevent Mortality
  • Over 165,000 children participated in these 8 trials

Vitamin A Implementation

  • Widespread implementation of Vitamin A supplementation often linked to immunization programs.
  • Is coverage sustainable outside of immunization campaigns?

Preventive Effect of Zinc Supplementation on Pneumonia Incidence in Continuous Supplementation Trials

  • 3
  • India(S)
  • Peru
  • Vietnam
  • Jamaica
  • India(B)
  • Pooled
  • 0
  • 0.5
  • 1
  • 1.5
  • 2
  • 2.5
  • Relative Risk and 95% CI

Effect of Zinc Supplementation on Malaria in Children

  • Location
  • Reduction in Clinic Visits for Malaria
  • The Gambia1
  • 32% (p=0.09)
  • Papua New Guinea2
  • 38% (p<0.05)
  • Combined
  • 36% (CI 9-55%, p<0.05)
  • 1Bates et al, Brit J Nutr, 1993
  • 2Shankar et al, Am J Trop Med Hyg, 2000

Trial in Bangladesh Evaluating the Preventive Effect of Weekly Zinc Supplementation

  • 1-23 mo. old children, weekly zinc (70 mg)
  • 6% less diarrhea, 17% less pneumonia, 49% less severe pneumonia and 42% less otitis media,
  • 85% less mortality
  • From Brooks et al, Lancet 2005

WHO Definition of Health System

  • All actors, institutions and resources that undertake health actions.
  • Health actions: all actions whose primary intent is to improve health.

Primary Intent

    • Not all policies and actions that have an important influence on health, such as educating young girls or poverty reduction programs, are part of the health system according to this definition.
    • A wide range of actions targeting individuals and communities would meet this definition: from surgery to campaigns to raise tobacco taxes to random breath testing for drunk driving.
  • HEALTH SYSTEM GOALS
  • Health
  • Responsiveness
  • Fairness in Financial Contribution
  • LEVEL
  • DISTRIBUTION
  • Quality
  • Equity
  • Efficiency

What determines effective coverage?

  • Price of health care
  • Perceived need and knowledge
  • Geographic proximity of providers - travel time
  • Cultural and social acceptability of intervention - responsiveness of health systems
  • Availability of necessary technology and resources
  • Technical quality of providers
  • Choice of an intervention
  • Adherence
  • Demand on health care
  • Quality of providers
  • Health outcomes

Main Revenue Generation Mechanisms

    • General taxation
    • Social insurance – payroll taxes
    • External assistance
    • Private insurance
    • Out-of-pocket payments
    • Direct care from private organizations

Composition of health expenditure

Risk Pooling

    • Systems that primarily use taxes or social insurance protect households, particularly poor households, most effectively from catastrophic health payments.

Epidemics, Surveillance, and Pandemic Flu

Know the nuances of the definitions

  • Epidemic = disease for which incidence of new cases is greater than expected; less predictable. (example, diarrhea is steady in the developing world, except when there is a cholera outbreak).
  • Endemic = a disease is maintained in the populations without introduction of cases outside the population

Understand the differences in response

  • Control = taking measures to reduce the disease to some stated objective; if we removed the control intervention, the disease could come back; no permanent change. For this reason, continuous intervention is needed.
  • Elimination of disease= reduce the incidence of the disease to zero in some defined area. If we stopped this type of intervention, the disease would come back. Again, continuous intervention is necessary.

Responses (cont’d)

  • Eradication = PERMANENT reduction to zero of the worldwide incidence of infection caused by a specific antigen. Intervention efforts are no longer needed.
  • Herd Immunity = when vaccination of a large fraction of a population is conducted, it provides protection to non-vaccinated individuals. The percent coverage needed to achieve herd immunity differs by disease.

Challenges in responding to epidemics

  • To respond to epidemics, we need to understand their origin—we need quick identification of outbreak and tracking trends.
  • MoH have legal obligations to report notifiable cases
      • What do you think are the limitations of this type of reporting???
  • WHO scans local media sources about local outbreaks (to supplement poor reporting)

Influenza Antigen

  • Need to understand structure of influenza antigen to understand concern over pandemic influenza
  • Type of nuclear material
  • Virus type
  • Geographic origin
  • Strain number
  • Virus subtype
  • A/Beijing/32/92 (H3N2)
  • Hemagglutinin
  • Neuraminidase

Antigen structure (cont’d)

  • Consider type A influenza (particular strain of influenza, we also have type B influenza)
    • Within the nucleus, there are 2 proteins we are concerned with: neuraminidase (N) and hemagglutirnin (H); N and H drive lethality!
    • N and A go through periodic changes
      • Drift (Minor Change): Some immunity is retained (same subtype)
      • Shift (Major Change): NEW subtype; has pandemic potential.

Response to Pandemic Flu

  • Developing nations (92% of mortality)
    • What is the likely response?
    • What will the response be limited by?
  • Developed nations
    • Vaccine, but may not be available in time due to lag in production time; 2 doses will likely be needed
    • Can promote antivirals
    • Promote antibiotics for secondary bronchial pneumonia
    • Supportive medical care (e.g. mechanical ventilation)
    • Travel bans, quarantine (challenging! Due to political and economic repercussions)

Mental Health

GBD of Mental Health

    • Neuropsychiatric burden: 12 percent worldwide (twice as big as AIDS at global level)
    • Major burden at the global scale (top four)
      • Unipolar depression (depression w/o mania)  40 percent
      • Alcohol use  12 percent
      • Schizophrenia  9 percent
      • Bipolar affective disorder  8 percent

Diagnosis of mental health conditions

  • Know the challenges!
    • No definitive biological, immunological, or radiological tests
    • Symptom-based as opposed to etiologic or pathologic
    • Epidemiological measurements and clinical diagnostic practice has varied widely over time and across cultures.

Culture and diagnosis

  • Challenges
  • Cultural Variation in Presentation:
    • Manifestation of depression and other mental health problems and symptoms vary by culture.
    • E.g. East Asia it is much more common for patients to report somatic symptoms as opposed to feeling sad or blue.
  • Differential Item Functioning Across Cultures:
    • People from different cultures may interpret questions differently).
    • This makes it difficult to distinguish real variation in the way a mental disorder is manifested from variation in the way individuals from different cultures respond to the same survey questions.

Treatment

  • Trxt options exist; combinations have been proposed and tested.
    • Tricyclic antidepressants (3-4 wks before impact); effectiveness?
    • Psychotherapy—equally effective in studies
    • SSrIS- more effective then tricyclics,, less side effects, good for youth
    • Proactive collaboration therapy+ antidepressants—most effective
    • Other things that are being researched: cranial magnetic resonance, electroconvulsive therapy.
    • BIG POINT: If we were to fully utilize all interventions that are currently available to us, we would only be able to reduce the avoidable burden by 20-30%.
  • Mycobacterium tuberculosis
  • Transmission through the air – not behavior
  • Pulmonary versus extrapulmonary TB
  • HIV is changing risk of breakdown, case fatality, and transmission
  • Latent infection versus active disease
  • What is the difference?
  • How do we test for each?
  • TB has a long memory – difficult to estimate incidence
  • Tuberculosis
  • Two types of pulmonary clinical disease: sputum-smear positive (more infectious) and sputum culture positive.
  • Diagnosis
  • Chest x-ray
  • Pulmonary sputum smear
  • Pulmonary sputum culture
  • PPD skin test
  • New interferon-γ blood test, more specific
  • Diagnosis
  • Decreasing probability of transmission: UV lights, negative air-pressure rooms, isolation
  • BCG Vaccination – prevents childhood extrapulmonary tuberculosis, indeterminate efficacy for adult pulmonary tuberculosis.
  • Chemoprophylaxis or preventive therapy for 2-6 months decreases breakdown by 60-80%.
  • Detection and treatment of smear positive cases reduces the risk of transmission.
  • Preventive Interventions
  • Before the advent of effective drugs, tuberculosis incidence was declining for 50 years in high-income countries.
  • DOTS – passive case finding
  • Individuals with symptoms go to the clinic
  • Improving sputum microscopy will raise case detection
  • Raising cure rates through DOTS
  • Control (1)
  • MDR-TB is being neglected.
  • Tuberculosis incidence continues to rise in communities with high HIV sero-prevalence.
  • Insisting on direct observation of therapy is not necessary and distracts from other efforts to increase case-detection.
  • Preventive therapy is being ignored.
  • Case-detection rates cannot be increased over 45% without addressing fundamental health system issues.
  • There are four types of human malaria falciparum, vivax, ovale, malariae, first two cause most human disease
  • Malaria is a disease that requires the presence of a vector which in this case is the anopheline mosquito.
  • Transmission happens at night
  • The severity of the attack is determined by the species and the strain, on age, genetic constitution, immunity, general health, nutritional status and use of antimalarial drugs
  • Human Malaria
  • Thick and thin smears of blood can be used to detect Plasmodium.
  • In developing countries, most malaria is diagnosed presumptively on the basis of fever and other symptoms.
  • False positives are common because in some endemic areas more than 50% of adults have parasites.
  • Malaria Diagnosis
  • The focus of most of is on malaria in endemic communities, endemic meaning where there is regular transmission each year.
  • In some communities, malaria transmission may occur under unusual environmental circumstances (heavy rains) and inmigration of infected individuals.
  • Individuals in these communities have not acquired immunity and are at high risk of severe malaria.
  • Preventing the malaria epidemics requires surveillance and appropriate vector control and prophylactic interventions.
  • Epidemic Malaria
  • Most of the malaria burden is
  • from deaths in young children
  • Natural exposure to P falciparum gradually elicits, in human hosts, short-lived strain-specific malaria immunity: first to severe disease and death, and then to mild disease.
  • Repeated infections are required to maintain immunity, which is both antibody and T-cell based.
  • Acquisition of immunity in endemic areas explains why clinical episodes are often more severe in children in these communities.
  • Impact of all intervention strategies requires long-term consideration of the consequences for acquired immunity.
  • Acquired Immunity
  • Vector control – DDT use recommended again
  • ITNs – also vector control
  • Prophylaxis for children - some fear may lead to increased mortality at older ages due to decreased acquired immunity.
  • Prophylaxis for pregnant women –reduced incidence of severe anaemia and reduced low birth weight.
  • Prophylaxis for Travellers
  • Management of Malaria epidemics
  • Prevention
  • Prompt treatment of clinical episodes decreases their duration and severity.
  • In children, cerebral malaria requires extremely rapid treatment. The main strategy to avoid progression to cerebral malaria is to presumptively treat episodes early.
  • Treatment has little or no effect on community transmission levels of malaria.
  • Treatment
  • Chloroquine has been the mainstay of treatment for clinical episodes for the last 4 decades. Because of drug resistance it is no longer effective in many areas. In vitro drug resistance is often higher than treatment failure rates.
  • Other agents such as SP have developed resistance rapidly.
  • Artemisin and Artemisin combination therapy (ACT) appears to be the only major agent with little resistance at the population level.
  • ACT costs 10-20 times more than chloroquine
  • Antimalarials
  • WHO launched a global eradication programme that was the centerpiece of global health in the 1960s.
  • In 1998, WHO launched the Roll-Back Malaria
  • RBM strategy: 1) Prompt effective treatment; 2) ITN; 3) Prophylaxis for pregnant women through antenatal clinics; 4) epidemic management.
  • Recent return of DDT
  • Control

Global Burden of Disease (GBD)

  • What is disease burden?
    • Gap b/w a population’s actual health status and some ideal/reference status
  • Mortality does not capture disease status while a person is alive
    • Implications for resource allocation
  • DALYs are a better measure of GBD

DALYs

  • DALY = YLL + YLD
    • YLL = years of life lost to premature death
    • YLD = years lived w/ a disability of specified severity and duration
  • 1 DALY = 1 year of healthy life lost
  • Premature death = occurs before age to which the dying person would have expected to live if they were a member of the standardized population.

DALY Value Choices

  • Assumes standard life table for all populations
  • Age-weighting: peaks in early twenties
  • Age discounting-future healthy life is valued less than healthy present life

Health Inequalities

  • Inequality-no normative judgment
  • Inequity-invokes the concept of social justice; normative judgment
  • Absolute/Relative inequality
    • Must consider both!!!


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