1. BME 301 Lecture Two

2. Review of Lecture 1 Course organization Course goals Four questions we will answer Technology assessment – The big picture What is health? Role of WHO Health data and uses

3. Overview of Lecture 2 What are the major health problems worldwide? Leading causes of mortality by age Developed world Developing world A Tale of Two Girls

4. One View of The World Developed Countries Developing Countries There is no universally accepted definition of what a developing country is Usually categorized by a per capita income criterion Low income developing countries: <$400 Middle income developing countries: $400-$4,000 WTO members decide for themselves if they are a developing country; brings certain rights

5. UN: Least Developed Countries In 1971, UN created a least developed country member category Countries apply for this status Low national income (<$900 per capita GDP) Low levels of human capital development Economic vulnerability Originally 25 LDCs As of 2001, 600 million people live in world’s 49 least developed countries

6. Map of LDCs

7. Health and Other Data in LDCs Average per capita GDP: LDCs: $235 All other developed countries: $24,522 Average life expectancy: LDCs: 51 years Industrialized nations: 78 years 1 child in 10 dies before his or her 1 st bday in LDCs 40% of all children under 5 are underweight or suffering from stunted growth in LDCs Half the population in LDCs is illiterate

8. Health and Other Data in LDCs Mortality rate for children under five: LDCs: 151/1,000 live births High income countries: 6/1,000 live births Average annual health care expenditures: LDCs: $16/person High income countries: $1,800/person A child born today in an LDC is more than 1,000 times more likely to die of measles than one born in an industrialized country.

9. Leading Causes of Mortality Ages 15-44 Developing World 1. HIV/AIDS 2. Road accidents 3. Inter-personal violence Developed World 1. Road accidents 2. Self-inflicted injuries 3. Inter-personal violence

10. Burden of HIV/AIDS United States 0.8-1.2 million people have HIV/AIDs (prevalence) 40,000-80,000 new HIV infections per year (incidence) Within 10 years of infection: 50% develop clinical AIDS 40% develop illness associated with HIV 5-10% remain asymptomatic Annual cost to treat: $15 billion

11. Burden of HIV/AIDS Worldwide 40-100 million HIV infected worldwide 90% of HIV infections occurs in the developing world 16,000 new infections per day 16 million people have died

12. Clinical Course of HIV/AIDS HIV Infection Virus deposited on mucosal surface Acute infection (mono-like symptoms) Viral dissemination HIV-specific immune response Replication of virus Destruction of CD4+ lymphocytes Rate of progression is correlated with viral load Latent Period

13. Clinical Course of HIV/AIDS AIDS Immunologic dysregulation Opportunistic infections and cancers Risk of infections is correlated with number of CD4+ lymphocytes Average patient with AIDS dies in 1-3 years

14. Pathophysiology of HIV/AIDS http://health.howstuffworks.com/aids3.htm

15. Pathophysiology of HIV/AIDS http://www.roche.com/pages/facets/ 4/hiv_life_cycle2.jpg

16. Treatments for HIV/AIDS Inhibit reverse transcriptase enzymes Enzyme is specific to HIV Combinations of RTIs appear effective Inhibitors of HIV protease HIV proteases are distinct from mammalian proteases Most significant advance in HIV therapy yet Highly Active Antiretroviral Therapy (HAART) Combination of three or more drugs Fusion inhibitors Subject of new research

17. Treatment for HIV/AIDS

18. Prevention of HIV Infections Vaccines Pre-clinical work in animals is promising Education, Counseling & Behavior mod. Worked in the US for homosexual men Free needles for IV drug users Societal debate Improved blood supply Greatly decreased risk for hemophiliacs Screening and treating pregnant women Area where interventions are well accepted

19. HIV/AIDS Historical Perspective 1981 CDC reported unexplained PCP in 5 previously health, homosexual men CDC reported Kaposi’s sarcoma in 26 previously healthy, homosexual men 1981-1982 Increased association with IV drug use, recipients of blood transfusions, hemophiliacs 1983 Virus isolated

20. HIV/AIDS Historical Perspective 1984 Virus shown to be causative agent 1985 ELISA test developed Today: Broad spectrum of disease Asymptomatic infection Clinical latency Advanced disease (AIDS) Clearly sexually transmitted, and transmitted through blood products

21. US Burden of Disease: Road Accidents Leading cause of potential years of life lost $137.5 billion total economic cost in 1990 Rates: 15.6/100,000 US population died in 1993 40,115 Americans killed 3,200 killed were under 16 years of age Rates >2X higher for males than for females Motorcycles: 20X higher death rate per mile traveled 44% of fatalities related to alcohol use

22. Prevention: Road Accidents Laws: Seat belts, Car seats, Air Bags Alcohol use Motorcycle helmets Restraints Physics Unintended consequences Education and counseling Seat belts, Car seats, Air Bags Alcohol use

23. Physics of Accidents/Restraints

24. Alcohol Related Deaths

25. Helmet Laws

26. Burden of Inter-personal Violence 75,000 Americans murdered in 1992 Persons at greatest risk: Young males Minorities Persons with a history of criminal behavior Persons in poor urban communities Firearms (most often handguns) used in 70% of murders and 25% of aggravated assaults in US in 1992

27. Prevention of Inter-personal Violence Causes: Complex: interactions between personal, family, community and societal problems Several factors can be screened in office: Ready availability of weapons Inadequate social problem solving skills Abuse of alcohol and drugs

28. Burden of Self-Inflicted Injuries 1993: Age-adjusted rate of suicide 11.2/100,000 31,230 suicide deaths 210,000 attempts per year 10,000 permanent disabilities 155,000 physician visits 259,000 hospital days 630,000 lost wage days $115 million in medical expenses Highest rate of completed suicides Men >65 years old Highest rate of attempted suicides Men and women ages 20-24

29. Risk Factors Associated with Suicide Psychiatric illness Affective, substance abuse, personality, other mental disorders Other risk factors Social adjustment problems Serious medical illness Living alone Recent bereavement Personal history of suicide attempt or completion Divorce or separation Unemployment

30. Methods of Suicide Most common: Firearms are used in 60% of suicides 2 nd leading cause: Men: Hanging Women: Drug overdose or poison Alcohol is involved in 25-40% of suicides

31. Screening and Prevention 50-66% of all suicide victims visit physician <1 month before event 10-40% in the preceding week Hard to identify who is at risk Direct questioning has low yield General questions about sleep disturbance, depressed mood, guilt and hopelessness Survey instruments aren’t good at predicting what will happen

32. Screening for Suicide Risk How do we quantify the efficacy of such questionnaires? Goal of screening: Catch as many positives as possible, even at the risk of some false positives Sensitivity: Se = probability of testing positive if you will commit suicide Sensitivity of best questionnaires: 56% (low)

33. Screening for Suicide Risk How many false positives result? Positive predictive value: PPV=probability of committing suicide if you test positive PPV of best questionnaires: 3% (pathetic)

34. Summary of Lecture Two Developing countries Leading causes of mortality: ages 15-44 Developing world 1. HIV/AIDS 2. Road Accidents 3. Interpersonal violence Developed world 1. Road accidents 2. Self-inflicted injuries 3. Interpersonal violence

35. Assignments Due Next Time WA1 HW1