Tufts University, Spring 2009 Measuring Health Ronald P Ruffing MD, MPH Chief, Division Pediatric Emergency Medicine Tufts Medical Center/ Floating Hospital for Children

Tufts University, Spring 2009 Students will be expected to… 1.Understand the idea of “Health” from the public health perspective. 2.Understand inherent difficulties in measuring “health” especially as it applies to developing countries. 3.Be familiar with the strengths and limitations of the common “health indicators”. 4.Understand the added value of measuring health using a summary indicator of health. 1

Tufts University, Spring What is “Health”? 2. How is health measure? a) Mortality-deaths b) Morbidity-non-lethal illness 3. What health-related information do we need to measure health? a) Individual data- (numerator data) i. Patient information b) Population data- (denominator data) i. Vital statistics information ii. Health statistics information 3

Tufts University, Spring Within any community there exist a general notion of health. Extremes of health-health abundance and significant lack of health-are widely understood and agree upon

Tufts University, Spring 2009 Health DISEASE MEDICAL MODEL 5 Health is what you have left, after you have treated or cut out all the disease

Tufts University, Spring 2009 “Health is a state of complete physical, mental, and social well- being and not merely the absence of disease or infirmity” World Health Organization 6

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1. Measures of lethal events (mortality) 2. Measure of non- lethal events or illness (morbidity) 8 Injury Pyramid

Tufts University, Spring 2009 The vast majority of health indicators measure mortality Mortality is easier to measure  Only occurs once per life time  Easily agreed upon event  Death registration and certification occurs in some countries 9

Tufts University, Spring 2009 Crude Mortality Rate - the total number of deaths that occur in a specific geographical location during a specific period of time. 10 Crude Mortality Rate = # of deaths in x total population of x

Tufts University, Spring 2009 How do you count the number of deaths? Death Certification Who certifies death? Physicians 11 Your Name01/20/ :3701/20/ :37 X X X Xunknown X X Cardiac Arrest Hypothermia Toxic ingestion Mental Health Disorder

Tufts University, Spring 2009  Even when medically certified establishing the underlying cause of death is not always possible or practical.  As people age and accumulate multiple chronic conditions identifying the underlying cause of death becomes increasingly murky.  Multiple studies have identified discrepancies on the order of 30-50%.  Little or no training on this subject is given in most medical schools and coronary artery disease is often the default diagnosis.  Approximately 70% of deaths in the world are not medically certified. 12 Problems with measuring deaths

Tufts University, Spring 2009 PROBLEMS WITH MEASURING DEATHS  42/46 African countries have no recent vital registration system data  0/11 South Asia countries have recent vital registration system data.  Gates Foundation initiative strengthen global HIS. 13

Tufts University, Spring 2009 PROBLEMS WITH MEASURING DEATHS Alternatives to vital event registration A. Population Census B. Demographic household surveys (DHS & UNICEF MICS) C. Sample registration systems D. Demographic surveillance sites 14

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Tufts University, Spring 2009  Death events (mortality) are easy relatively easier to count.  Illness events (morbidity) are not as easily defined, and therefore much more difficult to count. 16 mortalitymorbidity Injury Pyramid

Tufts University, Spring Abu Shouk IDP Camp North Darfur, Sudan Nov, 2005 Population ~45,000

Tufts University, Spring < 5 Yrs >5 yrsIRC Total < 5 yrs> 5yrs GRC Total Total Week 1 (Sept 25-Oct 1 ) 199 (921) 44 (419) 243 (1340) 62 (789) 12 (179) 74 (968) 317 (2487) Week 2 (Oct 2-8) 226 (1165) 59 (517) 285 (1682) 100 (860) 37 (291) 137 (1151 ) 422 (2833) Week 3 (Oct 9-15) 163 (932) 41 (589) 204 (1521) 76 (864) 31 (242) 107 (1106 ) 311 (2627) Week 4 (Oct 16-22) 135 (810) 55 (606) 190 (1416) 43 (673) 13 (223) 56 (916) 246 (2332) IRC ClinicGRC Clinic New cases of malariaTotal # of patients seen

Tufts University, Spring 2009 Comparing the IRC primary health clinic with the German Red Cross clinic, over the four weeks of this analysis  The number of malaria cases diagnosed in the IRC clinic is (922/5959) or 15 %.  In the German Red Cross Clinic, the number of malaria cases diagnosed is (374/4320) or 8 %. 19 Measuring Health: Case Study

Tufts University, Spring 2009 Physicians in the International Rescue Committee clinic are almost twice as likely to make a diagnosis of malaria as there counterparts at the German Red Cross. 20 Measuring Health: Case Study WHY THE DIFFERENCE?

Tufts University, Spring Abu Shouk IDP Camp North Darfur, Sudan Nov 2005 Population ~45,000 GRC Clinic IRC Clinic Measuring Health: Case Study

Tufts University, Spring  IRC Clinic  Made a diagnosis of malaria based upon clinical signs only.  No blood tests were performed.  GRC Clinic  Made a diagnosis of malaria based upon a blood test for malaria  Only those individuals with a positive blood test were diagnosis with malaria.

Tufts University, Spring  The clinicians did not agree on the case definition of malaria and therefore were counting two different conditions- clinical malaria and blood test positive malaria.

Tufts University, Spring Case definition: each condition being studied needs a strict definition in order to include those individuals with the condition and to exclude those with some other condition.

Tufts University, Spring Prevalence: total number of cases of a particular disease Incidence: the number of new cases of particular disease

Tufts University, Spring  Prevalence- measurements of prevalence are accomplished in a single point in time assessment or survey.  Incidence- measurements of incidence require a minimum of two measurements, over time to demonstrate that the condition was not present and then appeared.

Tufts University, Spring Incidence Rate – the number of new cases of a specific disease in a specific time period divided by the estimated population during that same time period.

Tufts University, Spring Prevalence Rate – measures the number of people in a population who have a disease at a given point in time, divided by the total population at that same point in time. Prevalence rates include both measures of both the incidence and duration of disease.

Tufts University, Spring 2009 Calculate the rate of any event one needs two elements 1. Individual data (numerator data) 2. Population at risk data (denominator data) What is the rate of pregnancy in this class? 29 Fertility Rate # of positive pregnancy test = Total number of women of child bearing age

Tufts University, Spring Population data (denominator) is often acquired from national governments as part of  Vital statistics registration  Participation in a national census

Tufts University, Spring  Births, deaths, marriages, divorces  Registration of vital events at a legally designated place.  Compiling of records by an administrative agency according to geographic divisions.  Fees are usually associated with registration.

Tufts University, Spring  Major functional age/sex groups are  Males/Females Under 5 (pre-school)  Males/Females 5-14 (school age)  Males/Females (working age)  Males/Females Over 65 (advanced age)  Geographic locations is identified  Certified by governments  Expensive

Tufts University, Spring * Gauthier Jason G. Measuring America US Bureau of the Census Census Year Total Population Census Cost Cost per Person ,323,175$ 127,934,000$ ,302,031$ 247,653,000$ ,542,199$ 1,078,488,000$ ,718,301$ 2,492,830,000$ ,421,906$ 4,500,000,000$ Cost of the US Census

Tufts University, Spring US Census Cost

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Tufts University, Spring Summary measurements of health 2.DALY-Disability Associated Life Year 3.Global Burden of Disease a)State of the world 1990 b)Future predictions

Tufts University, Spring 2009 Mortality based rates provide insufficient information about the health of a population or the comparative impact of health sector interventions because… 37 mortalitymorbidity …the contribution of chronic disease, injury and disability to population health goes unrecorded

Tufts University, Spring Health = mortality + morbidity

Tufts University, Spring SUMMARY HEALTH INDICATOR + = MortalityMorbidity Deaths from TB + Disability from blindness

Tufts University, Spring Time is the appropriate currency to measure health 1. Time (in years) lost due to premature death. (mortality data) 2. Time (in years) lived with a disability. (morbidity data)

Tufts University, Spring SUMMARY HEALTH INDICATOR Mortality (time lost) Morbidity (time lived with disability) = + +

Tufts University, Spring Incorporate non-fatal conditions 2. Disentangle epidemiology from advocacy 3. Measure disease in a currency that allows for assessing cost effectiveness of interventions

Tufts University, Spring DALY - Disability Associated Life Years Total DALYs YLLs (Years of Life Lost) = YLDs (Years Lived With a Disability ) +

Tufts University, Spring 2009 The “Burden of Disease” is the gap between a populations actual health and some “ideal” or reference state of health. 44

Tufts University, Spring What ideal health is involves making choices. The authors of DALYs identified five choices that they made about health.

Tufts University, Spring How long should people live? 2. Are years of healthy life worth more in young adulthood than in early or late life? 3. Is a year of healthy life now worth more to society than a year of healthy life in thirty years? 4. Are all people equal? 5. How do you compare years of life lost due to premature death and years of life lived with disabilities of differing severities?

Tufts University, Spring How long should people live?  Males 80 years  Females 82.5 years Note: 1. A standard life expectancy allows deaths in all communities at the same age to contribute equally to the burden of disease. 2. Life expectancy for men and women is not equal. This difference is arguably do to lifestyle risk factors.

Tufts University, Spring Are years of healthy life worth more in young adulthood than in early or late life? 48

Tufts University, Spring Is a year of healthy life now worth more to society than a year of healthy life in thirty years?. The GBD researchers decided to discount future life years by three per cent per year 49

Tufts University, Spring Are all people equal? Only two characteristics of an individual that are not directly related to health (age and sex) are taken into account when calculating the burden of disease. Other characteristics such as SES, race, level of education are not considered. 50

Tufts University, Spring How do you compare time lost due to premature death with time lived with a disability? 51

Tufts University, Spring  To equate death and years of disability a quality of life factor is added called the health- related quality of life (HRQL) factor.  Different summary measures use different HRQL factors to equate years of life and years of disability  HRQL is captured on a scale from 0 to 1.0 representing the extremes of health…full health (0) and death (1.0).

Tufts University, Spring (HRQL) (health related quality of life) Mortality Morbidity

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Tufts University, Spring  Time is an appropriate currency to measure morbidity and mortality in a single entity.  Mortality- time (in years) lost due to premature death.  Morbidity- time (in years) lived with a disability.

Tufts University, Spring Global Burden of Disease Study

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Tufts University, Spring  Group I: Communicable, maternal perinatal and nutritional conditions.  Group II: Noncommunicable diseases  Group III: Injuries

Tufts University, Spring Group II diseases cause a lot of the mortality in the developing world

Tufts University, Spring LRI, DD, Perinatal Conditions cause fewer deaths but result in greater years of life lost (YLL) ICD and CVD result in a large number of deaths but fewer years of life lost (YLL)

Tufts University, Spring The leading causes of disability are not at all similar to the leading causes of death

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Tufts University, Spring There is a uniform burden of disease associated with injuries across all regions

Tufts University, Spring “The GBD’s findings demonstrate clearly that disability plays a central role in determining the overall health status of a population…”

Tufts University, Spring …yet the role disability has until now been almost invisible to public health. …the leading causes of disability are to be substantially different from the leading causes of death, …the practice of judging a population’s health from its mortality statistics alone is unjustified.

Tufts University, Spring 2009 WHAT IS THE IMPACT OF CHANGING RISK FACTORS  Number of deaths (mortality)  Disability (morbidity)  DALY  Malnutrition  Water/sanitation  Unsafe sex  Tobacco  Alcohol  Occupation  Hypertension  Physical Activity  Illicit drug use  Air Pollution 66

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Tufts University, Spring  The underlying assumption is that priorities (money) should go to those health problems that cause the largest burden of disease and for which generally accepted cost-effective interventions are available.

Tufts University, Spring Looking into the future 2020

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Tufts University, Spring  Ischemic Heart Disease  Cerebrovascular disease  Lower respiratory infections  Diarrheal disease  Perinatal diseases  COPD  TB  Measles  Traffic Accidents  Lung cancers 2020  Ischemic heart disease  Cerebrovascular disease  COPD  Lower respiratory infections  Lung cancers  Traffic accidents  TB  Stomach cancers  HIV  Self-inflicted injuries

Tufts University, Spring  Lower respiratory infections  Diarrheal diseases  Perinatal conditions  Ischemic heart disease  Measles  TB  Cerebrovascular accidents  Malaria  Traffic accidents  Congenital anomalies 2020  Ischemic heart disease  Traffic accidents  Cerebrovascular accidents  Lower respiratory infection  TB  Diarrheal disease  HIV  WAR  Perinatal conditions  COPD

Tufts University, Spring  Lower respiratory infections  Diarrheal disease  Perinatal conditions  Unipolor depression  Ischemic heart disease  Cerebrovascular disease  TB  Traffic accidents  Congenital anomalies 2020  Ischemic heart disease  Unipolor depression  Traffic accidents  Cerebrovascular accidents  COPD  Lower respiratory infections  TB  WAR  Diarrheal disease  HIV

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Tufts University, Spring Summary measurements of health 2.DALY-Disability Associated Life Year 3.Global Burden of Disease a)State of the world 1990 b)Future predictions