Review questions for Chapter 3

At what ages is life expectancy calculated? What does it tell us about a population? Which country has the longest life expectancy?

At birth, 65 years and 75 years of age. It tells us which populations are living the longest on average. Japan has the longest life expectancy (84 years); while Africa have the shortest (51 years) America is at (79 years)

Why are prevalence rates more useful than incidence rate for measuring chronic diseases?

Because incident rate only measures the new cases of a disease and Prevalence rates measure all cases (old and new) of a disease. EX. Chronic disease usually last three months or longer, it is important to know how many people are currently suffering from a chronic disease ( arthritis, heart disease, cancer,diabetes)

Why are epidemiologists sometimes interested in epizootics?

Because some epidemics begin as outbreaks of disease in animals, and then spread to human populations.

How do experimental studies differ from observational studies?

Case/control studies compare people with disease(cases) to healthy people of similar age, sex, and background(controls) with respect to proportion of prior exposure to possible risk factors. Cohort studies in which researcher select a large number of healthy subjects that share a similar experience, such as year of birth or high school graduation. Cohort are classified on the basic of their exposure to one or more possible factor, such as cigarette smoking, dietary habits. Cohort is examined for a number of years to determine the rate at which disease develop.

What is the difference between crude and adjusted rates?

Crude Rate: rate in which the denominator includes the total population. - Can be misleading when populations differ in age structure or by some other attribute. Adjust rates: a rate used to make comparisons across groups and over time when groups differ in age structure. Ex. Crude birth rate: number of live birth in a year divided by midyear population Ex. crude death rate: number of deaths in a year for all cases divided by midyear population

What is an epidemic? A pandemic? Name some diseases that caused epidemics in the past. Name some diseases that are epidemic today.

Epidemic: an unexpected large number of cases of an illness in a particular population. Pandemic: outbreak over large geographical area. Past epidemic: Encephalitis Present Epidemic: AIDS

How would you define disability-adjusted life years (DALYs)?

Estimating the total years of life lost and the total years of life lived with disability, and then by summing these totals.

How would you define health-adjusted life expectancy (HALE)?

Healthy life expectancy, the number of years of healthy life expected, on average, in a given population or region of the world.

In general, contrast the leading causes of death in the US in 1900 with those in 2013. Comment on the differences.

In the 20th century the leading cause of death was COMMUNICABLE diseases (pneumonia,TB, gastrointestinal infections) however a century of progress in public health practice and biomedical resulted in reduction of death from communicable diseases. These diseases were contagious The four leading causes of death in the 21th century are NONCOMMUNICABLE diseases (heart disease, cancer, stroke and unintentional injuries). These diseases were not contagious.

What are notifiable diseases? Give some examples.

Infectious diseases for which health officials request or require reporting or require reporting for public health reasons. 1)Measles 2)Mumps 3)Malaria 4)Small pox 5)Syphilis

What is the difference between natality, morbidity, and mortality?

Natality: birth rate -The number of live births divided by the population. Morbidity: sickness rate - The number of people who are sick divided by the total population at risk. Mortality: death rates - The number of deaths in a population divided by the total population.

In a descriptive epidemiological study, what types of information does the epidemiologist gather?

When disease and /or death occur in unexpected or unacceptable numbers, epidemiologist carry out investigations. Answers Who, When, and Where WHO: They seek to describe the extent of disease in regard to person, time and place. Epidemiologist take a head count to determine how many cases of a disease has occurred ,who is ill(children, elders, men, women) data gathered permit them to develop a summary of cases by age, sex , race, marital status, occupation, and employer. WHERE: Characterize health events by time of occurrence. WHEN: The time period will vary and usually depends on the health condition in question.

What is an infant mortality rate? Why is it such an important rate in community health.?

the number of deaths under 1 years of age per 100,000 divided by the total # of live birth. It is an important rate in community health because it allows them to compare the mortality rates of infants to that of other age groups during a certain period of time.

What are Hill's criteria for judging whether an association between a risk factor and a disease can be considered causal?

-Strength: how strong the association is between the exposure and the disease? -Consistency: has the association been reported in a variety of settings? -Specificity: the disease associated with the exposure the only one -Temporality: Does A(the exposure) always precede B (the disease) -Biological Plausibility: Does the suspected causation make sense with what we know about biology, physiology, and other medical knowledge?

List 5 important national health surveys that are valuable sources of data about the health and healthcare of our population.

1) National Health Interview Survey (NHIS) 2) Behavioral Risk Factor Surveillance System (BRFSS) 3) Youth Risk Behavior Surveillance System (YRBSS) 4) National Health Care Survey (NHCS) 5) National Health and Nutrition Examination Survey (NHANES)

What kinds of data would you expect to find the Centers for Disease Control and Prevention's Morbidity and Morality Weekly Report?

1. List morbidity and mortality data by state and region of the country, based upon reports from state health department. 2. Report contains: outbreaks of disease, environmental hazards, unusual cases, or other public health problems.

What can be said about the reliability of self-reported health data?

1. The data generated by self reported respond to NHIS questions and not actual examinations. So respondents may over report good health habits or under report bad ones. Such reporting is often dependent on the respondent's perceived social stigma or support for a response and the degree to which people's responses are confidential or anonymous. People have widely different views on what is good vs poor health.

What does the term endemic disease mean? Give examples of such diseases.

A disease that occurs regularly in a population as a matter of course. Whether a disease is endemic or epidemic depends on the disease and the population. Ex. Heart disease in America, Malaria in Africa

What is the National Health and Nutrition Examination Survey? Why is it carried out?

Purpose is to assess the health and nutritional status of the general U.S population. Using a mobile examination center, the data are collected through direct physical examinations, clinical and laboratory testing, and related procedures on a representative group of americans. These examinations result in the most authoritative source of standardized clinical, physical, and physiological data on the American people. Allows them to detect the extent various health problems and risk factors have changed in the U.S over time. By identifying the healthcare needs of the population, government agencies and private sector organizations can establish policies and plan research, education, and health promotion programs that help improve present health status and will prevent future health problems.

Why are rates important in community health?

Rates enable one to compare outbreaks that occur at different times or in different places. Ex: Using rates it is possible to determine whether there are more homicides per capitia in city A than city B. To do this, the population at risk must be considered.

What is the purpose of an analytic study?

Test the hypotheses about relationships between health problems and possible risk factors, factors that increase the probability of disease. 2 TYPES: 1. Observational studies observe the nature course of events, who is exposed or unexposed and who has not developed the disease of interest. 2. Experimental studies identify the cause of disease or to determine the effectiveness of a vaccine, therapeutic drug, or surgical procedure.

What is the U.S. Census? How often is it conducted? What types of data does it gather?

The enumeration of the population of the U.S. Every 10 years. Gathers data about income, employment, family size, education, dwelling types.

What are years of potential life lost (YPLL)? How does calculating YPLL change the way we think about the leading cause of death?

The number of years lost when death occurs before the age of 65 or 75. Because it shows us the years they should have lived vs the years they actually lived because of a condition