For Exam 2 Flashcards
Demographic transition =
a shift toward lower birth and death rates that often occurs as pops move from being lower-income economies toward being middle-income and then higher-income economies
Continuous Common Source Epi Curve
persons are exposed to the same source, but exposure is prolonged over a period of days, weeks, or longer. The epi curve rises gradually and might plateau
Non-compliance and non-adherence
Non-compliance: gaps that occur for unintentional reasons or factors beyond the patients control
Non-adherence: gaps that occur because of unilateral and intentional decisions to alter therapy
Gini Index
a measure of the inequality in the distribution of incomes within a particular country
0 indicating complete inequality, 1 indicating complete equality
Obstetric transition =
the shift from a high mmr to a negligible rate that occurs with socioeconomic development
Infertility
the inability to become pregnant when sexually active and not using contraception or the inability to maintain a pregnancy to a live birth
Health disparity
= health inequality = an avoidable difference in health status between population groups
uneven distribution of resources
know diff between equality and equity
Parity =
the total number of live births
Women are at least ___ as likely as men to acquire HIV from an act of heterosexual intercourse
2x
Post-exposure prophylaxis (PEP)
taking ARVs after exposure to HIV in order to reduce the likelihood of contracting in infection
Emergent priorities in sexual and reproductive health
- infertility and access to reproductive health and services
- HIV/AIDS and STIs
- Men’s reproductive health
Health Inequity
unfair and unjust differences that are not inevitable or natural but the product of human behavior
know diff between equality and equity
Attributable Risk Percent (AR%)
proportion of exposed cases averted with the elimination of the exposure
AR% = ((Ie - Io) / Ie) *100
AR% = RR-1 / RR
WHO definition of risk factors
any attribute, characteristics, or exposure of an individual that increases the likelihood of developing a disease or injury
Endometriosis
the tissue that lines the uterus is located on the ovaries or in other parts of the abdominal cavity, and it bleeds with each menstrual cycle, often cuasing pain and resulting in the formation of scar tissue and adhesions
Fertility =
the total number of births, whether the result was a stillbirth or a live birth
Most global health reports use fertility to measure pregnancies in a population
PROGRESS-Plus framework for the SDoH
P. place of residence
R. race, ethnicity, culture, language
O. occupation and employment status
G. gender and sex
R. religion
E. education
S. socioeconomic position
S. social capital
Plus. age, disability, sexual orientation, etc
Gravidity
the total number of times a woman has been pregnant, including miscarriages, abortions, stillbirths, and live births
Odds Ratio
predicts past
tends to overestimate risk
OR = 0 to infinity
OR = 1, exposure is not associated with the disease
OR >1, exposure is positively associated with the disease
OR<1, exposure is negatively associated with the disease
The further OR is from 1, the stronger the association
OR in cohort: Odds of disease in the exposed group (A/B) divided by the odds of disease in the unexposed group (C/D)
OR in case control: odds that cases were exposed to the risk (A/C) divided by the odds that the controls were exposed (B/D)
The odds ratio is similar to RR when the disease does not occur frequently among the exposed (disease is rare)
Extinction
The specific infectious agent no longer exists in nature or in the laboratory (no examples)
Global Burden of Disease Study (GBD)
the most comprehensive worldwide observational epidemiological study to date. It describes mortality and morbidity from major diseases, injuries and risk factors to health at global, national, and regional levels
Examining trends from 1990 to the present and making comparisons across populations enables understanding of the changing health challenges facing people across the world in the 21st century
(For years, those working in global health have attempted to construct a single indicator that could be used to compare how far diff countries are from the ‘state of good health’
Elimination of disease =
reduction to 0 of the incidence of a specified disease in a defined geographical area as a result of deliberate efforts; continued intervention measures are required (ex: neonatal tetanus)
Fibroids
benign tumors in the uterus that can cause heavy bleeding and pelvic pain
SDGs (sustainable development goals) vs MDGs
the MDGs prefaced the SDGs and lumped together hunger and poverty, did not focus on peace-building, did not highlight education, and focused solely on low-income countries
Relative Risk
predicts future outcomes
The probability of an individual becoming diseased is risk
compares the risk of exposed and unexposed
RR = disease risk (incidence) in exposed / disease risk (incidence) in non-exposed
we know incidence because we have temporality
RR = 0 to infinity
1 = null (incidence is the same)
>1 = positive association
<1 = negative association
(further from 1, the stronger the association)
used in cohort studies
VMMC
voluntary male medical circumcision
Income
the amount of take-home pay earned by household members in a time period
Demography =
the study of the size and composition of human populations
In vitro fertilization
a woman’s eggs are extracted from her ovaries, fertilized with sperm in a lab setting, and the resulting embryos are transferred to the uterus
Pre-exposure prophylaxis (PrEP)
taking ARVs prior to a likely exposure to HIV in order to reduce the likelihood of contracting an infection
Attributable risk (AR)
estimates the additional risk (excess) attributed to the exposure
group of interest: exposed, quantifies the risk of disease in the exposed group attributable to the exposure
can use incidence rate (IR) or cumulative incidence (CI)
Policy makers + public health practitioners use this data
= Incidence in exposed group - incidence in the non exposed group
incidence in exposed group = Incidence not due to the exposure (background incidence) + (incidence due to the exposure)
incidence in nonexposed group = incidence not due to to the exposure (background incidence)
in a 2x2 table
= A/A+B - C/C+D
AR = 0 if there is no association (Ie = Io)
if AR>0 then there is causal association
- the value indicates the number of cases of the disease among the exposed, could be attributed to the exposure
Interpreations of the AR is dependent on the assumption that a cause-effect relationship exists between exposure and disease
indicates potential for prevention, if the exposure could be limited (RR, on the other hand, is a measure of strength of the association and the possibility of a causal relationship)
AKA the risk difference (RD)
removes background risk
Maternal and Child health (MCH)
focuses on helping babies and young children get their healthiest start in life
The healthiest babies are born to women who were healthy before they conceived their offspring, who had access to preventive health services during pregnancy, and who had skilled birth attendants assist with delivery and the postnatal period
The 15 by ‘15 goal
of 15 million taking ART/ARVs daily by 2015
was achieved
What is the goal of family planning?
think about gravidity, fertility, parity
To minimize unplanned pregnancies (to reduce gravidity) and to maximize the health of babies from pregnancies that do occur (so parity is as close to possible to gravidity)
Population pyramid
displays the number of males and females by age group in a population
Low income countries usually have a population pyramid with a wide base of many children that gradually narrows in older age groups
High income countries often have low fertility rates that make the population “pyramid” look more like a rectangle or cube
Socioeconoic status (SES) or socioeconomic position (SEP)
describes an individual’s standing in a society based on individual and household income, education, gender, occuption, ethnicity and race, and other chracteristics
People who have low SES tend to have significantly reduced health status compared to people from higher SES populations
WHO definition of Social Determinants of Health (SDoH)
The conditions in which people are born, grow, life, work, and age. These circumstances are shaped by the distribution of money, power, and resources at global, national, and local levels.
Are mostly responsible for health inequities
Eradication =
permanent reduction to 0 of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts; intervention measures are no longer needed (e.g. smallpox)
What is descriptive epidemiology?
The proces, in which the outbreak is characterized by time, place, and person
the step after identifying and gathering basic information on the persons with the disease is to systematically describe some of the key characteristics of those persons
Critical because:
- can infer the population at risk for the disease
- can provide clues abt etiology, source, + modes of transimission that can be turned into testable hypotheses
- allows you to begin intervention + prevention measures
- provides a comprehensive characterization of the outbreak - trends over time, geographic distribution (place) and the populations (persons) affected by the disease
90-90-90 goal
of having at least 90% of people w HIV infection known their status, at least 90% of people diagnosed w HIV taking ART, and at least 90% of people on ART achieving viral suppression by 2020
not quite achieved, but still on track
Primary infertility
infertility in a woman who has never had a live birth
Elimination of infections =
reduction to 0 of the incidence of infection caused by a specific agent in a defined geographical area as a result of deliberate efforts; continued measures to prevent re-establishment of transmission are required (ex: measles, poliomyelitis)
What are the additional steps in investigating outbreaks?
- developing hypotheses - the source of the agent, mode of transmission (vehicle & vector), any addtional time, person, place factors
- Evaluating hypotheses: comparing the hypotheses with the established facts - use analytic epidemiology
- Reconsider/Refine hypotheses
- Use laboratory or environmental studies to evaluate hypotheses and generate data (case/control and cohort studies for ex)
- implement control and prevention measures
- maintain surveillance
- Communicate the findings
Social Determinants of Health Graphic
CHENEF
Hill’s Inferential Framework
- Strength: stronger associations are less easily explained away by confounding variables than weak associations
2.Consistency: similar conclusions are drawn even with diverse methods and different populations under variety of circumstances + no other likely causation
3.Specificity: the exposure is linked to a specific effect or mechanism
4.Temporality: the exposure precedes the disease in time (mandatory, but not always easy to prove)
- ex: what is the relationship between lead consumption and neurological impairment/encephalopathy?
5.Biological Gradient: increases in the exposure/dose leads to increased dose/response risk (or an inverse relationship (less probable)) (basically, dosage is impt)
6.Plausibility: appears worthy of belief
7.Experimentation: experimental evidence supports observational evidence
8.Analogy: similarities in things that are otherwise different (similar to consistency)
9.Coherence: the facts stick together to make a coherent whole, or logical, supportive set of conclusions
Propogated Source Epi curve
there is no common source, because the outbreak spreads from person to person. The graph will assume the classic epi curve shape of progressively taller peaks, each being one incubation period apart
Health vs Wealth question
Which do you need first, health or wealth? Do you need one to gain the other?
What is an epidemic curve?
during an outbreak, is a histogram of the distribution of cases of a disease or condition by time of onset
-used to study the distribution of the disease by time
- the shape of the curve is studied to determine the type of epidemic (i.e. point source, common source, propogated)
- of point source, can also be used to determine the probable time of exposure whenever the causative agent is known
- in point source, can also be used when time of exposure is known and causative agent is unknown - info abt the probable causative agent can be obtained by assesing the approximated median incubation period (time between the known time of exposure and the peak of the curve).
a visual display of the onset of illness among cases associated with an outbreak: can learn abt
- time trend of the outbreak
- outliers
- general sense of the magnitude of the outbreak
- inferences about the outbreaks pattern of spread
- most likely time of exposure
Replacement Population =
each woman has on average, about 2 children, so those 2 parents will produce 2 offspring, “replacing” themselves but not increasing the size of the population
Premenstrual Syndrome (PMS)
the physical discomfort, depressed mood, and other symptoms caused by hormonal changes during a mesntrual cycle are severe enough to interfere with daily usual activities
Measures of association vs measures of public health impact
A measure of public health impact is used to place the association between an exposure and an outcome into a meaningful public health context (basically, how should we consider the results of our epi studies?)
- whereas a measure of association quantifies the relationship between exposure and disease, and thus begins to provide insight into causal relationships (OR, RR), measures of public health impact reflect the burden that an exposure contributes to the frequency of disease in the population
Preterm birth =
the delivery of a baby before the 37th week of pregnancy
survivors, especially those with very low birthweights may have long term special needs
Humans are _ for the life cycle of the agent
essential
Wealth
the accumulated worth of the household’s resources; can include a house, car, television or radio, livestock, and other consumer goods
Disease control =
the reduction of disease incidence, prevalence, morbidity, or mortality to a locally acceptable level as a result of deliberate efforts; continued intervention measures are required to maintain the reduction
ex: diarrhoeal diseases
Fertility Rate
the average number of children a woman gives birth to during her childbearing years
Countries with high fertility rates have a high percentage of children in their populations, while countries with low fertility rates have about as many older adults as children in their populations
Flattening the Curve - what does this look like?
The role of context in reducing disparities
addressing social determinants of health is important for improving health and reducing health disparities
Disability-Adjusted Life Year (DALY)
measure of health burden, including both reduction in life expectancy (mortality) and diminished quality of life (morbidity)
YLL + YLD = years lost due to premature death + years lost to disability
YLL = Life expectancy at time of death - age at time of death
YLD = disability weight * the average time a person lives with the disease before remission or death
Looking at the distribution of DALYs across a population provides us with the burden of disease
*who decides DW?
This is a burden of diseaes measure and relates to the SDoH
One DALY represents the loss of the equivalent of one year of full health
practice calculations!!
Doula
a person who provides emotional and physical support during pregnancy and childbirth. Not medical professionals. Dont ‘deliver’ babies or provide medical care. A certified doula has taken a training program and passed an exam in how to help pregnant women and their families
What is a cluster?
an aggregation of cases in a given area over a particular period without regard towhether the number of cases is more than expected
Secondary infertility
the inability to have additional offspring when attempting to conceive after having given birth to a child
Treatment compliance and treatment adherence
Compliance: passive: the degree to which the patient conforms to medical advice about lifestyle and dietary changes as well as to keeping appts for follow up and taking treatment as prescribed
Adherence: active: the extent to which a persons behavior - taking medication, following a diet, and/or executing lifestyle changes – corresponds with the agreed recommendations from a healthcare provider
Human Development Index (HDI)
estimate of national development based on composite data on longevity (life expectancy at birth), knowledge (such as the mean and expected years of schooling), and income
higher HDI is correlated with better health status and greater levels of happiness
has increased in most countries over the past 25 years, but still significant gaps between the richest and poorest countries (increases as people live longer, spend more years in school, and earn more)
Traditional Birth attendant (TBA)
a lay midwife who has been trained through an apprenticeship rather than a formal educational program, who may be able to handle uncomplicated births, but does not have the advanced training to safely manage complications
Population Attributable Risk (PAR)
The PAR helps us determine which exposures have the most relevance to the publics health
can help guide the allocation of resources aimed at interventions to a whole population instead of intervening on high risk individuals (i.e. the exposed)
Among both the EXPOSED and NONEXPOSED (total pop) - estimatest the excess rate of the disease in the “total study population” of exposed and nonexposed that is attributable to the exposure
Estimates the excess rate of disease in the total study population
This is where we see th real value for policy makers - what can be avoided through an intervention?
PAR = (incidence in total pop) - (incidence in non-exposed group) = incidence attributable to exposure
= (A/ (A+B)) - (C / (C+D))
Can also be calculated as PAR = (AR)Pe (Pe is the proportion of exposed people in the population)
ARVs and prevention
treatment of people with HIV is a critical part of prevention strategies, changing the impact of HIV/AIDS and STIs worldwide
Analyzing epi curves
remember when analzying the mode of spread:
the shape of an epi curve rarely fits any of these descriptions exactly. but you can still get a general sense about the mode of spread of an outbreak from its epi curve
Skilled Birth Attendant (SBA)
an obstetrician or gynecologist, another type of physician, a nurse midwife, a nurse, or another trained person who can recognize and treat potential complications during and after labor and delivery
1/4 of births worldwide occur without the assistance of an SBA
What is an outbreak or epidemic?
the occurrence of more cases of disease than expected in a given area or among a specific group of people over a particular of time
- usually the cases are presumed to have a common cause or be related to one another in some way.
Strenghts + Limitations of DALYs
Strengths:
can calculate DALYs at the community/populatin level too
Limitations:
They focus solely on health and still do not fully capture the broader societal impact of diseases. (e.g. intestinal nematodes which have lasting impacts on child development and education)
There is also an important equity issue that goes beyond health: ascariasis and other neglected tropical diseases affect the poorest communities and are diseases of neglected populations
Health adjusted life expectancy (HALE)
refers to the number of years a person of a given age can expect to live in good health (taking account of mortality and disability)
In principle, each country should strive to help its people live as long and as healthy as possible - if that is the case - life expectancy and a HALE should converge at a relatively high number
Total Fertility Rate (TFR)
the average number of births/woman over lifecourse (assumes she lives and age-speciic rates remain constant)
Reproductive health implies that
what does it encompass?
people are able to have a satisfying and safe sex life and that they have the capability to reproduce and the freedom to decide if, when, and how often to do so
Higher-income women experience a much lower mortality rate than lower-income women
The vast majority of maternal mortality cases occur in low income countries
It encompasses issues of fertility and infertility, contraception, pregnancy and childbirth, gynecologic and urologic health, and the prevention and treatment of STIs
Population Attributable Risk Percent (PAR%)
the proportion of disease in the study population that is attributable to the exposure and could be eliminated if the exposure was eliminated
PAR% = (It - Iu)/ /It
or = (CIt - CIu) / CIt
Health Belief Model (HBM)
suggests that a person’s believ in a personal threat of an illness or disease together with a person’s belief in the effectiveness of the recommended health behavior or action will predict the likelihood the person will adopt the behavior
6 components:
1. perceived susceptibility
2. perceived severity
3. perceived benefits
4. perceived barriers
5. cue to action
6. self-efficacy
Fertility transition =
a reduction in the average number of offspring the typical female gives birth to over her lifetime
Point Source Epi Curve
persons are exposed over a brief time to the same source, such as a single meal or an event . The number of cases rises rapidly to a peak and falls gradually. The majority of cases occur within one incubation period of the disease
