Readings MT 1

proposed mechanisms that link adverse social factors to poor health

risky behaviors, inadequate access to health care, poor nutrition, housing conditions, work environments.

how do social relationships tie to mortality

social ties influence health behaviors and social buffers against stress; in turn affects immune function, cardiovascular activity, and progression of existing disease

how do negative social interactions link to mortality rates 

potentially through adverse effects on mental health and physical health as well as decreased access to resources  

how might characteristics of somones residential environmnet affect mortality 

investment in health and social services in the community, effects of the built environment, and exposure to violence, stress, and social norms that promote adverse health behaviors 

PICOT 

(target) population, intervention of interest, comparator intervention, (key) outcomes, time frame over which outcomes are assessed

FINER

feasible, interesting, novel, ethical, relevant

what does PICOT do

requires the framing of the RQ to specify the target pop, intervention of interest, comparator interventions, key outcomes, and time frame

ideology

• a system of ideas to provide a foundation for social action

• conceptual scheme with practical application

• foundational belieffs and assumptions

theory 

• testable set of ideas 

• informed by ideologies 

• allows us to describe, explain, and predict our shared reality 

epidemiology

• study of population level health determinants

• a set of tools used to test a theory informed by ideology

Dr. galton ideas around racial disparities in health

• case definition for race is clearly defined and consistent

• between group genetic variations are consistent

Dr. brooks ideas arounf racial disparities in health 

• stigma → stressor → coping response → health outcome

• individual level of understanding of health disparities

dr. link idea around racial disparities in health

• health inequities are the result of a person’s SES status

• every person derives equal benefits from their SES

• all populations with comparable SES have the same health outcome

aspects of ecosoial theory

• cumulative interplay of exposure, susceptibility, and resistence

• accountability and agency

• political economy and ecology

• pathways of embodiment

• life course

• historical context and generation

• social injustice

• embodiment

underlyign theory of web of causation metaphor 

multiple causation 

what is the framework the web relies on to decide what factors are veen on the web

biomedical individualism

who is the spider representing

who or what is responsible for the array of factors

what is mostly focused on in epidemiologic textbooks

methodology over theory 

what preceded the web of causation metaphor

the chain of causation

what caused epidemiologists to further understand the ideas of confounding and effect modification

the multicausal view

what do the views of multifactoral etiology emit in their understandings of what causes outcomes 

the disussion of the orgins of the multiple causes (as opposed to how they interact with each other)

t or f - models can exist without underlying theories 

false 

what do theroeis do what do models do (in relation to each other)

• theories - explain why phenomena exist and how they are interrelated

• models - attempt to portray how these connection occur and are always structured by particular theories

in what way is the web hierarchical (despite the facts that it was made to not be)

ultimately focuses on the causes closest to the outcome, typically translates to direct biological causes → biological individualism

biomedical model key features 

• emphasis on biological determinets of disease amenable to the intervention of the health care system 

• considers social determinats of health to be secondary if not irrelevant 

• view of populations as the sum of individuals and population patterns of disease as simply being refelctive of individual cases

what main elements does the ecosocial theory include

embraces population level thinking and rejects underlying assumptions of biomeducal individualism without discarding biology entirely

attack rate 

the percentage of people who get ill after being exposed to a certain thing 

broad purposes of epi

• description

• causal inference

• application

two main factors in epi and what they include

• genetic - genes

• environmental - all non-genetic factors including things like behavior

three fundamental measures in epi 

• incidence rate 

• incidence proportion 

• prevalence 

what study is used to estimate prevalnce

cross sectional

what study design used to estimate incidence

cohort

attack rate other name

incidence rate (specifically for short time periods)

studies that compare things across populations

ecological studies

intervention study (RCT)

• randomly allocate people to treatment or control

• track outcomes

what does randomizing do

• random allocation (randomization) of individuals is the only way to ensure the groups are as similar as possible at the start of the study and is thus very important to this study design

  • avoids confounding

  • real strength of randomization is that, on average, it will also balance known, unknown, and poorly measured factors across the groups

crossover trial

• same group of people act as controls and cases

• ex - two period cross over intervention study to assess efficacy of an intervention

  • allocate half the group to get intervention (I) for a period of time and the rest to get control (C) for the same period of time

  • do alternative for the second period

  • half get I-C other half get C-I

  • reduces the effect of any factors that might change between the first and second period

why do a crossover trial (major advantage)

ensures the groups are truly exchangeable from a genetic perspective and in terms of other factors that do not change over time

best type of intervention for crossover studies

can only use crossover trials for interventions that have quick effects that wane rapidly when exposure is removed

n = 1 trial

variant of crossover trial that has a single person and thats it, like a case study

problem with pre-post studies 

assumes that the controlled change was the only or most important thing that had chanegd in that time 

intervention trials include

• RCTs

• crossover studies

observtaional studies

• cohort

• case-control

• cross-sectional

• ecological

cohort study 

follow people forwards over time to see what happens

variants/types of cohort studies

• prospective

• retrospective/historic

• prognostic or survival study

• case cohort

• nested case control

why is cohort a step below RCT

hard to disentable the effects of an exposure of interest from those of other personal characteristics or behaviors correlated to that exposure

why must participnats be free of outcome of interest before starting in a cohort study 

to establish a clear temporal relationship (exposure before outcome)

historical cohort

use records of past exposures for a group of people who can then be traced to determine their current health

prognosic or survivial studies

cohort studies where all people have some condition at the start and are followed after diagnosis to see what happens to them

case-cohort stud 

• a subset of participants is selected from total cohort at baseline

• detailed exposure information is retrieved for the sub-cohort and all those in the full cohort who develop the disease

• maintains the major advantage of a cohort study in the exposure data were collected before the development of disease

• much smaller scale in comparison to full cohort reduces effort and cost

• also has the advantage that the sub-cohort can be used for comparison with multiple different case groups

• main disadvantage is that the case-cohort study requires more sophisticated data analysis than traditional cohort and nested case-cohort studies

nested case control

• essentially a case control study

• just nested with existing cohort study

• as in the case cohort study the cases are all cohort members who developed the disease of interest

• this time each case is matched to one or more non-cases selected at random from cohort members of the same gender and age who were free of disease at the time the case was diagnosed

• assumed that the information obtained from these controls represents the exposure experience of all non-cases in the cohort when the case was diagnosed

why use a case control study instead of cohort 

sometimes outcome is very rare, so easier to do a case control, also more time and cost efficient design 

how are case control conducted

• identify a notional cohort - might include everyone in a particular geographic region or even a whole country

• try to recruit everyone in the population who develops the disease of interest or a representative sample of cases (depends on how rare the disease is)

• only recruit a small number of people without the condition

• controls are selected at random, hope they will be representative of the wider target population

• ask cases and controls about previous exposures

• effectively work backwards