Week of August 3 Flashcards
Differentiate between population attributable risk
and attributable risk / risk difference
Explain what a PAR of 0.009 is compared to a RD of 0.009
Population attributable risk is the amount of the excess risk in the population due to the exposure of interest. It account for the excess risk of the exposure and its prevalence in the population.
Attributable risk tells you the excess risk among the exposed compared to the unexposed. It does not account for the prevalence of an exposure.
a PAR of 0.009 means that the exposure is responsible for an 9 excess cases per 1000 people in the population
a RD of 0.009 means that for every 1000 people who experience the exposure you would expect 9 additional cases compared to if no one was exposed
The incidence of disease in the exposed group is 50 per 1000 and the incidence in the unexposed group is 25 per 1000
Calculate and attributable risk percent
Interpret this value
Two options
a) (RR-1)/ RR *100
or
(Incidence exposed - incidence unexposed) / incidence exposed
= 50%
so 50% of the outcome in the group that had the exposure could be attributed to having had the exposure
What can be the public health roles in addressing racial health inequity?
NCCDH, 2018
1) Building Capacity to analyze and take action on drivers that foster racial inequities
2) Create knowledge by assessing and reporting on the impact of racialization and racism including analyzing health outcomes utilizing an anti-racism lens, and measuring racism on both individual and structural levels
3) Re-orient/modify Health and social interventsion to eliminate racialized health inequities.
4) Develop Policies with an overt focus on tackling racism including implementing racial equity assessments
5) Develop partnerships with other sectors and communities
Name one Policy framework and describe its element.
Kingdom’s Multiple Stream Framework
- Problem Stream where a problem needs solutions
- Policy Stream where policies alternatives are debated by a policy community.
- Political Stream, where power comes into play (three elements= national mood, interest groups, government)
- When all three streams align, a policy window opens presenting an opportunity for a policy advocate to push their solution or raise awareness of their problem.
A vaccine has been newly licensed for the disease, Cute Aggression caused by the Adorable Bunny Virus with a R0 of 3. In a RCT with 200,000 study participants, 50% had the vaccine administered and 50% had a placebo administered. In the vaccinated group, 5,000 participants developed the disease; in the unvaccinated group, 100,000 participants developed the disease.
Please calculate the vaccine coverage required to achieve the herd immunity.
VE= (Incidence in unvaccinated - Incidence in vaccinated)/ Incidence in unvaccinated x 100% VE = (0.5 - 0.05)/0.5 x 100% VE = 0.45/0.5 x 100% VE = 0.9 x 100% VE = 90% This vaccine has 90% efficacy.
Vaccine Coverage = (1- 1/R0) / VE
Vc= (1-1/3)/0.9 = 0.666/0.9 = 0.74
You need at least 74% of the susceptible population administered to achieve herd immunity threshold.
What are the four population health indicators (according to CIHI)
Health Status
- deaths, health conditions, wellbeing
Non-medical determinants of health
- risk behaviours, living conditions, environment, personal resources (social supports)
Health System performance
- can the health system provide timely, accessible, safe and effective care
Community and health system characteristics
- demographic information (population, teen pregnancy rate)
- health system demographics (doctors per capita, hospital beds per capita)
List 8 measures and the associated data sources that you would use to assess the health of a population in a population health asesssment
Community and health system characteristics
- Age and sex breakdown (census data)
- Language spoken
- Cultural background
- Mortality, birth rate, infant mortality rate (vital statistics)
Health Status Indicators
- Immunization Status
- Chronic Conditions (CCHS)
- Mental Health Indicators
- Health Measures - blood pressure, obesity (CHMS)
- Screening received (i.e. cervical cancer, CRC)
Non-medical Determinants of Health
- Education
- Income and finances
- Personal Health Behaviors (smoking, alcohol, physical activity)
a) Define Program Planning
b) Outline steps in program planning
multi-step process that outlines the problem, proposed intervention, and evaluation plan.
- Manage the planning process (engage stakeholders, timelines, resources)
- Conduct a situational assessment
- Identify goals, populations of interest, outcomes and outcome objectives
- Identify strategies, activities, outputs process objectives and resources
- Develop indicators
Purpose: to develop a list of variables that can be tracked to assess the extent to which outcome and process objectives have been met - Review the program plan
Outline six steps in program evaluation
Six Steps
Engage Stakeholders
Describe Program
- Need (what does the program address)?
- Expected effects (what does it accomplish to succeed?)
- Activities (program logic / theory)
- Resources (what inputs go in)
Focus Evaluation Design
Gather Credible Evidence
Justify Conclusions
Ensure use and share lessons
What are three types of stakeholders that should be engaged during a program evaluation?
Three types of stakeholders
- Those involved with the program
- Those Served by the program
- Users of the Evaluation (decision makers)
What factors go into making a recommendation by the CTPFHC
- Quality of evidence (GRADE Evidence - Strong, Moderate, Weak)
- The balance between desirable and undesirable effects;
- The variability or uncertainty in values and preferences of citizens;
- Whether or not the intervention represents a wise use of resources.
What are the three GRADE recommendations and what criteria is used to put evidence into these categories?
The quality of evidence is categorized as strong, moderate or weak
Strong - a) many studies with no limitations, b) studies are consistent c) estimate of effect has narrow confidence interval
Quality of evidence might be seen as strong when; there is a wide range of studies included in the analyses with no major limitations, there is little variation between studies, and the summary estimate has a narrow confidence interval.
Quality of evidence might be seen as moderate when; there are only a few studies and some have limitations but not major flaws, there is some variation between studies, or the confidence interval of the summary estimate is wide.
We judge evidence to be low or very low quality when the true effect may be substantially different from the estimate of the effect. For example, evidence might be judged as low quality if any of the following applies: the studies have major flaws, there is important variation between studies, or the confidence interval of the summary estimate is very wide.
Outline the differences between social marketing and commercial marketing
Social Marketing
Ultimate Goal
- improvement of individual health and societal wellbeing
Proximate Goal
- change in desired behaviour
Target
- population in need / willing to change
Competition
- current behaviour
Commercial Marketing
Ultimate Goal
- Financial Gain
Proximate Goal
- selling product / services
Target
- population that will maximize sales
Competition
- other businesses offering similar services
7 attributes of a effective surveillance system
PS-FARTS + SVQ (acronym credit: Laura Bourns)
Positive predictive value: High proportion of positives are actually cases
Sensitivity: Ability of the surveillance system to detect the health problem it was intended to detect***
Flexibility: Ability of the surveillance system to accommodate changes in the operating conditions
Acceptability: To individuals and organizations who must participate
Representativeness: Extent to which surveillance findings accurately portray the event**
Timeliness: Data available rapidly enough for public health authorities to take action*
Simplicity: Ease of operation
Stability: Reliability of resources, personnel, and technology required to support the surveillance system
Validity: Surveillance data are measuring what they are intended to measure
Quality: Complete and valid data
List 4 indicators of health system performance, and one example of each.
Accessibility - proportion of population with a family doctor.
Acceptability - patient satisfaction scores.
Safety - incidence of hospital acquired infections.
Efficiency - wait times for diagnostic procedures.
List 4 indicators of health status, and one example of each.
Mortality - all cause mortality rate.
Health conditions - type 2 diabetes prevalence.
Well-being - self reported health status.
Function - disability adjusted life expectancy.
What are some population level interventions to reduce obesity rates?
- Restriction on marketing and advertising of junk food.
- Menu labeling.
- Taxation of sugar sweetened beverages.
- Nutrition policies in schools; availability of healthier food choices in cafeteria.
- Increased access to active transport - bike lane infrastructure.
- Subsidizing gym memberships.
A cohort study compares rates of disease by subtracting the rate of disease in an unexposed group from the rate of disease in the exposed group.
List all ways that this measure can be referred to
How do you interpret this measure
Attributable Risk, Risk Difference, Excess Risk, Absolute Risk Reduction, Absolute Risk
Subjects who had an exposure X had Y additional cases of outcome Z per 100 people compared to subjects who did not have exposure X.
Define Selection Bias
selection of subjects into a study or their likelihood of being retained in the study leads to a result that is different from what you would have gotten if you had enrolled the entire target population
What are three ways that selection bias can occur in a case-control study and provide an example
- Control Selection Bias.
Example - method of selecting controls into the study is more likely to recruit controls who have the exposure of interest than the general population.
Problem because controls are used to estimate prevalence of exposure in source population of cases.
- Self-Selection Bias - agreeing to participate in the study is related to the exposure of interest and the outcome.
- Differential surveillance / diagnosis of cases and controls. Cases and controls may have been subjected to different levels of case finding.
What are three ways that selection bias can occur in a cohort study
- Differential loss to follow up. Individuals with the exposure are more likely to develop a secondary condition and drop out of the study than individuals without the exposure.
- Subject Selection (retrospective only). Example, Individuals who had the outcome and exposure of interest are more likely to participate.
- Healthy worker effect (special type of subject selection bias)
What are the two general types of biases in a study that can occur and explain them.
Information bias: Systematic error in measurement, producing differential accuracy of information by level of exposure or outcome (e.g., recall, reporting, observer)
Example recall bias: respondent does not remember things correctly
Interviewer/observer bias: interviewer unintentionally influences subject’s responses
Example Selection bias: Subjects are selected such that the distribution of a characteristic among the subjects differs from the distribution of the characteristic in the target population (e.g., sampling, attribution, publication)
Most common cancers in men and women
- Prostate or Breast (Sex Specific Cancer)
- Lung
- Colorectal
Top cause of cancer death in men and women
Women
- Lung
- Breast
- CRC
Men
- Lung
- CRC
- Prostate
