PH Finals Review 5 PDF

Chapter 5: Epidemiology Study notes Epidemiology The study of the distribution and determinants of disease frequency in human populations ○ Determinants = risk factors/causes The study of the patterns and causes of diseases and injury (health conditions) in populations...

Chapter 5: Epidemiology Study notes Epidemiology The study of the distribution and determinants of disease frequency in human populations ○ Determinants = risk factors/causes The study of the patterns and causes of diseases and injury (health conditions) in populations Incidence (Risk)→Measure of new cases of a disease or injury occurring in a population during a specified period of time ○ Infectious disease Prevalence (proportion)→ measure of persons in the population suffering from a disease or injury cases at a specified point in time ○ Chronic disease Step 2 : identify risk factors or causes ○ Is X associated with increased risk of Y? ○ Does X cause Y? How do we determine this? What kind of data do we need? Where/how do we obtain those data? ○ Cohort study Formal epidemiologic studies ○ Cohort studies ○ Case control studies Data sources ○ Researchers collect primary data ○ Surveillance data can sometimes be used Cohort study ○ Start with healthy people ○ Compare incidence of disease or injury over some follow-up time period in exposed and non-exposed individuals Calculate relative risk (RR)= ○ Relative Risk (RR) = incidence rate in exposed / incidence rate in non-exposed  Case control studies ○ Start by identifying cases, then find healthy controls ○ Compare past exposure in cases and controls ○ Calculate odds ratio (OR) Odds ratio (OR) = odds of exposure in cases/ odds of exposure in controls Odds = ratio of number of cases ○ Odds of exposure cases = #cases exposed / #cases not exposed ○ Odds of exposure control cases = #controls exposed / #controls not exposed  Case control vs. cohort ○ Cohort takes a long period of time ○ Case control - looking at people who are already sick and looking into their past Doesn't take as much time Less expensive What happens if lots of studies, both cohort and case control, on one topic and the numbers don't agree ○ Usually depends on how the study was done e.g., looked at different populations e.g., measurement of variables were different Step 3: develop and test interventions ○ Does X cause improvement in Y? ○ Evaluation studies or interventions studies ○ Experimental studies/randomized controlled trials You hear about this one the most Used for drug testing all the time Quasi experimental studies/observational studies ○ Some things just can’t be randomly assigned→comparing communities Step 4: assurance widespread adoption ○ Policy research What kinds of policies or programs assure that interventions reach people who can benefit from them (policy analysis)  What package of policies or programs gives us the best outcomes for a given amount of resources (cost-effectiveness analysis) ○ Implementation research What factors facilitate the implementation of policies and programs What barriers hinder the implementation of policies and programs