Meredith ManningSeptember 10, 2013MBI 131Descriptive Studies Who? Case count, number of new and old cases, followed by who is ill? (women, children, men, what race, infants, etc.). Any idea of how fast it has spread to give a gage on the infectiousness. When? Time of onset for each case and epidemic curves created Where? Determine residential address and travel history This will allow us to create an epidemic curve—how many and in what amount of time. And is it isolate in one location?Epidemiological Studies Investigations carried out when disease or death occurs in unexpected or unacceptable numbers Descriptive studies describe epidemics with respect to person, place, and time. look at reverence and incidence rates to describe this disease—graphs and figures become very helpful at this point (example a graph of time from when exposed to death rate, etc.) Analytic studies are aimed at testing hypothesesEpidemic Curves Graphic display of the cases of disease according to the time or date of onset of symptoms. Secular, seasonal (what’s happening, when? Maybe it’s dealing with travel or maybe temperature related or maybe around water), and single epidemic curves Single epidemic curves have point source epidemic curve (can this be pointed to one place or reason as to why this is happening? Triggering when it occurs) and propagated epidemic curve (how long is it going to propagate?). These help us create that timeline!Analytic Studies Test hypotheses about relationships between health problems and possible risk factorso Through observational studies—investigator observes natural course of events, noting exposed vs. unexposed and disease developmento Case/control studies—. It compares those with disease to those without but with similar background and or with prior exposure to certain risk factors and it is aimed at identifying factors more commonin case than control group (keeping everything else the same (same sex, age, region) So what does everyone sick have in common and howdoes that differ from those who didn’t?o Cohort studies—classified by exposure to one of more risk factors and observed to determine rate of disease development. Cohort is a group of people who share important demographic characteristics.Gives an odds ratio and predicts relative risk so you can group them by exposure rates. Experimental studies—investigator allocates exposure and follows development of disease. Simulates a group and exposes them to determine outcome. This is carried out to identify cause of disease or determine effectiveness of a vaccine drug or procedure. o Control for variable uses control groups, randomization, and blindingo And they also use placebo treatmentso This also requires a large sample sizeCriteria of Causation Questions—exposure causing development of disease Criteria—strength, consistency, specificity (to an organism or to a kind of cell,etc.), temporality (how long does it take and is there a time frame that it was concentrated), and biological plausibility (what biological aspect of this organism causes it to be infectious and is it plausible that this is the source of the disorder?)Discussion Questions How can data collection for notifiable diseases be improved? 1) People need to go to the doctor when they are sick! It will improve our ability to have more accurate data. 2) Creating a more accessible, accurate database 3) giving healthcare professionals and local government access to a database that gives real-time tracking Why is tracking vital statistics so important? It determines your relative risk—are you potential for being exposed and contracting this disorder?  How does calculating Years of Potential Life Lost change the way we think about community health efforts? To be healthy you want to live longer so it is important to study life lost! It might change your mind about health choices you can