Epidemiology Of Periodontal Disease Flashcards
What does prevalence measure, and what is the formula to calculate it?
Prevalence = number of new cases at a given time divided by the number in the population at a given time
-measures how much of some disease or condition there is in a population at a particular point in time
What does incidence measure, and what is the formula used to calculate it?
Incidence = number of new cases of disease in specified time divided by the population initially disease free
-incidence measures the rate of occurrence of new cases of a disease or condition in a specified time period divided by the size of the population under consideration who are initially disease free
What does extent describe?
-how widespread the disease is in subjects
What is severity?
Examples would be mean CAL, mean bone loss, etc
What are the 7 main uses of epidemiology?
1) to study the rise and fall of disease in population
2) to diagnose community problems of health and disease
3) to estimate the individual risk and chances of developing disease
4) to help in completing clinical picture and natural history of disease by group analysis
5) to identify clinical syndromes by observation of group behavior
6) to evaluate the need and effective of health services and need for man power
7) to search for cause of disease and health by observation of group habits, customs, and lifestyle
Name the 3 observational study designs of epidemiology
Cross-sectional studies, cohort studies, and case-control studies
What are cross-sectional studies?
The presence or absence of disease and the characteristics of the members of a population are measured at a point in time
How are cross sectional studies useful?
They provide prevalence data on a disease, comparing the characteristics of persons with and without disease, and generating hypotheses regarding the etiology of a disease
What are cohort studies?
- subjects are classified into exposed and unexposed groups and then followed over time and monitored for the development of disease
- all subjects must be free from disease at the beginning of the study
- purpose is to determine whether an exposure or characteristics is associated with the development of a disease or condition
- disadvantages: can require long periods of follow up and can be expensive to conduct
What are case control studies?
- provides efficient way to investigate the association between an exposure and a disease, especially a rare disease
- require fewer resources and can be conducted quicker than cohort studies
- prevalence or incidence cannot be determined because the subjects are recruited into study based on their disease status
- disadvantage: temporal relationship between exposure and onset of disease cannot be determined because the exposure is usually assessed when the disease status is established
What is an index?
- a numerical value describing the relative status of population on graduated scale with definite upper and lower limits
- designed to permit and facilitate comparison with other population classified by the same criteria and method
What are the 9 characteristics of an ideal index?
1) validity
2) practicality
3) reliability
4) quantifiability
5) sensitivity
6) clarity
7) simplicity
8) objectivity
9) acceptability
What is the difference between parametric and non parametric?
- parametric makes assumptions about the parameters of the population distribution
- non parametric does not make any assumptions
what is microbial plaque?
- the soft deposits that form the biofilm adhering to the tooth surface or other hard surface in the oral cavity
- aka microbial biofilm, consisting of micro-organisms, organic compounds, and inorganic compounds
what are the main categories of periodontal disease?
- gingivitis
- periodontitis
- other
