final exam Flashcards
the study of the distribution and determinants of health related states or events in specified populations- or in other words, how often the disease occurs in different population groups and why
epidemiology
the constant presence of a disease or infectious agent within a given prevalence of a given disease within an area
endemic
an unusually high occurrence of disease or the occurrence in a community or region of cases of an illness clearly in excess of normal expectancy
epidemic
the occurrence and distribution of a disease or infection occurring world wide or over a wide area
pandemic
example: AIDS
the rate of development of a disease in a group over time, which is included in the denominator or the rate at which new disease cases occur in a population during a specified period
incidence
example: video
describes a group at a certain time
prevalence
example: snapshot
rates of disease
morbidity
rates of death
mortality
another way incidence can be defined as…
the number of persons developing a disease divided by the total time experienced for the subjects followed
must be divided by the total number of the group
proportion rates
is a graduation, numeric scale with upper and lower limits - used for the measurement of disease severity, rather than just disease incidence or prevalence
index
this type of study usually looks at the prevalence of disease by person (age, gender, race, ethnicity, socioeconomic status, occupation), place and time to describe groups at higher risk of developing disease
descriptive study
the most common descriptive study
cross sectional
an investigator studies the impact of a factor that he or she controls.
experimental studies
example: clinical trial testing fluoride varnish for the prevention of dental caries in which one half of the study participants receive the active agent and the other half receive a placebo
refer to the timing of the information and events of a study
retrospective and prospective
any designated group of individuals who are followed or traced over time.. new cases of disease are measured in a group of people who are or have been exposed to a factor believed to influence the occurrence of the disease
cohort study
also referred to as longitudinal studies
prospective
when a disease is constantly and consistently present in a population it is referred to as:
endemic
when the incidence of a disease is unusually high for a population it is referred to as:
epidemic
although a triangle has three sides, the epidemiologic triangle actually consists of four parts, which of the following is NOT part of the triangle?
a. time B. COFOUNDING VARIABLE c. environment d. agent e. host
rates of death:
mortality rates
which of the following terms describes the number of new disease cases that have occurred during a specific period?
incidence
incidence rates are generally used to describe the amount of dental caries in the United States (true or false)
false
which study design is usually the first step in looking at disease?
descriptive
which study design follows a group of individuals forward in time?
prospective cohort
the goal of any diagnostic or screening test is to have?
sensitivity and specificity 100%
what does the abbreviation DMFS mean?
decayed, missing, and filled permanent tooth surfaces
a 16 year old has occlusal decay on #2 and #15, occlusal fillings on all four first molars, an MOD filling on #18 and an MO filling on #31. Teeth #5 and #12 are missing. what are the DMFT and DMFS scores for this adolescent?
DMFT 8; DMFS 11
DMFS measures caries experience in permanent teeth and dmfs measures caries experience in the primary dentition.
true
if a person has a RCI of 25%, it means that 25% of their teeth have decay or fillings on the roots
false
the CPI evaluates three indicators of periodontal status. what are they?
gingival bleeding, calculus, and periodontal pockets
for adults, how many teeth does the CPI evaluate?
10
the OHI-S is the best index for evaluating plaque and calculus
false
a 12 year old child is being examined for dental fluorosis using deans fluorosis index. she has mild fluorosis on teeth #3,14,18, and 30. how would she be classified in terms of fluorosis?
mild
which of the following can be easily measured through a questionnaire or survey?
tooth loss
what are the two primary methods for measuring mortality and morbidity from oral and pharyngeal cancer?
mortality rates and incidence rates
the science of making statements about an entire population from a limited sample of that population
statistics
the application of these methods in biologically relevant areas
biostatistics
essentially can be considered as the outcome variables
dependent variables
this type of variable are the exposures
independent variable
example of dependent and independent variable…
dependent: DMFT, DMFS, and the presence or absence of carious lesions
independent: exposure to the preventative program
the arithmetic average which is the sum of observations divided by the number of observations
mean
the second measure of central tendency- the middle item of a data set, which will divide a data set arranged in order in half
median
the final measure of central tendency - number that occurs the most
mode
three measures of central tendency:
mean, median, mode
when considering the median, where do the distribution scores fall?
the point that divides the area under the curve into two equal parts to the left and the right
random sampling carried out in subgroups of population to ensure that selections will be made from each level of the subgroup
stratified random sample
a sampling scheme in which the subjects are selected, partly or entirely, at the convenience of the researcher
convenience sample
when using the mean as a measure of central tendency, the measure of spread presented is the..
standard deviation or the variance
the square root of the variance
standard deviation
the probability of obtaining the observed data or data that are more extreme if the null hypothesis were true
p-value
compares means between two categories- used when one variable is normally distributed and one is binary categorized
t-test
a statistical test that compares means across three or more categories; used when one variable is normally distributed (continuous) and one is multiple categorical
ANOVA- analysis of variance
from the following selections- classify gender, race and temperature in terms of type of variable
binary nominal category
what is the median, of the following numbers? 12, 0, 5, 4, 10, 10, 8, 2, and 3?
5
what is the SD of the series of numbers in the previous question?
3.9
consider, a standard normally distributed variable Z. determine the probability that it will lie between -2 and -1
13.6%
a hypothetical cohort study was conducted on the relationship between current smoking and the presence of gingivitis or periodontal disease. the study yielding the following table.. what is the risk ratio?
1.52
a longitudinal study was conducted to determine relationship between dmft in the first grade and DMFT in the fifth grade. how would you describe the linear relationship between dmft, DMFT?
positive
a study was conducted to determine the relationship between flossing and number of BOP sites. flossing was classified as daily, less than daily or never. assuming BOP was normally distributed, what statistical test would you use the formally asses the null hypothesis that daily flossers, less than daily flossers and never flossers have the same mean BOP?
ANOVA/F-test
a hypothetical cohort study was conducted on the relationship between presence of periodontal disease and subsequent development of coronary heart disease. both variables were binary categorical. the authors calculated the risk ratio to be 1.5. what is your interpretation of the risk ratio?
those people with periodontal disease were 1.5 times more likely to develop coronary heart disease
return to the example previously listed, by conducting a statistical test, the authors found the p value to be below the set a level of 0.05. what type of statistical error may be concerned about?
a error
does statistical significance always imply clinically?
no
this part of article is not solely for the purpose of being critical of the research or the authors. it is to asses the level of quality of the information and how it may be used appropriately if at all in practice
critical review
which method of scientific communication would be most appropriate for demonstrating a new method of fluoride application?
table clinic
which of the following is not one of four components of EBD as defined by the ADA?
presenting findings at a professional meeting
opinion leaders in the diffusion of innovations theory are most likely:
early adopters
the most current source of valid and reliable scientific information is most likely found:
at a professional meeting
the highest quality of scientific information is based on:
clinical trials with control groups
what are the 6 criteria for evaluating health information on the internet?
credibility (source, currency, relevance, review process)
content (accuracy, disclaimer, completeness)
disclosure (purpose of site, data collection)
links (external links provided)
design(navigation, logically organized)
interactivity (feedback, ?’s, accountable users)
what are the 6 sections in a normal journal article describing a new scientific development or program?
abstract, introduction or review of literature, methodology, results, discussions and references
limiting disability from a disease or rehabilitation of an individual… for ex. denture
tertiary prevention
treating or controlling disease after it occurs, but early in its process.. for ex. conservative amalgam restoration, remineralization of early caries, and conservative perio therapy
secondary prevention
the intervention in disease before it occurs.. for ex. community water fluoridation, fluoride varnish, pit and fissure sealant and preventive education
primary prevention
if a sample is not representative of the population of interest, it is a…
biased sample
