Term

Definition
 The conscientious and judicious use of current best evidence from clinical care research inthe management of individual patients



Term
Transdisciplinary Model of
Evidence Based Practices 

Definition
 clinical decision making should include some best available research evidence; patients characteristics, needs, values, preferences; and resources including providers expertise
 all of these are under the umbrella of environment and organizational context



Term
Dimensions of Any Benefit or Harm 

Definition
 nature(quality, intensity, time course)
 probability it will occur
 importance to the person
 how can benefits be maximized and harms minimized



Term

Definition
 13,000+ known diseases
 2,000+ new MEDLINE articles each day
 half life for clinical research is 5 1/2 years(the time it takes for a clinically important change to take place)



Term

Definition
 formulate an answerable question (EBM II)
 Track down the best evidence (EBM I)
 critically appraise the evidence for validity, clinical relevance and applicability (EBM!
 Individualize, based on clinical expertise and patient concerns (EBMII and beyond)
 Evaluate your own performance



Term
Problems with randomized trials 

Definition
 bias of researcher
 use of control groups
 placebo, current treatment, or biased comparison



Term
Problems with metaanalysis 

Definition
 missing negative trials
 cochrane group



Term

Definition
 experimental evidence trumps other evidence
 assumes researcher is unbiased
 excludes important information
 each patient is an individual (too many uncommon diseases and varients)
 could limit individual choice



Term
Types of Experimental Studies 

Definition
 randomized controlled trial (RCT)
 nonrandomized controlled trial



Term
Types of Observational Studies
(nonexperimental) 

Definition
 analytical(comparison group): cohort studies, case control studies, and crosssectional studies
 descriptive (no comparison group): case series, qualitative studies, crosssectional studies



Term
Randomized Controlled Trials 

Definition
 experimental group recieves an intervention
 control group receives no intervention(sometimes they receive usual care or a placebo)
 subjects are allocated at random
 outcomes are measured in both groups adn compared
 experimental treatment is blinded to subjects and clinicians(doubleblinded) to reduce bias
 intention to treat analysis provides conservative estimates



Term
Advantages and Disadvantages of
Randomized Controlled Trials 

Definition
 advantages: researcher has control over the experimental variable; way to control for extraneous factors;causation is easier to prove;short duration of study
 desadvantages: artificial environment; problems in generalizabilitywhou volunteers for studies?



Term
Superiority Vs Equivalence or
Noninferiority Trials 

Definition
 already an effective treatment and want to show equivalence
 easier to prove equivalence than superiority
 are results valid of did the researcher use poor reasearch methods: easier to find no diff than a significant one, blinding is no longer as effective and intention to treat is not as effective



Term
Cohort Study
(Prospective and longitudinal) 

Definition
 advantages: only way to establish incidence of a disease, able to look at several risk factors, not limited to 1 disease
 disadvantages: not practical for rare diseases, expensivemany subjects over time, takes a long time to get results
 population sample> exposed or not exposed



Term
The Framingham Heart Study 

Definition
 5,209 men and women, ages of 30 to 62
 framingham, massachusetts in 1948
 physical examinations and lifestyle interviews every two years
 1971, second generation enrolled
 risk factors are age, total cholesterol, HDL, blood pressure, smoking status and diabetes



Term

Definition
 cases(diseased) and controls (nondiseased)
 advantages: way to study rare diseases, short duration of study, study multiple causes of disease
 disadvantages: recall bias b/c retrospective, limited to study of 1 disease



Term

Definition
 descriptive studies: describethe distribution of disease or risk factors for disease, prevalence studies
 crosssectional: one point in time, difficult to determine causality
 case series studies
 qualitative studies: geater understanding of context and values



Term

Definition
 reference books
 web resources
 databases



Term

Definition
 PubMed
 OVID
 Review Articles



Term

Definition
 research journal articles
 thesises or dissertations
 conferences
 reports
 patents



Term
Why use Tertiary Resources? 

Definition
 general information
 learn a new subject or refresh your memory
 \background information about a disease or treatment
 looking for goldstandard diagnosis or treatment algorithm for a disease or condition



Term
Disadvantages to Tertiary Resources 

Definition
 information can become dated during the publication process
 information may be incomplete
 errors in transcription
 author bias
 lack of expertise of authors
 incorrect interpretation of information by authors



Term
Evaluating Tertiary Resources 

Definition
 authors experience/expertise
 publication date
 references
 relevant information
 bias or blatant errors



Term

Definition
 Lexicomp online
 micromedex
 access pharmacy
 accessmedicine
 all except accessmedicine have herbal monographs too



Term

Definition
 Medical Subject Headings
 on pubmed
 lets you search concepts instead of keywords
 generic name of a drug is always the MeSH term
 drugs that have not received a MeSH are designated as a substance name
 can build to searches
 refine your search by pub date, article type, language, gender/age, full text, journal subsets



Term

Definition
 you use it to create your clinical question
 establish your patient, population or problem, desired intervention, comparison and desired outcome
 makes it easy to evaluate the article to your needs



Term
PubMed Versus Google Scholar 

Definition
 pubmed: more limits to narrow searches, can use MeSH, search history available to user, can use truncation, save results to my NCBI
 google scholar: sorts search results by relevance, searches full text of article for keywords when fulltext article is available



Term
A study compared 150 adults with a rare disease to 300 disease free adults to examine past experiences that may have contributed to the development of the illness. what study design did they use?
Cohort
controlled clinical trial
casecontrol
case series
perspective 

Definition


Term

Definition
 each element has an equal probability of being selected



Term

Definition
 divide patients into males and females and select 10% of each gender
 ensures that both men and women are represented



Term

Definition
 select 10 anticoagulation clinics in NE OH and then select 50 patients from each clinic



Term

Definition
 select every 5th patient that walks through the door at your clinic?



Term

Definition
 p=probability of an event and q=1p(probability of event not occuring)
 adition rule where probability of any 1 of several events occuring is equal to the sum of their individual probabilities, if they are independent events
 multiplication rule where probability of two or more statistically independent events all occuring is equal to the product of their individual probabilities



Term

Definition
 nominal(male or femalecannot be ordered)
 ordinal(likert scales, strongly agree to strongly disagreecan be ordered)
 interval(has meaningful intervals btw categories
 ratio(agehas an absolute 0, rations are possible
 discrete(# of patients in a cliniccounts, no fractions)
 continuous(ageinfinite number of values)



Term
Measures of Central Tendency 

Definition
 mode: observed value that occurs most often, best for describing nominal or ordinal data
 median: the value in the middle of the distribution, 50th percentile, best for describing ordinal or interval/ratio level variables
 mean: the average, the sum of all the elements divided by the number of elements
 μ= population mean, Χ= sample mean



Term

Definition
 range is the difference btw the lowest and highest scores
 variance is the mean of the squares of all the deviation scores in the distribution



Term

Definition
 prevalence refers to the number of people with the diseases at a given time
 incidence refrs to the number of new cases of a diseases within a certain time period



Term

Definition


Term
Relative risks and Odds ratios 

Definition
 less than 1 indicates a protective effect
 a value of 1 indicates no effect
 a value over 1 indicates a risk factor
 if a 95% confidence interval crosses 1, then no effect, either positive or negative



Term

Definition
 what is the difference in incidence rates btw those exposed and those not exposed?



Term

Definition
 how many times more likely are exposed persons to become diseased, relatvie to nonexposed persons



Term

Definition
 NNT: number of people who would need to be treated with the experimental treatment in order to prevent one bad outcome
 NNH: number needed to harmnumber of people needed to treat in order to cause one person harm



Term

Definition
 what is the incidence of disease that is attributable to an exposure?
 AR=Incidence_{exposed}incidence_{nonexposed}
 example 28% of smokers develop lung cancer and 6% of nonsmokers develop lung cancer so only 22% is the risk of lung cancer attributable to smoker



Term

Definition
 validity did the study or test measure what it claimed to test? how accurate is the study or test? is there bias?
 internalare the results of the study valid for the population studied?
 externalare the results of the study valid for the larger population? are they genralizable?



Term

Definition
 how precise are the results?
 do you get similar results if you measure more than once? is the study or text precise in the measurement
 test/retest reliability
 repeatability and reproducibility
 precision of measure



Term
Journal Article Evaluation 

Definition
 relevancy to your question
 authors
 publication date
 abstract



Term
United States Preventive Services Task Force
(USPSTF) 

Definition
 conducts sytematic reviews of the evidence
 estamates the magnitude of benefits and harms
 makes recommendations
 grades strength of evidence: A(strongly recommend), B(recommends), C (no recommendation), D(recommends against), I(insufficient evidence to recommend for or against)



Term

Definition
 identify individuals with a disease before the presence of symptoms
 early treatment can save lives
 increases the number of false positives
 screening tests should be sensitve and specific, acceptable to the target population, have minimal risks, used when early interventions can reduce morbidity and mortality



Term
The Cage: Example of a diagnostic questionnaire 

Definition
 Cut down
 annoyed
 guilty
 eye opening
 this all is for drinking



Term
Basic Structure of Diagnostic Studies 

Definition
 series of patients
 index test
 reference(gold) standard
 compare the results of the index test with the reference standard, blinded



Term
Sensitivity (Sn) and Specificity(Sp) 

Definition
 sensitivity refers to the proportion of persons who truly have the disease who have a positive test result a/a+c
 specificity refers to the proportion of persons who dont have the disease who have a negative test result d/b+d



Term
Positive Predictive Value
(PPV) 

Definition
 refers to the probability that a person who tests positive really has the disease
 a/a+b



Term
Negative Predictive Value
(NPV) 

Definition
 refers to the probability that a person who tests negative is really disease free
 d/C+D



Term
Relationship btw PPV and NPV
and Sn and SP 

Definition
 they are inversely related: as PPV goes up NPV goes down
 as Sn goues up then Sp goes down
 vice versa is same for both



Term

Definition
 appers to be a graph
 tends to have to curves that stand for people who have the disease and dont have the disease according to a test
 cross over for false positives and negatives



Term

Definition
 method of finding the best cut point
 method of comparing tests
 test A is best, greater area under the curve
 best cut point is at top of curve



Term

Definition
 multiple tests are done and a positve result in any one of the tests is considered positive for a disease
 increases the sensitivityfewer false negatives
 used when rapid assessment is necessary
 used to rule out disease (SnOut)



Term

Definition
 given a positive result on one test, another test is conducted
 increases the specificityfewer false positives
 useful when no one test is high in specificity
 used to rule in disease (SpIn)
 used to rule in breast cancer
 causes fewer false positives and more false negatives because the mammogram has to be positive to continue



Term

Definition
 probability of a particular test result for a prson with the disease divided by the probability of that test result for a person without the disease
 probability of a positive test result: LR+= sensitivity/1Specificity)
 probability of a negative test result: LR=(1sensitivity)/specificity
 if LR=1 the test is of no use in dividing those with and without
 if LR+ >1 then there is a higher probability that those with the disease will score at that particular level than those without the disease
 IF LR <1 then there is a lower probability that those with the disease have a negative result than those without the disease



Term
Where Would I find a Systematic Review/MetaAnalyses 

Definition
 The cochrane Database of Systematic reviews
 the database of abstracts of reviews of effect
 PubMEd
 journals with metaanalysis are JAMA, lancet, chest, New England journal of medicine



Term

Definition
 increase statistical power for primary endpoints and subgroups
 resolve uncertainty when reports disagree
 improve estimates of effect size
 answer questions not posed at the start of individual trials
 chance, true effect, bias, error effect it



Term

Definition
 also known as a blobbogram
 quickly visualize the results of individual stidies and possibly for pooled data
 1 forest plot per outcome
 cochrane collaboration
 quick test for heterogeneity



Term

Definition
 quickly shows the amount of contribution of individual studies to the outcome
 sample size is proportional to circle



Term

Definition
 traditional test for testing heterogeneity
 generates a probability(X^{2} distribution)
 P<0.10heterogeneity present
 if p>0.10 but the ratio of cochran's Q/df>1 means possible heterogeneity
 cochran's Q/df<1no heterogeneity
 can be underpowered or overpowered
 low poper> possible type II error



Term

Definition
 percentage variability in results across studies due to differences in treatment effect and not chance
 I^{2} =0%  chance explains variability present
 I^{2}< 0.25  low heterogeneity
 0.25 to 0.5  moderate heterogeneity
 0.5 <  high heterogeneity



Term

Definition
 do the decisions made while doing the systematic review have a great effect on the results of the systematic review
 robustness of results
 "file drawer effect"



Term

Definition
 what causes a disease?
 multiple predictors of a disease
 study of causation
 what predicts positive health behaviors?
 what predicts positive health outcomes?



Term

Definition
 predicting a binary(dichotomous) outcome
 predicts the probability of the outcome variable
 examples: what predicts a 10% weight loss?
 regression coefficients can be transformed into odds ratios
 the odds of the occurrence of an event



Term

Definition
 adjustment to p values when several statistical tests are being performed
 if p is set to 0.05 then 1 time out of 20 we will get a false positive result
 we have 6 independent variables and 15 possible interactions between those 6 variables



Term

Definition
 we surveyed care managers at area agencies on aging
 attitudes toward advance care planning
 each case manager responded to 3 hypothetical vignettes:



Term

Definition
 serves to organize, summarize and describe data



Term

Definition
 serves to make inferences or generalizations about a total set of individuals or events on the basis of data from a smaller group



Term

Definition
 state null(H0) and alternate(H1) hypotheses
 choose a significane levl, α(0.05, 0.01,0.001)
 determine the critical region and the nonrejection region, based on the sampling distribution
 make a decision and state the conclusion



Term

Definition
 incorrect rejection of a true null hypothesis
 a false positive
 usually concludes that a relationship exists when it doesnt
 aplha
 the smaller the value the less chance that we are making this error



Term

Definition
 failure to reject a false null hypothesis
 it is a false negative
 example would be a blood test failing to detect the disease it was designed to detect
 beta



Term

Definition
 68% of the distribution lies one standard deviation from mean
 95% lies 2 standard deviations
 99.7 lies 3 standard deviations
 this is in a normal distribution



Term

Definition
 distribution of means from samples will always tend to be normal
 closer to normal as number of samples increases
 mean of these means is equal to the population mean
 standard deviation of this distribution is the standard error of the mean



Term

Definition
 estimate of the distance of a value from the population mean(number of std deveations)
 difference btw sample and population/standard error of the mean
 want to find if its less greater or inbtw



Term

Definition
alpha one tailed two tailed
0.05 1.645 1.96
0.01 2.33 2.58
0.001 3.09 3.30 


Term

Definition
 variability means that the patterns we notice may be illusory and we may miss the real patterns
 variability means that our conclusions will always be tentative
 variability means that we'll have to deal with uncertainty



Term

Definition
 1β
 most studies aim for 80% power(at least 80% of the time you will find a sginificant difference if there is in fact a difference
 how many people do you need depends on your expected difference(how small), depends on the variation in measurements, on the sig level, sample size, and on one or twotailed test



Term
Two additional commonly used tests
for mean differences 

Definition
 Ttest(n less than 30)one samples, two samples, paired(before and after)
 ANOVA(three or more groups



Term

Definition
 allows us to analyze one group at two different time points
 was the intervention effective
 difference of means within the individual
 difference btw 2 dependent means
 2 observations per person
 formulas are slightly different



Term

Definition
 used when longitudinal data are collected
 each person has repeated measures
 controls for dependence of measures
 similar to paired ttest



Term

Definition
 normally distributed dependent variable
 ratio or interval level data
 measures are independent
 usually used to examine means(sometimes difference in variance)



Term

Definition
 make no assumptions about normal distribution
 more conservative than parametric tests
 used for analysis of medians
 used for ranked data
 used for ordinal data



Term

Definition
 nonparametric test
 when the assumptions for a ttest do not hold
 also called mannwhitney u test
 ranks scores from lowest to highest
 ranks are analyzed as though they were original observations
 null hypothesis: means of the ranks are equal



Term

Definition
 nonparametric proportions
 do the proportions of observations falling in different categories differ significantly from the proportions that would be expected by chance
 test statistic: X^{2} calc
 use of contingency tables
 X^{2} calc=Σ[(OE)^{2}/E]



Term

Definition
 measure of bivariate association(direction and strength relationship)
 no association=0
 perfect positive association=1
 perfect negative association=1
 association does not mean causation
 cannot claim causation in a cross sectional study, need longitudinal data
 scattergram of no association r=0, dots evenly spaced everywhere



Term

Definition
 this is a pearsons r relationship
 where the scattergram goes up then comes back down like a curve(arch)



Term
R^{2}, The coefficient of Determination 

Definition
 always between 0 and 1
 percent of variation in one variable explained by a change in the second variable
 high R^{2} means one variable can be used to predict the other variable
 for example if there was a correlation of .50 between class attendance and test scores, then 25% of the variance in test scores would be predicted by class attendance



Term
Ordinary least squares(OLS)
Regression Line 

Definition
 line of regression with weird error bars


