Term
| overall conduction of experimental studies |
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Definition
- hypotheses formed
- study subjects recruited based on specific criteria and their informed consent is sought
- eligible and willing subjects randomly allocated to receive one of the two or more interventions being compared
- study groups monitored for outcome under study
- rates of outcome in various groups are compared
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Term
| ways to categorize experimental studies |
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Definition
- individual versus community treatment allocated to individual or entire community
- preventative vs. therapeutic
- therapeutic- tx given to diseased individual to reduce risk of recurrence, improve survival, quality of life
- preventative- px agent given to healthy or high risk individual to prevent disease
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Term
| Gold standard of epidemiologic research |
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Definition
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Term
| clinical trials- study design |
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Definition
- ID potential study population
- clear inclusion and exclusion criteria
- sample size should consider participation rates hypothesized differences between groups, non compliance with tx, etc.
- enroll study subjects
- assess whether each subject is eligible
- standard baseline examination
- allocate to treatment or control group
- importance of informed consent
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Term
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Definition
| general group to whom results of a trial should be applicable (all humans, or some restrictions may apply) |
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Term
| Factors to consider in sample size |
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Definition
- not just number of people in the trial, but how many endpoints are expected
- rate of outcome in population
- projected difference in outcomes expected between trial groups
- alpha and beta levels
- rates of noncompliance and lost to follow up
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Term
| Factors to consider in eligibility criteria |
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Definition
- logistics
- what group is accessible
- who will comply with study protocol
- how feasible is complete and accurate follow up on subjects
- characteristics of volunteers
- how does study population differ from total experimental population
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Term
| define randomization and give different methods of randomization |
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Definition
- definition- each individual has the same chance of receiving each possible "treatment"
- examples
- random number table- each subject enrolled is assigned a number from the random number table and you assign even numbers to treatment A and odd numbers to treatment B
- toss a coin for each subject
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Term
| goal of randomization and effect of larger groups |
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Definition
- achieve baseline comparability between compared groups on factors related to outcome
- essence of good comparison between "treatments" is that the compared groups are the same EXCEPT for the "treatment"
- compared groups should have same distribution for all of these characteristics
- equal distribution of all unknown factors relevant to response to the tx (confounders)
- larger groups = better randomizations works in controllin for confounding
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Term
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Definition
| only the investigator knows which intervention each subject is receiving (subject is blind) |
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Term
| How does blindin reduce bias? |
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Definition
- reduce bias from:
- different psychological effects of one trx vs. the other on the occurence of symptoms and side effects
- subjective perception/reportin of symptoms and side effects by study subjects
- difference in concomitant or compensatory treatment by either the subject or the investigator
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Term
| potential reasons for non compliance |
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Definition
- side effects
- illness
- level of inerest
- length of follow up
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Term
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Definition
- makes compared gropus more alike
- this will reduce the ability of investigator to detect a difference between the groups (diminish study power and drives findings toward null hypothesis)
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Term
| How to enhance compliance |
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Definition
- design phase
- pick interested group
- design simple protocol
- during study
- frequent contact with subjects
- incentives (ex: free check ups)
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Term
| goals in ascertain outcome |
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Definition
- high follow up rates
- uniform follow up for compared groups
- must be equally vigilant in follow up in all compared groups
- high compliance rate in all trial arms
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Term
| penalty of nonuniform ascertainment of outcomes |
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Definition
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Term
| different types of trial designs |
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Definition
- stratified randomized design
- take a factor like age or sex, than randomize each subgroup
- factorial design
- crossover design
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Term
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Definition
- type I error- conclude treatment are different when they are infact ARE NOT
- reject the null hypothesis when it is infact true
- type II error- conclude treatmens are not different when tey in fact ARE
- accept the null hypothesis when it is infact false
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Term
| key elements of informed consent |
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Definition
- participation is voluntary
- confidential of information from study subjects
- full disclosure of risks and benefits
- participants must know what to expect
- information must be understandable to participant
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