General

Question 1

What are the 2 primary methods of acquiring information?

Answer 1

1. Push: just in case, information sent to you, not efficient
2. Pull: just in time, create a question, search databases

Question 2

PICO Framework: how to formulate a question to research

Answer 2

P = Patient, problem, population, person (keep in mind who or what you’re asking the question about)

I = Intervention, diagnostic test, prognostic factor or issue (what will happen in the future; be specific about treatment intervention)

C = Comparison (compare intervention to)

O = Outcomes (eg reduction in death)

Know = Time/Type of study design/Type of question

Question 3

What is the difference between Qualitative & Quantitative research?

Answer 3

Qualitative research = is a scientific method of observation to gather non-numerical data. This type of research “refers to the meanings, concepts, definitions, characteristics, metaphors, symbols, and description of things” and not to their “counts or measures”.

Quantitative research = is used to quantify the problem by way of generating numerical data or data that can be transformed into usable statistics. It is used to quantify attitudes, opinions, behaviors, and other defined variables – and generalize results from a larger sample population.

Question 4

Explain Descriptive Studies

Answer 4

• Concerned with person, place, time
• Attempts to answer who, what, where & when
• Usually cannot answer why

Question 5

What is the difference between Observational vs Experimental research?

Answer 5

• Observational: observe only, no interventions

- Experimental: control/intervene & observe what happens

Question 6

What is the hierarchy of evidence?

Answer 6

Top to bottom of triangle:

1. Clinical practice guidelines (secondary, pre-appraised or filtered studies)
2. Meta-analysis systematic reviews (secondary, pre-appraised or filtered studies)
3. RCT (Primary studies)
4. Cohort studies (observational)
5. Case control studies (observational)
6. Case report or case series (narratice revies, expert opinions, editorials - no design)
7. Animal and laboratory studies (not involved with humans)

Question 7

What are 3 examples of analytical research designs?

Answer 7

1. RCT
2. Cohort study
3. Case control study

Question 8

What are 3 examples of descriptive research designs?

Answer 8

1. Cross-sectional study
2. Ecological study
3. Case reports / case series

Question 9

What is an example of experimental research?

Answer 9

RCTs

Question 10

What are 5 examples of observational research/studies?

Answer 10

1. Cohort study
2. Case-control study
3. Cross-sectional study
4. Ecological study
5. Case reports / case series

Question 11

What is the hierarchy of evidence based upon?

Answer 11

It’s based on ability to control for bias and demonstrate cause and effect in humans.

Question 12

What is a Meta-analysis?

Answer 12

A statistical technique that summarizes the results of several studies in a single weighted estimate, in which more weight is given to results of studies with more events and sometimes to studies of higher quality.

Question 13

What is a Systematic Review?

Answer 13

A review in which specified and appropriate methods have been used to identify, appraise, and summarize studies addressing a defined question. (It can, but need not, involve meta-analysis). In Clinical Evidence, the term systematic review refers to a systematic review of RCTs unless specified otherwise.

Question 14

What is a Randomized Controlled Trial?

Answer 14

A trial in which participants are randomly assigned to two or more groups: at least one (the experimental group) receiving an intervention that is being tested and another (the comparison or control group) receiving an alternative treatment or placebo. This design allows assessment of the relative effects of interventions.

Question 15

What is a Controlled Clinical Trial?

Answer 15

A trial in which participants are assigned to two or more different treatment groups. In Clinical Evidence, we use the term to refer to controlled trials in which treatment is assigned by a method other than random allocation. When the method of allocation is by random selection, the study is referred to as a randomized controlled trial (RCT). Non-randomized controlled trials are more likely to suffer from bias than RCTs.

Question 16

What is a Case Control Study?

Answer 16

a study design that examines a group of people who have experienced an event (usually an adverse event) and a group of people who have not experienced the same event, and looks at how exposure to suspect (usually noxious) agents differed between the two groups. This type of study design is most useful for trying to ascertain the cause of rare events, such as rare cancers.

Question 17

What is a Cohort Study?

Answer 17

A non-experimental study design that follows a group of people (a cohort), and then looks at how events differ among people within the group. A study that examines a cohort, which differs in respect to exposure to some suspected risk factor (e.g. smoking), is useful for trying to ascertain whether exposure is likely to cause specified events (e.g. lung cancer). Prospective cohort studies (which track participants forward in time) are more reliable than retrospective cohort studies.

Question 18

What is a Case Series?

Answer 18

Analysis of series of people with the disease (there is no comparison group in case series).

Question 19

What is a Pseudo Randomised Control Trial?

Answer 19

A quasi-randomised trial is one in which participants are allocated to different arms of the trial (to receive the study medicine, or placebo, for example) using a method of allocation that is not truly random. Allocation might be based on date of birth, medical record number, or the order in which people were recruited (for example, every other person might be allocated to the placebo group). With quasi-randomisation there is a greater risk that the investigator will be aware of which participant is in which group. There is therefore a risk of selection bias.

Question 20

Describe Case Report/Case Series

Answer 20

Its low on the pyramid

• Case report: Detailed description of a patient / presentation that is unusual for some reason: rare disease or unusual presentation of common disease
• Case series: A report that combines multiple cases

Question 21

Describe a Cross-sectional Study

Answer 21

• Analytical & descriptive
• Analytical studies attempt to describe
• Single point in time snapshot
• Primarily used to determine prevalence
• Obtain exposure & outcome data at the same time

Question 22

What is the difference between a case report and a case series?

Answer 22

• Case report: Detailed description of a patient / presentation that is unusual for some reason: rare disease or unusual presentation of common disease
• Case series: A report that combines multiple cases

Question 23

Explain how Randomised Controlled Trial (special type of cohort study) are designed including randomisation

Answer 23

• Examines cause & effect relationship between predictor & outcome variables
• At least 2 groups (experimental & control)
• Randomisation: ensures groups are similar as possible at the beginning of the study (minimises confounding)

Question 24

The difference between a case-control & a cohort study

Answer 24

• Cohort: always start with the exposure status of the participant, then look for the outcome of interest
• Case-control: start with the outcome of interest; then look for the exposure of interest

Question 25

What is Descriptive statistics?

Answer 25

Are brief descriptive coefficients that summarize a given data set, which can be either a representation of the entire or a sample of a population. Descriptive statistics are broken down into measures of central tendency and measures of variability.

Question 26

What is Inferential statistics?

Answer 26

Inferential statistics is one of the two main branches of statistics. Inferential statistics use a random sample of data taken from a population to describe and make inferences about the population.

Question 27

Explain Probability and P values.

Answer 27

Probability: P values. Mathematical techniques to predict outcomes. Value cannot be more than 1, cannot be less than 0.

• P value tells us the probability that the difference is due to chance alone
• Alpha: level of statistical significance

Question 28

What is Number Needed to Treat - NNT?

Answer 28

• Is the number of patients you need to treat to prevent one additional bad outcome (death, stroke, etc.). For example, if a drug has an NNT of 5, it means you have to treat 5 people with the drug to prevent one additional bad outcome.

Question 29

What is Relative Risk Reduction?

Answer 29

• Is the difference in event rates between two groups, expressed as a proportion of the event rate in the untreated group. For example, if 20% of patients die with treatment A, and 15% die with treatment B, the relative risk reduction is 25%.

Question 30

What is Relative Risk?

Answer 30

• Risk ratio is calculated by dividing the probability of an event occurring for group 1 (A) divided by the probability of an event occurring for group 2 (B). Relative Risk is very similar to Odds Ratio, however, RR is calculated by using percentages, whereas Odds Ratio is calculated by using the ratio of odds.

Question 31

What is the difference between Risks & Odds?

Answer 31

• Risks is the number of time it’s likely to occur divided by the number of times the event is likely to occur
• Odds: chance
• Odds ratio: is a measure of association between an exposure and an outcome. The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure.

Question 32

What type of error is involved with Hypothesis & Null Hypothesis: unproven theory.

Answer 32

• Type 1 error: null hypothesis is true. False positive. Statistically significant difference in results.
• Type 2 error: null hypothesis is false. No statistically significant difference in results.

Question 33

What is Clinical Significance?

Answer 33

• is the practical importance of a treatment effect—whether it has a real genuine, palpable, noticeable effect on daily life

Question 34

What is Confidence Intervals?

Answer 34

• P value: 0.05 or less than 0.05

- Range of values: 95% confidence. Likely range containing the true value.

Question 35

What is Confounding?

Answer 35

• Occurs when the experimental controls do not allow the experimenter to reasonably eliminate plausible alternative explanations for an observed relationship between independent and dependent variables. As a result, many variables are confounded, and it is impossible to say whether the drug was effective.

Question 36

What is Association?

Answer 36

A statistical relationship between 2 or more things. Is a relationship between two random variables which makes them statistically dependent

Question 37

What is Clinical Practice Guidelines?

Answer 37

Are statements that include recommendations intended to optimize patient care that are informed by a systematic review of evidence and an assessment of the benefits and harms of alternative care options.

Question 38

What is Chance?

Answer 38

Is a random error appearing to cause an association between an exposure and an outcome. However a problem with drawing such an inference is that the play of chance may affect the results of an epidemiological study because of the effects of random variation from sample to sample.

Question 39

What is the Intention to Treat Analysis?

Answer 39

Is a method for analyzing results in a prospective randomized study where all participants who are randomized are included in the statistical analysis and analyzed according to the group they were originally assigned, regardless of what treatment (if any) they received.

Question 40

What is Concealment?

Answer 40

A technique used to prevent selection bias by concealing the allocation sequence from those assigning participants to intervention groups, until the moment of assignment.

Question 41

What is Randomisation?

Answer 41

A method based on chance alone by which study participants are assigned to a treatment group. Randomization minimizes the differences among groups by equally distributing people with particular characteristics among all the trial arms. The researchers do not know which treatment is better.

Question 42

What is Causation?

Answer 42

Something that plays an essential role in producing an effect. When an article says that causation was found, this means that the researchers found that changes in one variable they measured directly caused changes in the other. An example would be research showing that jumping off a cliff directly causes great physical damage.

Question 43

What is Blinding?

Answer 43

Refers to a practice where study participants are prevented from knowing certain information that may somehow influence them—thereby tainting the results. This blinding can include clinicians, data collectors, outcome assessors and data analysts.

Question 44

What are the primary 4 Foreground Questions?

Answer 44

Therapy: Questions of treatment in order to achieve some outcome. May include drugs, surgical intervention, change in diet, counseling, etc.

Diagnosis: Questions of identification of a disorder in a patient presenting with specific symptoms.

Prognosis: Questions of progression of a disease or likelihood of a disease occurring.

Etiology/Harm: Questions of negative impact from an intervention or other exposure.