CREBM II

Closed ended questions

Closed ended questions

Questions that encourage one or two preselected answers (Quick & easy)

Ex: Yes or no; Check all that apply

Disadvantages of closed-ended questions

- Lead in certain direction

- Limits scope of answer

Fixed by = adding "Other, please specify"

Open-ended questions

Questions that encourage a more elaborate response

"Describe how you feel about this."
"Why do you think...?"

Open-ended questions are often used in the ___________ phase

Exploratory phase (can form basis of closed ended questions)

Disadvantages of open-ended questions

- Less complete
- Require qualitative methods or special systems (Coding)

The statistical aspects of a systematic review are called _________

Meta-analysis

Systematic Review becomes __________ when statistics are utilized

Meta-Analysis

Meta-Analysis

Statistical approach (quantitative index) to combining the data derived from a systematic-review

Systematic review

Entire process of selecting, evaluating, and synthesizing all available evidence (of all relevant, completed studies)

Systematic Review + ___________ = Meta Analysis

Statistical analysis

Experimental study

Evaluate cause & effect relationship between independent and dependent variables

- True experimental design

- Clinical trials

True experimental design

Subjects randomly assigned to at least 2 comparison groups

Clinical Trials

PRCT (prospective randomized controlled trial)

Used to describe experimental studies that examine the effects of interventions on pts/community

Clinical trial design

- Pre-clinical research

- Phase I: Safety; MOA

- Phase II: Effective; response rate

- Phase III: Compares to standard (Randomized, blinded)

- Phase IV: Populations (risks, benefits, optimal use)

Quasi experimental

Used where ethical concerns prevent a control group (involve non-equivalent groups)

Same as experimental but lacks random assignment or comparison groups

Example of quasi experimental

You hypothesize that a new after-school program will lead to higher grades.

Children who attend different schools, one of which implements the new program while the other does not.

Single Subject Design

Allow conclusions about effects of treatment based on the response of a single pt (N=1)

Randomized Controlled Trial

allows for conclusions about causality between a manipulated independent variable and an observed/measured dependent variable

Investigational studies (two types)

Therapeutic: effect of a treatment or intervention of a disease

Preventative: whether a procedure/agent reduces risk of developing a disease.

Observational studies

Gather information on human attributes and environmental characteristics that interact to control human behavioral responses -> data collected as they naturally exist

- Observational exploratory

- Observational descriptive

Observational exploratory studies

Test relationships supported by theory -> used to develop prognostic and diagnostic factors

Observational descriptive studies

structured around set of guided research questions/objectives to generate data or characterize a situation of interest-> used as basis for formulating a research hypothesis

Descriptive studies

Document the nature of existing phenomena and describe how variables change over time --> Research hypotheses

Ex: distributions of disease and health related characteristics in the general population

Developmental research

method used to document change

Ex: Cross-sectional method

Cross-Sectional Studies

Observations are made on a single occasion with no follow up period (think snapchat); examine associations

Linked to prevalence

What is the best design for causality?

Randomized control trial (RCT)

hierarchy of evidence pyramid

Meta analysis
Systematic review
Randomized control trial
Prospective (blind comparison to gold standards)
Cohort studies
Case control studies
Case series/Case report
Animal research

Incidence

The proportion of people who develop a given disease/ condition w/i a specified time period

Incidence is linked to ________

Cohort studies

Prevalence

The # of existing cases of a disease/condition at a given point in time (proportion of the total population at risk)

Prevalence is linked to _________

Cross-sectional studies

Cohort Studies

Observations made in a group of subjects that is followed over time (think facebook)

Linked to incidence

Cohort studies can be prospective meaning

begin in present and follow subjects into future

Cohort studies can be retrospective meaning

examine info and specimens that been collected in the past

Advantages of cohort retrospective studies

- Less cost & time

- Subjects already assembled

- Follow up period has already taken place

Case control studies

Begins by choosing one sample of people who have the outcome of interest (Case) and another sample w/out (Control)

Investigator works backwards

Useful for generating hypotheses

Quantitative research

Involves measurement of outcomes using numerical data under standardized conditions

Advantages:

- Preferred

- ability to summarize scales and use statistical analysis

Case control studies can be used for studying _____________

Studying rare diseases

Qualitative research

Measurement based on open ended questions, interviews, and observations

- Under less structured conditions

- Can generate hypothesis/theories

- Serious limitations to inference, causality & conclusion

Applied Research

Solving immediate practical problems with functional applications and testing theories that direct practice

- Carried out in actual practice conditions

Bench (Basic) Research

Obtains empirical data used to develop, refine, or test theory

- Acquire new knowledge

Ex: How do children acquire new languages?

A study design that randomly assigns participants into an experimental group or a control group. As the study is conducted, the only expected difference between the control and experimental groups in __________________ is the outcome variable being studied.

RCT

A study that retrospectively compares patients who have a disease or outcome of interest, with patients who do not have the disease or outcome, and looks back retrospectively to compare how frequently the exposure to a risk factor is present in each group to determine the relationship between the risk factor and the disease.

Case control study

Outcome of interest = Case
Pt w/o disease/outcome = Control

Research in which the investigator cannot randomly assign units or participants to conditions, cannot generally control or manipulate the independent variable, and cannot limit the influence of extraneous variables.

Quasi-Experimental

What type of research we use to develop testing instruments?

Methodologic studies

Goal of qualitative research

To examine experiences using a holistic approach concerned with patient perspective/view

Methodologic studies

Involves development and testing of measuring instruments for use in research or clinical practice (decision rules, etc)

- Reliability/validity of measure

- Use correlation

- Does NOT involve Tx effectiveness

Exploratory research

Examines the phenomena of interest and explores its dimensions, including how it relates to other factors

Epidemiology

Examines associations to describe and predict risks for conditions or disease

Blinding

Strategy for enhancing accuracy that does not ensure the overall accuracy of the measurements, but it can eliminate differential bias

Inclusion criteria

Specifying populations relevant to the research question and efficient for study (Demographics, clinical characteristics, geographic, temporal)

Exclusion criteria

Specifying subsets of the population that will not be studied

- high lost follow-up

- provide poor data

- high risk of ADR

Steps in prospective cohort studies

- Define selection criteria
- Recruit sample
- Measure the predictor variables
- Store data
- Follow cohort over time
- Measure the outcome variable(s) during follow up

Steps in retrospective cohort study

- Identify existing cohort that has some predictor information already recorded
- Assess loss to follow up
- Measure outcome variables that have already occurred

Limitations of scientific method

- Not perfect for studying human behavior

- Complexity/variability of nature

- Issues of generalizability (Cause does not always equal effect)

- Extraneous influences