Components, Basic Principles. Flashcards
Three components of EBM
Clinical expertise, patient values and preferences, best research evidence
What is EBM?
The conscientious, explicit, and judicious use of current best evidence in making decisions about patient care.
5 steps of using EBM in practice
Ask, Acquire, Appraise, Apply, assess outcomes.
Patient Oriented Outcomes that matter
Death, Disease, discomfort, disability, dissatisfaction.
Population
All the people in a defined setting, or with certain defined characteristics of interest.
Sample
The subjects from the population who are studied.
Internal Validity
The degree to which the results are accurate for the participants in the study; increased with less variability
External Validity
The ability of the results to be applied to the population of interest
Sampling
The act of choosing subjects for the sample. Want it to be manageable and limit variability
Simple Random Sampling
Every member of the population is a potential subject. Chosen randomly from whole population. May lead to a non-representative sample.
Stratified Random Sampling
To ensure that critical sub-populations or variables are represented. Subjects are stratified by traits and then chosen randomly from within these stratifications.
Systematic Sampling
Population ordered alphabetically or with another qualifier, and the 3rd person from each letter or weight or something is chosen to be a subject.
Purposive sampling
Hand-picking subjects to participate in the study
Convenience sampling
Subjects chosen based on their availability/willingness to volunteer for the study.
Quota Sampling
Convenience sampling, but with certain quotas included for different variables.
Independent variable
The variable manipulated by the researcher, the effect of which we are looking to understand.
Dependent variables
Measure outcomes dependent on the experiment/independent variable.
Extraneous variables
Other variables in the study that may addict the relationship between the independent and dependent variables.
Bias
Process at any stage of the experiment that tends to produce results that depart from true values
Sampling Bias
Bias in choosing the study subjects
Selection Bias
Bias resulting from not randomize get subjects into experimental/control groups. Hand picking who goes where. This makes NON EQUIVALENT GROUPS
Measurement Bias
Conditions in which results are measured in a non-objective or non-standardized way.
Confounding
Inability to attribute the results to an independent variable
Random Error/Chance
Variation in the measurements that occurs for reasons other than bias.
How to control random errors?
Limit population, improve measurements, control testing environment
PICO- What is P?
Patient. Ex: adult with severe pancreatitis.
PICO- What is I?
Intervention. Ex. Enteral feeding
PICO- What is C?
Comparison. Ex: total parenteral nutrition
PICO- What is O?
Outcome. Ex; Survival, complications, etc.
