Research Methods, Biostatistics, and Evidence-Based Medicine

Flashcards covering research methods, biostatistics, and evidence-based medicine based on lecture notes.

Research

The systematic collection, analysis, and interpretation of data to answer a certain question or to solve a problem.

The 4 main phases of research

Planning, implementation, data management and analysis, and writing up.

Research steps

Identification of research problem, literature review, formulating research question/objective, protocol writing, REC approval, data collection, data entry/analysis, and research dissemination.

Research design

Types of study designs -Interventional studies and Observational studies.

Interventional studies

Clinical trials.

Descriptive studies

Concerned with describing the distribution of a disease in relation to person, place, and time.

Types of descriptive studies

Case reports/series and cross-sectional surveys.

Observational analytical studies

Case-control, Cohort, and Cross-sectional analytical studies.

Measure of association in Case-control studies

Odds ratio.

Measure of association in Cohort studies

Relative risk.

Measure of association in Cross-sectional analytical studies

Odds ratio or prevalence ratio.

Relative Risk = 1

Risk in exposed equal to risk in non-exposed (no association).

Relative Risk > 1

Risk in exposed greater than risk in non-exposed (positive association; possibly causal).

Relative Risk < 1

Risk in exposed less than risk in non-exposed (negative association; possibly protective).

Relative risk, odds ratio, prevalence ratio <1

Exposure is Protective (decrease disease occurrence).

Relative risk, odds ratio, prevalence ratio= 1

No association between exposure & outcome.

Relative risk, odds ratio, prevalence ratio>1

Exposure is Risk (increase disease occurrence).

Probability sampling methods

Simple random, systematic, stratified random, cluster, and multistage sampling.

Non-probability sampling methods

Quota, judgmental/purposive, and snowball sampling.

Data collection methods/tools

Questionnaire, household interview/examination surveys, observation, and data collection forms.

Sensitivity

The ability of the test to detect +ve cases where they are truly +ve by the diagnostic test

Specificity

The ability of the test to detect -ve cases where they are truly-ve by the diagnostic test

Positive predictive value

The proportion of true positive among all screening test positive

Negative predictive value

The proportion of true negative among all screening test negative

Statistics

A scientific field that deals with the collection, classification, description, analysis, interpretation, and presentation of data.

Medical statistics

A branch of statistics concerned with medical topics.

Descriptive statistics

Tries to describe a situation through data organization, summarization, and presentation.

Inferential statistics

Numerical techniques for making conclusions about a population based on a sample.

Variable

A type of information/characteristic being measured that varies among the studied cases.

Quantitative data

Expressed in numbers (discrete or continuous).

Qualitative data

Expressed as description (nominal or ordinal).

Dichotomous variables

Nominal variables with only two categories.

Data

Measurement with precise definition.

Information

Translation of the measurement to a meaningful knowledge.

Tables

Show data details in an arranged and grouped way.

Graphs

Show simple impression of the data.

Parameters

Give mathematical summary of the data.

Quantitative variables categories

Measures of central tendency (location) and measures of scatter/variations/dispersion.

Qualitative variables categories

Proportion and ratio.

Arithmetic Mean

Sum of values divided by their number.

Median

The value in the middle of an arranged group of values.

Mode

Most frequent value.

Midrange

The smallest observation + the largest observation divided by 2.

Graphs for quantitative data

Histogram, frequency polygon, frequency curve, line graphs, and scatter diagram.

Graphs for the qualitative data

Pie chart and bar chart.

Range

difference between the smallest and the largest observation

Evidence Based Medicine

1-the current best evidence in decision-making in medicine together with 2-expertise of the decision-makers and 3-expectations and values of the patients/people

the three components of evidence based medicine

Expectations and values of the patients/people, Expertise of the decision-makers and current best evidence

Evidence Base Practice

Process of clinical decision-making based on the best available clinical expertise Literature, and patient preference

Goal of EBM

Improve the health of people through decisions that will maximize their health-related quality of life and life span

Hierarchy of Evidence Quality of information

Meta-Analysis, Systematic Review, Randomized Controlled Trials, Cohort Studies, Case Control Studies, Case Series/Case Reports Background Information/Expert Opinion

Transnational Research

Applying knowledge from basic biology and clinical trials to tools that address critical medical needs

EBM process steps

Ask the question, Acquire the evidence, Appraise the evidence talk with the patient, Self-Evaluate

PICO Format

Patient/Population, Intervention Prognostic Factor; Exposure, comparison and outcome

Acquire the Evidence (Literature search)

Select the appropriate resource. And conduct a search by Identify terms to fit PICO question, Look for secondary sources, Search for primary source, Narrow search with limiters.

EBM Benefit

Integrates medical education, research, and clinical expertise optimizes quality of patient care. Reduce cost in medical care

EBM Limitation

time to. Learn and practice Cost to establish resource infrastructure Required computer skills, May expose your current practice as obsolete or dangerous