CPHM: LESSON 2 Introduction to Biostatistic Flashcards
•…application of statistical methods to the life sciences like biology, medicine and public health”…
Biostatistics
two Branches of Statistics
Descriptive Statistics and Inferential Statistics
Statistical techniques for summarizing and presenting data in a form that will make them easier to analyze and interpret
Descriptive Statistics
Concerned in making estimates, predictions, generalizations, and conclusions about a target population based on information from a sample
• Estimation
• Hypothesis testing
• Inferential Statistics
• Demographic
• Health Status
• Health Resources
• Health-related Socio-economic Environmental Factors
Statistical Data
Used to describe the variety and frequency of past outcomes under similar conditions as a way of predicting what should happen in the future
Probability
used to express the degree of probability or improbability of a certain result in an experiment.
P value
Expresses the probability that the observed result could have occurred by chance alone.
P value
• This is a range of values within which the true result probably falls.
Confidence Interval
the lower the likelihood of random error.
Confidence Interval
Are often expressed as margins of error, as in political polling, when a politician’s support might be estimated at 50 percent. The confidence interval would be 47% to 53%
Confidence Interval
• While p values and confidence intervals are useful concepts in deciding how seriously to take an experimental result, it is wrong to place too much confidence in an experiment just because it yields a low p value or a narrow confidence interval.
True
measurement of a characteristics
Variable
variables whose categories are simply used as labels to distinguish one group from another
Qualitative
numerical representation of the categories are for labeling/coding and NOT for comparison
Qualitative
sex, religion, place of residence,
Disease status
Qualitative
values indicate a quantity or amount and can be expressed numerically
Quantitative
values can be arranged according to magnitude
age, height, weight, blood pressure
Quantitative
a classificatory scale where the categories are used as labels only
example: sex, race, blood group, patient ID
Nominal
used for categories which can be ordered or ranked
Example: likert scale, psychosocial Scale
ordinal
same characteristics as ordinal; zero point is arbitrary and does not mean absence of the characteristic
Example:temperature, IQ
Interval
same characteristics as ordinal; a meaningful zero point exist
example: weight, BP, height, doctor visits
Ratio
It refers to the arrangement of any data in an orderly sequence, so that they can be presented concisely and compactly and so that they can be understood easily.
TABULATION
• Data are grouped according to some scale of classification, where the sum of the entries is equal to
• the total. The figures may either be in equal numbers, in percent, or in both. The scales used may be qualitative, quantitative, or both.
• A frequency distribution shows the number of observations falling into each of several ranges of values.
Frequency distributions are portrayed as frequency tables, histograms, or polygons.
Frequency distribution
used to compare two or more frequencies
Correlation data
some variable changes over a while is the one being presented
Time series data
it should state the objective of the table. It should clearly, briefly and comprehensively what the figures in the body of the table stand for. How the data are classified, where and when obtained
Title
indicate the basis of classification of the rows or horizontal series of figures
Stubs
indicate the basis of classification of the columns or vertical series of figures.
Column headings
this is made up of the figures filling the cells or compartments brought about by the coordinates of rows and columns
Body of the table
refer to the column totals and row totals
Marginal Totals
indicate the source of information
Footnote
• The purpose is to convey a simpler idea of what the statistical table contains.
• Statistical graph either a series of lines joined together, or bars or enclosed areas, drawn to represent certain statistical information under consideration.
• Intended for comparison, to show correlation, or simply for data presentation
• Primary tools for presentation and analysis.
Graphing
Parts of a Graph: indicate clearly and briefly what the figures in the body of the graph stand for, how the data were classified, and where and when obtained. This is placed at the bottom of the graph, preceded by number for easy reference.
title
a graph has 2 axes, the vertical and the horizontal:
Axis
true or false: Each represents separate scales of classification corresponding to the row and column headings of the table being graphically presented.
true
true or false: • One of the axes is always quantitative scale while the other is either qualitative or quantitative scales.
true
this is needed when one is drawing more than one graph in a graphing space. This clarifies to what particular item each of the graph refers. It is placed either at the bottom of the graph or as close as possible to the figures being identified.
Legend
these are the lines, bars or figures drawn within the graphing
Body of the graph
there are two kinds of scales used, the qualitative and the quantitative which may discontinuous variety (counts) or continuous (measurement)
Frequency Distribution
numbers (count) or raters (measurements) plotted over a given time period
trend
maybe either of the two
Correlation data
