Statistics For Nursing And Allied Health

Front 1

What has become the standard by which clinical guidelines are produced?

Back 1

Evidence-based research
p2

Front 2

What produces the largest collection of clinical guidelines?

Back 2

Cochrane Collaboration
p2

Front 3

What are the four main purposes of empirical research?

Back 3

description
exploration
explanation
prediction and control
p5

Front 4

Empirical studies use two different categories of statistics, what are they?

Back 4

Descriptive
Inferential
p5

Front 5

What is descriptive statistics?

Back 5

Numerical or graphical summaries of data, and may includr charts, graphs and simple summary statistics such as means and standard deviations, used to describe characteristics of a problem sample.
p5

Front 6

What is inferential statistics?

Back 6

statistical techniques (chi-square test, the t-test, the one-way ANOVA) that allows conclusions to be drawn about the relationships found among different variable in a population sample.
p5

Front 7

What is a descriptive study/ descriptive statistics?

Back 7

Studies whose primary purpose is descriptive and explorative simply describe situations and events.

Ex: What is the marital status of people in the US?

p5

Front 8

What is an Explanatory study and Inferential statistics?

Back 8

Primary purpose is explanatory elucidate the relationship among variables...more complex than descriptive.

Their questions and lines of inquiry are often based on established theories from the research literature.

Explanatory studies depend on inferential questions: Are women who are sedentary during third trimester of pregnancy more likely to have a cesarean section than women who exercise regularly during the third trimester?

studies do not necessarily attempt to establish causality but often attempt to understand how variable are r/t each other.
p6

Front 9

What do prediction and control studies and Inferential statistics seek to determine?

Back 9

Seek to determine which variables are predictive and to determine causality (one event causes another to happen)

Prediction and control studies are typically quasi-experimental or experimental studies in which researchers introduce an intervention (change one of the variables being examined).

p6

Front 10

What is a true experimental design?

Back 10

random selection/assignment

an intervention

one or more control groups that do not receive an intervention

random assignment of study participants to either the control/intervention group
p5

Front 11

What is a Quasi-experimental design?

Back 11

Are similar to true experimental designs except that they lack one or more of the following:
random assignment to the intervention or the control group
a true control group
andorm assignment to the intervention or control group

This design is often used in the health-related research

Quasi-experimental typically use inferential statistics
p5

Front 12

What are the 8 common mistakes in research?

Back 12

1. Undertaking a research project w/out reviewing the existing literature on the subject
2.Collecting data w/out a well-defined plan, hoping to make sense of it afterwards.
3.Trying to fit meaningful research questions to existing data
4.Defining terms in general or ambiguous language
5.Failing to base research on a sound theoretical foundation
6.Failing to make explicit and clear the underlying assumptions
7.Failing to recognize the limitations of the approach
8.Failing to anticipate rival hypotheses that would account for findings and that challenge interpretations and conclusions.
p6

Front 13

Its important to have a study plan prior to starting research, why?

Back 13

Mistakes are often made when there is no study plan or when the plan is insufficiently detailed.
p6

Front 14

What is a study plan?

Back 14

It is a written presentation of how the researcher is going to obtain and analyze the numerical data needed to answer the research questions.

keeps the analysis focused and relevant
it serves as the basis for the introduction and methods section of research papers after the data have been collected and anaylzed.
study plan can also serve as the basis for the first sections of a dissertation or thesis.
p8

Front 15

What are the ten steps to a study plan?

Back 15

1.Statement of the problem and its significance
2.Theoretical or conceptual framework
3.Research questions to be answered by the study
4.List of hypotheses to be tested
5.Definitions of key terms and variables
6.Description of the research design
7.Description of the sample and how it was obtained
8.Description of the planned statistical analysis
9.Statement of assumptions and limitations.
10. Dissemination plan
p7

Front 16

A study plan begins with a what?

Back 16

with a statement of the research question that the study is trying to answer (purpose of the study) and a short description of the significance or the importance of the question.

A study also needs a theoretical or conceptual framework on which research questions and hypotheses are based.

Front 17

The first step in the study plan is the "statement of the purpose", explain in detail what this is?

Back 17

The purpose of the study, what the study is trying to solve.

A short description of the significance of the problem, no more than 2-3 sentences

THE STATEMENT OF PURPOSE IS THE GUIDING FORCE BEHIND THE ENTIRE RESEARCH PROJECT.
p8-9

Front 18

The second step in a study plan is "theoretical or conceptual framework", explain?

Back 18

A study plan needs a theoretical or conceptual framework on which research questions and hypotheses are based.
This framework presents a structured way of thinking abt the interrelationships of the variables, how they relate to one another.
p7

Front 19

What is empirical research?

Back 19

Empirical research is a way of gaining knowledge by means of direct and indirect observation or experience. Empirical evidence (the record of one's direct observations or experiences) can be analyzed quantitatively or qualitatively. Through quantifying the evidence or making sense of it in qualitative form, a researcher can answer empirical questions, which should be clearly defined and answerable with the evidence collected (usually called data). Research design varies by field and by the question being investigated. Many researchers combine qualitative and quantitative forms of analysis to better answer questions which cannot be studied in laboratory settings, particularly in the social sciences and in education.

Front 20

What are the 2 models under theoretical or conceptual framework?

Back 20

1. Andersons model of Health Care Use
2. Theory of Planned Behavior
p9

Front 21

What is the Anderson's Model of Health Care Use?

Back 21

It postulates that the use of health services is a function of the perceived need for care

enabling factor/ need factor ex. model to study condom use among adolescents having easy access to condoms is viewed as enabling.
p9

Front 22

All studies need to have an underlying framework that does what?

Back 22

that organizes the analysis by stating how all of the variables are expected to relate to one another. p9

Front 23

What is the Theory of Planned Behavior?

Back 23

A theory often used in the research of individual health behavior and behavioral intentions.

The performance of any behavior depends on behavioral beliefs, normative beliefs and control beliefs.
p9

Front 24

Describe the 3rd step of the study plan, Research questions to be answered by the study.

Back 24

It is important to ground research questions in the existing literature.

Questions should be clear abt the relationships that are expected.

Research questions should stem directly from the statement of the purpose of the study and the theoretical framework on which it is based.
p9-10

Front 25

An example of Descriptive questions.

Back 25

What is the level of intention to engage in physical activity among a group of adults that recently joined a fitness facility?
p10

Front 26

An example of an Inferential question.

Back 26

Does attitude toward exercise affect participation in physical activity?
p10

Front 27

The 4th step in the study plan is a list of Hypotheses to be treated, please describe.

Back 27

Hypothesis is a tentative prediction or explanation of the relationship b/w 2or more variables.

The purpose of a hypothesis is to translate problem statements and research questions into predictions of expected outcomes.
p10

Front 28

The fifth step in a study plan is definitions of key terms and variables, describe.

Back 28

In a research plan, it is important to clearly define key terms and variables. Terms are best defined when they first appear so that readers do not initially make assumptions about definitions only to discover later that different definitions apply. It is especially important to define terms that readers outside the field of study may not understand.
p11

Front 29

What is an independent variable?

Back 29

Are those that are manipulated (ie by the intervention) or that may affect the outcome.
Ex: age, income, preexisting health conditions.
p11

Front 30

What are dependent variables?

Back 30

Are those that are expected to change in response to the intervention such as health status, # visits to the doctor, costs of inpatient stay
p11

Front 31

The sixth step to a study plan is Description of the Research Study Design, describe.

Back 31

Every study plan must include a description of how the data that will be collected.

When collecting original data, the plan must describe in detail exactly how this will be accomplished.

Research design is the art and science of conducting studies that maximize reliability and validity of the findings and minimize bias.
p12

Front 32

Research designs commonly used in health care services include (3) what?

Back 32

observational studies
quasi-experimental
experimental studies
p12

Front 33

What is an Observational Study design?

Back 33

Are those in which a phenomenon is simply observed and no intervention is instituted.
They are appropriate when the purpose of the study is descriptive, when the hypotheses are explanatory, or when it is not possible to manipulate the exposure being studied.

p12

Front 34

What are the three main types of observational studies?

Back 34

Cross sectional
Longitudinal study (cohert studies)

case control studies

p12

Front 35

Observational Study Design:
What is a cross-sectional study?

Back 35

Study that involves the collection of data at one point in time, the sample can be random or use intact groups or convenience samples.

Provides only indirect evidence about time and order because of this inability to determine time and order, causal statements can't be made from analysis of cross-sectional studies.
p12

Front 36

Observational Study Design:
What is a longitudinal study?

What is a case-control study?

Back 36

Are designed to collect data at more than one point in time. they are appropriate when casual links need to be established b/w independent and dependent variables.

Involve the collection of data about the study participants current outcome status and past exposure status. Most researchers avoid making causal statemts due to possible mis-recall of past exposures.
p12

Front 37

How does Observational studies differ from Quasi-experimental and experimental study designs?

Back 37

The researcher is an active agent in the quasi-experimental and experimental study designs.
p12

Front 38

How do Quasi-Experimental and Experimental studies differ and how are they the same?

Back 38

Same:
*Involve measurements taken during at least 2 separate pts in time, pretest and posttest.
*involve an intervention
*comparision group (control)

Differ:
Quasi is not random and exper. is.

Exp. differ in the amt of control has over external sources of bias and random error.

**Evidence from experimental studies is considered to be stronger than evidence from quasi-experimental studies and observational studies.
p13

Front 39

T or F
The mechanism by which participants are selected to be in a study is a critical part of the research design.

Back 39

T

p13

Front 40

What is sampling?

Back 40

The process of selecting a portion of the population to represent the entire population.

Can be random or nonrandom
p13

Front 41

Number 7 of the study plan is "Description of the sample and how it was obtained", describe.

Back 41

In general, studies attempt to find participants who represent all members of the population of interest cause it is generally impossible to gather the data from the entire pop. So its done thru sampling.

Important to state exactly what the target population is.

Sampling can be random or non-random
p13

Front 42

8th step of the study plan:
Description of the statistical analysis, happens is 4 stages what are they?

Back 42

data entry

Cleaning the data
describing the sample
inferential statistics used to test each hypothesis.
p14-15

Front 43

Description of the statistical analysis:
What is cleaning the data?

Back 43

Involves making certain that all the variables have valid and usable values and to check the variables with missing data...examining for valid values, unusual values, large amts of missing data and adequate variability.

For example: female=1, male=2 but there is a 3 or if the pts weight is 890lbs
p14

Front 44

Description of the statistical analysis:
Describing the sample?

Back 44

Describe the sample characteristics using descriptive statistics. it is common practice to create tables.

p15

Front 45

Description of the statistical analysis:
Inferential statistics used to test each hypothesis?

Back 45

List the inferential statistics that will be used to test the hypotheses.

ie. independant/dependant varibles,,
p15

Front 46

The 9th point of a study plan is "statement of assumptions, limitations and delimitations, what are each of these?

Back 46

Every study has these, all of which must be stated explicitly.
Assumptions: statemts that are taken to be true even if the direct evidence of truth is either absent or not well documented. Ex:it is assumed that participants are honest.
Limitations: weaknesses that potentially limit the validity of the results. Ex. using only a limited non-random sample, sample sizes fewer than 100
Delimitations: boundries in which the study was deliberately confined, EX. study focuses on adults and not adolescents/adults.
p15-16

Front 47

The 10th point of the study plan is dissemination plan, describe.

Back 47

A study is not truly complete until the knowledge gleaned from the work is disseminated for use. The most important part of a research project is sharing the knowledge obtained from the project.
p16

Front 48

What is a variable?

Back 48

Variables measure the different characteristics or parameters of a given sample. A variable is any characteristic that can and does assume different values for different people, objects, or events being studied. for examp: demographic variables describe basic charc of human pop such as gender, age, ethnicity, marital status.
To be considered a variable it is critical that every1 in a given sample doesn't have the same value. For exam: gender can assume 2 values (male/female), in a study of pregnant women, gender doens't vary and can't be considered a variable.
p22

Front 49

In data analysis, what are the 4 basic types of measurement?

Back 49

Categorization
rank ordering
interval ordering
numerical scoring
p22

Front 50

Types of measurement (categorization, rank ordering, interval ordering, numerical scoring) corresponds to 1 of 4 measurement scales, what are they?

Back 50

nominal (categorization)
ordinal (rank ordering)
interval (interval ordering)
ratio (numerical scoring)
p22

Front 51

What is a nominal scale?

Back 51

Is the lowest form of measurement, the numbers are simply used as labels, representing categories or characteristics and there is no order to the categories.

Ex.: gender, religion, ethnicity, etc.

Each value can be assigned a #, Males=1, females=2...numerical assignmt is arbitrary cause assigning #2 to females and 1 to males changes nothing.
p23

Front 52

What is an ordinal scale?

Back 52

Can be placed in a meaningful numerical order (lowest to highest), but there is no info abt the specific size of the interval b/t the different values and there is no true zero. Numbers are simply used to put observations in rank order.
Ex: it is possible to rank military personnel from lowest to highest, private, corporal, sergeant, lieutenant but it is impossible to say anything meaningful abt how much greater a corporal is than a private.

**All subjective rating scales are considered ordinal, including satisfaction scales, etc.
p23

Front 53

What is an interval scale?

Back 53

Can be placed in a meaningful numerical order and have meaningful intervals b/w values cause the units of measure are in equal intervals.
*no true zero
*EX: PHQ-2 test for depression, SAT, it is impossible to say people that score a 6 are twice as likely to be depressed
p24

Front 54

What is a ratio scale?

Back 54

*Can be placed in meaningful numerical order, have meaningful intervals and have a true zero.
*Ex: wt, ht, bp, pulse rate, age, income and # of children.
p24

Front 55

Converting interval or ratio variables to lower-level nominal or ordinal variables can be unwise, why?

Back 55

it results in a loss of information p25

Front 56

Descriptive statistics are used for what?

Back 56

to describe and summarize data. p25

Front 57

Three common ways of presenting and organizing data to describe a variable are?

What are the 4 things you should know about the measures of each variable?

Back 57

Freq distibutions, graphical displays, descriptive stat. p 25

central tendency
dispersion
shape
outliners
p25

Front 58

What is central tendency?

Back 58

The values that best represent the middle of a distribution.

They provide info abt the values that are most typical.

The mean, median, mode are all measures of central tendency.
p25

Front 59

What is dispersion?

Back 59

Describes the extent to which the values of the variable are spread out around the measure of central tendency.

Standard deviation, interquartile range and range are all measures of dispersion
P24

Front 60

What is the shape of the distribution?

Back 60

Describes how the values of the variable are distributed (symmetricall or asymmetrically) around the measure of central tendency.
This is typically determined visually using graphical methods such as histograms/stem-and-leaf plots.
p25

Front 61

What are outliners?

Back 61

Values that do not fit the pattern of the rest of the values of the variable, they are either much larger/smaller than the rest, they stand out cause they are unusual.
p25

Front 62

What are the 3 most common ways to present and organize data to describe its distribution?

Back 62

descriptive statistics
frequency distributions
graphical displays
p25

Front 63

What are the questions answered by descriptive statistics?

Back 63

It is used to describe and summarize data to make them more meaningful. These include measures of central tendency, dispersion, shape and skewness.
*It is often presented visually using frequency distributions and graphical displays such as histograms and bar charts.
*Overall this allows readers to better understand the pop on which the studies were focused.
p25-6

Front 64

What is a frequency distributions?

Back 64

It provides a way of organizing data using a table format.
*They allow readers to grasp the basic charac of the distribution of the variables quickly.
*When the data are organized into a table format, it is much easier for readers to glean info abt central tendency, dispersion and outliners of the variable of interest.
*Is useful when describing ordinal, interval and ratio data.
p26

Front 65

Give a description of a confidence interval.

Back 65

Most studies are conducted using only a sample of data from the population of interest. The assumption made is that the results obtained from the sample are a valid respresentation of the whole population. However, an estamate of a mean made from sample data does not provide the exact value of the true mean of the population. One way to assess how good an estimate is obtained from the sample is to compute confidence intervals around the estimate of the mean.
CI are typically constructed as either 95% or 99% CI. A 95% CI is interpreted as follows: if the study were repeated over and over again, drawing different samples of the same size from the same population, 95% of the time the estimated mean would fall within the CI. Statistics book p71

Front 66

Description of CI and something to keep in mind.

Back 66

The program of adolescent youth that was discussed in the previous section had 62 participants. However, there are many more adolescents in the city of Buffalo that could have participated; these 62 participants represent the larger population of all adolescent girls who could of enrolled in the program. Then it would be reasonable to ask the following question: Was the population used in the study representative of a good population?
Statistics book p71

Front 67

What is a p-value?

Back 67

The actual probability of getting the obtained results or results even more extreme. The smaller the p-value, the more statistically significant (i.e., the less likely the result is due to chance)
p412

Front 68

How are p-values associated with alpha-levels?

Back 68

The specific level of a p-value that is defined as "statistically significant" is called the alpha-level ( -level). This value is defined by the researcher before any statistical tests are conducted. Common -levels used are .10, .05 and .01. An -level of .10 means that for a result to be significant, it cannot occur more than 10% of the time by chance. Similarly, an -level of .05 means that the result cannot occur more than 5% of the time by chance, and an -level of .01 mans that it cannot occur more than 1% of the time by chance. p85

Front 69

Symbols and formulas vary depending on whether one is describing a sample or population.

What is a population?

Back 69

all members of a defined group

*Characteristics of populations are called parameters. p 20

Front 70

What is a sample?

Back 70

a subset of the population

*characteristics of samples are called sample statistics. p20

Front 71

See p 20-21 for the mathematical symbols in statistics

Back 71

p 20-21

Front 72

What are the most common statistics used to describe sample characteristics?

Back 72

frequency tables, bar charts, histograms, percentages, and measures of central tendancy and dispersion. p.20

Front 73

What is a frequency distribution table?

Back 73

this table provides a way of organizing data by using a table format. p27

Front 74

When data is organized in a table format it is much easier for readers to get what information?

Back 74

central tendancy, dispersion and outliers of the variable of interest p27

Front 75

Standard deviation is useful for examining the spread of data for a single variable or among variables measured in the same units. However, to to compare the variation of 2 different variables (body wt, bl glucose), the SD can't be used, what can?

Back 75

coefficient of variation p 47

Front 76

A normal distribution is

Back 76

symmetrical, bell-shaped and has only one mode p47

Front 77

When a variable's distribution is asymmetrical, it is

Back 77

skewed p48

Front 78

A skewed variable is what?

Back 78

the mean is not in the center of the distribution,

the mean and median are different

Front 79

2 measures of symmetry are?

Back 79

Pearson's skewness coefficient

Fisher's measure of skewness p48

Front 80

Kurtosis

Back 80

indicating whether a distribution has the right bell shape for a normal curve, measures whether the bell shape is too flat or too peaked. p48