Lab 7, 8, 9_3rd Shifting Flashcards
other name for Cross-Sectional Studies
prevalence studies
Cross-Sectional Studies can be thought of as a ____________ because data are collected and
evaluated at a single point in time
snapshot (or slice) of time
Cross-Sectional Studies can be thought of as a snapshot (or slice) of time because data are collected and
evaluated at a __________ in time
single point
Cross-Sectional Studies this study design is more of a ________
hypothesis generating
Cross-Sectional Studies are not suited for testing the _________
effectiveness of interventions
Cross-Sectional Studies are more hypothesis (generating/testing)
generating
most often used descriptively to capture information about a population (eg. disease prevalence)
Cross-Sectional Studies
may also be used to examine associations between an independent (exposure) and a dependent (outcome) variable
Cross-Sectional Studies
causality between an exposure and outcome (can/cannot) be established from a cross-sectional study.
cannot
T/F
Cross-Sectional Studies are quick and easy to perform
T
it is useful for measuring current health status or setting priorities for
disease control
Cross-Sectional Studies
a survey of smokers is ___________ (type of study) when the questionnaire is administered once, even though the questions contained in the survey may focus on smoking habits over the past 10 years
cross-sectional
standardized questionnaire used to describe a population at a given
point in time
Surveys
study design Generally conducted to characterize a population
Surveys
instruments used for Cross-Sectional Studies
Questionnaire (eg. Answer a census or through mail), telephone call, Surveys
Cross-Sectional Studies: steps in study design
- Identifying target population
- Select individuals from population to complete questionnaire
- Data collection
- Analysis
population with desired clinical and demographic characteristics that will ultimately benefit from generalization of the study findings.
target population
refers to the extent to which observations in the study population extrapolates to the overall population of interest.
Generalizability
process of selecting a subset of the target population to conduct a study
Sampling
eg. Random sampling, stratified random sampling using characteristics such as age or gender, convenience sampling
Sampling
Data collection: Prescription records
retrospective or prospective?
Retrospective
Data collection: Survey
retrospective or prospective?
prospective
Analysis is purely descriptive
Cross-Sectional Studies
Analysis
* Purely descriptive
* summarizing the characteristics of the population using means and percentages
Cross-Sectional Studies
Analysis
* sometimes a researcher may examine an association between two variables collected during the same cross-section in time.
Cross-Sectional Studies
“analytical cross-sectional studies” have no potential biases that should be considered by researchers and this type of analysis should be interpreted freely.
false
have no potential –> have potential
freely –> cautiously
Efficient means of capturing descriptive information about a population at a given point in time
Cross-Sectional Studies
Limitations: bias on sampling and temporality, may not give generalizations
Cross-Sectional Studies
data that is collected sequentially from the same respondents over time
longitudinal data
CONCERNS:
* problems are errors in data collection and transient effects that may influence observations
Cross-Sectional Studies
are those responses that are affected by event, feeling or other circumstance that happened prior to data collection; it may not reflect actual responses when taken in a different time.
transient effect
CONCERNS:
inaccuracies in data collection may go unnoticed because there are no prior data for comparison
Cross-Sectional Studies
these designs can observational or interventional reports.
(1) Case studies, (2) Case reports, and (3) Case series
It describes a patient’s or patient group’s exposure to a drug or intervention and can be valuable to record preliminary findings that lead to further study.
(1) Case studies, (2) Case reports, and (3) Case series
key characteristic to these reports is the lack of a control or comparison group
(1) Case studies, (2) Case reports, and (3) Case series
a record of descriptive research that documents a practitioner’s experiences, thoughts, or observations related to the care of a single patient
Case study
a descriptive record of a single individual (case report) in which the possibility of an association between an observed effect and a specific intervention or exposure (often an unexpected complication of treatment or procedure) based on detailed clinical evaluation and history of the individual
Case report
a group of records (case studies) that documents a practitioner’s experiences, thoughts, or observations related to the care of multiple patients with similar medical situations
Case series
Uses information obtained from a select members of the population, analyzes the responses, and the draws conclusions applicable back to the same population.
Survey Research
It can be considered as either descriptive (such as opinions and attitudes) or explanatory (such as explaining a cause and effect) in nature.
Survey Research
The validity of the results depends on the quality of the study’s internal rigor (methodology).
Survey Research
the validity of the results from Survey Research depends on the quality of the study’s __________.
internal rigor (methodology)
study the incidence, distribution, and relationships of sociologic and
psychological variables.
Survey Research
collect information from a sample and generalize the findings to a larger,
target population.
Survey Research
identify, assess, and compare respondents’ ideas, feelings, plans, beliefs,
and demographics.
Survey Research
determine how health care programs should be implemented by utilizing
the opinions of experts with experience in a particular area.
Survey Research
study effectiveness of a program by surveying individuals who
have used its services.
Survey Research
understand attitudes and behaviors of patients or members of the profession the program affects.
Survey Research
types of survey research
Descriptive surveys, Explanatory surveys
Survey Research Types
attempt to identify psychosocial variables such as attitudes, opinions, knowledge, and behaviors in a population
Descriptive surveys
Survey Research Types
attempt to explain causal relationships between variables
Explanatory surveys
Types of Data Collected in survey research
incidence, attitudinal, knowledge, behavior measurements
Types of Data Collected in survey research:
try to determine the occurrence of events without drawing any relationships between variables
Incidence
Types of Data Collected in survey research:
morbidity or mortality data, manpower data
Incidence
Types of Data Collected in survey research:
try to compare this dependent variable with independent variables such as age, education, or salary
Attitudinal
Types of Data Collected in survey research:
job satisfaction surveys
Attitudinal
Types of Data Collected in survey research:
attempt to document a person’s knowledge or understanding about a specific topic
Knowledge
Types of Data Collected in survey research:
physician’s knowledge of retail prices of medications
Knowledge
Types of Data Collected in survey research:
pharmacist’s knowledge of state pharmacy laws
Knowledge
Types of Data Collected in survey research:
documents what a person actually does in a particular situation rather
than asking him or her in a survey, which may reflect an attitude, rather than the actual observed behavior
Behavior measurements
Data collection:
* it can be performed using questionnaires, examination of historical
records, telephone interviews, face-to-face interviews, web-based questionnaires, focus groups, or panel interviews.
Survey Research
Characteristics of well-conducted survey
- objective and carefully planned
- data are quantifiable
- subjects surveyed are representative of the target population
Errors affecting Precision and Accuracy of survey research (4)
1.Coverage Error
2.Sampling Error
3.Measurement error
4.Nonresponse Error
Errors affecting Precision and Accuracy:
a bias in a statistic that occurs when the target population you want to survey does not coincide with the sample population that is actually surveyed
Coverage Error
Errors affecting Precision and Accuracy:
can compromise the ability to generalize study results
Coverage Error
Errors affecting Precision and Accuracy:
refers to the difference between the estimate derived from a sample survey and the true value that would result if a census of the entire target population were taken under the same conditions
Sampling Error
Errors affecting Precision and Accuracy:
occurs when the researcher surveys only a subset (sample) of all possible subjects within the population of interest
Sampling Error
Errors affecting Precision and Accuracy:
occurs when the collection of data is influenced by the interviewer or when the survey item itself is unclear from the respondent’s point of view
Measurement error
Errors affecting Precision and Accuracy:
occurs when a significant number of subjects in a sample do not respond to the survey
Nonresponse Error
Errors affecting Precision and Accuracy:
bias can result in surveys, where the answers of respondents differ from the potential answers of those who did not answer
Nonresponse Error
Errors affecting Precision and Accuracy:
strive for response rates in the _______ range
80% to 90%
Evaluation of Survey:
there must be attempts to assess validity and reliability of the survey and efforts made to validate factual data
Factual Data and Internal Validity
T/F
asking more than one question about a concept can increase the external validity of a survey
F
external –> internal
purpose of Cronbach alpha or similar statistical tests in evaluation of survey
Factual Data and Internal Validity:
measures correlation between items should be calculated and the
coefficient factor(s) reported in the article; CONSISTENCY
minimum valid coefficient score in Cronbach alpha
0.8
Evaluation of Survey:
_________ section should report sample size, along with a description of how it was determined
methods
___________ computation provides the minimum number of individuals that needs to be sampled from the population
sample size
appropriate sample size will give sufficient _________ to demonstrate a difference between two groups
statistical power
describes the population from where actuals samples will be drawn from for the survey respondents
Sample Frame
T/F
a sample is comprehensive if all members of a population had a chance to be chosen and no one was systematically excluded
true
Evaluation of Survey:
methods section should supply the reader with enough information to ensure that nonresponse error was assessed and measures were taken to control the possible errors
Sampling Strategy and Response Rates
T/F
authors should relate as less information about non-responders as possible i.e., reasons for non-response or non-participations.
F
less –> more
Evaluation of Survey:
assess the reliability i.e., can the results of the survey be repeated by another investigator and present the results of reliability estimates.
Survey Instrument Reliability
an assessment of a questionnaire made before full-scale implementation to identify and correct problems such as faulty questions, flawed response options, or interviewer training deficiencies
pretest or pilot test
Review articles are classified as _______ literature
tertiary
