Ch19,20,21 Flashcards

Question

“____ ____ occurs when different eligibility criteria are applied to cases and controls, such as when controls with health conditions related to an exposure are excluded but cases with those comorbidities are not excluded.”

Answer 1

“Exclusion bias occurs when different eligibility criteria are applied to cases and controls, such as when controls with health conditions related to an exposure are excluded but cases with those comorbidities are not excluded.” -For example, if patients died from toxic effects of an experimental treatment and were subsequently excluded from the trial analysis, perhaps as 'early deaths', the estimate of effect would be biased in favour of that experimental treatment.

Answer 2

“may result in nonresponse bias if the members of a sample population who agree to participate in a study are systematically different from nonparticipants.

Answer 3

“Uses acceptable and carefully explained sampling methods Takes appropriate steps to maximize the participation rate Recruits an adequately large sample size Reports the number of potential participants at each stage Even so, researchers should develop a recruiting strategy that will encourage a high rate of participation.”

Answer 4

“19.5 Populations for Cross-Sectional Studies”

Answer 5

“The results of cross-sectional studies are often used to make important resource and policy decisions, so the study population for a cross-sectional study should adequately represent the target population.”

Answer 6

“A population-based study

Answer 7

census - count

Answer 8

“When a census of the source or target population has been recently conducted, the sample and study populations for a cross-sectional study should reflect the demographics of that census.”

Answer 9

“For example, suppose the goal of a study is to quantify the prevalence of tobacco use among high school students in a county. The county’s 14 high schools together serve as the target population and the source population. Selecting only 1 high school as the sample population is probably not sufficient. Working intensely with 1 school might maximize participation rates. However, the selected school might enroll students who are different from county students as a whole—more rural or urban, more or less diverse, or from more or less wealthy households. In such a situation, the results from that one high school would not be an accurate reflection of adolescent health across the county.”

Answer 10

1.Study approach Cross-sectional study(observational study design..the investigator measures the outcome and the exposures in the study participants at the same time.) 2. Study question -“What proportion of high school students in North County smoke cigarettes?” 3. Data collection method -Participants will complete their own paper-based questionnaires. 4. Target population -“Students in grades 9–12 in North County” 5. Source population -“All students enrolled in any of the 14 high schools in North County” 6. Source population list -“A list of the number of students in each homeroom provided by each high school” 7.Sample population: -“Based on estimated sample size requirements, 20% of homerooms will be randomly sampled from the lists provided, and all students in these sampled homerooms will be asked to participate in the study.” 8. Study population: -“Eligible individuals from the sample population who agree to participate” 9. Confidentiality -“No student names will ever be provided to researchers; surveys will be anonymous.”

Answer 11

“When census data are not available for a source or target population, careful planning can help a researcher recruit a study population that is reasonably representative of the target population. Recruiting participants for a general population survey from among the spectators at a football game, the shoppers in a particular grocery store, or the donors at a volunteer blood drive will likely result in a sample population that does not represent the target population. Convenience populations are not suitable for most cross-sectional studies because they are not population-based.”

Answer 12

an appropriate and available source of cases.

Answer 13

“The study’s case definition should be very clear about the characteristics that must be present and absent for an individual to be categorized as a case. For example, a researcher may want to select only candidates with advanced disease or, alternatively, may prefer to study only cases whose symptoms began recently. The case definition should specify both the inclusion and the exclusion criteria. The case and control definitions for a study can be written to exclude borderline cases from serving as either cases or controls.”

Answer 14

“Hospitals, specialty clinics, public health offices, disease support groups, and advocacy organizations may be helpful resources for locating individuals or groups of individuals who are likely to meet the study’s case definition. However, care must be taken to ensure that the sample population is not healthier, sicker, or more or less socially connected than the typical person who meets the case definition. ”

Answer 15

“Another option may be to conduct a nested case–control study that uses the participants of a large longitudinal cohort study as the source population for both cases and controls. A nested case–control study design minimizes recall bias because data about past exposures were collected at the time of the exposure and are not based on participants’ memories. However, a cohort study will yield a sufficient number of cases only when the disease being studied is relatively common.”

Answer 16

“Once a source of cases is identified, a valid control group must be selected. The controls must be similar to the cases in every way except for their disease status. For example, it would be inappropriate to compare cases with heart disease to controls who are marathon runners. A study examining a chronic disease should choose a control population representative of the general public, not a population that is unusually physically active. Similarly, it would be inappropriate to compare older adult women to teenage boys, or to compare big-city businessmen to men who are subsistence farmers in remote areas. All cases and controls for any one study should come from similar sociodemographic and geographic source populations.”

Answer 17

“Many different types of populations may be suitable sources of controls for a case–control study. For some hospital-based studies, it may be appropriate to use as controls individuals hospitalized with a condition other than the one being studied. For some population-based studies, random-digit telephone dialing may yield a representative population—or, because many people will refuse to answer personal questions over the telephone, this strategy may result in a very unrepresentative population. In some situations, friends or family members of the cases may be the best controls because they are likely to have sociodemographic characteristics similar to the cases. When making this important decision, the researcher should consider the possibilities for matching cases to controls using group or individual matching.”

Answer 18

“to participate in a study and the exclusion criteria that require an individual (or manuscript) to be removed from the study population. All cases and all controls in a case–control study must meet the same eligibility criteria, except for the ones relating to disease status. For example, a study targeting septuagenarian women should require both cases and controls to be women in their 70s who live in the same general area” Excerpt From: Jacobsen, Kathryn H.;. “Introduction to Health Research Methods.” Apple Books.

Answer 19

1. Study approach Case–control study 2. Study question “What are the risk factors for hip fractures in adult women in the United States?” 3. Data collection method participants will be interviewed in person or by telephone 4. Target Population “Women ages 70–79 years living in the United States” 5. Source population (cases) “All women ages 70–79 who were admitted to St. Luke’s Hospital System in Center City with an incident (new) hip fracture in the past 12 months” 6. Source populations list “A list of the hospital registration numbers for each inpatient female ages 70–79 at admission whose electronic medical record indicates a diagnosis of a hip fracture (ICD10 code S72) during the eligible 12-month period” 7. Sample populations (cases) “All members of the source population for cases will be asked to participate in the study.” 8. Source population (controls) “Each case will be asked to provide the names of three female friends in the same age range who live in the same county and might be able to serve as controls.” 9. Sample population (controls) “All of the friends listed by cases in the study will be invited to serve as controls.” 10. Study population “Eligible individuals from the sample populations who agree to participate” 11. Confidentiality “The hospital will provide the researcher with the names, addresses, and phone numbers of potential case participants. Personally identifying information will not be included in the electronic file that contains questionnaire responses.”

Answer 20

“The sampling methods used for a cohort study must align with the particular type of study design that will be applied. Some longitudinal studies follow a population-based sample of individuals forward in time. For longitudinal cohort studies, the process of identifying representative source and sample populations is similar to the process for identifying these populations for a cross-sectional study. The researchers should try to recruit a stable study population in order to retain as many participants as possible for the duration of the study. Some longitudinal studies are case series that follow individuals with a particular health condition forward in time (Figure 19-5).”

Answer 21

1. Study Approach Cohort study 2. Study question “What is the incidence rate of pneumonia and other lower respiratory infections among children with cystic fibrosis?” 3. Data collection method “Participants’ parents will be asked to log all infections throughout the 5-year prospective study period, and these will be checked against the patients’ medical records.” 4.Target population “All children with cystic fibrosis in Canada” 5. Source population “All children ages 2–12 years who were patients of the cystic fibrosis clinics at any of the six participating university-affiliated hospitals in the past 12 months” 6. Source population lists “A list of all children ages 2–12 years who were patients of the cystic fibrosis clinics of the six participating hospitals during the past 12 months” 7. Sample population “Approximately 25% of the patients on the source population list will be randomly sampled. The parents of sampled children will be asked if they will allow their children to participate in the study.” 8. Study population “Eligible individuals from the sample population whose parents consent to participation” 9. Confidentiality “All guidelines and regulations for the protection of patient information will be strictly adhered to, and only essential personnel will have access to patient records.” “For prospective cohort studies that seek to compare exposed and unexposed populations, identifying exposed and unexposed participants is similar to the steps for identifying cases and controls for a case–control study. For example, studies of the aftereffects of occupational exposures often recruit individuals exposed to on-the-job hazards (similar to cases for a case–control study) through employers, and the researchers then ask those exposed individuals to help recruit unexposed friends and family members to serve as members of the comparison population (similar to the controls for a case–control study).”

Answer 22

“Sampling methods for experimental studies focus on the validity of the study and the safety of participants. Validity usually requires a sample population that is reasonably representative of the target population. For example, suppose that the goal of an experimental study is to test whether nutritional counseling during the first semester at a residential college prevents weight gain during the first year of college. For this intervention study to be valid, the researcher needs to recruit a reasonable cross-section of the first-year student population (Figure 19-6). If the researcher recruited students majoring in nutrition, asked for volunteers, or sampled from among student athletes, the study population would likely be much more concerned about weight than the average first-year student. ”

Answer 23

1. Study approach Experimental study 2. Study question “Does nutritional counseling during the first semester of college prevent weight gain?” 3. Data collection method “Half of the participants will be assigned to meet weekly with a nutritionist during their first semester, and half will have no intervention. All participants will complete nutritional assessments during the first and last weeks of the fall and spring semesters of their first year at college.” 4. Target population “First-year students at primarily residential colleges” 5. Source population “All first-year students at East State College” 6. Source population list “A list of all students enrolled in the mandatory first-year seminar class at East State College” 7.Sample population a randomly selected sample of students from the source population 8. Study population “Eligible individuals from the sample population who agree to participate” 9. Confidentiality “Nutritional counseling and assessment sessions will be conducted in a private setting, and only essential personnel will have access to participants’ records. Participation in the study will be voluntary, and professors teaching first-year seminars will not know which students have enrolled in the study.” “Some experimental studies require participants to be exposed to potentially risky substances or activities. In such studies, the risk of harm can be reduced by selecting an appropriate source population and defining strict inclusion and exclusion criteria. For example, studies that involve exercise must target potential participants who are likely to be healthy enough to engage in physical activity. ”

Answer 24

-“Qualitative data collection is not a detached, structured process based on a random sample of individuals.” -“Instead, researchers typically have intense contact with a selected group of informants. ” - individuals selected to participate in a qualitative study because they have expertise relevant to the study question.” -“ is a nonprobability-based sampling method that recruits participants for a qualitative study based on the SPECIAL INSIGHTS they can provide. ” -“For example, focus group participants are typically recruited through purposive sampling because they are able to provide valuable perceptions about the study question. Research projects using focus groups often hold discussions with several different sets of informants. Membership in each group is designed to minimize power differentials and allow for the open sharing of perspectives. A study of workplace safety issues might include separate groups for factory workers who use heavy equipment, their supervisors, and safety engineers at the factory. If supervisors and safety engineers were included in the discussions with the floor workers, it might be difficult for the people operating the machinery to be honest about their concerns. They might feel pressured to provide the answers they thought the company wanted to hear rather than acknowledging the need to address hazards.”

Answer 25

-“Qualitative studies often do not start with a set number of participants who are supposed to be recruited. -Instead the goal is to reach data saturation, a time in the research process in which no new information about a particular theory is emerging from additional data collection because variations across population members have already been captured. Some studies with homogeneous populations might reach saturation after 15 or 20 interviews. Some studies might require larger numbers of participants, especially if they include members with a diversity of perspectives.”

Answer 26

“populations whose members might have limited ability to make an autonomous decision about volunteering to participate in a research study. ” -“young children, some individuals with serious health issues, people in prison and some other socially marginalized populations, and others who might have limited ability to make an independent decision about volunteering to participate in a research study. ” -“These populations should not be selected as the source population for studies that do not require their participation” -“ problematic when members of vulnerable populations are systematically excluded from research, since the only way to study health issues of special importance to potentially vulnerable populations is to allow members of those populations to participate in relevant research studies.” -“Research studies including members of vulnerable populations require extra consideration of the potential risks of research to participants. The study must be sufficiently important to justify gathering new data from members of a vulnerable population. The study must allow every participant (or, for young children and those with significantly diminished cognitive abilities, a legally recognized representative) to provide informed consent free from coercion. Further, it must address concerns about the increased risks of adverse effects from study participation. For example, people with fragile health may have an elevated risk of injury from physical tests, ”

Answer 27

-“When determining how many participants are needed for a quantitative or qualitative study to be meaningful, the goal is to recruit just the right number of participants—not too many and not too few.” -“Resources are wasted when a study recruits more participants than it needs.” -“When study materials, tests, or other implementation activities have a per-participant cost, researchers do not want to spend money on excess participants.” -“They also do not want to waste the time of the research team or study participants by continuing to collect new data after they already have a sufficient number of participants. ” -“Resources are also wasted when a study recruits too few participants.” -“If a primary research project does not collect sufficient data to answer the study question, then all of the time and money invested in the project will have been wasted. ” -“Most researchers do not have the luxury of worrying about a surplus of participants, but many struggle to “recruit a sufficient study population. -A shortage can make getting statistically significant results almost impossible.”

Answer 28

-“sample size is the number of observations in a data set.” (in hs it is number of individual humans in the study population) -“The desired sample size for a quantitative study is based on statistical estimations about how many data points are required in order to answer the study question with a specified level of certainty.” -“Large samples from a population are usually better than small ones at yielding a sample mean close to the true population value. ”

Answer 29

-“A confidence interval (CI) is a statistical estimate of the range of likely values of a parameter in a source population based on the value of that statistic in a study population.” --“A narrow CI indicates more certainty about the value of the statistic than a wide CI.” --“When the sample size is small, the sample mean might be quite far from the mean in the total population. ” -“This is represented by a wide CI that reaches far to the left and right of the sample mean.” -“When a greater proportion of the total population is sampled for inclusion in the estimation of the mean age, the CI for the mean age will be narrower because there is greater certainty about the sample mean being close to the population mean.” -“The 95% CI is calculated for each sample based on the number of individuals included in the sample, the mean age of those individuals, and the standard deviation of their ages” -“If all 20 people in the total population are included in the analysis, no CI is required because the population mean age will be known exactly.” -“For the top line in Figure 20-2, the sample mean is 34 years, and the CI stretches from 18 to 50 years. Based on this sample, a researcher can be 95% confident that the mean age in the total population is somewhere between 18 and 50 years. If hundreds of random samples of 3 individuals are drawn from the total population of 20, about 95% of those samples will have a 95% CI that includes the true population mean of 39 years. About 5% of the time, the random sample of 3 individuals will include an unusually young or unusually old set of individuals, and the CI will not overlap the population mean.”

Answer 30

- identify an appropriate number of participants to recruit for a quantitative study. ”

Answer 31

- -“an error is a difference between the value obtained from a study population and the true value in the larger population from which the study participants were drawn that occurs by chance rather than as a result of system” -“Bias is a flaw in the way a study was designed or conducted that leads to an inaccurate result. -Errors, by contrast, occur _____

Answer 32

-a study population yields a statistically significant test result even though a significant difference or association does not actually exist in the source population ” -a test that shows a patient to have a disease when in fact the patient does not have the disease,

Answer 33

-a statistical test of data from a study population finds no significant result even though a significant difference or association actually exists in the source population.” -have a large sample size.

Answer 34

-“power is the ability of a test to detect significant differences in a population when differences really do exist.” -“Power is defined as 1 – β, so a 20% likelihood of a type 2 error (that is, β = 20%) corresponds to a power of 80%. -“The standard expectation is that the statistical tests that will be used to answer a study’s main research question should have a power of 80% or greater.” -“The power of statistical tests is increased when the number of participants included in the analysis is large.” -when two means or proportions are close to each other then a very large sample size is required to detect a significant difference between them --“When an incidence rate ratio or an odds ratio has a point estimate close to 1, a very large sample size will be required to yield a CI that is statistically significant and does not overlap 1.”

Answer 35

“Studies with too few participants lack adequate power to detect meaningful differences or associations in source populations.” “A study that recruits a small number of participants will not generate statistically significant test results even when there really is a substantial difference in the mean survival duration of males and females in a case series or when an exposure in a cohort study is truly a risk factor for the disease outcome of interest in the source population.” -“If the power estimates for a study are lower than desired, the easiest way to improve the power is to increase the sample size.”

Answer 36

--“Initial sample size estimates should be generated early in the study design process so that researchers can determine whether they are likely to be able to recruit a sufficient number of participants. Researchers must be prepared to rethink the study approach if their estimated number of available participants will not yield sufficient power.” - --“The sample size estimates generated by sample size and power calculators refer to the study population (the actual number of participants), not the sample population (the number of individuals invited to participate in the study).” -“The number of people sampled for a study needs to be larger than the required number of participants, because the participation rate is unlikely to be 100%.”

Answer 37

tool for systematically gathering data from study participants.”

Answer 38

series of questions used as a tool for systematically gathering data from study participants.”

Answer 39

-carefully crafted for a specific purpose

Answer 40

“Questionnaire design usually works best when it starts with the identification of the general and specific content to be covered by the survey instrument and progresses to choosing the types of questions and responses that will be most appropriate for each topic”

Answer 41

-The first step in designing a questionnaire is to list the topics that the survey instrument must cover. -first few questions enables the researcher to confirm that participants meet the eligibility criteria for the study.” -“The remaining questions ask about all of the exposure, disease, and population (demographic) areas that are the focus of the study question ”

Answer 42

-“ is the process of identifying the underlying causes of complex problems so that sustainable solutions can be developed and implemented.” -“include questions about the various factors that might influence the relationships between key exposures and outcomes.” -“For example, adults who smoke tobacco products may be more likely than other adults to consume large volumes of alcohol.”“In a study of the relationship between smoking and liver disease, alcohol consumption could be a potential confounder. ”“Because smokers are more likely than nonsmokers to drink, tobacco users may appear to be at a greater risk of liver disease than nonsmokers, even if the rate of liver disease is the same in smokers who drink as it is in nonsmokers who drink. Asking questions about both tobacco use and alcohol use enables the researcher to statistically adjust for different levels of alcohol use by smokers and nonsmokers and thus to more accurately examine the possible relationship between smoking and liver disease.”

Answer 43

inform the diversity of questions that may be relevant to include in the survey instrument.”

Answer 44

“An agent is a pathogen or a chemical or physical cause of disease or injury. -Infectious agents differ in how contagious, pathogenic, or virulent they are and whether they are drug resistant. -Drugs and other chemical agents vary in how toxic or addictive they are. ”

Answer 45

“A host is a human (or animal) who is susceptible to an infection or another type of disease or injury. Host factors describe the intrinsic characteristics that influence an individual’s vulnerability to an agent. People may have different risks of exposure, illness, and adverse outcomes as a result of age, genetics, immunology, comorbidities, nutritional status, health behaviors, psychological factors, and other characteristics.”

Answer 46

“The environment includes the external factors that facilitate or inhibit health. This construct may refer to physical characteristics of the natural and built environment, such as water quality, air quality, climate, extreme weather events, noisiness, occupational hazards, or proximity to recreational areas, major roads, and various types of healthcare services. The environment can also refer to the social and political context in which health and disease occur. ” -“Researchers seeking to understand the causes of an epidemic should gather data about all of the AHE components they think might have contributed to the event. While some agent characteristics must be determined through laboratory testing, data about many of the host and environmental factors can be collected from patients and controls using a survey instrument.”

Answer 47

“Each survey item should be assigned a specific question type, such as a date question or a yes/no question.”

Answer 48

“allow a limited number of possible responses.” -easier to statistically analyze -cons: may force individuals to choose an answer that really doesn't match their true opinion -date and time questions (used to calculate the duration of time between events)..numeric(q needs to be specific w units) and categorical questions->(which can have as few as two response options{dichotomous responses=yes/no) can have also have dozen of possible answers

Answer 49

“allow an unlimited number of possible responses.” -harder to statistically analyze relative to closed end questions -“ to give multiple answers, and to provide responses not anticipated by the researchers.” -cons: take long to ask and answer, may result in irrelevant responses -most useful when they capture initial impressions or clarify responses to close-ended questions

Answer 50

-ordinal, nominal

Answer 51

-have inherent order ex, education lvl “For example, an ordinal question should not allow response of only “less than half” and “more than half,” because that would not allow a response of “exactly half” to be recorded.”

Answer 52

-no built-in order (ranked) -like occupation -“For nominal questions, it may be helpful to include an “Other” category that allows respondents to fill in their own answers if none of the listed responses is applicable. (Typically this means asking two questions rather than one. If the response to the main closed-ended question is “Other,” the participant is asked to record a response to a second question that is open-ended.) ” -“For ranked questions, the researcher chooses how many entries to include on the scale and whether there will be a neutral option.” “A Likert scale presents ordered “responses to a questionnaire item that asks participants to rank preferences numerically, such as by using a scale for which 1 indicates strong disagreement and 5 indicates strong agreement. Most scales with a neutral option list 5 to 7 categories. Most scales without a neutral option list 4 or 6 categories.”

Answer 53

a series of yes/no questions rather than asking respondents to “check all that apply.”

Answer 54

need an i do not know category to avoid information bias(individuals choosing an answer that they think the research team would like to hear even if they have are unsure about the question.

Answer 55

“is the inability of a participant’s identity to be discerned from his or her responses to a survey instrument or records in a database. Anonymity protects participants and allows them to provide honest answers to sensitive questions.” -if they ask for too much info that might be too personal...this can lead to question skipping, dropping out of study, instead of asking for specific birth date, they can ask give them a range of age

Answer 56

Does each question ask what it is intended to ask? Is the language of each question clear and neutral? Will members of the study population understand the language? Do questions about sensitive topics use language acceptable to the source population? Are the response options clearly presented? For scaled questions, is the rank order clear? (For example, is it obvious that 1 is“strongly disagree” and 5 is “strongly agree”? Or, alternatively, that 1 is “excellent” and 7 is “poor”?) For questions with unranked categories, is the order of possible responses alphabetical or otherwise neutral?”

Answer 57

-“Habituation is an error that occurs when participants completing a questionnaire or interview become so accustomed to giving a particular response (like “agree . . . agree . . . agree . . .”) that they continue to reply with the same response even when that does not match their true perspectives.” -“Survey developers must carefully consider how previous questions could taint the answers to later ones. For example, once a participant has considered a variety of opinions about a topic, he or she can no longer provide an unbiased first impression “the researcher may want to order questions about impressions this way:” “ First, an open-ended question to garner an initial impression from participants: “What do you do most often when _____?” Second, a series of yes/no questions to clarify beliefs, perceptions, and practices: “Do you ever _____?” Last, a concluding open-ended question to allow participants to express final impressions: “Now that you have considered the possibilities, what would you say you do most often when ______?”

Answer 58

-“When a paper-based survey (sometimes called a paper-and-pencil survey) is used, the pages should not be too crowded. White space is the blank areas between printed content on a page. White space is helpful for separating sections and making the pages visually appealing. ” -“When an Internet-based or computer-based survey is used, there must be a high level of contrast between the colors selected for backgrounds and text.” for both...font should be large and readable

Answer 59

there are many questions in the survey instrument, when some questions will be irrelevant to some participants, and when the researcher wants to require participants to provide an answer to one or more questions before the next set of questions is revealed.”

Answer 60

one that determines whether the respondent is eligible to answer a subsequent question or set of questions.” “For example, participants who indicate that they have never used tobacco products can be prompted to skip a series of questions about smoking habits.” “For paper-based forms, instructions for skips must be carefully described in words. ”

Answer 61

automatically hide irrelevant questions from participants based on their responses to filter questions. (In some data collection programs, skip logic is called routing or branching.)”

Answer 62

“ “Fill in the oval in front of your answer completely using blue or black ink.” “Write your answer in block capital letters, as shown in the example below.” “Select the one answer that best describes you.” “Circle all options that apply to you.” “If you answered ‘NO’ to Question 4, then skip to Question 8. If you answered ‘YES’ to Question 4, then please answer Questions 5, 6, and 7 before moving on to Question 8.” ”

Answer 63

consistent answers are given to similar questions and when an assessment yields the same outcome when repeated several times.” “Agreement between two or more evaluations is another facet of reliability.”

Answer 64

established when the responses or measurements are shown to be correct. ”

Answer 65

the items in a survey instrument measure various aspects of the same concept. Some survey instruments ask the same question several different ways, or ask a series of similar questions, in order to confirm the stability of participants’ responses.” ex, including two questions that are opposite to one another -if they get both questions right it means that it is reliable and they are not just bs

Answer 66

two or more related items in a survey instrument measure various aspects of the same concept.”

Answer 67

“ is a measure of internal consistency that is used with variables that have ordered responses.” -expressed as numbers 0-1 (near 1 high reliability)

Answer 68

is a measure of internal consistency that is used with binary variables.” -expressed as numbers 0-1

Answer 69

interesting

Answer 70

“is demonstrated when people who take a baseline assessment and then retake the test later have about the same scores each time they are tested”

Answer 71

“describes the degree of concordance among independent raters assessing the same study participants.”

Answer 72

“whether two assessors who evaluated the same study participants agreed more often than is expected by chance ” “For example, the value of the kappa statistic can indicate whether two radiologists examining the same set of x-ray images reach the same conclusion about the presence or absence of a fracture more or less often than expected. If the two radiologists agree as often as expected, κ = 0. If they agree on the interpretation of 100% of the x-ray images shown to both ofthem, κ = 1. If they agree more often than expected, kappa will have a positive value somewhere between 0 and 1. Although complete agreement is rare, a valid study will have a value of kappa that is close to 1.”

Answer 73

concept(also general abstraction, construct(multidimensional concept that has been carefully designed for research purposes (ex, trust and leadership are more difficult to quantify)

Answer 74

subject-matter experts agree that a set of survey items captures the most relevant information about the study domain. Content validity requires consideration of the technical quality of the survey items as well as their representativeness of all the dimensions of the theoretical construct being measured by the survey instrument.”

Answer 75

is present when content experts and users agree that a survey instrument will be easy for study participants to understand and correctly complete.”

Answer 76

principal component analysis (PCA) PCA

Answer 77

a set of questions in a survey instrument measures the theoretical construct the tool is intended to assess. Construct validity requires the development of an explicit theoretical construct and a rigorous examination of how well an assessment tool represents that construct. Ideally, empirical tests can be used as part of the examination of construct validity. Various measures of correlation are often used for the process of examining interrelationships among variables measuring different aspects of the same theme.”

Answer 78

measured variables to model a latent variable that represents a construct that cannot be directly measured with one question but appears to have a causal relationship with a set of measured variables.”

Answer 79

“is present when two items that the underlying theory says should be related are shown to be correlated.”

Answer 80

two items that the construct says should not be related are shown not to be associated.”

Answer 81

an established test or outcome as a standard (or criterion) for confirming the utility of a new test that examines a similar theoretical construct. For example, a new test of intelligence can be validated against standard IQ tests, and a shorter version of a widely used assessment tool can be validated against the longer original version. ”

Answer 82

-Concurrent validity is evaluated when participants in a pilot study complete both the existing and new tests and the correlation between the test results is calculated. A strong correlation between the tests is evidence that the new test is valid.” -ex,Concurrent validity could be demonstrated by comparing scores on the new test with scores on the MCAT, which is the current standard test for medical college admission in the United States. -Predictive validity is appraised when the new test is correlated with subsequent measures of performance in related domains. Suppose researchers create a new test intended to predict success in medical school. ex, administering the test to incoming medical students and comparing their results on the new test with their performance on the initial licensing exam (USMLE Step 1) taken 2 years later.”

Answer 83

“include survey questions or modules that are identical to the ones used in previous research projects. ” “new research projects usually require the development and testing of a completely new survey instrument.” “However, several widely used and validated tests are available to researchers, ”

Answer 84

“a multidimensional construct that captures an individual’s perceived physical, mental, emotional, and social well-being and the perceived impact of health status on the quality of daily life”

Answer 85

one person translates the questionnaire from the original language to a new language and then a second person translates the survey instrument in the new language back into the original language.” -“A comparison of the original version of the survey with the back-translated version will reveal where the second-language “translation does not match the intended meaning of the original version. A second approach is to have two translators independently translate the survey instrument from the original to the new language. The two translations are compared, and a consensus process is used to decide which words and phrases best convey the precise meaning and complexity of the original questionnaire.”

Answer 86

small-scale preliminary study conducted to evaluate the feasibility of a full-scale research project. A pilot test of a questionnaire is helpful for checking, among other issues:” “ The wording and clarity of the questions The order of the questions The ability and willingness of participants to answer the questions The responses given, and whether the responses match the intended types of responses The amount of time it takes to complete the survey” “The researcher should ask several volunteers to help with the pilot test. These volunteers should be from the target population and meet the eligibility criteria for the study (in terms of age, exposure and disease status, and other key factors), but they should not be members of the sample population. They should be asked to complete the preliminary survey and then provide feedback about content, clarity, layout, timing, and other factors. Feedback may be provided individually or as part of a focus group. The survey instrument is revised based on these observations. Several rounds of pilot testing may be required to develop a sound survey instrument.”

Ch19,20,21 Flashcards

(122 cards)