Answer :- All of the above.
What is bias?
Bias is the lack of neutrality or prejudice. It can be simply defined as "the deviation from the truth". In scientific terms it is "any factor or process that tends to deviate the results or conclusions of a trial systematically away from the truth. Such deviation leads, usually, to over-estimating the effects of interventions making them look better than they actually are.
Bias can occur and affect any part of a study from its planning phase to its publication. It arises mainly due to the adoption of an inadequate design, misconduct of the research methodology or the inadequate analysis of data. As research is important for determining whether a new intervention is effective or not and if effective what is the magnitude of its effectiveness, bias is obviously detrimental to research and hence to clinical practice.
There are many types of bias that affect scientific research.
Confounders
Research aims primarily at measuring the association between two variables; an intervention (or exposure) and an outcome. This can be achieved by designing a comparative research with at least two groups; one receiving the intervention under investigation (study group) and another either receiving a placebo or another intervention
(a control group). The outcomes in both groups are then compared.
A confounder is defined as "a variable, other than the one studied, that can cause or prevent the outcome of interest." For any outcome in research there are many confounders that should be considered in the planning phase of the trial, reported in the results section and analyzed for significant differences between the groups. Any confounding variable should be equally distributed in the two groups to give balanced groups. Some other examples of confounders are the effect of smoking, life style, and dietary habits on bone mineral density and the frequency of sexual intercourse, duration of sexual activity, and number of partners on cancer cervix.
Selection bias
Interferences from researchers to divide patients into groups (select which patient goes to which group) will result in dissimilar or unbalanced groups and would introduce bias into the study. Such type of bias is known as "selection bias." If investigators "thought wrongly" that they can equally distribute or balance all the basic characteristics and risk factors or confounders between the groups, they definitely can not ensure balancing unknown risk factors or unknown confounders. The best way of eliminating selection bias, then, is by randomizing patients properly into groups.
Recall bias
Recall bias is a systematic error that occurs when participants do not remember previous events or experiences accurately or omit details: the accuracy and volume of memories may be influenced by subsequent events and experiences. Recall bias is a problem in studies that have self-reporting, such as case-control study and retrospective cohort studies.
The "Healthy Worker" Effect
The "health worker" effect is really a special type of selection bias that occurs in cohort studies of occupational exposures when the general population is used as the comparison group. The general population consists of both healthy people and unhealthy people. Those who are not healthy are less likely to be employed, while the employed work force tends to have fewer sick people. Moreover, people with severe illnesses would be most likely to be excluded from employment, but not from the general population. As a result, comparisons of mortality rates between an employed group and the general population will be biased.
Suppose, for example, that a given occupational exposure truly increases the risk of death by 20% (RR=1.2). Suppose also that the general population has an overall risk of death that is 10% higher than that of the employed workforce. Given this scenario, use of the general population as a comparison group would result in a underestimate of the risk ratio, i.e. RR=1.1.
Question 24 2 pts A systematic deviation of results or inferences from the truth includes O...
A systematic deviation of results or inferences from the truth includes O confounding O recall bias O selection bias O healthy worker effect O all of the above
HELP ME PLEASE DQuestion 1 1 pts Which of the following is NOT a source of bias? O A. Random error O B. Confounding ° C. Systematic error o D. Healthy worker effect
l-) Moving to another question will save this response Question 31 Which term is defined as "the deviation of the results from the truth?" Chance Bias 0 Random variation Confounding Effect modification Moving to another question will save this response. F7 F6 名 F3 2 Moving to another question will save this response. Question 32 of 50 Question 32 If a causal factor can produce an outcome withou 2 points Save Answ ut any other factors present and is required...
PLEASE HELP ME ANSWER THESE QUESTIONS! Question 2 Validity of a study depends on systematic error. O A. True B. False Question 3 1 pt A study found that the effect of binge drinking on health was shown to vary by gender. This is an example of 0 external validity O B. confounding. 0 C, effect modification. D. internal validity MacBook Ai
Question 1 2 pts The difference between the mean outcome of those who are treated and those who are untreated when the assignment of treatments is random is a good estimate of the Average treatment effect (ATE) but not the Treatment on the treated (TT) Selection bias Treatment on the treated but not the average treatment effect Average treatment effect which is equal to the treatment on the treated Sum of treatment on the treated and selection bias Question 2...
Please answer this ENTIRE question. Question 3 (33 pts.) Michael is a health economics student interested in estimating the effect of health insurance coverage Di on the number of doctor visits Y, by estimating the population regression function (PRF) Y-B+ β2D, + ui by using the sample reported in Table 2, Enrollment in a health insurance plan is voluntary. Table 2 ups D Michael has heard that observational studies produce biased results, while randomized experiments deliver the causal effect if...
2 pts D Question 23 Question 24 2 pts s Quiz Will Be S 2 pts This is O The r 2 pts D Question 23 Question 24 2 pts s Quiz Will Be S 2 pts This is O The r
QUESTION 4 In a systematic review with a meta-analysis, researchers combine the results of each of the individual studies to create a larger sample size (and therefore greater power), then re-run the statistics to capture the true magnitude of the effect. The single-effect measure calculated and reported when the results from all the studies are combined is called what? A. Summary statistic B. Power analysis eC. Confidence Interval e D.Chi square E. Pearson's co-efficient
5 pts Question 1 What are cognitive biases? O subconscious factors that affect the formation of beliefs O psychological forces that skew our reasoning processes O things like the false consensus effect and the bandwagon effect all of the above D Question 2 5 pts Consider the following argument 1. If Greg is a philosopher, then Greg is a horse. 2. Greg is a philosopher. 3. Therefore, Greg is a horse. This argument is O vallid but not sound O...
Question 1 O pts (Systematic vs. Non-Systematic). For this Pause-Problem, I want you to think of a study idea that you can approach first from a non- systematic perspective and second from a systematic perspective. My hint is to start with the non- systematic research first! HTML Editorga BIUA- A - I E E D T T 12pt Paragraph Non systematic: Systematic (Your Lab Study). For this Pause-Problem, look at your lab hypothesis for study one. Does it meet /not...