Full Answer
What is a treatment variable in research?
What is a treatment variable? Treatment. In an experiment, the factor (also called an independent variable) is an explanatory variable manipulated by the experimenter. Each factor has two or more levels, i.e., different values of the factor. Combinations of factor levels are called treatments.
How is efficacy measured?
Efficacy can be assessed accurately only in ideal conditions (ie, when patients are selected by proper criteria and strictly adhere to the dosing schedule). Thus, efficacy is measured under expert supervision in a group of patients most likely to have a response to a drug, such as in a controlled clinical trial.
What is the difference between efficacy and effectiveness of an intervention?
INTRODUCTION. Intervention studies can be placed on a continuum, with a progression from efficacy trials to effectiveness trials. Efficacy can be defined as the performance of an intervention under ideal and controlled circumstances, whereas effectiveness refers to its performance under ‘real-world' conditions.
Do efficacy and effectiveness trials use the same statistical analysis methods?
Both efficacy and effectiveness trials typically use an intention-to-treat approach for statistical analysis. However, given that efficacy trials aim to address if interventions work under ideal circumstances, secondary analyses using a per-protocol approach may be informative.
What type of variable is treatment?
Parts of the experiment: Independent vs dependent variablesType of variableDefinitionIndependent variables (aka treatment variables)Variables you manipulate in order to affect the outcome of an experiment.Dependent variables (aka response variables)Variables that represent the outcome of the experiment.1 more row•Nov 21, 2019
Is treatment dependent or independent variable?
independent variablethe independent variable, whose effect on a dependent variable is studied in a research project.
Is treatment variable the same as independent?
In an experiment, the factor (also called an independent variable) is an explanatory variable manipulated by the experimenter. Each factor has two or more levels, i.e., different values of the factor. Combinations of factor levels are called treatments.
Is effectiveness a dependent variable?
For example, if a study investigated the effectiveness of an experimental treatment for depression, then the measure of depression would be the dependent variable.
What are some examples of independent and dependent variables in healthcare?
For example: In a study of how different doses of a drug affect the severity of symptoms, a researcher could compare the frequency and intensity of symptoms when different doses are administered. Here the independent variable is the dose and the dependent variable is the frequency/intensity of symptoms.
How do you identify treatments in an experiment?
Treatments are administered to experimental units by 'level', where level implies amount or magnitude. For example, if the experimental units were given 5mg, 10mg, 15mg of a medication, those amounts would be three levels of the treatment.
Which variable is the treatment or intervention in a study?
In a scientific study, a control group is used to establish a cause-and-effect relationship by isolating the effect of an independent variable. Researchers change the independent variable in the treatment group and keep it constant in the control group.
What is a treatment group in statistics?
Treatment groups are the sets of participants in a research study that are exposed to some manipulation or intentional change in the independent variable of interest.
What is an example of a moderating variable?
Moderating variables can be qualitative (non-numerical values like race, socioeconomic class or sex) or quantitative (numerical values like weight, reward level or age). For example: According to the American Psychological Association, stress has a bigger impact on men than women.
Is medication a dependent variable?
When a researcher gives an active medication to one group of people and a placebo, or inactive medication, to another group of people, the independent variable is the medication treatment. Each person's response to the active medication or placebo is called the dependent variable.
What are the types of dependent variables?
In statistics, dependent variables are also called:Response variables (they respond to a change in another variable)Outcome variables (they represent the outcome you want to measure)Left-hand-side variables (they appear on the left-hand side of a regression equation)
What are some examples of dependent and independent variables?
Independent variable causes an effect on the dependent variable. Example: How long you sleep (independent variable) affects your test score (dependent variable). This makes sense, but: Example: Your test score affects how long you sleep.
What are independent and dependent variables?
You can think of independent and dependent variables in terms of cause and effect: an independent variable is the variable you think is the ca...
What is a confounding variable?
A confounding variable , also called a confounder or confounding factor, is a third variable in a study examining a potential cause-and-effect r...
What is the difference between quantitative and categorical variables?
Quantitative variables are any variables where the data represent amounts (e.g. height, weight, or age). Categorical variables are any variables...
What is the difference between discrete and continuous variables?
Discrete and continuous variables are two types of quantitative variables : Discrete variables represent counts (e.g. the number of objects in a...
How is treatment effectiveness measured?
There are three main ways in which treatment effectiveness is measured: the patient's own impression of wellness, the therapist's impression, and some controlled research studies.
Why is cognitive therapy effective?
These kinds of studies have shown that for depression and panic disorders, cognitive therapy is most effective, potentially because these disorders are in part caused by the kind of negative thinking directly addressed by cognitive therapy.
Why do people with schizophrenia have lower recovery rates?
Patients least likely to get better tend to think negatively and behave hostilely. For reasons therapists don't thoroughly understand , personality disorders and psychotic disorders, like schizophrenia, tend to have lower rates of recovery in general.
What are the shortcomings of a therapist's evaluation?
Shortcomings of Therapist's Evaluations. Therapists' evaluations of patients are subject to all of the same problems as patients' evaluations. They, too, may mistake regression to the mean for positive effects of treatment.
Can a Freudian model cause false memories?
Those who, in a Freudian model, try to produce false memories of past trauma can end up setting a patient back in recovery. Finally, it should be obvious that a sexual relationship between a patient and therapist could be harmful to recovery; still, it happens, and is a serious ethical violation.
Do patients expect to get better?
If patients expect to get better, they probably will , at least in some ways. On a related note, patients sometimes feel like they should be getting better as a way of justifying the effort involved in seeking treatment; going to see the therapist, paying money for sessions or for drugs.
Does systematic desensitization help with phobias?
For specific phobias, systematic desensitization really does help patients face their fears. Influence of Attitude On Treatment Effectiveness. Studies also isolated certain characteristics of the patient and the therapist that affect how well any of these treatments will work.
What are the two types of variables?
Variables can be broadly classified into one of two types: Quantitative. Categorical. Below we define these two main types of variables and provide further sub-classifications for each type. Categorical variables take category or label values, and place an individual into one of several groups. Categorical variables are often further classified as ...
What are the variables in medical records?
In our example of medical records, there are several variables of each type: Age, Weight, and Height are quantitative variables. Race, Gender, and Smoking are categorical variables.
What is discrete variable?
Quantitative variables take numerical values, and represent some kind of measurement. Discrete, when the variable takes on a countable number of values. Most often these variables indeed represent some kind of count such as the number of prescriptions an individual takes daily.
Do categorical variables have arithmetic?
They have no arithmetic meaning (i.e., it does not make sense to add, subtract, multiply, divide, or compare the magnitude of such values). Usually, if such a coding is used, all categorical variables will be coded and we will tend to do this type of coding for datasets in this course.
Is ordinal variable categorical?
However, ordinal variables are still categorical and do not provide precise measurements. Differences are not precisely meaningful, for example, if one student scores an A and another a B on an assignment, we cannot say precisely the difference in their scores, only that an A is larger than a B.
Why do researchers use variables?
Researchers and statisticians use variables to describe and measure the items, places, people or ideas they are studying. Many types of variables exist, and you must choose the right variable to measure when designing studies, selecting tests and interpreting results. A strong understanding of variables can lead to more accurate statistical ...
What is a control variable?
Control variables. Control or controlling variables are characteristics that are constant and do not change during a study. They have no effect on other variables. Researchers might intentionally keep a control variable the same throughout an experiment to prevent bias.
What is extraneous variable?
Extraneous variables are factors that affect the dependent variable but that the researcher did not originally consider when designing the experiment. These unwanted variables can unintentionally change a study's results or how a researcher interprets those results.
How does moderating change the relationship between dependent and independent variables?
A moderating or moderator variable changes the relationship between dependent and independent variables by strengthening or weakening the intervening variable's effect. For example, in a study looking at the relationship between economic status (independent variable) and how frequently people get physical exams from a doctor ...
How many variables are there in an experiment?
Every experiment has at least two variables—an independent variable and a dependent variable. The independent variable is what you are testing, and the dependent variable is the result. Any other variables in your experiment build on or affect the independent or dependent variables. Most experiments also include a controlled variable.
What is a confounding variable?
Confounding variables. A confounding variable is one you did not account for that can disguise another variable's effects. Confounding variables can invalidate your experiment results by making them biased or suggesting a relationship between variables exists when it does not.
What are dependent variables? What are some examples?
Independent variables can influence dependent variables, but dependent variables cannot influence independent variables. For example, the time you spent studying (dependent) can affect the grade on your test (independent) but the grade on your test does not affect the time you spent studying.
When is efficacy measured?
Thus, efficacy is measured under expert supervision in a group of patients most likely to have a response to a drug, such as in a controlled clinical trial.
What does numerical variables mean in clinical trials?
Numerical variables, unlike dichotomous outcomes, may indicate the magnitude of an effect. Thus, use of surrogate outcomes can often provide much more data for analysis than can patient-oriented outcomes, allowing clinical trials to be done using many fewer patients.
What is the NNT of a risk reduction?
NNT can be simply calculated as the inverse of the absolute risk reduction; if the absolute risk reduction is 5% (0.05), the NNT = 1/0.05 = 20. NNT can be calculated for adverse effects also, in which case it is sometimes called the number needed to harm (NNH).
What factors are considered when deciding if a drug is indicated?
In making such judgments, clinicians often consider factors that are somewhat subjective, such as personal experience, anecdotes, peer practices, and expert opinions.
Why are benefits reported as relative risk reductions?
Most often, benefits are reported in the literature as relative risk reductions because these make a drug look more effective than the absolute risk reductions (in the previous example, a 50% reduction in mortality sounds much better than a 5% reduction).
What is a narrow therapeutic index?
If the therapeutic index is narrow (eg, < 2) , factors that are usually clinically inconsequential (eg, food-drug interactions, drug-drug interactions , small errors in dosing) can have harmful clinical effects. For example, warfarin has a narrow therapeutic index and interacts with many drugs and foods.
When should a drug be used?
Obviously, a drug (or any medical treatment) should be used only when it will benefit a patient. Benefit takes into account both the drug's ability to produce the desired result (efficacy) and the type and likelihood of adverse effects (safety). Cost is commonly also balanced with benefit (see Economic Analyses in Clinical Decision Making ).
What is the efficacy dose response curve?
In defining the efficacy dose-response curve, it is important to define what elements of efficacy you want to maximize. For example, you may want to find the dose that maximizes the intervention's ability to: Cure a disease: For example, resolve pneumonia. Eliminate symptoms: For example, headache.
What are the three parameters of antibiotics?
For many years, traditional teaching about antibiotics focused on three classic parameters: efficacy, safety, and cost-effectiveness. With respect to safety, the major considerations were allergic reactions and adverse effects. In the new era of “bad bugs and no drugs,” 2 an important new safety issue should be added: unintended consequences of antibiotic therapy. An insightful report termed such unintended consequences the “collateral damage” of antibiotics, in which some unwanted event occurs in the process of trying to achieve clinical efficacy through antibiotic killing. 97 In this report, collateral damage referred to the ecologic adverse effect of selecting drug-resistant organisms and the unwanted development of colonization or infection with multidrug-resistant organisms. In the worldwide epidemic of antibiotic resistance, this prob-ably is the best-characterized form of collateral damage to date. Some important new considerations recently described in the literature, however, may influence initial antibiotic selection for serious infections in the ICU.
What is the best index of aerobic capacity and maximal cardiorespiratory function?
Maximal oxygen uptake is considered the best index of aerobic capacity and maximal cardiorespiratory function. By defining the limits of the cardiopulmonary system, maximal oxygen uptake has been an invaluable measurement clinically for assessing the efficacy of drugs, exercise training, or invasive procedures.
Is acute toxicity more important than cumulative toxicity?
For example, acute toxicity is more important for a drug given for a very short time. Cumulative toxicity is more important for a drug given over a long period of time.
Is dose selection stochastic?
One important aspect of dose selection is that many dose related responses, such as pharmacokinetic and pharmacodynamic, are not stochastic. There is enough reproducibility and low enough variability so that deterministic methods can be used with some pharmacokinetic and pharmacodynamic parameters.
