Comparing Categorical Data Flashcards
What is a baseline measurement in clinical research?
A baseline measurement is taken at the beginning of a trial or experiment, before any intervention starts. It helps to describe the population being studied and serves as a reference to detect any changes during the experiment.
Why is it important to match groups for characteristics in a clinical trial?
Groups should be well-matched for characteristics (e.g., sex, age, etc.) to ensure a fair test and allow for the true effect of the treatment to be observed, minimizing biases.
What is categorical data in clinical research?
Categorical data is reported as numbers or counts and percentages with no units, often representing different categories or groups within the population.
What is quantitative data in clinical research?
Quantitative data is reported as means, standard deviations, or medians (with interquartile range), and it includes units of measurement. This type of data represents numerical values that can be analyzed statistically.
What are the two main types of groups in clinical research?
The two main types of groups in clinical research are the treatment group and the control group.
What are some examples of patient characteristics in clinical research?
Patient characteristics in clinical research include sex, ethnic group, smoking history, and other demographic or health-related factors.
What types of events might be studied in clinical research?
Events studied in clinical research include diagnoses, healthcare utilization, and death or survival rates.
What is the purpose of calculating a P value in hypothesis testing?
The P value helps to determine the probability of obtaining a test statistic (e.g., z-score, t-statistic, chi-squared statistic) under the assumption that the null hypothesis is true. It indicates whether the observed results are statistically significant.
What does it mean if the P value is less than 0.05?
If the P value is less than 0.05, it means that the chance of obtaining the test statistic under the null hypothesis is less than 5%, so the null hypothesis is rejected, and the result is considered statistically significant.
What does it mean if the P value is greater than 0.05?
If the P value is greater than 0.05, it means that the chance of obtaining the test statistic under the null hypothesis is greater than 5%, so the null hypothesis is accepted, and the result is not statistically significant.
What is a null hypothesis in clinical research?
A null hypothesis is a statement that there is no effect or no difference between groups or treatments in an experiment. It is tested to determine if there is enough evidence to reject it.
What test statistics can be used to calculate a P value?
Common test statistics used to calculate a P value include the z-score, t statistic, and chi-squared statistic.
What is the purpose of standard deviation in quantitative data analysis?
The standard deviation measures the amount of variation or dispersion in a set of data. A larger standard deviation indicates greater variability in the data.
What does a mean represent in quantitative data analysis?
The mean represents the average of a set of data points and provides a measure of central tendency.
What is a median, and when is it used in quantitative data analysis?
The median is the middle value in a dataset when the values are arranged in order. It is often used when the data is skewed or contains outliers, as it is less affected by extreme values than the mean.
What is interquartile range in quantitative data analysis?
The interquartile range (IQR) is the difference between the first quartile (25th percentile) and the third quartile (75th percentile) of a dataset. It measures the spread of the middle 50% of the data.
What is the difference between treatment and control groups in clinical trials?
The treatment group receives the intervention being studied, while the control group does not receive the intervention and serves as a comparison group to evaluate the effects of the treatment.
What is the significance of describing patient characteristics in a clinical trial?
Describing patient characteristics ensures that both groups in the trial are comparable, which helps to attribute observed effects specifically to the intervention rather than differences in the population.
What kind of data can be used to describe health care utilization in clinical research?
Data on health care utilization can include the number of hospital visits, treatments received, surgeries performed, or any other healthcare services used by patients during the study period.
Why is it important to have baseline measurements before starting an intervention?
Baseline measurements provide a reference point for comparison, allowing researchers to detect changes that occur as a result of the intervention and assess the true effect of the treatment.
