Evidence Based Practice Week 4 – Clinical Interventions Study

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Questions and Answers

In a clinical study, if researchers incorrectly apply a statistical analysis designed for nominal data to continuous data, what is the most likely consequence?

The study's conclusions will be strengthened, since the analysis will uncover hidden patterns undetectable via correct methods.
The study's findings will be more generalizable to a broader population, as advanced statistical methods enhance external validity.
The study will yield more precise p-values, enhancing the statistical power and minimizing type II errors.
The study's results will be considered invalid due to the inappropriate application of statistical methods. (correct)

A researcher wants to categorize patients based on their primary mode of transportation to the clinic: car, public transportation, bicycle, or walking. Which data type is most appropriate for this categorization?

Nominal, because the modes of transportation are distinct categories without inherent order. (correct)
Scale, because the data will be used for complex modeling and regression analysis.
Ordinal, because the modes of transportation can be ranked based on environmental impact.
Continuous, because the distance traveled by each mode could theoretically be measured.

A physical therapist measures a patient's shoulder range of motion using a goniometer. Which data type do these measurements represent, and why?

Discrete, because the goniometer only provides measurements in whole number increments.
Continuous, because the range of motion can be measured on a scale with potentially infinite values between any two points. (correct)
Nominal, because each degree of motion is simply a label without quantitative meaning.
Ordinal, because range of motion is clinically categorized into poor, fair, good, and excellent.

A survey asks participants to rate their satisfaction with a new rehabilitation program on a scale from 1 to 7, where 1 = 'Extremely Dissatisfied' and 7 = 'Extremely Satisfied.' This type of data is best described as:

Ordinal, because the scale represents a ranked order of satisfaction levels, but the intervals may not be equal. (A) Signup and view all the answers

In what critical way does continuous data differ from ordinal data?

Each unit of measurement in continuous data has a meaningful value, whereas in ordinal data the intervals may not be equal or meaningful. (C) Signup and view all the answers

In a clinical trial, a new drug reduces the risk of a certain condition from 10% in the control group to 6% in the treatment group. What is the Absolute Risk Reduction (ARR)?

0.04 (B) Signup and view all the answers

A study finds a statistically significant difference between two groups with a p-value of 0.01. Which of the following is the most accurate interpretation of this p-value?

If the null hypothesis were true, there is a 1% chance of observing a result as extreme as, or more extreme than, the one observed. (B) Signup and view all the answers

Which of the following statements correctly differentiates between Relative Risk Reduction (RRR) and Absolute Risk Reduction (ARR)?

ARR provides the actual reduction in risk, while RRR expresses this reduction as a proportion of the control group's risk. (A) Signup and view all the answers

In a study comparing a new treatment to a placebo, the Number Needed to Treat (NNT) is calculated to be 5. What is the best interpretation of this NNT?

For every five patients treated with the new treatment, one additional patient benefits compared to placebo. (C) Signup and view all the answers

A researcher is evaluating the effectiveness of a new educational program. They find a Cohen's d effect size of 0.8. How should this effect size be interpreted?

The program has a large effect, indicating a substantial impact. (B) Signup and view all the answers

In a study on a new drug, the risk of a side effect in the treatment group is 5%, while in the control group, it is 8%. Calculate the Relative Risk Reduction (RRR).

37.5% (A) Signup and view all the answers

A study reports a Pearson's r correlation coefficient of -0.7 between two variables. Which of the following interpretations is most accurate?

There is a strong negative correlation between the two variables. (B) Signup and view all the answers

A researcher conducts a study and calculates a 95% confidence interval for the mean difference between two groups. The confidence interval ranges from -2.5 to 1.2. What can the researcher conclude?

There is no statistically significant difference between the two groups because the confidence interval includes 0. (C) Signup and view all the answers

In the context of research study appraisal, why is it crucial to evaluate the similarity of groups at baseline?

To confirm that any observed differences post-intervention are likely due to the intervention rather than pre-existing differences. (A) Signup and view all the answers

What is the primary distinction between intra-rater and inter-rater reliability?

Intra-rater reliability evaluates the repeatability of measurements by the same therapist, while inter-rater reliability assesses the repeatability between two or more therapists. (C) Signup and view all the answers

When interpreting research results, a narrow confidence interval (CI) is preferred because it suggests:

The computed mean closely represents the true population mean, enhancing the measure's clinical utility. (D) Signup and view all the answers

How does the interpretation of clinical relevance differ from that of statistical significance in research?

Statistical significance determines if a result is likely due to chance, whereas clinical relevance assesses the practical importance of the result for patient care. (D) Signup and view all the answers

What does the 'Number Needed to Treat' (NNT) indicate in the context of evaluating an intervention's effectiveness?

The number of patients needed to be treated with a new intervention to observe one additional positive outcome compared to a control. (D) Signup and view all the answers

In the context of descriptive statistics, when is it most appropriate to report the median and mode instead of the mean and standard deviation?

When the data is skewed and you want to minimize the influence of outliers. (C) Signup and view all the answers

Which type of data is characterized by having a true zero point, indicating the complete absence of the quantity being measured?

Ratio data, allowing for calculations of ratios and proportions due to a meaningful zero. (C) Signup and view all the answers

What is the fundamental difference between reliability and accuracy in the context of measurement?

Reliability is the ability to consistently replicate a measurement, whereas accuracy is about obtaining the correct result. (B) Signup and view all the answers

In research, a p-value of 0.06 is obtained. Assuming an alpha level of 0.05, what is the most accurate interpretation of this finding?

The results are not statistically significant, suggesting the observed difference may be due to chance. (A) Signup and view all the answers

Consider a scenario where an Intraclass Correlation Coefficient (ICC) is calculated to assess inter-rater reliability and yields a value of 0.1. How should this value be interpreted?

The raters’ agreement is poor, implying substantial discrepancies in their measurements. (C) Signup and view all the answers

What is meant by 'intra-individual reliability'?

The consistency of the individual's physiological response or measurement over repeated trials, reflecting natural variations within the individual. (B) Signup and view all the answers

How does 'intra-rater inter-session reliability' differ from 'intra-rater intra-session reliability'?

Intra-rater inter-session reliability pertains to measurements taken by a single rater across separate sessions, whereas intra-rater intra-session reliability concerns measurements within the same session. (C) Signup and view all the answers

Which of the following scenarios would MOST likely necessitate the use of non-parametric statistical tests?

Analyzing customer satisfaction ratings on a Likert scale, where the data is ordinal. (B) Signup and view all the answers

A researcher aims to measure pain levels in patients using a visual analog scale (VAS). What type of data is produced by this measurement?

Ordinal, because pain levels can be ranked. (A) Signup and view all the answers

In a study evaluating a new drug, researchers report a statistically significant result with a small effect size (Cohen's d = 0.2). How should these findings be interpreted?

The drug has a small effect on patient outcomes, and the statistical significance may be due to a large sample size. (B) Signup and view all the answers

Which of the following statistical tests is LEAST appropriate for analyzing the association between two categorical variables when one or both variables have a small sample size, potentially violating assumptions of expected cell counts?

Chi-square test (C) Signup and view all the answers

In the context of research study appraisal, which factor would most significantly undermine the applicability and generalizability of a randomized controlled trial's findings to a broader clinical population?

The study population has narrowly defined inclusion criteria that exclude a substantial portion of typical patients. (A) Signup and view all the answers

Which strategy offers the MOST direct and effective approach to mitigate confirmation bias in clinical research?

Implementing blinding procedures to conceal the treatment allocation from participants and researchers. (B) Signup and view all the answers

A dataset exhibits a distribution where the mean is substantially lower than the median. What can be inferred about the distribution's shape?

The distribution is negatively skewed (left skew). (D) Signup and view all the answers

In the context of descriptive statistics, what is the MOST significant limitation of using the range as a measure of data spread?

The range is highly sensitive to extreme values or outliers. (D) Signup and view all the answers

A research study reports a 95% confidence interval (CI) for the difference in mean scores between two treatment groups as (-1.5, 0.5). What is the MOST appropriate interpretation of this CI?

We are 95% confident that the true difference in means lies between -1.5 and 0.5, and there is no statistically significant difference between the groups at the 0.05 alpha level. (A) Signup and view all the answers

A researcher is designing a study to assess the test-retest reliability of a new goniometer for measuring joint range of motion. To minimize potential sources of error and obtain a more accurate estimate of intra-individual reliability, what control procedures should be implemented?

Ensure that the same therapist performs all measurements, and standardize the measurement protocol across all sessions. (B) Signup and view all the answers

In hypothesis testing, what is the practical implication of increasing the sample size in a study?

It increases the power of the test, making it more likely to detect a true effect if one exists. (B) Signup and view all the answers

A study investigates the effectiveness of a new rehabilitation program on functional mobility in stroke patients, using the Rankin Scale as the primary outcome measure. The researchers perform a statistical analysis that assumes the Rankin Scale data is interval data. What potential issue arises from this approach?

The analysis may yield inaccurate results because the Rankin Scale is ordinal data, and the intervals between categories may not be equal. (B) Signup and view all the answers

A researcher aims to assess the inter-rater reliability of a physical therapist's assessment of posture using a newly developed observational scale. What statistical measure is MOST appropriate for quantifying the level of agreement between multiple raters using this scale?

Intraclass Correlation Coefficient (ICC) (C) Signup and view all the answers

In the context of clinical trials, what is the PRIMARY advantage of using intention-to-treat (ITT) analysis?

It maintains the randomization and minimizes bias due to attrition or non-compliance, providing a more realistic estimate of treatment effectiveness in clinical practice. (B) Signup and view all the answers

A research study reports a statistically significant treatment effect (p <0.05) but with a small effect size (Cohen's d = 0.2). What is the MOST appropriate interpretation of these findings?

The treatment effect is statistically significant but may not be clinically relevant due to its small magnitude. (A) Signup and view all the answers

When appraising a research study, what is the MOST critical consideration when evaluating the validity of the outcome measures used?

Whether the outcome measures accurately reflect the constructs they are intended to measure and are relevant to the research question. (D) Signup and view all the answers

In a study comparing two interventions for pain management, researchers fail to reject the null hypothesis. However, they later discover that the sample size was too small to detect a clinically meaningful difference between the treatments. What type of error occurred in this scenario?

Type II error (false negative) (A) Signup and view all the answers

Flashcards

Nominal Data

Data categorized by name or label, without numerical meaning or order.

Continuous Data

Numerical data with meaningful intervals and potential for infinite values.