What Do You Mean?
Because it is less affected by highly skewed data, this measure of central tendency is the best choice for reporting a variable like "duration of symptoms" in patients with chronic back pain.
What is the median?
This type of observational study design starts with people who already have a specific outcome or disease and looks backward in time to identify potential exposures.
What is a case-control study?
In a 2x2 diagnostic table, this statistic tells you the proportion of people who actually have a condition who also test positive for it.
What is sensitivity?
The initial phase of creating a Clinical Decision Instrument, where researchers look at a multitude of variables to find the most parsimonious set of predictors.
What is a derivation study?
Defined as the probability of finding a statistically significant difference if such a difference actually exists in the real world.
What is statistical power?
In a normal distribution curve, this percentage of scores will always fall between -2 and +2 standard deviations.
What is 95.44%?
Often used pragmatically in clinical settings when randomization is unethical, this category of research design uses similar structures to experiments but lacks either random assignment, a comparison group, or both.
What is a quasi-experimental design?
A positive response to the cervical distraction test would prompt you to use this specific metric to mathematically estimate your patient's new post-test probability of having a radiculopathy.
What is a Positive Likelihood Ratio (+LR)?
Because derivation results may have occurred by chance alone or might not apply to a new population, a clinical prediction rule cannot be implemented until it passes this second phase of research.
What is a validation study?
You tell a patient they do not have a tear, but they actually do. In hypothesis testing, failing to reject a false null hypothesis is known as this.
What is a Type II error (or false negative)?
This measure of variability is calculated by dividing the standard deviation by the mean and converting it to a percentage, allowing you to directly compare the variability of goniometry to blood pressure without worrying about units.
What is the coefficient of variation?
In this type of experimental design, subjects act as their own controls because they are exposed to all levels of the independent variable, though researchers must randomize the intervention sequence to prevent "order effects."
What is a repeated measures (or within-subjects) design?
You'll want to use this specific appraisal tool, currently in its second iteration, to grade the methodological quality and risk of bias in diagnostic accuracy studies.
What is the QUADAS (or QUADAS-2) tool?
Often done as a "pre-and-post" institutional design, this is the final developmental stage to determine if a Clinical Decision Instrument actually saves time, money, and resources in the real world.
What is an impact analysis?
In clinical research, calculating an a priori power analysis using a program like G*Power is primarily done to determine this specific number before data collection begins.
What is the required sample size?
Simply calculate the sample standard deviation divided by the square root of the sample size to find this theoretical value.
What is the Standard Error of the Mean (SEM)?
Serial observations of an individual patient before, during, and after interventions (such as an A-B-B-A format) are the hallmark of this specific study design.
What is a single-subject (or N=1) design?
These two diagnostic metrics are considered "old school" and less reliable for generalizing to your clinic because they are highly influenced by the prevalence of the condition within the study sample.
What are Positive and Negative Predictive Values (PPV/NPV)?
A major limitation of developing a clinical prediction rule within a single treatment group is the inability to differentiate if a variable predicts a response to the specific intervention or if it is just a good one of these.
What is a general prognostic indicator?
If a study reports a 95% confidence interval for a mean difference between groups as (-6.8 to 0.08), the results are considered not statistically significant because the interval includes this.
What is zero?
These three elements make up the "pillars" that increase statistical power when they are optimized: decreasing variance, increasing the effect size, and increasing this.
What is sample size?
The "PEDro scale" uses 11 criteria to appraise the methodological quality of this specific type of study design.
What is a Randomized Controlled Trial (RCT)?
A positive likelihood ratio of 0.4 is a major red flag; it implies the patient is less likely to have the condition than if they tested negative, a scenario usually caused by this flaw.
What is measurement error?
To remember the three steps of Clinical Decision Instrument development in order, remember the letters D.V.I., which stand for these three study types.
What are Derivation, Validation, and Impact Analysis?
While p-values and confidence intervals tell you about statistical significance, they cannot tell you about this type of significance, which requires you to compare the effect size to the MCID and use your own judgment.
What is clinical significance?