Questions tagged [diagnosis]
medical diagnosis: diagnostic accuracy and diagnostic research
24 questions
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Are diagnostic tests and clinical (risk) prediction models in medicine essentially the same thing?
In medicine, are diagnostic tests (e.g. covid test, HIV test, ...) and risk prediction models essentially the same thing? If not, in which aspects do they differ (from statistical point of view)? ...
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What data are used to find the final threshold for a medical diagnostic test?
Suppose I have some blood measurement X whose values correlate with some disease Y (so people with the disease use to have larger values of X). Moreover suppose that the disease is rare, say 1% of a ...
- 3,979
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Interpretation on SEM - diagnosis (Chi-square not good fit)
I'm running SEM in lavaan, but my model seems not fitting correctly based on the chi-square value and it's p-val = 0.000.
When i look at other fit measurements, the model is close to fit well. Below ...
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Generalized linear mixed model for assessing diagnostic accuracy of doctors
I am trying to determine how a doctor's expertise (either expert:1 or not an expert:0) affects their diagnostic accuracy of medical images. Additionally, I'd like to examine how the hospital at which ...
- 11
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674
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Diagnosing cause of very wide confidence interval (in multivariate logistic regression)
I am trying to use Binomial Logistic regression to identify features from X-rays, which are associated with a disease state. The idea was to try get Odds Ratios for important radiographic features*. ...
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The different usage of ROC between diagnotic tests and machine learning
I am currently very confused about the ROC usage in diagnostic tests and machine learning.
In the scenario of medical diagnostic studies, many tutorial does not mention the data split procedure as ...
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33
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P-curve analysis for meta-analysis of diagnostic accuracy study
I tried to do a meta-analysis of diagnostic accuracy study. I found out that I have a publication bias based on the Deek's regression test. Thus, I want to supplement my analysis with P-curve analysis ...
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Demonstrating that proposed cutoff score is non optimal
I have a small data set with a test score and classification (positive or negative diagnosis). There is already clinical evidence that the cut point suggested by the test manufacturer produces too ...
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93
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Probability of disease in a patient with risk factor
I'm a doctor so I'm sorry for my basic knowledge of statisctics.
I have a prior probability of the disease D
$$P(D) = 0.12$$
I know that risk factor RF can cause the disease.
Total probability of ...
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4
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52
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Correction for multiple testing required for combined metrics
Let's say I compare two diagnostic procedures (A and B) and want to check if one outperforms the other one using the metric diagnostic accuracy where diagnostic accuracy is commonly described using ...
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314
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Network meta-analysis of correlation coefficients: a logical paradox?
A colleague of mine wishes to conduct a network meta-analysis of correlation coefficients for a set of imaging tests (eg ultrasound, computed tomography, magnetic resonance imaging, and so forth).
...
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Assess sensitivity of a binary screening result across other continuous covariate(s)
I want to assess the sensitivity of a diagnostic screening test, which is a binary test (screen +ve and screen -ve). There is no continuous measure from this test - it is literally yes or no.
My ...
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1
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167
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Post-hoc power calculation for AUC analysis, to evaluate a new diagnostic test in a cohort
I need some urgent advice for a grant application. I am evaluating a new diagnostic test and at the last minute a Professor has offered me the dataset from a completed prospective study of the disease ...
- 457
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353
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Network meta-analysis of diagnostic test accuracy studies
I need to make a network meta-analysis of diagnostic studies.
Is there a good explanation to do it with R?
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Calculating sensitivity and specificity from survival data
I have a diagnostic test performed on 100 participants at baseline. I then follow up these participants for variable periods of time and have data regarding survival.
I have used a Cox regression ...
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Handling incomplete information properly when using Bayes' theorem
Just for fun I'm trying to do some simple medical diagnosis using Bayes' theorem. Right now I'm calculating
...
- 247
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1
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431
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Over-fitting diagnosis method
How much difference between train and test set errors can indicate over-fitting? For example in logistic regression.
I am trying to classify 11746 comments based on their sentiments in three classes ...
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Conflicting definitions of logistic regression
I do diagnostic research and am interested in determining how the probability of a patient having cancer is related to the concentration of different molecules in the blood.
I have received ...
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when add-on test is necessary? better diagnosis strategy
Suppose there are two types of tests available. Test A: low-cost, but relatively less precise; Test B: high-cost, but more precise. Test B can be considered as the good standard with 100% accuracy. ...
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Interpretation of Bayes Theorem applied to positive mammography results
I'm trying to wrap my head around the result of Bayes Theorem applied to the classic mammogram example, with the twist of the mammogram being perfect.
That is,
Incidence of cancer: $.01$
...
- 229
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2
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320
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Which statistical model to use when trying to find the beginning of a time-dependent increase
I have a repeated measures data set with time as the independent variable and a single dependent variable, y. That is, for each subject, I have a certain (small, from 1 to 3) number of measurements. ...
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What happens with sensitivity and specificity after a second test?
What happens with sens/spec and PPV/NPV if one performs a test twice (or three times etc.)?
I will give an example from my own clinical practice. At many hospitals, we have a problem with ...
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Estimate ROC curve using binormal distribuiton
I am conducting a meta-analysis on diagnostic studies but for each study I have only mean and standard deviation reported. How can I estimate the ROC curve using the binormal assumption in R ?
Tks,
2
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959
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Relationship between ROC curve and statistical significance in comparison of two groups
My question is about any possible relationship between the significance of a comparison test (Mann-Whitney U) and the ROC curve.
If the comparison test is strongly significant, should we expect a ...
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