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Questions tagged [case-control-study]

An observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute.

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Meta-analysis for case control studies

I am working on a method of meta-analysis for case-control studies by stratifying cases and controls then calculating the effect size. Can I do a meta-analysis including only case-control studies for ...
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Correlation analysis using a case-control study-based data

I have a case-control study-based data. This is a data to confirm the association of hypertension and BMI. The definition of the case group (hypertension group) is SBP(systolic blood pressure)>=140. ...
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Difference between N case studies and case series with N patients

Is there any reason to treat data from multiple case studies differently from data from a case series that reports data on multiple patients? Assuming the case-series intervention was the same for ...
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Medical or Intervention Study

A friend and I are trying to better understand proper design of a randomized trial, from beginning to end, with an eye to creating an informal one showing the benefits of a particular academic ...
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Power Analysis for Case Control Regression?

If we conduct a case control study and plan to analyze the results with multiple linear regression, which power analysis should be conducted to select sample size? There are separate calculators for ...
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R - multivariate glm, what to use as a p-value and odds ratio?

This is for a case-control study. I need to get a p-value and an odds ratio with confidence intervals from my glm, but I'm unsure of the best approach. I have the <...
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49 views

propensity score matching by disease and cox PH regression.. am I right?

Normally I understood propensity score matching is the way to match the treated group and untreated group. But I noticed some studies that used propensity score matching to match disease and non-...
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Econometric Models in Economic Development Theory

I have been reading some Economic Development and Policy Research papers and I realise there is extensive employment of econometric tools and models. For example, one of the papers used an Oaxaca ...
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47 views

Ratio of cases to controls in retrospective cohort study

I am conducting a retrospective cohort study in which I have 10,000 cases with exposure to X, and a very large control population (10,000,000+ subjects) without exposure. I am taking an individual ...
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Compare hazard ratios in case-control setup

quick disclaimer: first time poster; i have searched through the forums extensively but please bear with me if this is a silly question or point me towards the solution if it has been answered before. ...
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24 views

Variable ratio matching

I am working on a simulated study where I have variable number of control matches for my treatment subjects. I am new to this type of analysis. I realize after matching I can utilize logistic ...
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1answer
682 views

3:1 matching with MatchIt in R. The number of matched control is not equal to 3 times the number of cases

Hello I'm using the MatchIt package in R I have a total of unmatched 116 treated cases and 462 unmatcehd non-treated case with the command ...
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Interacting treatment variables with independent variables in matched samples

Can we interact the treatment variables with independent control variables that have been used for matching? I have a binary treatment variable called 'medicine'. It indicates whether a person ...
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Any downsides in giving a participant A and B then compare the results?

Almost all the experimental design studies that I came across randomly separates participants into bucket A or B. Then they study the effects to identify a causal relationship. Are there any ...
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Validation of multivariate analysis by case-control study

Apologies if this exposes a gross misunderstanding. If have an outcome e.g. death and I perform and multivariate analysis and then a univariate analysis on a particular vatiable of interest which ...
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convert case-control to cohort

We know that a cohort is "stronger" than a case Control study. So, if I have a case control study I start with the outcome (cancer) then go and look back to see if the subject was a smoker or not and ...
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Case-control study design and continuous outcome variable other than the case-control status

Suppose in a population-based nested multi case-control study several diseases (asthma, chronic bronchitis, rhinitis) were evaluated simultaneously in association with different exposures. Controls ...
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464 views

Nested Case-Control vs propensity score matching vs inverse probability when comparing differences in incident outcomes

I am not sure about the best design in this case. I have a representative sample (N=15,000) of individuals with a moderately rare condition and I want to match them to controls who do not have this ...
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Matching inflation

I have data on a few millions of patients, about 1000 of them are cases, that is, they were diagnosed having a certain disease at some timepoint in their life. I think I basically have two options: 1)...
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58 views

What statistical model to use for assessing the effect of a new tree pesticide?

I have 2 sites with 15 trees on each site. I plan to treat all 15 trees in site 1 with a new pesticide and leave all 15 trees in site 2 untreated. The total number of bugs on each tree is measured ...
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What statistical test should I use for the comparison of multiple dependent variables?

I'm doing research on the influence of one kind of pill on the heart rate. I have two groups: control group and medication group. The control group has 10 subjects while the medication group has 20 ...
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Analysis of Pre-post Likert-type scales: Intervention vs. Control group

I gathered the following data: Intervention group (n= 24, received treatment): pre- and post- scores of different psychometric questionnaires Control group (n=23, inactive): same questionnaires, same ...
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How can I test, that stock price changed significantly after certain event?

I need to test whether stock price changed statistically significant after certain event. I got time series of stock price before and after that event. What test or methodology should I use? (not very ...
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Population stratification: adjustment via principal components analysis

I'm new to statistical genetics and trying to learn more about using principal components to adjust for population stratification in case-control studies. My understanding is that the PCA approach ...
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538 views

Odds ratios are inappropriate for a cross-sectional or cohort study

I'm aware of the issues regarding the use of relative risk in a case control study. But a colleague recently told me that odds ratios are inappropriate for cross-sectional and cohort studies but can't ...
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Any R packages that can perform generalized linear mixed model with Firth correction? [closed]

I am performing a genetic association analysis with binary outcomes (case-control study) and would like to include a genetic relatedness matrix (GRM or kinship matrix) as a covariate along with others....
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Selecting controls from a case-cohort study when location is important

I am looking at the causes of a disease in cows, both 'environmental' (ie ground-drainage, bedding type etc) and 'biological' (previous disease, sex, weight etc). Most environmental variables are the ...
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Potential bias in a study design

I am trying to design a study regarding Diabetes. I have patients with test results of some indicator about their situation - sugar levels, but not in the classic sense that you may know. Every ...
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1answer
158 views

Covariates in regression difference in difference

I am posting today because I got some issues to understand how to add covariates in a regression difference in difference. I understand the primary goal of the regression difference in difference. I ...
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79 views

How can I combine point estimates and standard errors from non-independent datasets?

I will conduct a 1:2 or 1:3 matched case-control study in order to examine risk factors related to a rare disease. Under this study, I'm planning to repeat selection of matched controls for at least ...
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169 views

General Additive Model problems with case-control data in r

I am trying to run the following code using R packages mgcv and survival: ...
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326 views

During oversampling of rare events, why are the beta coefficients of the independent variables not affected, but only the intercept?

I have followed the King and Zeng paper and understand the consistency of the prior correction after oversampling in logistic regression. But I am trying to understand why the beta coefficients of the ...
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Can I use the eigenvectors of a principal component for gene discovery?

I am working on a microarray dataset with n samples x m genes, with metadata including a grouping of interest and other summary statistics, e.g. age, bmi. My objective is to find genes that may be ...
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33 views

Interpret case control study statistic result

In unmatched case control study, calculating odds ratios, CI and chi-squared values and found out the statistically significant variables. In next step performing multiple logistic regression some of ...
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75 views

R or spss? For a conditional regression with 2 dependent variables?

Maybe you find my question a bit simple but I'm really confused as I'm not statistician. I have 2 SNPs (can be proposed 2 genes instead) that are related to a primary disease (like major depression), ...
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Comparing pre/post percentage change between pairs of random samples

I am studying cycling rates along a street that recently received a bike lane. The data I have consists of 4 random samples of people intersected on the sidewalk. For each person, we know if they rode ...
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Why is relative risk not valid in case control studies?

I'm getting my information from: http://sphweb.bumc.bu.edu/otlt/mph-modules/ep/ep713_analyticoverview/EP713_AnalyticOverview5.html It says that in a case-control study, you can not compute the ...
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Case control study for a beginner student

I am a medical student and new to this site so please be patient with me. I am doing a study on effect of zinc on bronchiolitis in children,taking clinical findings over time period in patients given ...
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1answer
321 views

Interpretation of Random Forest model-predicted probabilities based on case-control training data

I am training a binary classifier using random forest. I'm interested in a clinical event, and my raw data is longitudinal electronic medical records. The goal for this classifier is to be able to ...
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How to improve structural bias correction using propensity scores

Given a control group and a treatment group, which are not equivalent (different distributions on a number of variables), I want to estimate the probability of an event given that the observation was ...
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Correcting bias in non-equivalent group analysis with logistic regression

I have constructed two groups based on observational data: control (C) and treatment (T). T was exposed to a feature that C was not exposed to. My total number of observations is very high (> 300K). ...
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454 views

How to calculate odds ratios and probabilities in case-control studies?

I came across this study, Case-control study of stroke and the quality of hypertension control in north west England. In this study I find numerous odds ratio. As far as I understand, all the ...
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174 views

Normality test in a case-control study

I have conducted a research testing the associations between vitamin D, CRP, C3, and insulin resistance. The design was a case-control design. the sample size was 134, of which 67 are cases (obese) ...
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What is the effect of caliper size in case-control study

I'm reading some literature on case-control studies, in which they discuss the use of "calipers" for matching on continuous variables. However, I can't seem to find anything about the relationship ...
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817 views

P values for demographic variables in a paper — which test was performed?

I'm reading a paper and they have a table describing the distribution of demographic variables by case and controls, but there is also a Ps column. I assume this is a p-value, but what are they ...
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104 views

Covariates in a case control study

I am doing a retrospective analysis on a study has has cases and controls. I am looking to see if there is an association with death, using exact logistic regression. I am confused on whether I need ...
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560 views

Can you calculate the Area under the ROC curve (or C-statistic) using logistic regression from case control data?

I know you can estimate odds ratios based on logistic regression of case control data because the baseline risks cancel out. Does this mean that only the intercept is contaminated by the analysis of ...
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351 views

Can you use survival analysis (e.g. Cox PH model) on case control data when only cases have an uncensored survival time?

In my data I have $n_1$ people who had an "event" and $n_2$ people who did not. Cases (those with an event) were oversampled substantially (the true prevalence is probably more like 1 in 10000). If it ...
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385 views

matched cohort with 1:n pairs - correct stratified logistic model

In this hypothetical example we have access to a database. In it cases are people with children and controls are those without kids. We want to measure the association between having children and Lung ...
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Case Control Sampling in Logistic Regression [duplicate]

In this lecture by Hastie and Tibshirani, it is mentioned that with case-control samples, we can estimate the logistic regression parameters accurately, but the intercept term is incorrect. It also ...