Questions tagged [relative-risk]

The relative risk (also called 'risk ratio') is the quotient of the probabilities of an event under two conditions (ie, p1/p2). The RR has a possible range of [0, +infinity). It is a common measure of effect size in biomedical research.

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Kernel Density: How do the terms 'global' and 'pilot' translate?

I nearly most of the articles on kernel smoothing or concepts that use kernel density estimations, authors speak of 'pilot' and 'global'. https://link.springer.com/article/10.1023/A:1008925425102 &...
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calculating relative risks and odds ratio

How do I calculate : "cc":relative odds of preemployment testing only among non-marijuana users, "dd":relative odds of preemployment testing & random testing among marijuana ...
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for fun: can I estimate prevelance in a local population based on global exposure-outcome meta analyses?

I have the RR of miscarriage if exposed to moderate alcohol during pregnancy = 1.8. I have a small population where 7% is moderately exposed to alcohol during pregnancy. How can I ESTIMATE how many ...
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risk ratio and risk difference consistent?

how do you determine whether the results for risk difference and risk ratio are consistent? Risk difference = 0.02, 95% CI [-1.05, 0.1] Risk ratio = 1.1, 95% CI [0.82, 1.5] Study on whether or not ...
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Is there a good graphical representation for the sampling distribution of relative risk?

For pedagogical reasons, I am interested in communicating graphically the sampling distribution of relative risks (histogram and CDF plot), specifically in the context of a matched-pair study design: ...
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efficient frontiers are equal

I created 3 different efficient frontiers with 3 different risk factors(sharpe ratio, ulcer performance index and serenity ratio) and I wanted to find both MSR and GMV(and their equivalent for the ...
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What is the covariance between two log relative risks?

In a randomized experiment with two groups (treatment and control), suppose the response variable, $Y$, has 3 categories (0,1,2): $y_{0_{i}}$,$y_{1i}$ and $y_{2i}$, in which $i$ denotes the $i^{th}$ ...
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Relative risk trees (recursive partitioning for survival data) - node outcome

I am fitting relative risk trees for right-censored data (LeBlanc M. & Crowley J. Relative risk trees for censored survival data. Biometrics, pages 411–425, 1992) with rpart, but I have some ...
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convert the ATE Average Treatment Effect from a doubly robust model into Risk Ratio

How would one convert the ATE Average Treatment Effect from a doubly robust model into Risk Ratio? Can this be done directly without having to convert to odds ratio first. If so, how is this done. Can ...
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How/whether to adjust 95% CI for risk ratio with multiple comparisons?

I am evaluating the racial equity of a binary outcome, and we have landed on using risk ratios (RRs) for reporting differences between groups. The issue I am grappling with arises from the fact that ...
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Power analysis for relative risk equivalent to power analysis for difference between two proportions?

I need to make a power analysis calculation to estimate the minimum sample size for a relative risk statistic (ratio of two proportions) for unmatched data - two independent samples. Can I use the ...
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Interpretation of the E-value for non-epidemiologists

A recent method for sensitivity analysis is the E-value (VanderWeele and Ping, 2017). Yet, I'm still struggling with the interpretation of such a value. Coming from outside of epidemiology, where risk ...
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Metanalysis in R risk ratio compared to log risk ratio?

I have conducted a meta-analysis with the risk ratios and standard errors that have been provided to me. I cannot use the raw data. I was wondering if I should use the log of the risk ratio and the ...
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Paremater estimation in relative risk regression

While reading a study on leukaemia risk from ionizing radition, I am trying to understand how the model parameters are estimated. The outcome variable $y$ in this study is binary (leaukaemia or not), ...
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Combined relative risk in meta study

I am looking at a meta study, and I've never done one (or looked at it much) before. From what I've learned about it so far, the way you calculate the compounded effect is by first calculating this $\...
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Comparing risk of event in a subsample compared to the entire sample (with overlap)

I have a relative risk (RR_homeless_SMI) that provides me with the likelihood of becoming homeless in people with a serious mental illness (SMI) compared to those not having an SMI at all (NO_SMI). I ...
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Is combining Odds Ratios with Relative Risk in a Meta-Analysis Possible?

Can I combine ORs and RRs using generic inverse variance if the the event rare? There appears to be simple methods for converting ORs into RRs so would I do the conversion first and then apply the ...
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Comparison of predictors in multinomial logit

I have been reading up on ways to understand variable importance in multinomial logistic so as to compare the predictors. My goal is to understand whether predictor A or B is playing a more ...
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Relative Risk, confidence interval and sample size relationship

I'm following this example (see below for the source): Breast Cancer No Breast Cancer Total DDT exposed 360 13636 13996 Unexposed 1079 76313 77392 ...
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odds ratio to relative risk equation, how is it derived?

How is this equation derived? thanks RR=OR/((1−Pref)+(Pref∗OR)) RR = risk ratio; OR = odds ratio; Pref = Prevalence of the outcome in the reference group
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How we can obtain RR from case-control study through Poisson regression?

I found an article: https://link.springer.com/article/10.1007/s13300-020-00876-0 with case-control study design: "We conducted an open, multicenter, randomized, case-control study in a real-life ...
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Is this how to convert odds ratio intervals to risk ratios

I have a binary logistic regression with just one binary factor predictor. I would like to report the 'risk ratio' (probability ratio) with a confidence interval. I'm using R 4.0.4 for statistical ...
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I have calculated relative risk in SPSS with 95% CIs via a 2x2 table, but how do I then calculate the p value?

I have calculated relative risk in SPSS with 95% CIs via a 2x2 table, but how do I then calculate the p value? I thought I could use a two-tailed z test but can't seem to work it out
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Am I misunderstanding Zou's method for computing relative risk for binary outcomes using Poisson regression?

It seems that relative risk estimation using Poisson regression is a popular approach in epidemiology, with a couple of papers I have recently looked at (for example [3] and many others like it) ...
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Converting Hazard Rate Ratio and Relative Risk to standardized effect size (eg Cohen's d)

We are 2 psychology students writing a systematic review. We need to convert the effect sizes from the different studies to Cohen's d (or another standardized effect size). Can anyone help converting ...
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Estimating risk ratio instead of odds ratio in mixed effect logistic regression in `R`

glmer is used to estimate effects on the logit scale of y when the data are clustered. In the following model ...
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How to tackle increasing survival probability?

I want to model probability of an event, which is typically modelled by survival methods. However, the predicted survival function is always non-increasing. My case is however opposite: The ...
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Confidence interval for relative risk with uncertain incidences

The usual suggestion for computing a confidence interval for a relative risk estimate is to start from the variance: $$ \text{CI}_R = R \pm z \cdot \exp \sqrt{\sigma^2_{\log R}} $$ where $R$ is the ...
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Can the Fisher exact test be used to get a confidence interval for the efficiency of a vaccine (risk ratio or relative risk)?

Consider the Pfizer vaccine for COVID-19. The data from the phase 3 trials shows that they had 21720 people in the vaccinated group and 21728 people in the control group: ...
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Sum of $n$ relative risk ratios and Poisson regression

Consider $n$ joint PMF defined by two Bernoulli r.v. $X_i$ and $Y$. The probability $P(X_i, Y)$ is estimated as: $$\begin{array}{c|cc} & Y = 1 & Y = 0 \\ \hline X_i = 1 & \frac{a_i}{a_i + ...
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Confidence interval of Relative Change using Delta method

I have the following equation for relative change (RC): RC = (P1 - P2)/P2 * 100 Here, P1 and P2 are both ratios. For example, P1 = A1/n1 and P2 = A2/n2, where n1 and n2 are the sample sizes of both P1 ...
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interpretation of odds ratio for continuous predictor

I'm examining the influence of new venture product maturity on different type of investments (none, angel, crowdfunding, and series investments). I have multiple measures for each firm. The variable ...
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Why is the log of relative risk ratio closer to normal distribution?

See here: https://en.wikipedia.org/wiki/Relative_risk#Inference The sampling distribution of the $\log(RR)$is closer to normal than the distribution of RR, with standard error $$SE(\log(RR)) = \sqrt{\...
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Which statistical model is being used in the Pfizer study design for vaccine efficacy?

I know there's a similar question here: How to calculate 95% CI of vaccine with 90% efficacy? but it doesn't have an answer, at the moment. Also, my question is different: the other question asks how ...
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How exactly is the "effectiveness" in the Moderna and Pfizer vaccine trials estimated?

As in the title. Is this "a risk ratio"? How is it calculated, if you could provide an example with numbers for both trials, please? I am not a statistician, but I am familiar with the ...
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How to convert relative risk and confidence intervals/standard error to odds ratio and confidence intervals/standard error

I am conducting a meta-analysis and have one study which reports relative risks, and several studies reporting odds ratios. I would like to convert the relative risks to odds ratios and obtain ...
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Estimating the random effect structure and variance-covariance matrix for RRs from observational studies

long time reader, first time poster. Have found this community to be extremely helpful but alas have not had luck finding a previous question relating to this: I am attempting to run a meta-regression ...
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Stratified logistic regression with log link

I noticed the other day that I can mimic a stratified logistic regression using a meta-analytic approach at least when there is only one stratification variable with two different values. This is the ...
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Calculating Risk Ratio: different results with different R-packages (epitools and epiR)

if someone could educate me on how R functions calculate risk ratios I would be grateful. I'm having trouble interpreting results from different packages: epitools ...
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Are the confidence intervals and p-value for this risk consistent? [duplicate]

I'm trying to calculate a risk ratio with the following 2x2 contingency table, where the rows are exposure groups and the columns are disease status. The first row of the matrix shows that 1/38 ...
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Relative risk not making sense for meta-analysis

I am doing a meta-analysis and struggling with the relative risk values. Looking at the forest plot and the RR for some relative risks I can tell it is incorrect. i.e first study rr should be 0.33. I ...
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Can someone explain as simply as possible why you use OR in retrospective studies while using RR in prospective studies?

I've really tried to understand why you can't use relative risk (RR) in retrospective studies but for some reason I can't understand it. Has anyone been able to convey this simply to their students?
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Reporting significance values for relative risk (RR) and number needed to treat (NNT)

I have calculated the relative risk & number needed to treat using the log-binomial regression model. NNT is calculated as the reciprocal of the marginal difference. Does it make sense to report ...
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Why I estimate huge RR?

I am trying to do an excercise about temperature related mortality. I want to plot exposure-response curve, identify the temperature threshold and estimate Relative Risk of mortlaity above this ...
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A regression model for ratio of two Binomial success probabilities

There are two series of observations of two Binomial trials. Observation $i$ of series 1 includes $n_{1i}$, the number of Bernoulli draws and $\overline{p}_{1i}$, the ratio between number of success ...
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how do i calculate a population size weighted risk ratio?

I am a bit stuck. I have age startified risk ratios from published data from which i have sampled 10,000 iterations. I have a population census data of the population that i am going to apply the ...
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How do you calculate a paired risk ratio and its confidence interval?

I have some data showing the number of times individuals make GP appointments at the week and at the weekend, over a period of about 5 years. The data also show the number of times each individual ...
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Identifying risk factors in a study

I have a dataset of patients who have been inpatients (admitted to hospital) and not admitted (but visited as outpatients). Class proportion is 66:34. I have collected a list of features for all ...
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Posterior of risk ratio as ratio of samples from posteriors of risks

I want to sample from the posterior distribution of a risk ratio. My idea is: define the posterior of risks $R_A$ and $R_B$) for two subgroups (e.g, exposed and non-exposed) in my data, using Beta(1....
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What's "the clinically important absolute scale"?

In this article, the authors used the sentence "...risk difference (i.e., treatment effect on the clinically important absolute scale)". What did they mean by "clinically important ...
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