Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

Questions tagged [incidence-rate-ratio]

85 questions
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Interpretation of incidence-rate ratios

So, I want to fit a random effects negative-binomial model. For such a model STATA can produce exponentiated coefficients. According to the help file such coefficients can be interpreted as incidence-rate ratios. Unfortunately I am not a native…
Adrian
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Survival rate trends in case-control studies

I submitted an article which was rejected due to the improper way of performing the survival analysis. The referee left no other details or explanations other than: "survival analysis on time trends requires more sophisticated ways of…
Frank49
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Calculate incidence rates using poisson model: relation to hazard ratio from Cox PH model

I want to calculate incidence rates to present along hazard ratio's in order to present both relative and absolute measures of risk. I saw in other studies that such incidence rates can be calculated using poisson models with follow-up time in the…
Rob
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Comparing incidence rates

I want to compare to incidence rate's between two groups (one without a disease and one with). I was planning to calculate the incidence rate ratio (IRR), i.e. incidence rate group B/ incidence rate group A, and then test if this rate equals to 1,…
Edwin
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How to handle count data (categorical data), when it has been converted to a rate?

I am working on disease infection data, and I am puzzled on whether to handle the data as "categorical" or "continuous". "Infection Count" the number of infection cases found in a specific period of time, the count is generated from…
lokheart
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Calculate probability of disease appearance

I am a doctor so please be kind with me and my basic understanding of statistics. I have a dataset consisting of patients and their visits and I have labelled the presence of a specific kind of mole in their left and/or right hand with {0,1} values…
azal
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Incidence Rate Ratio (IRR) in R from linear regression using log-transformed data?

I was wondering if it would make sense to calculate IRR for OLS (not poisson), but the OLS is done using log-transformed data? I have a set of crude death rate data (which I'm still debating whether they are count data (because they are, after all,…
user28610
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Comparing multiple incidence rates

I asked the following question on stack overflow yesterday: Negative binomial function in R Reading comment 2, I understand that I cannot use a negative binomial modeling approach (a Poisson model works, but I suspect the assumption of equal mean…
Misha
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Are these negative binomial regression results reasonable?

I did a negative binomial regression on a data set with 4 covariables. The count outcome has values up to 600. I did a mixture model with 2 components, also called a latent class model. However, I am not sure if the results make sense. These are the…
spore234
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Alternative name for "incidence rate ratio"

I'm using a negative binomial GLM to predict individual level scores on a psychometric test that ranges from 0-27 and presenting the coefficient "incidence rate ratios". It seems a little strange to use the term "incidence rate ratio" when actually…
fmark
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Is calculating Incidence Rate Difference/Ratio appropriate for single case experimental design?

(This is part-2 of my long question, you can have a look at part-1 here) I am going to do a quasi-experiment, with measuring the base line of a sample (actually not quite a sample, but a ward, with high patient turn-over rate), and then we do a…
lokheart
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Interpretation of log transformed predictor in negative binomial regression

I mainly want to make sure that I'm making the correct interpretation here. I built a negative binomial regression model predicting a count variable. There was evidence of overdispersion or I would have used regular Poisson. The predictor variable…
Joe
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Comparing the ratios of occurrences

There are two groups: treatment control. Each group has three categories of outcomes: High medium and low blood pressure. The number of subjects is 100 for each group. Now, let's say, for control group, the number of observations is 40, 40, 20…
Jen
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Meta-analysis with random effects on prevalence data with > 2 possible outcomes: is it necessary that the weighted prevalences all add up to 100?

I am running a meta analysis on prevalence data. Participants can belong to one of four groups. Each study produces the percentage of participants that belong to each group (e.g., Group A: 50%; Group B: 20%; Group C: 10%; Group D: 20%). I am running…
Dave
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Incident rate ratios with log-transformed variables in Poisson regression

I'm in a bit of a mess with interpreting the output of a Poisson regression model with log-transformed predictors. The predictors are counts, and the log transforms them for the linear part of model. glm(y ~ log(x1) + log(x2), data=dt,…
Mainard
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