# Questions tagged [incidence-rate-ratio]

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### How to convert life-time incidence to rate using median OS?

Background In a microsimulation, I use transition probabilities (defined as probability of an event per cycle of 30d-length) to simulate a patient's course of disease. The values derive from the ...
11 views

### Calculating rates where the exposure has different weights

I'm working on a problem where I'm calculating rates for three different groups. These are rates of events over time, where each individual in every group can experience the event multiple times. I'm ...
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### Comparing two groups of incidence rates

Thank you for your time with this question. I'm trying to answer whether an exposure is correlated to incidence of disease. I have a group of 100 counties in California, and I have the incidence of ...
1 vote
207 views

### Is there a difference between rate ratios and hazard ratios?

In Epidemiology, an incidence rate ratio is the ratio between the incidence rate in the exposed and the incidence rate in the unexposed, where an incidence rate is the number of events divided by the ...
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### Subgroup analysis results are different if I conducted each subgroup separately in metarate in R

I am doing a single arm meta-analysis of incidence rate using Poisson regression and doing subgroup analysis using meta and ...
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### Test for incidence-rate trend in Stata

I am using Stata 17.0 MB and working on a dataset of Enterococci bacteria infections in the previous ten years (2012–2021). These bacteria have more dangerous subtypes resistant to one antibiotic (...
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### Double-count in Poisson Regression (SAS) for repeated measurement?

my team is working on a project about covid incidence in elderly nursing home in a particular state. We tried using proc genmod in SAS with link=log and dist=poisson to calculate the incidence but it ...
229 views

### Translate Excel's NORM.S.INV function to Python to calculate confidence interval of an incidence rate

I have an Excel-sheet with some formulas which are able to calculate the confidence interval of an incidence rate. The formulas not from me but they work. Beside some other stuff the Excel-sheet use ...
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### Advantage of Poisson model over Cox PH model for analyzing first event?

For analysis of the first event, I am wondering if Poisson model has any advantage over Cox model, besides some people find rate ratio easier to interpret than hazard ratio? I notice some people use ...
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### What should we report in our manuscript for negative binomial regression, IRR or OR?

I have applied negative binomial regression analysis for my data in SPSS. However I am not sure what do I have to report. Is it called IRR and CI or odds ratio (OR) and CI like in logistic regression. ...
102 views

### Can Marginal effects and Incidence Rate Ratios be exactly the same?

Consider a boring count data model of citations of an article in relation to its page number and the price of the journal. I prefer an ordinary negative binomial regression. Can it be that the ...
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### How to interpret this formula with probability of an individual becoming infected over x days?

I am trying to understand a formula in this paper (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5444538/#:~:text=Low%20Risk%20of%20International%20Zika,the%202016%20Olympics%20in%20Brazil). In the ...
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### Comparing multiple incidence rates of disease

I have a set of data of patients from different places who have had the same operation to remove their appendix. A small subset of the these patients have come back with cancer in the appendix. I ...
1 vote
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### Calculation of 95% Confidence Interval for an Incidence Rate Difference

Suppose that I have two pre-computed Incidence Rates with 95% CI, calculated from the same sample. Let's say IR1: 10.0% [8.0-12.0%] IR2: 21.0% [15.0-27.0%]. If I want to calculate an IR difference, ...
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### Network Meta-analysis with poisson regression

I recently got interested in evidence sinthesis and, while studying, a little doubt came up to my mind: Is it possible to do Network Meta-analysis using poisson regressions? Also, is it possible to ...
309 views

### Derivation of confidence interval of incidence rate ratio

I am trying to understand the confidence interval equation for a Incidence Rate Ratio (IRR) given several places: $95\text{% CL(IRR)} = \exp(\log(\text{IRR}) \pm 1.96\times \text{SE(log(IRR))})$, ...
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### Conway-Maxwell-Poisson (CMP) - Coefficient interpretation (Log/IRR)

I'm using the Conway-Maxwell-Poisson (CMP) distribution to model the amount of nouns in a clause (data is under-dispersed). I've run the model using glmmTMB (family= "compois") but I'm ...
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### How to estimate prevalence with a zero incidence (rare disease)? [duplicate]

I had to solve the following problem. Newborn screening has been implemented for a very rare pathology. For 6 months, and out of 50,000 births observed, no sick case was observed. What is the ...
718 views

### Incidence rate ratio after negative binomial results in R

I am trying to calculate the incidence rate ratio of my negative binomial model. After running my negative binomial regression model, I use exp(Mymodel) in order to ...
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### Calculation of the Confidence Interval for Incidence Rate Ratio using Exact Approach

I have incidence rate ratio equal to 0.04: If I am not mistaken, normal computation of CI is: ...
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### Are there any difference between irr (Incidence Rate Ratio) and exp (beta) coefficient?

I am wondering that are there any difference between IRR (Incidence Rate Ratio) and the exp(beta) coefficient?
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### Standard incidence rate

I am conducting a meta-analysis where I pool standard incidence ratio's. Several of the studies do not give the SIR between the groups I would like to compare but do give the SIR relative to another ...
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### Determining the statistical significance of change in incidence rates

What is the approach to use to determine the statistical significance of change in incidence rate over years? Below is at table showing such kind of data of incidence rate per 1000. ...
1 vote
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### Zero-Inflated Negative Binomial Theta and Incident Rate Ratios (IRR)?

I am trying to determine the best regression model for data with many zeros; I have about 200 with non-zero DS scores and 600 with zero DS scores. ...
1 vote
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### Is there a way to compare incidences of 2 diseases in the same cohort?

I would like to compare incidences of 2 diseases in the same cohort for the past 10 years. Eg. I want to see whether there's an association between incidence of heart disease and incidence of ...
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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 ...
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### Which statistical analysis model to use to calculate the relationship between diabetes incidence and endothelial function?

I have longitudinal data with 2 follow ups at year 1 and 3. At baseline we have measure of endothelial function and we want to calculate the relation ship between endothelial function and diabetes ...
1 vote
330 views

### What is the difference between 1-year partial prevalence and annual incidence?

In cancer research, like in this article, partial prevalence is sometimes used to assess the epidemiological state of a disease in a population. The document I'm trying to understand (link, in french) ...
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### How to model counts of a categorical variable?

I'm interested in assessing the impact of various covariates (age, sex, Charlson comorbidity score, etc.) on the incidence rate of a pulmonary event. However, the event is not binary. Each patient ...
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### comparing incidence rate

I have a data set of individual level data for the outcome in question. I also have aggregated data (at a national level) from which I'm obtaining the denominator. Using this information, I've ...
1 vote
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### Test for yield and disease incidence in block design

I need to analyse a set of data coming from an agricultural experiment, with the intention of assessing the incidence of a certain disease in potatoes under three different treatments (plus blank). I'...
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### Calculate incidence rate per person or in total

For my study I am doubting about the following: First I want to present the incidence rate for patients who received an CT-scan. I thought I would just count all the CT-scans that took place and ...
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### what is x per 100 person years mean?

In medical papers, it is very common to calculate incidence rate and mention it's unit as per 100 person years. What does this means? I know that incidence rate is the amount of people got the event ...
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### Confidence intervals for Ratios of Correlated (nested) Age-Adjusted Rates

I am interested in calculating the incidence of disease in an ethnic subpopulation (denoted $X$) and comparing this with the incidence in the entire population ($\Omega$) (where $X$ is a true subset ...
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### Modeling hip fracture incidence (hospital-based cohort design)

Hoping someone can help me out with a question I have on an analysis looking at prosthetic hip fracture incidence following hip replacement surgery (exposure=type of implant, with reference being the ...
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### Validity of non independent observations in Poisson regression when modelling incidence rates

I have a question regarding fitting a poisson model to non-independent observations when assessing the incidence of an outcome. I am interested in the incidence of some outcome, O, over time. I have ...
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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 ...
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### Visualize the rate of reported cases of disease with respect to the population

I have to do some visualizations about vaccines. I downloaded data on reported cases of vaccine-preventable diseases (for example, measles, tetanus, etc.) here. These data are absolute values. I ...
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### Interpreting Poisson regression model [duplicate]

I am having a mighty difficult time interpreting the following results given to me based on a generalized linear model with a Poisson distribution: Data: data represents the number of visitors to a ...
1 vote
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### Standardized Infection Rate from predicted probabilities. Which method?

I need to calculate the Standardized Infection Rate (SIR), that is the ratio between actual cases of infection and predicted cases based on a predictive model. According to CDC https://www.cdc.gov/...
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### Compare incidence rate

During the follow-up time, event A will happen multiple times, and there are 3 types of A, I call it A1, A2 and A3. I wonder if there is a statistical method that I can calculate the incidence rates ...
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### Interpreting incidence rate ratios in poisson without exposure variable [duplicate]

I have a dataset made up of observations of procedural cases, with a count outcome (variable X carries the number of times a specific finding was detected in one procedure/case). My denominator is the ...
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### Calculation of person years in a cohort study for survival analyses

I am analysing data from a cohort study using primary care data (but I linked them up to secondary care data only for the outcome). Specifically, I am looking at the adoption of a specific care ...
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### How to calculate relative risk if the reference group has an incidence of 0?

this appears to be a quite difficult question. As we know, if 20% of the smokers developed lung cancer and 10% of the non-smokers developed lung cancer, then we say that cigarette smoking is ...
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### Adjusting variable for covariate to calculate rates or metric

In this report by Dartmouth Institute, rates of utilisation (per patient) were reported by year and regions. The input measure of utilisation were said to have been adjusted for differences in age, ...
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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. ...
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### Can odds ratio be in different direction to rate ratio?

My question is whether it is plausible to have "Rate Ratio" showing an increased risk while "Odds Ratio" (based on the same data) showing decreased risk? I have an example in this article: http://...
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### How to Assess Significance of the Difference in Incidence Rate Ratios?

Imagine we estimate two sequential negative binomial regressions. In the first one, we use say 3 predictors (x1, x2,x3), and in the second, we use the same 3 plus an additional variable (x4). We are ...
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