Questions tagged [incidence-rate-ratio]

The tag has no usage guidance.

9
votes
2answers
295 views

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 ...
9
votes
3answers
11k views

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 ...
8
votes
1answer
5k views

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 ...
8
votes
3answers
235 views

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 ...
6
votes
1answer
1k views

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 ...
5
votes
2answers
1k views

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 ...
4
votes
1answer
636 views

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 ...
4
votes
0answers
233 views

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 ...
4
votes
0answers
593 views

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 ...
3
votes
2answers
519 views

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. ...
3
votes
2answers
3k views

How to calculate 95% CI for cumulative incidence rate using R?

for example, 30 events during 10000 person-years, the cumulative incidence rate is 3 per 1000 person-years, how to calculate its 95% CI?
3
votes
1answer
3k views

Interpreting negative binomial regression with log transformed independent variables

My independent variables were highly skewed, so to normalise the distribution they were log transformed. Also since there were zeros in the data, I've added + 1 to transform the variables. This is ...
3
votes
1answer
2k views

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 ...
2
votes
1answer
55 views

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 ...
2
votes
3answers
239 views

How to prove that one variable's change is influenced by another variable; that is to say, are they related?

I major in bioinformatics. We all know that temperature changes during a year. I find that a disease incidence is really high when temperature is relatively high, while it becomes really low when the ...
2
votes
1answer
699 views

Inverse Incidence Rate Ratio

I wondered if it is possible to calculate the inverse of an IRR like we can for odds ratio (inverse = 1/x). For example: IRR = 1.40, 95% CI = 1.18 -1.65 Inverse IRR: = 1/1.40 = 0.71 Thank you (...
2
votes
1answer
57 views

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 ...
2
votes
0answers
367 views

Interpreting incidence rate ratios in poisson without exposure variable

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 ...
2
votes
0answers
673 views

Calculating p-value from chi-square when comparing two incidence rates

I am trying to follow this guide to calculate the p-value from an incidence rate between two samples. The raw data is patients' use of an action plan before and after education. Before education 7 ...
2
votes
0answers
395 views

Estimating mortality rates with direct age-standardization

I'm attempting to calculate the mortality rates of AMI (acute myocardial infarction) in patients (cases) with high bloodpressure, between the years 2001 to 2008. For every case I have 2 matched ...
2
votes
0answers
725 views

How to calculate SE for the ratio of two proportions?

I have evaluated the prevalence (proportion) of a disease in men and women, in different studies available in the literature. So I have sample sizes for men and women (in different studies) and also ...
1
vote
2answers
953 views

Calculate confidence interval from point estimate and standard error

Im having a problem with calculating a confidence interval for an incidence rate ratio between two populations. Using PROC STDRATE from SAS, I've obtained the Incidence Rate Ratio (the difference in ...
1
vote
2answers
49 views

What type of statistical test should be used to compare successes of two treatments?

Say I have two treatments, "hot" and "cold". I care about a certain outcome, say "success". I have data on the number of successes out of, say 100 trials in the "hot" treatment. Similarly, I have data ...
1
vote
1answer
115 views

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 ...
1
vote
1answer
59 views

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://...
1
vote
1answer
44 views

Relationship between survival time and incidence rate

I am working on an operations issue. We process patients in care and pay close attention to their discharge rate, which is more or less calculated as an incidence rate (discharges per 100 patients). ...
1
vote
1answer
26 views

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 ...
1
vote
1answer
2k views

How can I calculate a confidence interval for a rate ratio, if I only have the rates?

I want to calculate the 95% CI for an incidence rate ratio (IRR), but I only have incidence rates per 10,000. (I do not have counts for the 2x2 table.) Specifically, the incident rates were ...
1
vote
1answer
142 views

Simulation of woman's age of getting breast cancer (cumulative incidence rate)

I am writing a programme to simulate the age at which women will get breast cancer. I have data on the cumulative incidence rate for the whole population. What I am doing right now is using Monte ...
1
vote
0answers
10 views

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'...
1
vote
0answers
26 views

Another question- Interpretation of incidence-rate

Suppose the Incidence Rate for an event is 5.43 between 1991-995 Is it okay to say that, on an average one can expect 5 events every year between 1991-1995 ?
1
vote
0answers
26 views

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 ...
1
vote
0answers
20 views

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 ...
1
vote
0answers
25 views

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/...
1
vote
0answers
46 views

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 ...
1
vote
0answers
118 views

Interpreting categorical x categorical interaction in a poisson regression

I have run a poisson regression with two categorical predictors (treatment and disease severity) and their interaction, controlling for a number of relevant covariates. Treatment has two levels (...
1
vote
0answers
189 views

Modeling incidence rates in family-based cohort: Poisson vs Cox

I have a cohort made of family trios and affected sib pairs (probands have rheumatoid arthritis - RA). I would like to calculate some incidence densities (for example apparitions of RA, of disease 1, ...
1
vote
0answers
849 views

Can you calculate a standard error from confidence intervals?

Specifically, can I calculate a standard error from an incidence rate with known confidence intervals but no population size data?
1
vote
0answers
38 views

Considering Age-standardized incidence rates: Will changing the reference population change the incidence rates

Im trying to calculate the mortality rates for males and females in two different disease groups (type 1 and type 2 diabetes). In my primary analyses i forgot to use respective gender as the ...
1
vote
0answers
46 views

Rolling twelve-month crime rate

I need to do a 12 month rolling crime rate. I have monthly crime counts and population counts every 3 months. For a calendar year I would usually use a population from mid-year as the denominator and ...
0
votes
1answer
1k views

Comparing Incidence Rate Ratios

I am trying to compare incidence rate ratios (IRR). This is what I have: Group A (exposed vs. unexposed) IRR and Group B (exposed vs. unexposed) IRR So how would I correctly test for the ...
0
votes
1answer
19 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)...
0
votes
2answers
78 views

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 ...
0
votes
1answer
477 views

Can I compute the p-value for a list of incidence rates?

Coming back to statistics after a long time, so please forgive any ignorance. I'm curious how I might be able to argue for statistical significance of a test. Specifically, I'm after a ...
0
votes
1answer
677 views

Calculating OR and IRR for a zero-inflated negative binomial model from estimates

I used the PSCL package to run a zero-inflated negative binomial model on some count data I have. This package gives the following output: for the zero part of the model: ...
0
votes
1answer
973 views

Negative binomial — IRR interpretation for predictors

I have a zero-inflated negative binomial model. I have used incidence rate ratios and I'm trying to interpret the coefficients in relation to my predictors. Most of my predictors are continuous ...
0
votes
0answers
15 views

Interpreting incidence rate ratios (IRR) in panel data

I am running a negative binomial panel regression (xtnbreg) that includes a pre/post estimator for an intervention (with controls) and am trying to understand how the incidence rate ratio should be ...
0
votes
0answers
15 views

Standardize prevalence and incidence rates calculation in R

There is a cohort study of 500,000 individuals with over 70 conditions. For each condition, I need to calculate Annual standardized prevalence, with time since birth as the underlying time scale ...
0
votes
0answers
18 views

Calculating the confidence interval for an incident rate ratio for a continuous spline variable from a Poisson GLM

I have a rather large and complicated Poisson GLM with a mix of categorical (many binary, yes-no) and continuous values. To calculate the incident rate ratios (IRR) for the binary variables, I simply ...
0
votes
1answer
19 views

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 ...