Questions tagged [incidence-rate-ratio]
The incidence-rate-ratio tag has no usage guidance.
80
questions
0
votes
0answers
7 views
Incident Rate Ratios opposite sign from change in volume
I am calculating IRRs on events $x$ over a time period, say t=1-10, in two different years. Using a poisson IRR, I find an estimate of >1.00 (but not statistically significant), even though $x_{...
1
vote
1answer
24 views
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, ...
1
vote
1answer
30 views
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 ...
0
votes
0answers
12 views
significance testing for incidence rate ratios
For comparison of two different incidence-rates (comparing 2 medications)I determined Odds ratio using SPSS. Now I'm wondering which significance test is most suitable.
Any help is warmly welcomed :)
2
votes
1answer
47 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))})$, ...
0
votes
0answers
20 views
Why does my GLM show IRR and CI of 1
I'm running GLMs with occurrence data from a camera trap study. Cameras were set at various distances from a railway. I set up a poisson model and used the number of days the camera traps were active ...
0
votes
0answers
10 views
Compare incidence of 2 geographic regions over time with multiple testing
I have time series data on daily numbers of new cases - for the sake of example, let's say Influenza. This data can be broken down by city. Let's also say there are 30 cities present in my dataset.
If ...
0
votes
0answers
81 views
Interpreting Incidence Rate Ratios - Poisson Regression in R
So I've got 4 computer systems - Emis, Microtest, Vision and TPP, and they each record numbers of a condition: CKD, for each doctor. I've added a covariate of region.
I'm using poisson since it's ...
0
votes
0answers
11 views
Comparison of accident/injury/fatality rates per vehicle miles travelled
How can a difference between two rates measured as the number of accidents/fatalities/injuries per vehicle mile travelled be tested for significance?
For example, 100,000 crashes per 70 billion ...
1
vote
1answer
46 views
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 ...
0
votes
0answers
9 views
How to determine "per" population size for incidence rate
I am reading notes for a given assignment and incidence rate is defined as
$$
\frac{new cases}{observed population} x 10^n
$$
The only thing that is confusing me is that what to use for ...
0
votes
0answers
28 views
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 ...
2
votes
1answer
134 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 ...
2
votes
1answer
840 views
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:
...
0
votes
1answer
198 views
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?
2
votes
0answers
35 views
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 ...
0
votes
1answer
336 views
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
1answer
19 views
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 ...
2
votes
1answer
449 views
3
votes
1answer
100 views
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 ...
0
votes
0answers
27 views
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
1answer
181 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) ...
1
vote
1answer
252 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 ...
0
votes
1answer
67 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 ...
1
vote
0answers
12 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'...
2
votes
1answer
78 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 ...
1
vote
1answer
5k 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
0answers
39 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
22 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 ...
0
votes
2answers
499 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 ...
8
votes
3answers
286 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 ...
2
votes
1answer
71 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 ...
0
votes
0answers
492 views
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
0answers
39 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/...
0
votes
1answer
419 views
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 ...
2
votes
0answers
444 views
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 ...
0
votes
0answers
352 views
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 ...
0
votes
1answer
531 views
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 ...
0
votes
1answer
829 views
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, ...
3
votes
2answers
2k 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.
...
1
vote
1answer
79 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
0answers
54 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
2answers
208 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
0answers
145 views
Interpreting categorical x categorical interaction in a poisson regression [duplicate]
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 (...
4
votes
0answers
424 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 ...
3
votes
2answers
7k 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?
1
vote
0answers
242 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
1answer
72 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
0answers
1k 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
1answer
3k 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 ...
