Questions tagged [incidence-rate-ratio]
The incidence-rate-ratio tag has no usage guidance.
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12 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
...
1
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1answer
23 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 ...
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0answers
15 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 ...
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1answer
15 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 ...
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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'...
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1answer
53 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 ...
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0answers
25 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 ?
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1answer
92 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 ...
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0answers
22 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 ...
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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 ...
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2answers
67 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 ...
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0answers
3 views
Compare health spending per capita of 5 countries conditional on their age structure, health index and GDP per capita
I am interested to answer the following question: How does the health spending per capita in 2010 of 5 countries different if they have the same age structure in their population, health index and GDP ...
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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 ...
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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 ...
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0answers
24 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/...
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1answer
228 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 ...
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0answers
355 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 ...
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0answers
140 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 ...
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1answer
297 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 ...
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1answer
169 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, ...
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2answers
494 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.
...
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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://...
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0answers
45 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 ...
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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 ...
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0answers
115 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 (...
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0answers
223 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 ...
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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?
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0answers
188 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, ...
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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). ...
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0answers
804 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?
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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 ...
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1answer
467 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
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1answer
652 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:
...
2
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0answers
662 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 ...
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2answers
290 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 ...
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0answers
47 views
Aggregating rates of events in a population
For every 100,000 people, 4 people succumb to event $X$, a different 10 to $Y$, and 2 others to $Z$. I would like to know the number of people that succumb to any of $X$, $Y$ or $Z$ per 100,000. Is it ...
3
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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 ...
2
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0answers
390 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 ...
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0answers
584 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 ...
8
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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 ...
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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 ...
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2answers
944 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 ...
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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 ...
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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 ...
3
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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 ...
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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 ...
2
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0answers
712 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 ...
6
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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 ...
2
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1answer
689 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
(...
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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 ...
