# Questions tagged [hazard]

The hazard rate is the instantaneous rate at which units that have survived until time $t$ die at $t$. The hazard ratio is the ratio of 2 specified hazards.

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### Am I able to calculate the p-value from hazard ratios and effect size? [duplicate]

I ran a Cox proportional-hazards (coxph) model on my data, which contains individuals with either a disease status1 or disease status2, and they have been administered either treatment A or treatment ...
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### Survival analysis interaction interpretation: interaction is insignificant, but pairwise comparison does hold significance

I'm new with survival analyses, and have been breaking my head over this for a while, so I hope someone can explain this in a simple manner: Variable HR Gender(Female) 1.391* Treat (Yes) 0.544*** ...
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### In a survival meta-analysis shouldn't you use HR instead of RR?

I found this interesting survival meta-analysis: https://pubmed.ncbi.nlm.nih.gov/23216926/ Why do they compare OS between the different studies using RR and not HR? Indeed the authors of this paper ...
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### Cox regression hazard ratio (group 1 vs. group 4) changes calculation changes after combining group 2 and 3?

I am working on a project which involves fitting a Cox proportional hazard model to a time to event situation in SAS. We have the variables: y - event or censor (0/1) timeto - time to event y x - ...
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### Estimating probability of attack in Ukraine, given count data

I was looking at some attack count data in Ukraine for different days. The data is gathered from the ACCLED dataset, and there is a picture below. The picture shows individual attacks, but I can apply ...
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1 vote
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### Competing Risks without Censoring

I am trying to estimate the probability that an entity goes from state $A$ to either state $B$, $C$, or $D$. The probability should be dependent on how long the entity has been in state $A$. My data ...
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### My teacher names hazard rates "probability". How can it be, since h(t) is unbounded as quotient?

Hazard rate, depending on the time scale, can be 0.1 or 100 or 1000. It's just a ratio. So why do people call it a "conditional probability"? Will I fail an exam, if I say that? So, is this ...
1 vote
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### Statistical terminology: "hazard ratio" or "hazards ratio"

I have a question related to statistical terminology. More specifically, about the hazard ratio. When describing the ratio between two hazard rates, we use the term "hazard ratio". The term &...
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### Is it possible to calculate number of events in each treatment arm if we have hazard ratio and number of patients in each treatment group

I have a question regarding calculating event numbers. I have a trial where the hazard ratio of treatment arm compared to control arm is 0.75 (95% CI: 0.59-0.96). I know the number of patients ...
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### Extracting hazard ratio for subgroup from overall hazard ratio and hazard ratio of another subgroup?

Hi I have a relatively naive question here. Suppose in a clinical trial the overall HR of treatment A compared to treatment B is 0.66 (95% CI: 0.61 to 0.73). Now we perform a subgroup analysis of the ...
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### Why don’t we just model the hazard ratio directly as a linear function of the covariates in a cox regression model?

Came across this question in my notes and I wish for some confirmation in my answer. The full question is : why don't we just model the hazard ratio $\phi= \frac{\lambda_{1}(t)}{\lambda_{0}(t)}$, ...
1 vote
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### What if proportional hazard assumption does not hold for a confounder in Cox PH model

If proportionality hazard assumption does not appear to hold for a covariate in the Cox PH model, is it a serious matter? The covariate is included in order to adjust for potential confounding. I am ...
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### How to simulate a time dependent variable on a existing dataset?

I made a coursera course abouth survival analysis. It uses a heart failure dataset for the examples. (That same dataset can be found on Kaggle https://www.kaggle.com/jackleenrasmybareh/heart-failure) ...
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### Combining Time-Defined Hazard Ratios and Odds Ratios in Meta-Analysis

I am attempting to complete a meta-analysis of studies that variously report Odds Ratio of death at 30 days, and Hazard Ratios for death at 30 days. All are reported as being close to 1 (range 1.2-1....
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### Is it possible to calculate conditional PD / unconditional PD from Hazard Rate?

I'm just wondering that can I convert hazard rate to probability of default? Suppose I have the lifetime table data as per below: Time Total Default Non-Default At Risk 0 - - - 356,335 1 5,587 1,...
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### I cannot match the results of KaplanMeier and Nelson Aalen by hand

I have fitted both models by using lifelines python library. The results of .event_table from both models are identically matched. However, when I try to ...
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### Calculate the confidence interval of a Hazard Ratio from the ones of the survival

I have 2 populations with their survival at n years and their 95% confidence interval. Under the assumption of exponential distribution, the hazard ratio can be ...
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