<p>Hazard ratio (HR) is interpreted as the factor by which the given predictor level's effect on the outcome is lower or higher relative to the reference level. Generally speaking, on the outcome hazard rate, defined by wikipedia as &quot;event rate at time t conditional on survival until time t or later&quot;.</p>
<p>You don't provide any information about your data so none of us can help with specific interpretations. But take a look at what your reference/intercept is for the cell fractions predictor. If cell fraction is categorical, the outcome for the cell fraction that is not the reference is 0.351382 times the reference cell fraction. If it is numerical, each unit increase in cell fraction decreases outcome by a factor of 0.351382.</p>

CC BY-SA 4.0
2024-11-06T16:36:03.067Z
2024-11-06T16:36:03.067Z
Teodor
<p>Good morning,</p>
<p>I was wondering whether anyone could advice me on the following: I have a Cox survival model in R (function coxph), which ,among other variables (e.g. age, sex), contains a variable with percentage (cell fractions, e.g. 10% endothelial cells, 50% epithelial cells). Having a variable with a percentage makes it hard to interpret the Hazard Ratio (HR) in the model.</p>
<p>Does anyone who how to deal with a variable with percentage in a model (particular in Cox models) to make them easier to interpret?</p>
<p>Please find an example below:</p>
<pre><code>coxph(formula = Surv(PFI.t_5y, PFI.e_5y) ~ gender + age +
percentage_cell_fractions, data = combined, model = TRUE)

HR for percentage:  0.351382 (What does this mean??)
P value for percentage: 0.044

Comment: HR &lt; 1 normally means reduction of hazard of dying (e.g. being male reduces the HR of dying). But in the case of percentage how do I interpret that? 
</code></pre>
<p>Thank you &amp; Best Regards!</p>

CC BY-SA 4.0
2024-07-03T11:13:33.450Z
Please [edit] your question and give us _way_ more details. What do you mean by "model"? In vivo? In vitro? In silico? Define "HR" and explain what you need from it. Explain what these "variables" you mention are, where and how they are set and what they represent. Basically, write this assuming the people who read it know _nothing_ abut your research project since that is precisely the case. We might be able to help, but you need to explain what you are doing in detail first.
terdon
CC BY-SA 4.0
2024-07-03T11:49:46.610Z
Okay, thanks, I have added some details.
Bine
<r><modelling>
Cox model with percentage interpretation
# Cox model with percentage interpretation

(Asked by: username_0 on 2024-07-03)

Good morning,
I was wondering whether anyone could advice me on the following: I have a Cox survival model in R (function coxph), which ,among other variables (e.g. age, sex), contains a variable with percentage (cell fractions, e.g. 10% endothelial cells, 50% epithelial cells). Having a variable with a percentage makes it hard to interpret the Hazard Ratio (HR) in the model.
Does anyone who how to deal with a variable with percentage in a model (particular in Cox models) to make them easier to interpret?
Please find an example below:
coxph(formula = Surv(PFI.t_5y, PFI.e_5y) ~ gender + age +
percentage_cell_fractions, data = combined, model = TRUE)

HR for percentage:  0.351382 (What does this mean??)
P value for percentage: 0.044

Comment: HR < 1 normally means reduction of hazard of dying (e.g. being male reduces the HR of dying). But in the case of percentage how do I interpret that? 

Thank you & Best Regards!

**Tags:** r, modelling
> **Comments:**
> **username_1**: Please [edit] your question and give us _way_ more details. What do you mean by "model"? In vivo? In vitro? In silico? Define "HR" and explain what you need from it. Explain what these "variables" you mention are, where and how they are set and what they represent. Basically, write this assuming the people who read it know _nothing_ abut your research project since that is precisely the case. We might be able to help, but you need to explain what you are doing in detail first.  
> **username_0**: Okay, thanks, I have added some details.  

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## 1 answers

### Answer by username_2 on 2024-11-06. Score: 2

Hazard ratio (HR) is interpreted as the factor by which the given predictor level's effect on the outcome is lower or higher relative to the reference level. Generally speaking, on the outcome hazard rate, defined by wikipedia as "event rate at time t conditional on survival until time t or later".

You don't provide any information about your data so none of us can help with specific interpretations. But take a look at what your reference/intercept is for the cell fractions predictor. If cell fraction is categorical, the outcome for the cell fraction that is not the reference is 0.351382 times the reference cell fraction. If it is numerical, each unit increase in cell fraction decreases outcome by a factor of 0.351382.


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