Enter Model Inputs
Supply time points, baseline cumulative hazards, coefficient estimates, and two profiles. The calculator then evaluates adjusted survival curves from the Cox proportional hazards structure.
Example Data Table
This sample shows a typical baseline cumulative hazard schedule for follow-up modeling.
| Time | Baseline Cumulative Hazard H₀(t) | Baseline Survival S₀(t) |
|---|---|---|
| 0 | 0.00 | 1.0000 |
| 6 | 0.05 | 0.9512 |
| 12 | 0.12 | 0.8869 |
| 18 | 0.20 | 0.8187 |
| 24 | 0.31 | 0.7334 |
| 36 | 0.52 | 0.5945 |
Formula Used
The calculator applies a Cox-model-style survival transformation using user-entered coefficient estimates and a baseline cumulative hazard schedule.
This page evaluates survival from supplied model outputs. It does not estimate coefficients from raw subject-level event data.
How to Use This Calculator
- Enter comma-separated follow-up time points in increasing order.
- Enter baseline cumulative hazard values for the same times.
- Paste the fitted coefficient estimates from your survival model.
- Add optional standard errors for interval estimation.
- Define two covariate profiles for direct adjusted comparison.
- Choose the time unit that matches your model output.
- Press calculate to display summary metrics, table output, and plot.
- Use the CSV or PDF buttons to export the results.
Frequently Asked Questions
1. What is an adjusted survival curve?
An adjusted survival curve estimates survival for a chosen covariate profile after accounting for model coefficients. It helps compare expected outcomes while holding the statistical model structure constant across scenarios.
2. Why do I enter baseline cumulative hazard values?
The calculator transforms the baseline cumulative hazard into baseline survival, then scales it by each profile’s relative hazard. This mirrors a standard Cox-model post-estimation workflow.
3. How should binary treatment be coded?
Use the same coding used during model fitting. Most analyses code untreated as 0 and treated as 1, but any consistent scheme can work if coefficients match it.
4. What is the difference between baseline survival and adjusted survival?
Baseline survival represents the reference hazard schedule before covariate scaling. Adjusted survival applies the profile-specific linear predictor, producing survival estimates tailored to the entered covariate values.
5. Can I compare two adjusted profiles directly?
Yes. The calculator reports both survival curves, final risk values, restricted mean survival, and a hazard ratio comparing Profile A against Profile B.
6. What happens if hazards are not increasing?
Cumulative hazards should never decrease over time. If they do, the input is inconsistent with a cumulative hazard function, and the calculator flags the issue.
7. Does this tool replace full model fitting software?
No. It is a post-estimation calculator for interpreting fitted results. You still need proper survival-analysis software to estimate coefficients, standard errors, and baseline hazards.
8. Which time unit should I use?
Use the same unit used to derive your baseline cumulative hazards, such as days, months, or years. Consistent units keep medians and restricted mean survival interpretable.