Calculator Inputs
Example Data Table
| Scenario | Start CIF | End CIF | Start Time | End Time | Beta | Covariate | Reference | Events | Risk Set |
|---|---|---|---|---|---|---|---|---|---|
| Study arm A | 0.12 | 0.25 | 6 | 12 | 0.35 | 2 | 1 | 18 | 160 |
| Study arm B | 0.08 | 0.19 | 3 | 9 | -0.22 | 1 | 0 | 14 | 175 |
| Registry sample | 0.20 | 0.31 | 12 | 18 | 0.10 | 3 | 1 | 25 | 210 |
Formula Used
This calculator converts cumulative incidence values into cumulative subdistribution hazard, then estimates an interval hazard over the selected time span.
Cumulative subdistribution hazard: H*(t) = -ln(1 - CIF(t))
Interval subdistribution hazard: h* = (H*(t2) - H*(t1)) / (t2 - t1)
Fine-Gray style hazard ratio: HR = exp(beta × (x - x_ref))
Adjusted interval hazard: h*_adj = h* × HR
Adjusted CIF from cumulative hazard: CIF_adj = 1 - exp(-H*_adj)
The observed risk and observed rate are simple supplements. They do not replace a full competing-risks model fit with weighted risk sets and full variance estimation.
How to Use This Calculator
- Enter the starting and ending cumulative incidence values for the event of interest. Use proportions, not percentages.
- Provide the start and end times for the interval. The calculator uses that width to estimate an average subdistribution hazard.
- Add a regression beta and covariate values if you want a Fine-Gray style hazard ratio and adjusted hazard output.
- Optionally enter the beta standard error and confidence level to produce a hazard ratio interval.
- Optionally enter observed event count and an effective risk set for a crude observed risk and simple observed rate.
- Press the calculate button. Review the result card above the form, then export the summary as CSV or PDF.
FAQs
1. What does this calculator estimate?
It estimates cumulative subdistribution hazard from cumulative incidence, then converts the interval change into an average subdistribution hazard for the chosen time span.
2. When is subdistribution hazard useful?
It is useful in competing-risks settings when you want direct interpretation in terms of cumulative incidence for the event of interest.
3. Does this replace a full Fine-Gray model?
No. This tool gives interval-based educational estimates and covariate adjustments. Formal inference still needs full model fitting in statistical software.
4. Why must the ending CIF exceed the starting CIF?
The interval hazard formula here assumes cumulative incidence increases across the interval. If it does not, the interval summary becomes inconsistent or uninformative.
5. What units should cumulative incidence use?
Use proportions from 0 to 1. For example, enter 0.25 instead of 25 for a twenty-five percent cumulative incidence value.
6. What does the hazard ratio output mean?
It is the Fine-Gray style multiplier created from exp(beta times covariate difference). Values above one suggest higher subdistribution hazard than the reference.
7. Why are event count and risk set optional?
Those fields provide simple descriptive checks only. The main hazard estimate comes from cumulative incidence values across the selected interval.
8. Can I use this for publication-ready analysis?
Use it for screening, teaching, and quick comparisons. For publication work, confirm estimates with full competing-risks modeling and sensitivity checks.