Measure treatment performance against a predefined non-inferiority margin. Test means or rates easily. Make stronger statistical decisions with structured output today.
| Scenario | Type | Treatment | Control | Margin | Alpha |
|---|---|---|---|---|---|
| Pain score improvement | Means | n=120, mean=78, sd=12 | n=120, mean=75, sd=11 | 5 | 0.025 |
| Response rate trial | Proportions | 36 / 120 | 40 / 120 | 0.10 | 0.025 |
A non-inferiority test checks whether a treatment is not worse than a control by more than a chosen margin.
Estimate: Difference = Treatment - Control
For means: SE = √[(SDt² / nt) + (SDc² / nc)]
For proportions: SE = √[(pt(1-pt) / nt) + (pc(1-pc) / nc)]
Test statistic: Z = (Estimate + MarginEffect) / SE
When larger values are better, MarginEffect = Margin and the lower bound must be greater than -Margin.
When smaller values are better, MarginEffect = -Margin and the upper bound must stay below Margin.
The calculator also reports a two-sided confidence interval and a one-sided p-value.
A non-inferiority test calculator helps researchers compare a new treatment against an active control. The main goal is to show that the new option is not unacceptably worse. This matters in clinical trials, quality studies, and product benchmarking.
This calculator supports two common settings. It handles independent means and independent proportions. You can define whether larger outcomes are better or smaller outcomes are better. That keeps the interpretation aligned with your endpoint.
The most important input is the non-inferiority margin. This value defines the largest acceptable loss. You also enter treatment and control sample sizes. For continuous data, add means and standard deviations. For binary data, enter event counts.
The calculator returns the estimated treatment difference, standard error, z statistic, p-value, and confidence interval. It also reports the critical one-sided bound. Non-inferiority is supported when that bound stays beyond the required threshold.
Use this tool during protocol planning, result checking, or report preparation. It is useful for fast validation of trial outputs. It also helps students understand how margins, variance, and sample size influence decisions in non-inferiority analysis.
Always choose a clinically justified margin. Make sure your outcome direction is correct. A wrong direction can reverse the conclusion. This calculator is best for quick analysis and educational review. Formal studies should still follow the full statistical analysis plan.
It is a one-sided statistical test used to show a new treatment is not worse than a control by more than a preselected margin.
The margin is the largest acceptable loss compared with the control. It should be justified before the study starts.
Because the question focuses on ruling out unacceptable worsening, not on checking both directions of difference equally.
Yes. This calculator supports independent group comparisons for continuous outcomes and binary event rates.
Select the smaller-is-better option. The calculator then evaluates the upper bound against the positive margin.
No. It is useful for quick calculation and learning, but formal studies should follow approved trial methods and expert review.
Larger samples usually reduce standard error. That makes the bound tighter and can improve the chance of showing non-inferiority.
Report the estimate, margin, one-sided alpha, confidence interval, p-value, direction setting, and the final non-inferiority conclusion.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.