One-way sensitivity analysis
Set up, run, and review this analysis in Lifescio.
Supported analysis
The app varies one state cost or non-self transition at a time. A transition change is offset against that row’s self-transition to preserve its total. Other inputs stay at their base values.
Supported scope: Only state costs and non-self transitions are varied in this workflow. Simultaneous changes, parameter correlations and alternative model structures require separate analyses. The variation percentage is a sensitivity range, not a confidence interval.
Prepare data and configure the analysis
Enter the same validated cohort model used for the base comparison, then set Relative variation as a decimal; 0.20 evaluates 80% and 120% of each selected input. The workflow varies state costs and positive off-diagonal transition probabilities in each strategy.
When an off-diagonal probability changes, the same row's self-transition changes in the opposite direction. Utilities, zero transitions, and other model settings are not automatically varied. The chosen willingness-to-pay threshold sets the net-benefit scale used for the comparisons.
Input reference (12 fields)
Enter your data and prespecified choices. Ranges include both limits. For table fields, use cell editing, Paste data, or Import CSV / TSV. Review whether the first imported row contains headings and map the source columns before applying the import. Empty numeric cells are not treated as zero. Open file is for an exported Lifescio analysis JSON file, not a spreadsheet.
| Input | Format | Allowed range | Guidance |
|---|---|---|---|
| Health states | Text | — | Names correspond to transition rows and columns. Add one name or comma-separated names in the State manager. It creates matching matrices for both strategies. |
| Comparator transitions | Table | — | Each row must sum to 1. Probabilities apply to one model cycle. Rows and columns follow the order in the State manager. Fill every cell, including zeros, before saving or running. |
| Intervention transitions | Table | — | Use the same state order as the comparator. Rows and columns follow the order in the State manager. Fill every cell, including zeros, before saving or running. |
| Annual state rewards | Table | — | Costs per year and utilities; the engine applies cycle length. Columns in order: Comparator cost; Comparator utility; Intervention cost; Intervention utility. |
| Initial state proportions | Text | — | One proportion per state, summing to 1. |
| Number of cycles | Whole number | 1–500 | — |
| Cycle length (years) | Number | 0.01–10 | — |
| Annual cost discount rate | Number | 0–0.2 | — |
| Annual QALY discount rate | Number | 0–0.2 | — |
| State reward timing | Selection | — | Choices: trapezoid, start. |
| Willingness to pay per QALY | Number | 0–10000000 | — |
| Relative variation | Number | 0.01–0.8 | — |
Run and review
- Give the analysis a descriptive name and review every example value. Record units, data preparation, and planning assumptions in Reproducibility & notes. For simulations, record the seed and replication or sampling settings.
- Choose Run analysis. Resolve input errors before interpreting output. In the connected app, a run uses a saved input revision; local preview runs need the page to stay open.
- Review Diagnostics for method limitations, warnings, and available numerical checks. A completed run means computation finished; it does not establish that the assumptions fit your study.
- Use the Result table selector to inspect each output. Editing inputs does not recalculate existing results: an earlier-input notice means you need to run again to obtain matching results.
Understand the outputs
One-way sensitivity reports Low-input incremental NMB and High-input incremental NMB for each varied parameter. These labels identify the input setting, not necessarily the smaller or larger outcome. Review the sign relative to zero and the span between the two results.
The chart includes parameters with both endpoints estimable. Base strategy and occupancy tables retain the original inputs. A blank endpoint indicates an invalid transition scenario, not a zero impact or an unchanged result.
Troubleshooting and common mistakes
For a missing endpoint, check whether the varied transition or the compensating self-transition crossed zero or one. Reduce the range only if that revised range is scientifically defensible.
An unchanged zero cost is expected under relative variation. If an important utility or structural choice is absent from the ranking, create a separate saved model scenario; this workflow does not sweep every input. Avoid treating its ranking as a complete uncertainty assessment.
After correcting inputs, run again and check that the results belong to the new input snapshot. Increasing simulation draws improves numerical precision only; it does not repair invalid data or an unsuitable model.
Save, compare, and export
In the connected app, Save analysis retains the inputs in your account. Run history lets you inspect earlier runs, each with the input revision it used. In local preview, Save analysis downloads an input file instead; download results before leaving the page.
Use Result + inputs for a JSON archive containing the completed result and its inputs, Download CSV for the selected result table, PDF report for a report, and a chart's SVG button for its figure. Table displays round to three decimals; CSV and JSON exports retain calculation precision. Use those values when assessing a result near a decision boundary.
To reopen an archive, select the matching analysis method and choose Open file. Imported inputs start a new draft; a result archive can also display its retained result. It does not attach itself to an existing account analysis or recompute the result. Save or run the imported draft when you want a new account record.