Position
Explainable MVP
A documented proxy engine, not a final clinical formula.
Shiftwell
Sleep, biological rhythms, atypical schedules
Method
Methodology
Readable first, perfect later.
Shiftwell reads a work and sleep week as a tension between load, recovery, biological night and regularity. The current version is still a traceable MVP aligned with external references without claiming to reproduce them exactly.
Primary reference
Workbook
Thresholds and factors are continuously compared against the working copy.
Ambition
Traceable
Every visible factor should map back to a source and status.
What the formula reads today
What the formula reads today
- The risk score summarizes weekly load from work segments, long shifts, short breaks, nights, and biological and social loss proxies.
- The sleep score combines average sleep duration and a regularity proxy from the entered schedule, without actigraphy or physiological measurement.
- The adaptability score combines inverse risk and sleep into a simple product layer that remains useful for exploration but is not cohort-calibrated yet.
Mapping
| External reference | Shiftwell variable | Status |
|---|---|---|
| Hours worked | Computed from weekly work segments | Implemented |
| Long shifts | Count of long work segments (proxy threshold) | Implemented (proxy) |
| Recovery | Longest recovery window between shifts | Implemented (proxy) |
| Night shifts | Overlap with biological night window | Implemented (proxy) |
| Biological loss | Work encroachment in biological window (23:00-07:00 proxy) | Implemented (proxy) |
| Social loss | Work encroachment in social window (proxy) | Implemented (proxy) |
| SRI/TST | Regularity proxy + total sleep time | MVP proxy |
Current limitations
Current limitations
- Current version = proxy v0.1, with several thresholds still to be locked against the final protocol.
- Input is self-reported: there is no actigraphy or wearable capture in the MVP.
- The adaptability score is not yet calibrated on a reference cohort.
- The interface explains an active formula, but still does not provide clinical recommendations.
Next clarifications
Next clarifications
- Continue strict alignment with the workbook and formalize disputed gaps.
- Refine biological and social factors where runtime still remains proxy-based.
- Extend the trace to reduce remaining explainability fallbacks on the UI side.
- Stabilize the parts that are robust enough to welcome calmer open-source contributions.
MVP
Proxy, but readable
- The current priority is to make the engine clear enough that contributors understand what is implemented.
- The goal is not to over-claim clinical precision, but to document clearly what already exists.