# Cluster base-rate test: listed deaths against expected suicides in the source workforce

> To tell whether a reported cluster of deaths in an occupation is larger than chance before looking for a common cause. Run 1 times on the site, with…

Source: https://mysteriesdept.com/methods/MTH0DGGBP3AS2EZ/cluster-base-rate-test-listed-deaths-against-expected  
Publisher: Mysteries Department  
Licence: CC BY 4.0 (credit Mysteries Department and link the page)  

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[Methods](https://mysteriesdept.com/methods)[Epidemiology / statistics](https://mysteriesdept.com/methods?kind=statistics-and-information)Cluster base-rate test: listed deaths against expected suicides in the source workforce

Method · epidemiology / statistics

# Cluster base-rate test: listed deaths against expected suicides in the source workforce

To tell whether a reported cluster of deaths in an occupation is larger than chance before looking for a common cause.

**Epidemiology / statistics** Version **1.0** Licence **MIT1** runUsed on **1** mystery

## Questions it answers

- [Were there more deaths among British defence scientists and engineers in 1982–1990 than ordinary death rates would produce?](https://mysteriesdept.com/mysteries/marconi-scientists/questions/QST0DGG9HRA9QAX/were-there-more-deaths-among-british-defence-scientists-and)

## Code Python

[Download module (.py)](https://mysteriesdept.com/files/private/55e3522a92a82cd1cff29df674aae0638236085dec5677a2d4e0d817e3c1de01)`base_rate.py`[View source](https://mysteriesdept.com/files/private/55e3522a92a82cd1cff29df674aae0638236085dec5677a2d4e0d817e3c1de01)

## Runs and results 1 run

| Run | Mystery | Measured | Result | Against | Date |
|---|---|---|---|---|---|
| RUN0DGGDGRHYP78 | Marconi | Observed/expected ratio with exact Poisson 95% interval | 0.25 | 1 (as many listed deaths as ordinary rates predict) | |

## Applied to

**[Marconi scientists' deaths, 1982–1990](https://mysteriesdept.com/mysteries/marconi-scientists)1 dataset** The Marconi deaths case table, 1982–1990

## References

1. [House of Commons 1987. Goods and Services (defence employment): written answer, House of Commons, 24 March 1987 (HC Deb vol 113 c137W).](https://mysteriesdept.com/sources/SRC0DGG5Z3Y5V7X/goods-and-services-defence-employment-written-answer-house)
1. [Office for National Statistics 2026. Suicides in England and Wales: reference tables, 2025 registrations.](https://mysteriesdept.com/sources/SRC0DGG78MHBCW8/suicides-in-england-and-wales-reference-tables-2025)
1. [Monopolies and Mergers Commission 1989. The General Electric Company plc, Siemens AG and The Plessey Company plc: a report on the proposed mergers (Monopolies and Mergers Commission, 1989), chapter 2.](https://mysteriesdept.com/sources/SRC0DGG78YY6FZK/the-general-electric-company-plc-siemens-ag-and-the-plessey)

[Download module](https://mysteriesdept.com/files/private/55e3522a92a82cd1cff29df674aae0638236085dec5677a2d4e0d817e3c1de01)

Category

Epidemiology / statistics

Version

1.0 · 3 Nov 2026

Licence

MIT

Language

Python

Inputs

A case table with each death's date, employer group and the kind of death the list presents; age-specific suicide rates (ONS definition, including undetermined intent) by year and sex; workforce sizes from official sources.

Output

For each workforce: expected count, observed count, observed/expected ratio with exact Poisson 95% interval, one-sided Poisson probabilities, and the workforce size at which the observed count would equal the expected one.

Cite

[BibTeX](https://mysteriesdept.com/methods/MTH0DGGBP3AS2EZ/cluster-base-rate-test-listed-deaths-against-expected/cite.bib) · [APA](https://mysteriesdept.com/methods/MTH0DGGBP3AS2EZ/cluster-base-rate-test-listed-deaths-against-expected/cite.txt)

Develop this method

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Authors

**[apollo](https://mysteriesdept.com/u/apollo)** Wrote version 1.0