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Research Christmas: Years Like This

Ingested foreign bodies and societal wealth: three year observational study of swallowed coins

BMJ 2009; 339 doi: (Published 04 December 2009) Cite this as: BMJ 2009;339:b5066
  1. P G Firth, instructor in anesthesia, Harvard Medical School1,
  2. H Zheng, assistant professor, Harvard Medical School2,
  3. J A Biller, assistant professor, Harvard Medical School3
  1. 1Anaesthetist, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit Street, Boston, MA 02114, USA
  2. 2Biostatistician, Biostatistics Center, Massachusetts General Hospital, 50 Staniford Street, 5th Floor, Suite 560, Boston
  3. 3Gastroenterologist, Department of Gastroenterology, Mass General West, 40 Second Ave, Suite 340, Waltham, MA 02451, USA
  1. Correspondence: P G Firth pfirth{at}
  • Accepted 16 November 2009


Objective To examine the relation between coins ingested by children and the Dow Jones Industrial Average.

Design Observational study.

Main outcome measures Total value of coins ingested and number of incidents of coins versus other objects swallowed, measured before and after the stock market crash of October 2008.

Results Eighteen objects, including 11 coins, were ingested (NASDAQ (numismatic and sundry detritus acquired) composite of 18). The total value of the 11 coins swallowed was $1.03 (FTSE 100 (fraction of the US$ or 100 cents) index of 103). The pecuniary extraction ratio (PE ratio) was 0.57 (9/16). Comparing values for a period before and after October 2008, the mean monthly NASDAQ composite (0.41 (SD 0.67) v 0.5 (0.85), P=0.75), FTSE 100 index in cents (2.3 (6.8) v 3.1 (7.8), P=0.77), and PE ratio (0.54 (0.52) v 0.66 (0.29), P=0.50) did not change. The mean end-of-month closing value of the Dow Jones, however, decreased significantly (12 537 (841.4) v 8388 (699.8), P<0.001)

Conclusion There was no detectable difference in the total value of coins ingested, or ratio of coins to other objects swallowed, before or after a massive stock market crash.


  • We thank Eric Brynjoffsen, MIT Sloan School of Management, for economic advice on monetary theory and why it is important to pay off your credit card; Elizabeth Hohmann of the Massachusetts General Hospital for humour in ethics; Scott Tolle of the Massachusetts General Hospital for clarity in imaging as usual; Allan Low, Gerry McCartney, and the BMJ editors for economic and epidemiological advice.

  • Contributors: PGF conceived the study and wrote the manuscript with input from HZ and JAB; HZ performed the statistical analysis; JAB provided details of the foreign bodies. PGF is guarantor.

  • Funding: Funding was obtained from the gastrointestinal tracts of our patients. Absolutely no taxpayer money was used for this research.

  • Competing interests: The desires of the authors to earn Wall Street salaries conflict with their jobs in academic medicine.

  • Ethical approval: A member of the institutional review board of the Massachusetts General Hospital thoroughly approved of this study.

  • Data sharing: No additional data available.

  • Accepted 16 November 2009

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