1% Rule (aviation medicine)

In the field of aviation medicine, the 1 percent rule refers to a risk threshold that is applied to the medical fitness of pilots. The basic application of this aviation "1 percent rule" is that a 1% per annum risk (See also Risk management) of medical incapacitation is the threshold between acceptable and unacceptable.

Applying this "1 percent rule" would result in an airline pilot being denied a medical certificate if their risk of a medical incapacitation (e.g. heart attack, convulsion, stroke, faint etc) was determined as being greater than 1% during the year.

This "1 percent rule" took its genesis in the late 1980s and early 1990s in a series of British and then European aviation cardiology workshops. The application of this "1 percent rule" has subsequently spread beyond the domain of aviation cardiology to all potential causes of medical incapacitation.

The reasoning that was used in the development of the original aviation medical "1 percent rule" is well described in the Mitchell & Evans (2004) reference. In that article the authors argue that changes in the underlying assumptions, that were the basis of the "1 percent rule", have been such that a "2 percent rule" may be an appropriate modern analogue.

The application of this one percent rule is controversial. The civil aviation regulatory authorities of some nations employ such numerical risk thresholds (criteria) while others do not. Of those that use numerical risk criteria there are differences in the levels of measured / calculated risk that are applied (1% per annum, 2% per annum etc). There is also debate concerning the application of population statistics to an individual (pilot) and the utility and validity of the risk screening tools that are used by the civil aviation regulatory authorities (e.g. Data from the Framingham Heart Study).

References

* [http://www.ingentaconnect.com/content/asma/asem/2004/00000075/00000003/art00011 Flight Safety and Medical Incapacitation Risk of Airline Pilots] . Mitchell SJ & Evans AD. Aviation, Space, and Environmental Medicine 2004; 75(3):260–8.
* [http://www.ncbi.nlm.nih.gov/pubmed/6373281 Risk of a coronary heart attack in the normal population and how it might be modified in flyers] . Tunstall-Pedoe H. [http://eurheartj.oxfordjournals.org/ Eur Heart J] 1984; 5(Suppl A):43–9.
* [http://www.ncbi.nlm.nih.gov/pubmed/3402499 Introduction to section 1: Acceptable cardiovascular risk in aircrew] . Tunstall-Pedoe H. [http://eurheartj.oxfordjournals.org/ Eur Heart J] 1988; 9(Suppl G):9–11.
* [http://www.ncbi.nlm.nih.gov/pubmed/3402489 The concept of risk] . Tunstall-Pedoe H. [http://eurheartj.oxfordjournals.org/ Eur Heart J] 1988; 9(Suppl G):13–5.
* [http://www.ncbi.nlm.nih.gov/pubmed/1493822 Cardiovascular risk and risk factors in the context of aircrew certification] . Tunstall-Pedoe H. [http://eurheartj.oxfordjournals.org/ Eur Heart J] 1992; 13(Suppl H):16–20.
* [http://cat.inist.fr/?aModele=afficheN&cpsidt=1817937 How cardiovascular risk varies with age, sex, and coronary risk factors: Do standard risk scores give an accurate perspective?] Tunstall-Pedoe H. [http://eurheartj.oxfordjournals.org/ Eur Heart J] 1999; 1(Suppl D):25–31.
* [http://www.ingentaconnect.com/content/asma/asem/2005/00000076/00000001/art00010 Aeromedical Decision-Making: An Evidence-Based Risk Management Paradigm] . Watson DB. Aviation, Space, and Environmental Medicine 2004; 76(1):58-62.

See also

* 1% Rule (Disambiguation)
* 1% Rule (Internet culture)
* Risk management
* Framingham Heart Study