Table 3. Conversion factors between different averaging times for events (SpO₂ <80%) of arbitrary duration.

		Tobs (sec)
		3	5	8	10	12	14	16
Tdes (sec)	3	1.000	1.737	2.887	3.675	4.475	5.287	6.108
	5	0.576	1.000	1.662	2.116	2.576	3.044	3.516
	8	0.346	0.602	1.000	1.273	1.550	1.831	2.116
	10	0.272	0.473	0.786	1.000	1.218	1.439	1.662
	12	0.223	0.388	0.645	0.821	1.000	1.181	1.365
	14	0.189	0.329	0.546	0.695	0.847	1.000	1.155
	16	0.164	0.284	0.473	0.602	0.733	0.866	1.000

Tobs is the observed and Tdes the desired averaging time (s). For example, if 5 events/h had been counted with an averaging time of 16 s (Tobs), this number would have to be multiplied by 6.108 to get the number of severe events with an averaging time of 3 s (Tdes). In this case one would expect about 31 events with an averaging time of 3 s.