Table 7.

A comparison of the sensitivity and specificity of existing LL criteria and proposed cut-off values and of heart rate, respiratory rate, and SPO₂ for diagnosing HAPE occurring at 2700–3500 m.

	Heart rate (bpm)		Respiratory rate (breaths/min)		SPO2 (%)
	Proposed >95	Existing >100	Proposed >21	Existing >20	Proposed <86%	Existing nil
Sensitivity	0.66	0.49	0.83	0.83	0.82
(59.9–72.0)		(78.1–87.8)		(77.0–86.9)
Specificity	0.94	1.0	0.95	0.83	0.93
(90.9–97.0)		(92.2–97.7)		(89.7–96.2)
Positive predictive valuea	0.92	1.0	0.94	0.83	0.92
(88.5–95.4)		(90.9–97.0)		(88.5–95.4)
Negative predictive valuea	0.74	0.66	0.84	0.83	0.83
(68.3–79.6)		(79.3–88.6)		(78.1–87.8)

A heart rate of greater than 100 bpm and a respiratory rate of greater than 20 breaths/min have been used to define ‘tachycardia’ and ‘tachypnoea’ for the existing LL criteria. Values in brackets indicate 95% confidence limits.

^aValid for a disease prevalence as evident in the given study population.