How useful is AHI?
Reviewed by Vik Veer

There is a growing unease in the sleep medicine world about the usefulness of the apnoea-hypopnoea index (AHI). Most of our objective evidence about obstructive sleep apnoea (OSA) is in some way related to the AHI, and the respiratory physicians have led the way with their CPAP research. Many people controlled on CPAP however still feel that their sleep is not adequate and have no alteration in symptoms. These patients typically are the ones that become ‘non-compliant’ and this is a major component of the 82% long-term non-compliance rate for CPAP. In this study, 285 patients with simple snoring and OSA had their quality of life (QOL) and AHI scores measured. The crux of the article was that the patient’s subjective appreciation of their sleep quality is not related to their AHI. A rhinology comparison may be made with the benefit patients seem to gain after septoplasty without clear objective evidence of improvement. Very few surgeons routinely use rhinomanometry for their septoplasty patients. This is rather disturbing, particularly for the sleep surgeon who is desperately searching for an objective measure to validate his or her operative results. In an evidence-based medical world, it simply isn’t enough to claim that all your patients ‘feel’ much better and were therefore discharged. There are several authorities around the world attempting to find a better way of objectively measuring OSA, in particular Pang & Rotenberg and their SLEEPGOAL criteria. The body of evidence is growing and it is crucial we understand how AHI and other parameters influence our patients, and how this relates to treatment success. Without an objective measure, how can we possibly show that any intervention actually works?

The quality of life of suspected obstructive sleep apnea patients is related to their subjective sleep quality rather than the apnea-hypopnea index.
Kang JM, Kang SG, Cho SJ, et al.
SLEEP AND BREATHING
2017;21(2):369-75.