How is the effectiveness of CPAP therapy measured?

The effectiveness of CPAP (Continuous Positive Airway Pressure) therapy is primarily measured by changes in the Apnea-Hypopnea Index (AHI) and patient-reported symptoms. The AHI quantifies the severity of sleep apnea by counting the number of apneas and hypopneas that occur per hour of sleep. A significant reduction in the AHI after starting CPAP therapy indicates that the therapy is effectively preventing airway obstructions during sleep.

In addition to objective measures like AHI, patient-reported symptoms, such as improvements in daytime sleepiness, energy levels, and overall quality of sleep, are also crucial indicators of the therapy's success. These subjective assessments provide insight into how well the therapy is addressing the patient's sleep-disordered breathing and leading to an improved quality of life.

Other options, while relevant to overall health management, do not directly reflect the effectiveness of CPAP therapy. For example, patient weight loss can benefit sleep apnea but isn’t a direct measure of how well CPAP is working. Similarly, the length of use of the device provides information on adherence rather than efficacy, and subjective family reports may not accurately capture the patient's experience or the clinical changes related to therapy effectiveness.