What indicates that an adolescent understands how to use a peak expiratory flow meter?

The correct choice, which states that the adolescent will record the highest reading of three attempts, demonstrates a clear understanding of the proper usage of a peak expiratory flow meter (PEFM). This device is designed to measure the peak expiratory flow rate (PEFR), which helps in assessing the function of the lungs and is particularly useful for individuals with asthma or other respiratory conditions.

Using the PEFM, it is essential to take multiple readings – typically three – to ensure accuracy and reliability. Recording the highest reading out of these attempts is crucial because it provides the best indicator of the individual's maximum airflow. This approach allows for better monitoring of lung function over time and helps in managing any potential respiratory issues.

In contrast, taking the test only once a day, sharing results with friends, or omitting use when feeling well reflect misunderstandings about the purpose and optimal use of the PEFM. Regular monitoring, even when feeling well, can catch any potential problems early and assist in managing asthma or similar conditions effectively, making the understanding of recording multiple attempts imperative.