Which of the following is NOT a method to identify a substance abuse problem?

Peer referral is not an established method for identifying a substance abuse problem because it relies on informal observation and reporting from individuals who may not be adequately trained to assess such issues. While peers can play a supportive role in encouraging someone to seek help, their observations are subjective and can be influenced by personal relationships or biases.

In contrast, voluntary self-identification involves an individual recognizing their own substance use issues and seeking assistance, which can be the first and most critical step towards recovery. Commander or supervisor identification relies on trained personnel who can observe behavioral changes aligned with substance abuse and take appropriate action. Medical identification is facilitated through professional healthcare assessments and screenings that provide clinical insight into a person's substance use. These methods are more systematic and reliable, aiming at objectively identifying substance abuse issues and facilitating timely intervention.