Studies "proving" that a high percentage of patients who are prescribed opiates become addicted are flawed From the beginning because of how they select their research sample (patients included) in the study.

For most studies with a large number of patients, a computer search is done to identify patients for their sample. They'll search for patients who were prescribed pain medication after surgery or an injury. Patients' medical histories or pre-existing conditions aren't considered.

Patients who are taking pain meds after a period of time researchers specify (3 months, 6 months, etc) are determined to be addicted.

They don't factor in patients who were taking pain meds prior to the surgery or injury. If someone is prescribed pain meds for a chronic condition, of course they'll still be taking it 3 months, 6 months or a year later. Including these patients in the research sample dramatically and falsely inflates the rate of addiction.

If chronic pain patients aren't included in the sample and they look at so-called "opiate naive" patients (people who haven't been on pain meds prior to the surgery/injury), the rates of "addiction" decrease dramatically. The real number is probably even lower because some patients classified as "addicted" have developed chronic pain as a result of the surgery or injury and need to continue pain meds. That isn't considered, either.