Adherence to (compliance with) drug treatment is important. However, only about half the people who leave a doctor's office with a prescription take the drug as directed. Among the many reasons people give for not adhering to drug treatment, forgetfulness is the most common.
Definition of periodical. 1  1 : periodic 1. 2  2a : published with a fixed interval between the issues or numbersb : published in, characteristic of, or connected with a periodical.
newsletter. 1  a written report, issued periodically, typically by a business, institution, or other organization, that presents information and news to people with a specific interest in the organization or subject: our co-opâs monthly newsletter; an employee newsletter.