The Outcome Questionnaire 45 (OQ-45), created by Gary M Burlingame and Michael J. Lambert at Brigham Young University, is a 45-item multiple-choice self-report inventory used to measure psychotherapy progress in adults patients. The OQ-45 is currently in its second version (OQ-45.2), which was released in October 2013 by OQ Measures, the company founded by Burlingame and Lambert. 
Clinical use.
The instrument was designed as a brief scale to measure the subjective experience of a person, as well as the way they function in the world. Authors intended it to be a low cost instrument with a quick administration time that is sensitive to change across time. The inventory is not intended to be used for diagnostic purposes. 
Format.
The OQ-45 contains 45 items. Individuals are asked to describe their experiences in the last week, using a multiple choice format. This response format is consistent across questions: Never, Rarely, Sometimes, Frequently, and Almost Always. The questionnaire was originally developed as a paper version, and was later made available in mobile and web-based formats.
Domains of Measurement.
The OQ-45 measures progress across three different domains of experience: 
Scoring.
Points are assigned for each response using the following scoring rubric: Never (0), Rarely (1), Sometimes (2), Frequently (3), and Almost Always (4). Individual subscales are totaled using addition, after reverse-coding procedures are performed. Higher scores indicate more severe distress and functional impairment. The Symptom Distress subscale contains 25 items, and scores range from 0 to 100. The Interpersonal Relations subscale contains 11 items, and scores range from 0 to 44. The Social Role subscale contains 9 items, and scores range from 0 to 36. A total score (TOT) is calculated by summing the subscales, and scores range from 0 to 180. The instrument's administration and scoring manual provides thresholds for clinically significant distress and impairment, and for reliable change. 