Assessment of functional outcomes is increasingly recognized as an important component in patient care. Unlike screening, assessment of functional outcomes can occur on an ongoing basis in order to identify any changes in a patient’s symptoms or functioning during treatment. Functional outcomes can encompass different concepts, including health-related quality of life (e.g., pain, physical function), psychosocial interaction (e.g., social interactions, daily tasks), or quality of life (e.g., perceived enjoyment and satisfaction).613,614 There are a multitude of clinician- and patient-rated instruments that measure global and specific aspects of functioning,614 and the decision of which instrument(s) to administer should be based on clinical need and the patient’s preferences and treatment goals. The following list of instruments is non-exhaustive and there is not a best choice of instrument. Clinicians may find these or other instruments useful as part of care planning and follow up.
The World Health Organization Disability Assessment Schedule 2 (WHODAS 2.0) was designed to assess global functioning and impairment, and is applicable to all health conditions, including substance use. This instrument is reliant on patient self-report and evaluates the patient’s ability to perform activities in 6 domains of functioning during the previous 30 days: cognition, mobility, self-care, social and interpersonal functioning, home, academic, and occupational function, and participation in society. There are 36- and 12-item versions of the instrument, both of which can be self-administered, proxy-administered, or rater-administered. The APA endorses the use of WHODAS 2.0 to assess function and includes both the 36- and 12-item self-administered questionnaires in the DSM-5. The WHODAS 2.0 has demonstrated good face validity, including replicability across countries, populations, diagnostic groups, ages, and genders. It has further demonstrated reliability and validity in discerning differences across the general population and among those with mental health issues or addictions.
The Injection Drug User Quality of Life Scale (IDUQOL) was designed to assess the complex circumstances (e.g., cultural, socioeconomic, political, medical, and geographic) that influence quality of life for people who inject drugs. The IDUQOL relies on patient self-report and contains 21 life domains that are relevant to the daily lives of people who inject drugs. Each domain is displayed on a small card that includes the name, description, and visual representation of the domain. Individuals rate themselves on each domain using a 7-point Likert-type scale that ranges from 1 (very dissatisfied) to 7 (very satisfied). The IDUQOL has demonstrated weak criterion-related validity, good internal consistency and one-week test-retest reliability, and strong convergent and discriminant validity.
The EuroQol Group’s 5-domain (EQ-5D) questionnaire is a widely used instrument that measures general health status. The instrument relies on patient self-report and consists of 5 dimensions with 3 or 5 levels: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. The EQ-5D was designed to be self-administered, but may also be interviewer-administered or proxy-administered. An extensive body of evidence supporting the validity and reliability of the EQ-5D for numerous health conditions exists, and there is growing evidence of its validity in populations of people with opioid use disorder.615,616 The EQ-5D has demonstrated strong concurrent validity and construct validity, and can detect clinically important changes in unregulated drug use.616,617
The above appendix was developed to support clinical practice using a different methodology from the process utilized for the main body of the guideline.
The clinical guidance provided in the appendix has been derived through guideline committee consensus following iterative discussions in reference to existing evidence and national and international evidence-based clinical practice guidelines.
The content presented in the appendix is also informed by the opinion of expert reviewers, personal communication with study authors, and a review of position papers and practice bulletins issued by recognized addiction medicine professional organizations and authorities. In addition, where appropriate, Health Canada-approved drug product monographs, and previous and current guidance from the College of Physicians and Surgeons of BC (CPSBC) and Health Canada were consulted to ensure compliance with provincial and national safety regulations and standards for practice.