Apr 24, 2024  |   5 minute read

OSI | Ottawa Self-injury Inventory

Ottawa Self-Injury Inventory (OSI)

Recommended frequency: Once at the start of treatment

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The Ottawa Self-Injury Inventory (OSI) is a self-report measure used to assess nonsuicidal self-injury including frequency, types of self-injury, functions of the behaviour, potential addictive features of the behaviour, and motivation for change. There is an abbreviated version of the OSI known as the OSI-Functions inventory. Dr. Mary K Nixon was the lead author of the pen and paper version of the OSI in the early 2000’s, in addition to Paula Clourtier.

We want to thank Dr. Mary K Nixon for sharing her expertise with us in the development of the electronic version and accompanying Assessment Guide. Several minor modifications have been made from the pen and paper version including addition of questions relating to social media.

Dr. Nixon has retired from clinical work as a Child and Adolescent Psychiatrist, and is a former Clinical Associate Professor with the Department of Psychiatry at the University of British Columbia, and  Affiliate Associate Professor with the Division of Medical Sciences at the University of Victoria. She is the Founding Editor of the Journal of the Canadian Association of Child and Adolescent Psychiatry and  was the network leader for INSYNC (Interdisciplinary National Self-Injury in Youth Network of Canada), a group of researchers studying self-injury across Canada that was initiated in 2005. Dr Nixon has published a number of articles on self injury and co-edited and contributed to a number of chapters in the book ’Self Injury in Youth: The Essential Guide to Assessment and Interventions, Routledge Press, 2009’.

About the OSI

The OSI was developed during Dr Nixon’s career at the Children’s Hospital of Eastern Ontario in Ottawa in the late 90s, while she was pioneering a new partial hospitalization program for adolescents.

Self-injury was becoming a more prominent and troubling issue at the time. While their team was using a standardized assessment to evaluate mental health symptoms there was often considerable debate as to youths’ self-injury behaviour, motivations, and triggers. Dr Nixon felt it would be valuable to develop a more structured assessment to dig deeper into the understanding of self-injury and ask the youth directly. Several youth in their clinical interviews discussed their drive to repeat the behaviour, alluding to addictive qualities behind non-suicidal self-injury. By adapting questions from the DSM-IV surrounding substance use, they were able to begin measuring and better understanding the potential addictive tendencies associated with the behaviour.

In their 2002 study conducted by Nixon, Cloutier, and Aggarwal with both partial hospitalization youth and inpatient youth, they found that 97.6% of the 42 adolescents studied exhibited at least three dependence items— which is the threshold for substance use disorder according to the DSM-IV. Those with addictive features had higher frequency and severity. 

At the time of its development, there were a number of existing self-report measures for the assessment of non-suicidal self-injury, including the Functional Assessment of Self-Mutilation, the Ottawa/Queen’s Self-Injury Questionnaire, the Self-injurious Thoughts and Behaviors Interview, and others. However, there was great variability between each assessment tool in terms of what aspects of this condition were being measured—varying from frequency and methods used, to motivations.

Dr. Nixon’s team has adapted the OSI over the years, primarily by removing some of the functions questions based on research they conducted within different age groups and settings. Dr. Nixon explains how these studies helped them fine-tune the functions section of the OSI:

They also added a Motivation for Change Likert Scale as this serves as a helpful indicator of what stage of treatment a client might be in, which can help inform their care strategy. The scale can also be a valuable tool to better understand and identify potential barriers to treatment progress.

Key Considerations for the OSI Assessment

Several studies have been completed in inpatient use and outpatient college samples to validate this instrument. Early research on the OSI found that a wide range of functions and addictive features were indicated across clinical samples.

The OSI is designed to be used as an initial assessment to inform treatment planning, goal setting, and to identify in what ways self-injury is impacting the client or what role it plays in their life. It should be used to supplement a formal clinical interview, rather than to replace it.

Who is the OSI Assessment for?

Review the list below to determine if this assessment should be used with your client. If you answer YES to both questions, the OSI is likely a good fit to use with your client.

  1. Is your client 14 years of age or older?
  2. Has your client demonstrated signs of self-injury or risk of self-injury?

The OSI Scale

The OSI is a self-report measure, which means clients can fill it out independently before session or with the assistance of their clinician. The full measure takes approximately 40  minutes to complete and asks clients various questions about the motivations, frequency, recency, functions, and addictive qualities of their self-injury.

Measuring Occurence and Frequency

The occurrence and frequency of non-suicidal self-injury are determined by responses to the question “How often in the past 6 months have you actually injured yourself without the intention to kill yourself?” (range from 0 – not at all, to 4 – daily).

Questions Regarding Suicidal Ideation

There are questions that flag for suicidality early on in the OSI which are designed to help measure the distinction or relationship between self-injury and potential suicidal ideation.

Dr. Mary Nixon explains how the two are connected and can often overlap.

Assessing the Functions

The OSI uses a 5 point Likert Scale to assess the functions of non-suicidal self-injury. Clients are asked to indicate the degree to which 31 items (e.g., “to release unbearable tension,” “to get care and attention from others”) relate with their reasons for self-injury, with options ranging from 1- ‘Never a reason’ to 5 – ‘Always a reason’.

Assessing Addictive Features

To measure the addictive features of non-suicidal self-injury, the OSI leverages seven items adapted from the DSM-IV-TR for substance dependance (e.g., “Despite a desire to cut down or control this behavior, you are unable to do so”). Depending on the question, clients can either select from a scale from 0 – “Never” to 4 – “Always” or simply respond “Yes” or “no.”

Motivation to Change

The OSI features an item to measure motivation to change, as this can be  an important predictor of success in treatment and can help clinicians determine the most appropriate treatment approach.

Interpreting OSI Scores

Dr. Nixon encourages clinicians to use the score key as a guideline to inform treatment plans and approach. She notes that the score key itself does not encompass all of the results of the OSI. The OSI assessment helps to illustrate the various factors and contributors to self-injury, in order to help clinicians identify which components are most prominent and therefore should become a focus in treatment planning.

It is helpful to remind clients that information shared on the OSI is confidential, so they are encouraged to be as open as possible. However, as per local jurisdictions and their laws of reporting, clients should also be made aware that if acute suicide risk is evident you are required to act accordingly and report.

Developed by Mary K Nixon and Paula Cloutier. No permission required to reproduce, translate, display or distribute.

Frequently Asked Questions
When should the OSI be administered in treatment and at which frequency?

The OSI is designed to be used at the beginning of treatment to determine a framework of understanding of your clients needs and to inform the development of a treatment plan. In addition to the OSI, Dr. Nixon recommends using other short assessments (like the Self Assessment Sheet or S.A.S.) regularly throughout treatment to regularly monitor progress and self-injury.

Are there any challenges to using this assessment that clinicians might encounter?

Dr.  Nixon shares that though it’s rare to encounter difficulties with the OSI, it’s important to cross review with the clinical interview the information shared. Dr. Nixon also discusses the importance of providing a rationale for the assessment, particularly if there is any hesitancy from clients around completing it. In doing so, you can support your clients’ understanding of the OSI and the value it will bring to their care process, ultimately encouraging them to complete it to the best of their abilities.

How should clients complete this assessment?

Dr. Nixon recommends that clients complete the OSI on their own and offers additional insight into how she facilitates the process.

How should I introduce the OSI to clients in session?

Dr. Nixon offers an example of how you can introduce the OSI to clients in session and explain the value it will bring to care.

Are there any special considerations to using the OSI assessment?

Dr. Nixon explains the importance of screening clients for suicidal ideation first and foremost, seeing as it is a high-risk issue. When introducing the OSI, she always explains the value it’ll bring to session and reiterates the confidentiality of their responses.

When should OSI results be shared with parents or guardians?

Dr. Nixon does not typically share OSI results with a client’s parents or caregivers. She advises that it’s important to be sensitive when sharing information with family and care teams, and ensure they have the context necessary to best support the client. This project is best negotiated with the client, if they are willing. The success of the OSI has largely been based on the level of trust offered between client and therapist, as well as the willingness of the client to share in a non-direct fashion what is often felt as a difficult behaviour to discuss otherwise.