Participants
The initial sample consisted of 66 work-disabled individuals (15 women, 51 men) with musculoskeletal pain and depression. The study sample was recruited through local media advertisements. The media advertisements solicited individuals who had sustained a musculoskeletal injury to the back or neck and were currently absent from work. The inclusion criteria were as follows: 1) work-disability greater than 4 weeks associated with a musculoskeletal injury to the back or neck, 2) a score above clinical threshold on a self-report measure of depression, and 3) between 25 and 55 years of age. Participants who met inclusion criteria for the study were invited to watch an introductory video that provided detailed information about the procedures (i.e., behavioral activation) and the goals (i.e., return to work) of the RTBA intervention. Participants received 25$ for each session of the intervention program they attended. Compensation was provided to defray the costs of inconveniences (e.g., travel, childcare) that might be associated with participation.
Risk-Targeted Behavioral Activation (RTBA). Behavioral activation is a structured approach to treatment that was originally developed for the treatment of depression [20]. Numerous investigations have supported the use of behavioral activation as an effective treatment for depression [26]. There are also indications that behavioral activation might improve return to work outcomes in individuals with chronic depression [27]. The behavioral activation component of the treatment program focused on goal setting, structuring and scheduling activities, increasing success and achievement experiences, and problem-solving. In order to maximize the impact of behavioral activation on disability reduction, goal setting and scheduling of activities focused primarily on resumption of discontinued activities as opposed to focusing on the scheduling of pleasant activities. One objective of goal setting and activity scheduling was to reduce the discrepancy between the client’s pre-injury activity repertoire and the client’s current activity repertoire.
Behavioral activation was supplemented by a collection of techniques designed to reduce catastrophic thinking and perceptions of injustice, two psychosocial risk factors that have been shown to contribute to prolonged work-absence [19, 25]. Techniques for reducing catastrophic thinking included education, guided disclosure, and increasing behavioral flexibility. Techniques for reducing perceptions of injustice included validation, identifying sources of the client’s perceptions of injustice, and injustice-focused problem-solving. The intervention also involved engaging with the primary care professional, the case manager and the employer to collaborate on the development of a safe and sustainable return-to-work plan.
Participants first viewed an introductory video providing an overview of the procedures and objectives of the treatment program. The content of the video clearly identified return-to-work as a central objective of the treatment program. A client workbook was used for activity scheduling and to guide participants through exercises aimed at reducing catastrophic thinking and perceived injustice. Clinicians met individually with participants once per week for a total of 10 weeks. The clinicians for the study included 10 rehabilitation professionals (9 occupational therapists, 1 physiotherapist). All clinicians followed a two-day training workshop to acquire the skills necessary to deliver the intervention. All clinicians received weekly supervision by a senior clinician with extensive experience in risk-targeted behavioral activation.
Measures
Pain Severity. The McGill Pain Questionnaire Short-Form (MPQ-SF) was used to measure pain severity [28]. Participants rated their current pain experience according to 15 pain descriptors on severity scale with the anchors (0) none, (1) mild, (2) moderate, or (3) severe. Scores range from 0 to 45 where higher scores represent more severe pain. The measure has been shown to be reliable and valid in various clinical populations [29, 30] .
Depressive symptoms. The Patient Health Questionnaire-9 (PHQ-9) was used to assess depressive symptom severity. On this measure, respondents indicate how frequently they experience each of 9 symptoms of depression. Ratings are made on a 4-point frequency scale with the endpoints (0) ‘not at all’ and (3) ‘everyday’. PHQ-9 scores can range from 0 to 27 with higher scores indicating more severe depressive symptoms. A PHQ-9 score of 10 (i.e., moderate depression) was used as the criterion for clinically significant depression. The reliability and validity of this measure have been established in several different clinical samples [31, 32].
Pain Catastrophizing. The Pain Catastrophizing Scale (PCS) was used to assess catastrophic thinking related to pain [33]. The PCS consists of 13 items describing different thoughts and feelings that individuals might experience when they are in pain. The PCS has been shown to have high internal consistency (coefficient alpha = .87) and to be associated with heightened pain, emotional distress, disability as well as employment status [34-36].
Perceived injustice. The Injustice Experiences Questionnaire (IEQ) was used to measure injury-related perceptions of injustice [22]. The IEQ consists of 12 items assessing a range of injury-related injustice appraisals. The IEQ has been shown to have high internal consistently and test-retest reliability, and to be associated with prolonged occupational disability in individuals with musculoskeletal pain [17, 22].
Self-Reported Disability. The Pain Disability Index (PDI) [37] was used to assess self-rated disability. Respondents rated their level of disability in 7 different areas of daily living (home, social, recreational, occupational, sexual, self-care, life support) due to their pain. The PDI has been shown to be internally reliable and significantly correlated with objective indices of disability [38].
Return to Work. Return to work status was assessed by telephone interview at 6-month follow-up. Participants responded to a number of employment-related questions including whether they have returned to full-time work, part-time work, transitional work or whether they remained occupationally disabled.
Acceptability of treatment. The degree of acceptability of the treatment program was assessed by computing a) the proportion of respondents who agreed to watch the introductory video, b) the proportion of respondents who agreed to participate after watching the introductory video, and c) the proportion of patients who completed the treatment program.
Treatment satisfaction. Satisfaction with participation in the intervention program was recorded using a 5-point numerical scale with the verbal anchors (0) not at all satisfied, (1) somewhat satisfied, (2) moderately satisfied, (3) very satisfied, and (4) completely satisfied.
Procedure
This study was approved by Institutional Review Board of McGill University. During an initial telephone screening interview, participants responded to the two questions that comprise the PHQ2. Participants who scored above clinical threshold on the PHQ-2 during the screening interview, and on the PHQ-9 at the pre-treatment assessment (approximately 2 weeks later), were considered to be experiencing clinically significant symptoms of depression [39, 40]. All participants were enrolled in the treatment program between January 2016 and December 2017. The intervention was offered as a complement to any other pharmacological or physical interventions that might have been prescribed for symptom management. Study measures were completed at pre-, mid- and post-treatment. Treatment satisfaction was only assessed at post-treatment.
Data Analytic Approach
Descriptive statistics were computed on all study variables. Tests of mean differences were used to compare pre- and post-treatment scores on outcome measures. Percentage change values were computed on measures of symptom severity and psychosocial risk in order to address the clinical significance of treatment-related changes. Correlational analyses were conducted to examine inter-relations among indices of change. A logistic regression was used to address the role of treatment-related changes in psychosocial risk measures as determinants of return-to-work outcomes.
Five participants returned to work prior to completing all 10 sessions of the treatment program. For these participants, mid-treatment assessment results were carried forward and used as their post-treatment evaluation. Participants who completed fewer than 10 sessions and did not return to work were considered to have prematurely terminated the intervention (i.e., dropped out).