Data Collection and Measures
Participants were interviewed by research assistants in interviews spread over two sittings (range of one to four sittings) and received £15 per interview. The interview schedule contained a range of measures, and some data were also collected from clinical records and from the service user’s main professional caregiver.
The primary dependent variable of service engagement was measured with the Service Engagement Scale (SES) (
2), adapted by our team for service user completion. The SES is a 14-item measure with a possible total score of 42. High scores indicate low engagement. It has four subscale domains: availability, collaboration, help seeking, and treatment adherence. The scale, which was originally developed for completion by clinicians, was completed by both the participant’s main professional health care provider and by the service user. For service users, the wording was changed from “the client” to “I,” with other minor wording changes and the reversal of two items (numbers 10 and 13) to make it suitable for service user completion. [The service user version is available in the online
supplement.]
In this study, we elected post hoc to use only the service user–completed version of the SES (SES-SU) because 13% of the clinicians contacted (26 of 156) reported that they knew the service user only “a little.” Nine percent of service users (18 of 197) had had little contact (two or fewer appointments) with their community mental health team in the past 12 months. In addition, data from professionals were missing for 23% of those invited to participate (46 of 202), with consequent reduction in statistical power.
We undertook preliminary validation of the SES-SU in the study sample. Cronbach’s alpha was .75, indicating good internal reliability. As predicted, the SES-SU correlated with service users’ ratings of their therapeutic relationship with their main professional caregiver, which was measured with the Scale to Assess Therapeutic Relationships (
15) (ρ=–.56, p<.001). It also correlated with the number of total perceived barriers to care on the Barriers to Access to Care Evaluation (
16) (ρ=.28, p<.001) and with the professional-rated SES (ρ=.19, p=.019). Although the latter correlation is low, we would not necessarily expect a higher correlation because service users and providers may have different views of engagement, and one is not necessarily more valid than the other (
17). In addition, research on a related concept found a lack of correlation between service users and providers’ views when alliance was measured (
18). Furthermore the SES-SU subscale score for availability correlated, as predicted, with data from clinical records on the percentage of scheduled appointments kept by the service user (ρ=–.25, p=.004).
The Discrimination and Stigma Scale (DISC) (
19) is an interviewer-delivered measure of experiences of discrimination (“unfair treatment”) in the past 12 months due to having a diagnosis of mental illness. Participants report experiences of discrimination across 21 items, such as employment, parenting, and mental health treatment, on a 4-point Likert scale (not at all, 0; a little, 1; moderately, 2; and a lot, 3). The DISC has good psychometric properties (
16). A mean discrimination score is calculated (range 0–3) by adding each item score and dividing by the number of applicable, nonmissing items.
Other measures were the Questionnaire on Anticipated Discrimination (
20), Internalized Stigma of Mental Illness Scale (
21), Stigma Stress Appraisal (
22), Scale to Assess Therapeutic Relationships (
15), and Brief Psychiatric Rating Scale (BPRS) (
23). Lack of social support was measured with a scale adapted from that used by Brohan and colleagues (
24). Single items were used to assess mistrust in mental health services and discomfort disclosing information about one’s mental illness (
25,
26).
Analysis
We used a structural equation model to examine associations between experienced discrimination and service engagement on the basis of our a priori conceptual model, including the following variables: experienced and anticipated discrimination, internalized stigma, mistrust in mental health services, Stigma Stress Appraisal score, lack of social support, quality of the therapeutic relationship, and discomfort disclosing information about one’s mental illness. The model was adjusted for key sociodemographic and clinical variables: age, race-ethnicity, and symptomatology (BPRS). [Further details about the measures and the analysis are available in the online supplement.]