Development and validation of the treatment expectations in chronic pain scale

Abstract

Objectives: To develop and examine the psychometric properties of the Treatment Expectations in Chronic Pain (TEC) scale, a brief measure of treatment expectations of chronic non-cancer pain treatment.

Design: A cross-sectional study design was used.

Methods: After conducting a literature review and expert discussions, a preliminary version of the TEC scale was developed. Cognitive interviews with 10 clinicians and 14 patients were conducted to examine the scale's face validity and item wording. Last, two hundred and five patients on the waitlist for a multidisciplinary pain treatment centre completed a battery of self-report questionnaires to examine the TEC scale's reliability and construct validity. Mokken scale analysis was conducted to select the final items. Reliability (Cronbach's alpha and Guttman's lambda2 ) and construct validity (Pearson correlations) were assessed.

Results: The final scale was composed of nine items that each measured ideal and predicted expectations about process and outcome of treatment. Mokken scale analysis showed the presence of two subscales: ideal and predicted expectations. The TEC scale had good internal consistency (α = 0.876-0.869) and adequate discriminant validity as assessed by its low correlation with measures of depression, anxiety, and quality of life (r = -.038 to .114). The scale had however low correlation with a theoretically related measure of optimism (r = .240).

Conclusion: The TEC scale is a reliable scale measuring pain treatment expectation. Further evaluation of its psychometric properties is needed. The scale has the potential to deepen our understanding of the role treatment expectations play in chronic non-cancer pain treatment response. Statement of contribution What is already known on this subject? Expectations play a role in pain perception and the response to pain treatment Patients' expectations about pain and its management are associated with treatment satisfaction The absence of a validated tool to measure treatment expectations in chronic non-cancer pain prevents further exploration and understanding of the role of expectations in the context of multidisciplinary pain treatment . What does this study add? A new, reliable 9-item scale measuring treatment expectations among chronic non-cancer pain patients attending specialized multidisciplinary pain clinics .