How well do cancer survivor self-classifications of anxiety, depression and stress agree with a standardised tool? Results of a cross-sectional study.

Background: There is poor uptake of psychosocial interventions offered to people with cancer who record high scores on distress screening scales. Intervention uptake may be influenced by a mismatch between consumer (bottom-up) and professional (top-down) paradigms of wellbeing. The current research aims to compare cancer survivors' 'self-judgements' about their levels of anxiety, depression and stress, to classifications derived via a professional-driven measure, the Depression, Anxiety and Stress Scale (DASS-21). Methods: A cross-sectional study was undertaken with haematological cancer survivors recruited from three population-based cancer registries in Australia. Consenting participants were mailed a questionnaire package; and non-responders received a second questionnaire package after 3-weeks and a reminder call after 6-weeks. The consumer-driven perspective was assessed via three separate single items asking survivors to self-classify their levels of anxiety, depression and stress over the past week on a scale from 'normal' to 'extremely severe'. The professional-driven classification was assessed via the DASS-21. Kappa statistics were used to assess agreement between consumer- and professional-driven measures. Results: Of 2,971 eligible haematological cancer survivors, 1,239 (42%) provided written consent and were mailed a questionnaire package. Of these, 984 (79%) returned a completed questionnaire. The simple kappa for agreement between the DASS-21 and self-classified measures for anxiety was 0.47 (95% CI: 0.39 to 0.54, p<0.0001). The weighted kappa for agreement between the DASS-21 and self-classified measures of depression was 0.60 (95% CI: 0.53 to 0.67, p<0.0001) and for measures of stress was 0.51 (95% CI: 0.44 to 0.59, p<0.0001). Conclusions: Moderate agreement between self-classification and professional-driven assessments was found. The value of screening is predicated on the assumption that those with identified needs will be offered and take up services that will benefit them. Our results suggest that to improve the utility of distress screening it may be important to include assessment of survivor views about their symptoms.