Concurrent validity of the PSYCH-6, a very short scale for detecting anxiety and depression, among oncology outpatients

Objective: To improve the acceptability of screening for depression and anxiety among patients with cancer there is a need for scales that are both very short and accurate. To date no very short questionnaire has been found to provide optimal performance for screening in oncology populations and other candidates must be examined. This study examined the concurrent validity of a relatively new, very short scale, the six item PSYCH-6 subscale of the Somatic and Psychological Health Report (SPHERE-12), in an oncology outpatient population. Methods: Cross-sectional survey of 340 oncology outpatients attending a regional hospital in Newcastle, Australia. The performance of the PSYCH-6 against the Hospital Anxiety and Depression Scale (HADS) was evaluated using correlation, Cohen's kappa, positive agreement and negative agreement. Results: The PSYCH-6 subscale of the SPHERE-12, at a cut-off point of 3, had substantial agreement with the total score of the HADS (HADS-T; = 0.73, p 0.001). Negative agreement (0.92) was marginally higher than positive agreement (0.80). Conclusions: The PSYCH-6 scale of the SPHERE-12 at a cut-off point of 3 is an equivalent instrument to the HADS-T for detecting cases and excluding non-cases of anxiety and depression and is suitable for deployment in oncology populations.