Single Question in Delirium (SQiD): testing its efficacy against psychiatrist interview, the Confusion Assessment Method and the Memorial Delirium Assessment Scale

In this study we address the research question; How sensitive is a single question in delirium case finding? Of 33 'target' admissions, consent was obtained from 21 patients. The single question: 'Do you think [name of patient] has been more confused lately?' was put to friend or family. Results of the Single Question in Delirium (SQiD) were compared to psychiatrist interview (Psi I) which was the reference standard. The Confusion Assessment Method (CAM) and two other tools were also applied. Compared with Psi I, the SQiD achieved a sensitivity and specificity of 80% (95% CI 28.3-99.49%) and 71% (41.90-91.61%) respectively. The CAM demonstrated a negative predictive value (NPV) of 80% (51.91-95.67%) and the SQiD showed a NPV of 91% (58.72-99.77%). Kappa correlation of SQiD with the Psi I was 0.431 (p = 0.023). The CAM had a kappa value of 0.37 (p = 0.050). A further important finding in our study was that the CAM had only 40% sensitivity in the hands of minimally trained clinical users. Conclusion: The SQiD demonstrates potential as a simple clinical tool worthy or further investigation.