Measurement of Depression in Breast Cancer Patients by Using a Mobile Application : A Feasibility and Reliability Study

Objectives This study examined feasibility and reliability of a mobile application to measure depression in breast cancer patients. Methods Forty-two breast cancer patients from the Department of Surgery at Asan Medical Center were included in the study. The Beck Depression Inventory (BDI), EuroQol Five Dimensional Questionnaire, and EuroQol Visual Analogue Scale were assessed at baseline and twice after surgery at regular intervals. The Patient Health Questionnaire-9 (PHQ-9) was delivered by as a push notification via mobile application every two weeks for 12 months. Feasibility was calculated using number of respondents and total number of PHQ-9 completed. Reliability was calculated from the relationship between PHQ-9 and BDI scores obtained within each two week period. Agreement between PHQ-9 and BDI scores in the diagnosis of depression was evaluated by kappa statistic and McNemar s test. Results One thousand and ninety-two notifications for PHQ-9 were sent, and 622 responses were reported (compliance rate=57%). The compliance rate was not related to demographic factors except for the date of the first use of the application. Pearson s r between PHQ-9 and BDI scores was 0.599 (p<0.001), and kappa analysis demonstrated moderate level of agreement in diagnosis of depression (κ=0.431). Conclusion The compliance rate for patients reporting their symptoms by mobile application is high and the scores of PHQ-9 and BDI are correlated, which suggests that the mobile data measuring depression is reliable. However, this is a preliminary study and further study is needed to determine other factors that influence compliance rate.