Prostate cancer is the fourth most common cancer affecting South Korean males, and the biochemical recurrence (BCR) of prostate cancer occurs in approximately 25% of patients five years after radical prostatectomy. The ability to predict BCR would help clinicians and patients to make better treatment decisions. Therefore, in this study, we have proposed a web-based clinical decision support system that predicts the BCR of prostate cancer in Korean patients. The data were obtained from the Korean Prostate Cancer Registry (KPCR) database, which contained information about 7394 patients with prostate cancer who were treated at one of the six major medical institutions in South Korea between May 2001 and December 2014. We tested 13 prediction models and selected the gradient boosting classifier because it demonstrated excellent prediction performance. Using this model, we were able to create a web application and once clinical data from patients were entered, the three-and five-year post-surgery BCR predictions could be extracted. We developed a clinical decision support system to provide a prostate cancer BCR predictive function to facilitate postoperative follow-up and clinical management. This system will help clinicians develop a strategic approach for prostate cancer treatment by predicting the likelihood of prostate cancer recurrence.

Objective The increased use of smartphones has led to several problems, including excessive smartphone use and the decreased self-ability to control smartphone use. To prevent these problems, the MindsCare app was developed as a method of self-management and intervention based on an evaluation of smartphone usage. We designed the MindsCare app to manage smartphone usage and prevent problematic smartphone use by providing personalized interventions. Methods We recruited 342 Korean participants over the age of 20 and asked them to use MindsCare for 13 weeks. Subsequently, we evaluated the changes in average smartphone usage time and the usability of the app. We designed a usability evaluation questionnaire based on the Technology Acceptance Model and conducted factor and reliability analyses on the participants’ responses. In the eighth week of the study, participants responded to a survey on the usability of the app. We ultimately collected data from 190 participants. Results The average score for the usability of the system was 3.61 on a five-point Likert scale, and approximately 58% of the participants responded positively to the evaluation items. In addition, our analysis of MindsCare data revealed a significant reduction in average smartphone use time in the eighth week compared to the baseline (t = 3.47, p = 0.001). Structural equation model analysis revealed that effort expectancy and performance expectancy had a positive relation with behavior intention for the app. Conclusions Through this study, we confirmed the MindsCare app's smartphone usage time reduction effect and proved its good usability. As a result, MindsCare may contribute to achieving users’ goals of reducing problematic smartphone use.

Objectives: As the surgical techniques are developed such as adopting robotic surgery etc. It has been reduced postoperative side effects such as urinary incontinence and sexual dysfunction etc., but also remain constant risk of recurrence after the treatment. It is very important to figure out the predictive factors, whichincreasing the probability of long-term survival, by Analyzing the progression of the disease according to biochemical recurrence (BCR). This study aims to figure out the influential predictive factors on BCR by using Korean Prostate Cancer Registry (KPCR) database, which constructedwith providing data from Korean manifold, because of therecurrence-free survival rates are reported to vary according to geographical location and race. Methods: KPCR database consists 7,394 patients' data which collected from six medical institutions, and final analysis was conducted with 5,119 patients' data which collected from December 2003 to December 2014. Statistical analysis was conducted with the multivariable Cox proportional hazard regression models to figure out the correlation of clinical factors which affect BCR. The biochemical recurrence free survival rate (BCR-FS) was calculated using with Kaplan-Meier method. Results: The 5 year BCR occurred in 23.6% (1,209 patients). As a result of the recurrence rate, prostate specific antigen (PSA) value ≥ 20.1 ng/mL was 49.3%, the clinical T3 stage was 40.4%, Gleason score ≥ 8 was 54.4%, Gleason score 7 was 21.8%. The mean duration of BCR was 20.7 months and the strongest predictor of BCR was Gleason scoreand PSA value ≥ 20.1 ng/mL. Conclusions: It has been verified that, Gleason scores and PSA value are the most influential factors for biochemical recurrence after radical prostatectomy. These results will be helpful fordetermining the treatment direction in postoperative follow-up and able to contribute to improving survival outcome in the future.

BACKGROUND As the use of smartphones increases, mental health problems may be caused by problematic smartphone use. To prevent these problems, we need a method of self-management and intervention based on smartphone usage evaluation. OBJECTIVE The objective of this study was to develop the MindsCare application, featuring various interventions such as prevention and diagnosis of problematic smartphone use and communication between users and clinicians and to evaluate the usability and effectiveness of this system. METHODS We developed the application MindsCare that stores and manages smartphone usage data. Based on the usage data stored in the app, the user can manage their own smartphone use. The app can help prevent problematic smartphone use with personalized interventions. We recruited 342 Korean participants over the age of 20 and asked them to use MindsCare for 13 weeks. In addition, to evaluate the effectiveness of the MindsCare system, a study was conducted to evaluate the changes in average smartphone usage time and the usability of the app. We designed a usability evaluation survey questionnaire based on the Technology Acceptance Model and conducted factor and reliability analyses on the questionnaire responses. System usability was measured using three factors: behavioral intention, performance expectancy, and effort expectancy. At the 8th week of the study, participants were asked to respond to a survey on the usability of MindsCare. RESULTS When the MindsCare app usage experiment data were analyzed, the average smartphone usage time significantly decreased at the 8th week compared to the baseline (t =3.47, p =.001). The usability evaluations scores were generally high (average overall of 3.61 on a 5-point Likert scale; 3.40 for behavioral intention; 3.64 for performance expectancy; and 3.80 for effort expectancy). CONCLUSIONS MindsCare, developed in this study, is a smartphone usage management application that stores usage data stably and can help prevent problematic smartphone use through customized intervention and evaluation. We confirmed the smartphone usage time reduction effect and proved that MindsCare satisfies users because it received a high overall usability evaluation.