Use and Engagement With Low-Intensity Cognitive Behavioral Therapy Techniques Used Within an App to Support Worry Management: Content Analysis of Log Data.

BACKGROUND: Low-intensity cognitive behavioral therapy (LICBT) has been implemented by the Improving Access to Psychological Therapies services across England to manage excessive worry associated with generalized anxiety disorder and support emotional well-being. However, barriers to access limit scalability. A solution has been to incorporate LICBT techniques derived from an evidence-based protocol within the Iona Mind Well-being app for Worry management (IMWW) with support provided through an algorithmically driven conversational agent. OBJECTIVE: This study aims to examine engagement with a mobile phone app to support worry management with specific attention directed toward interaction with specific LICBT techniques and examine the potential to reduce symptoms of anxiety. METHODS: Log data were examined with respect to a sample of "engaged" users who had completed at least 1 lesson related to the Worry Time and Problem Solving in-app modules that represented the "minimum dose." Paired sample 2-tailed t tests were undertaken to examine the potential for IMWW to reduce worry and anxiety, with multivariate linear regressions examining the extent to which completion of each of the techniques led to reductions in worry and anxiety. RESULTS: There was good engagement with the range of specific LICBT techniques included within IMWW. The vast majority of engaged users were able to interact with the cognitive behavioral therapy model and successfully record types of worry. When working through Problem Solving, the conversational agent was successfully used to support the user with lower levels of engagement. Several users engaged with Worry Time outside of the app. Forgetting to use the app was the most common reason for lack of engagement, with features of the app such as completion of routine outcome measures and weekly reflections having lower levels of engagement. Despite difficulties in the collection of end point data, there was a significant reduction in severity for both anxiety (t53=5.5; P<.001; 95% CI 2.4-5.2) and low mood (t53=2.3; P=.03; 95% CI 0.2-3.3). A statistically significant linear model was also fitted to the Generalized Anxiety Disorder-7 (F2,51=6.73; P<.001), while the model predicting changes in the Patient Health Questionnaire-8 did not reach significance (F2,51=2.33; P=.11). This indicates that the reduction in these measures was affected by in-app engagement with Worry Time and Problem Solving. CONCLUSIONS: Engaged users were able to successfully interact with the LICBT-specific techniques informed by an evidence-based protocol although there were lower completion rates of routine outcome measures and weekly reflections. Successful interaction with the specific techniques potentially contributes to promising data, indicating that IMWW may be effective in the management of excessive worry. A relationship between dose and improvement justifies the use of log data to inform future developments. However, attention needs to be directed toward enhancing interaction with wider features of the app given that larger improvements were associated with greater engagement.

Design of a Novel Variable-Diameter Cortical Threaded Screw and its Application in Improving Cortical Bone Trajectory in Lumbar Spine / 医用生物力学

Objective A novel variable-diameter cortical threaded screw used in a modified cortical bone trajectory(MCBT)was designed to verify its mechanical properties using the MCBT technique.Methods According to MCBT technology,the screw pitch was fixed at 2 mm,the total length was 45 mm,the diameter of the thick rod was 5.5 mm,the diameter of the thin rod was 4.0-4.5 mm,and the length of variable-diameter position connecting the thick rod and the thin rod was 2 mm.The parameters were set based on three aspects:variable-diameter position,thread depth,and thread type.Three-factor and three-level L9 tests were conducted and screw models were established.The torsion and the bending and pull-out force of the designed screws were calculated based on the finite element method,the results were analyzed using range analysis,and then the screw models were determined.The three-dimensional(3D)model of L4 vertebral body in osteoporosis specimens was established and screws were placed according to the MCBT technique.The pull-out force of the novel variable-diameter cortical threaded screw was compared with that of a conventional non-variable-diameter cortical threaded screw.Results Range analysis showed that screw No.6(variable-diameter position:24 mm from the screw head,thread depth:0.7 mm,45° symmetrical thread)was the optimal screw.The anti-pull-out force of the No.6 variable-diameter cortical threaded screw was 13.1%higher than that of the 4.5 mm conventional non-variable-diameter cortical threaded screw,and no statistical difference in anti-pull-out force was found between the No.6 variable-diameter cortical threaded screw and the 5.5 mm conventional non-variable-diameter cortical threaded screw.Conclusions The variable-diameter position has the smallest influence on pull-out force of the screw,the thread type has the largest influence on pull-out force,and the thread depth has the largest influence on torsion and bending.Compared with that of the conventional non-variable-diameter cortical threaded screw,the variable-diameter cortical threaded screw had a smaller front end,which prevented splitting at the entrance point of the screw.The screw has a large diameter at rear end,thereby showing improved pull-out performance.The results provide a new theoretical basis for the clinical application of MCBT technology.

Finite Element Analysis on Biomechanical Properties of Traditional Trajectory and Modified Cortical Bone Trajectory / 医用生物力学

Objective To study mechanical properties of traditional trajectory (TT) and modified cortical bone trajectory (MCBT) on osteoporotic vertebrae through finite element analysis. Methods The three-dimensional model of L4 segment was established, and pedicle screw (PS) (diameter 6.0 mm, length 45 mm) and MCBT screw (diameter 4.5 mm, length 40 mm) were placed on both sides of the lumbar spine. The pull-out strength and the load-displacement ratio of screws in two different screw trajectories under up, down, left, right working conditions were analyzed, and the stability between the screw and vertebral body under osteoporotic conditions was evaluated. Results Compared with TT, the pull-out strength of MCBT screw was increased by 13.1%. Compared with PS, the load-displacement ratio of MCBT screw under up, down and left working conditions was increased by 57.2%, 32.4%, and 31.6%. Under right working condition, although the load-displacement ratio of MCBT screw was higher than that of PS, no statistical difference was found. The load-displacement ratio of vertebral body in MCBT group under lateral bending and axial rotation was significantly higher than that in TT group. The load-displacement ratio of vertebral body in MCBT group under flexion was lower than that in TT group. Although the load-displacement ratio of vertebral body in MCBT group under extension was higher that that in TT group, no statistical difference was found. Conclusions MCBT is superior to TT in pull-out strength, screw stability and vertebral body stability under lateral bending and axial rotation, but its vertebral body stability under flexion and extension was weaker than that of TT. The research findings demonstrate the superiority of MCBT under osteoporotic conditions and lay the foundation for clinical application of MCBT.

A SMART approach to optimizing delivery of an mHealth intervention among cancer survivors with posttraumatic stress symptoms.

BACKGROUND/AIMS: Many cancer survivors who received intensive treatment such as hematopoietic stem cell transplantation (HCT) experience posttraumatic stress disorder (PTSD) symptoms. PTSD is associated with lower quality of life and other symptoms that require clinical treatment. The iterative treatment decisions that happen in clinical practice are not adequately represented in traditional randomized controlled trials (RCT) of PTSD treatments. The proposed stepped-care SMART design allows for evaluation of initial response to the Cancer Distress Coach mobile app; adaptive stepped-care interventions; and precision treatment strategies that tailor treatment selection to patient characteristics. METHODS/DESIGN: HCT survivors (N = 400) reporting PTSD symptoms are being recruited at two cancer centers and randomly assigned to: 1) Cancer Distress Coach app or 2) Usual Care. The app includes educational and cognitive behavioral therapy (CBT)-based activities. Four weeks post-randomization, participants re-rate their PTSD symptoms and, based on intervention response, non-responders are re-randomized to receive video-conferenced sessions with a therapist: 3) coaching sessions in using the mobile app; or 4) CBT specific to HCT survivors. Participants complete outcome measures of PTSD, depression, and anxiety after Months 1, 3, and 6. Participant characteristics moderating intervention responses will be examined. CONCLUSIONS: This novel adaptive trial design will afford evidence that furthers knowledge about optimizing PTSD interventions for HCT survivors. To our knowledge, this study is the first SMART design evaluating PTSD symptom management in cancer survivors. If successful, it could be used to optimize treatment among a range of cancer and other trauma survivors.