Visualizing Triplet Energy Transfer in Organic Near-Infrared Phosphorescent Host-Guest Materials.

Limited by the energy gap law, purely organic materials with efficient near-infrared room temperature phosphorescence are rare and difficult to achieve. Additionally, the exciton transition process among different emitting species in host-guest phosphorescent materials remains elusive, presenting a significant academic challenge. Herein, using a modular nonbonding orbital-π bridge-nonbonding orbital (n-π-n) molecular design strategy, we develop a series of heavy atom-free phosphors. Systematic modification of the π-conjugated cores enables the construction of a library with tunable near-infrared phosphorescence from 655 to 710 nm. These phosphors exhibit excellent performance under ambient conditions when dispersed into a 4-bromobenzophenone host matrix, achieving an extended lifetime of 11.25 ms and a maximum phosphorescence efficiency of 4.2%. Notably, by eliminating the interference from host phosphorescence, the exciton transition process can be visualized in hybrid materials under various excitation conditions. Spectroscopic analysis reveals that the improved phosphorescent performance of the guest originates from the triplet-triplet energy transfer of abundant triplet excitons generated independently by the host, rather than from enhanced intersystem crossing efficiency between the guest singlet state and the host triplet state. The findings provide in-depth insights into constructing novel near-infrared phosphors and exploring emission mechanisms of host-guest materials.

Family Cancer Caregiver Use of and Benefit from an Internet-delivered Insomnia Intervention: Results from a Single-Group Feasibility Trial.

Background: Cancer caregivers are more likely to report clinically significant symptoms of insomnia than cancer patients and the general population, yet research has been limited regarding cognitive-behavioral therapy for insomnia (CBT-I) among this population. Methods: To better understand cancer caregivers' engagement with and benefit from CBT-I, cancer caregivers were enrolled in a nonrandomized pilot feasibility trial of an evidence-based Internet-delivered insomnia program. Thirteen caregivers completed mixed-methods assessments prior to receiving the insomnia program and after the nine-week intervention period. Results: Compared to the five caregivers who did not complete any intervention Cores, the eight caregivers who completed at least one of the intervention Cores tended to report more sleep impairment (insomnia symptom severity; minutes of sleep onset latency and wake after sleep onset), less physical and emotional strain from caregiving, and less maladaptive sleep beliefs at the baseline assessment. These caregivers who used the program also showed large improvements in their insomnia symptoms. Caregivers' qualitative feedback about their experience with the program identified potential areas that might be modified to improve caregivers' engagement with and benefit from Internet-delivered insomnia programs. Conclusions: Findings suggest that family cancer caregivers can use and benefit from a fully-automated Internet-delivered CBT-I program, even without caregiving-specific tailoring. Further rigorous research is needed to better understand whether and how program modifications may allow more caregivers to initiate and engage with this program.

Eliminating the Burn-in Loss of Efficiency in Organic Solar Cells by Applying Dimer Acceptors as Supramolecular Stabilizers.

The meta-stable active layer morphology of organic solar cells (OSCs) is identified as the main cause of the rapid burn-in loss of power conversion efficiency (PCE) during long-term device operation. However, effective strategies to eliminate the associated loss mechanisms from the initial stage of device operation are still lacking, especially for high-efficiency material systems. Herein, the introduction of molecularly engineered dimer acceptors with adjustable thermal transition properties into the active layer of OSCs to serve as supramolecular stabilizers for regulating the thermal transitions and optimizing the crystallization of the absorber composites is reported. By establishing intimate π-π interactions with small-molecule acceptors, these stabilizers can effectively reduce the trap-state density (Nt) in the devices to achieve excellent PCEs over 19%. More importantly, the low Nt associated with an initially optimized morphology can be maintained under external stresses to significantly reduce the PCE burn-in loss in devices. This research reveals a judicious approach to improving OPV stability by establishing a comprehensive correlation between material properties, active-layer morphology, and device performance, for developing burn-in-free OSCs.

Assessing intra- and inter-molecular charge transfer excitations in non-fullerene acceptors using electroabsorption spectroscopy.

Organic photovoltaic cells using Y6 non-fullerene acceptors have recently achieved high efficiency, and it was suggested to be attributed to the charge-transfer (CT) nature of the excitations in Y6 aggregates. Here, by combining electroabsorption spectroscopy measurements and electronic-structure calculations, we find that the charge-transfer character already exists in isolated Y6 molecules but is strongly increased when there is molecular aggregation. Surprisingly, it is found that the large enhanced charge transfer in clustered Y6 molecules is not due to an increase in excited-state dipole moment, Δµ, as observed in other organic systems, but due to a reduced polarizability change, Δp. It is proposed that such a strong charge-transfer character is promoted by the stabilization of the charge-transfer energy upon aggregation, as deduced from density functional theory and four-state model calculations. This work provides insight into the correlation between molecular electronic properties and charge-transfer characteristics in organic electronic materials.

Investigating psychological mechanisms linking pain severity to depression symptoms in women cancer survivors at a cancer center with a rural catchment area.

PURPOSE: Women cancer survivors, especially those in rural areas, with high levels of depression may be acutely susceptible to pain due to the ways they think, feel, and behave. The current study seeks to elucidate the relationship between symptoms of depression and pain severity in women cancer survivors, by examining the putative mediators involved in this relationship, specifically their self-efficacy for managing their health, how overwhelmed they were from life's responsibilities, and relational burden. METHODS: Self-report data were collected from 183 cancer survivors of breast, cervical, ovarian, or endometrial/uterine cancer, who were between 6 months and 3 years post-active therapy. RESULTS: Women cancer survivors with higher (vs. lower) symptoms of depression had more severe pain. Individual mediation analyses revealed that survivors with higher levels of depression felt more overwhelmed by life's responsibilities and had lower self-efficacy about managing their health, which was associated with greater pain severity. When all mediators were simultaneously entered into the same model, feeling overwhelmed by life's responsibilities significantly mediated the link between survivors' symptoms of depression and their pain severity. CONCLUSIONS: The relationship between symptoms of depression and pain severity in women cancer survivors may be attributed in part to their self-efficacy and feeling overwhelmed by life's responsibilities. Early and frequent assessment of psychosocial factors involved in pain severity for women cancer survivors may be important for managing their pain throughout the phases of cancer survivorship.

Development of favipiravir dry powders for intranasal delivery: An integrated cocrystal and particle engineering approach via spray freeze drying.

The therapeutic potential of pharmaceutical cocrystals in intranasal applications remains largely unexplored despite progressive advancements in cocrystal research. We present the application of spray freeze drying (SFD) in successful fabrication of a favipiravir-pyridinecarboxamide cocrystal nasal powder formulation for potential treatment of broad-spectrum antiviral infections. Preliminary screening via mechanochemistry revealed that favipiravir (FAV) can cocrystallize with isonicotinamide (INA), but not nicotinamide (NCT) and picolinamide (PIC) notwithstanding their structural similarity. The cocrystal formation was characterized by differential scanning calorimetry, Fourier-transform infrared spectroscopy, and unit cell determination through Rietveld refinement of powder X-ray analysis. FAV-INA crystalized in a monoclinic space group P21/c with a unit cell volume of 1223.54(3) Å3, accommodating one FAV molecule and one INA molecule in the asymmetric unit. The cocrystal was further reproduced as intranasal dry powders by SFD, of which the morphology, particle size, in vitro drug release, and nasal deposition were assessed. The non-porous flake shaped FAV-INA powders exhibited a mean particle size of 19.79 ± 2.61 µm, rendering its suitability for intranasal delivery. Compared with raw FAV, FAV-INA displayed a 3-fold higher cumulative fraction of drug permeated in Franz diffusion cells at 45 min (p = 0.001). Dose fraction of FAV-INA deposited in the nasal fraction of a customized 3D-printed nasal cast reached over 80 %, whereas the fine particle fraction remained below 6 % at a flow rate of 15 L/min, suggesting high nasal deposition whilst minimal lung deposition. FAV-INA was safe in RPMI 2650 nasal and SH-SY5Y neuroblastoma cells without any in vitro cytotoxicity observed. This study demonstrated that combining the merits of cocrystallization and particle engineering via SFD can propel the development of advanced dry powder formulations for intranasal drug delivery.

The role of interfacial donor-acceptor percolation in efficient and stable all-polymer solar cells.

Polymerization of Y6-type acceptor molecules leads to bulk-heterojunction organic solar cells with both high power-conversion efficiency and device stability, but the underlying mechanism remains unclear. Here we show that the exciton recombination dynamics of polymerized Y6-type acceptors (Y6-PAs) strongly depends on the degree of aggregation. While the fast exciton recombination rate in aggregated Y6-PA competes with electron-hole separation at the donor-acceptor (D-A) interface, the much-suppressed exciton recombination rate in dispersed Y6-PA is sufficient to allow efficient free charge generation. Indeed, our experimental results and theoretical simulations reveal that Y6-PAs have larger miscibility with the donor polymer than Y6-type small molecular acceptors, leading to D-A percolation that effectively prevents the formation of Y6-PA aggregates at the interface. Besides enabling high charge generation efficiency, the interfacial D-A percolation also improves the thermodynamic stability of the blend morphology, as evident by the reduced device "burn-in" loss upon solar illumination.

Sleep Disruption Moderates the Daily Dynamics of Affect and Pain in Sickle Cell Disease.

Persons with sickle cell disease (SCD) often experience pain that can interfere with quality of life and daily activities. Pain can modulated by affect and sleep continuity; however, few studies have explored how these factors complementarily influence pain in adults with SCD. The study aims were to investigate 1) whether pain levels were heightened on days characterized by low positive affect and high negative affect, and 2) whether the relationship between affect and pain was intensified following nights of disrupted sleep. Adults with SCD (N = 25) completed ecological momentary assessments and daily sleep diaries. Mixed models were used to analyze the main and interactive effects of daily affect (positive affect and negative affect) and sleep disruption (wake after sleep onset and frequency of awakenings) on both daily average pain and daily maximum pain. Results suggested that daily average pain and maximum pain tended to be higher on days of low positive affect and high negative affect. Furthermore, the frequency of nocturnal awakenings moderated the relationship between positive affect and pain. On days where there were higher frequencies of nocturnal awakenings, low positive affect was associated with both average and maximum pain; however, this association was not observed with lower frequencies of nocturnal awakenings. The association between negative affect and maximum pain was also stronger at higher levels of awakenings. Results highlight the relevance of adjunctive interventions that target affect among populations with SCD and further suggest that sleep continuity may further facilitate these interventions, highlighting the importance of multimodal treatments. PERSPECTIVE: This study examined the effects of affect and sleep on pain among adults with sickle cell disease (SCD). Higher pain occurred on days of low positive affect and high negative affect, particularly following nights of more frequent awakenings. These findings emphasize the importance of addressing affect and sleep in SCD treatment.

Mobile sensing to advance tumor modeling in cancer patients: A conceptual framework.

As mobile and wearable devices continue to grow in popularity, there is strong yet unrealized potential to harness people's mobile sensing data to improve our understanding of their cellular and biologically-based diseases. Breakthrough technical innovations in tumor modeling, such as the three dimensional tumor microenvironment system (TMES), allow researchers to study the behavior of tumor cells in a controlled environment that closely mimics the human body. Although patients' health behaviors are known to impact their tumor growth through circulating hormones (cortisol, melatonin), capturing this process is a challenge to rendering realistic tumor models in the TMES or similar tumor modeling systems. The goal of this paper is to propose a conceptual framework that unifies researchers from digital health, data science, oncology, and cellular signaling, in a common cause to improve cancer patients' treatment outcomes through mobile sensing. In support of our framework, existing studies indicate that it is feasible to use people's mobile sensing data to approximate their underlying hormone levels. Further, it was found that when cortisol is cycled through the TMES based on actual patients' cortisol levels, there is a significant increase in pancreatic tumor cell growth compared to when cortisol levels are at normal healthy levels. Taken together, findings from these studies indicate that continuous monitoring of people's hormone levels through mobile sensing may improve experimentation in the TMES, by informing how hormones should be introduced. We hope our framework inspires digital health researchers in the psychosocial sciences to consider how their expertise can be applied to advancing outcomes across levels of inquiry, from behavioral to cellular.

A multi-dimensional assessment of financial hardship of cancer patients using existing health system data.

BACKGROUND: Existing financial hardship screening does not capture the multifaceted and dynamic nature of the problem. The use of existing health system data is a promising way to enable scalable and sustainable financial hardship screening. METHODS: We used existing data from 303 adult patients with cancer at the University of Virginia Comprehensive Cancer Center (2016-2018). All received distress screening and had a valid financial assistance screening based solely on household size-adjusted income. We constructed a composite index that integrates multiple existing health system data (Epic, distress screening, and cancer registry) to assess comprehensive financial hardship (e.g., material conditions, psychological responses, and coping behaviors). We examined differences of at-risk patients identified by our composite index and by existing single-dimension criterion. Dynamics of financial hardship over time, by age, and cancer type, were examined by fractional probit models. RESULTS: At-risk patients identified by the composite index were generally younger, better educated, and had a higher annual household income, though they had lower health insurance coverage. Identified periods to intervene for most patients are before formal diagnosis, 2 years, and 6 years after diagnosis. Within 2 years of diagnosis and more than 4 years after diagnosis appear critical for subgroups of patients who may suffer from financial hardship disparities. CONCLUSION: Existing health system data provides opportunities to systematically measure and track financial hardship in a systematic, scalable and sustainable way. We find that the dimensions of financial hardship can exhibit different patterns over time and across patient subgroups, which can guide targeted interventions. The scalability of the algorithm is limited by existing data availability.

Associations between context and affect within the daily lives of cancer caregivers.

PURPOSE: This study used ecological momentary assessment (EMA) to test the association between activity, location, and social company contexts with cancer caregivers' in-the-moment affect to identify precisely when and where to deliver psychological interventions for caregivers. METHODS: Current cancer caregivers (N = 25) received 8 EMA prompts per day for 7 consecutive days. At each prompt, caregivers reported their current positive affect and negative affect, as well as what they were doing, where they were located, and who they were with. Multilevel logistic regressions tested the associations between caregivers' contexts with their own person-mean-centered state (concurrent momentary level) and trait (overall weekly average) positive or negative affect. RESULTS: Caregivers reported lower state negative affect, as well as higher state positive affect, when socializing (ps < .001), when at a public location (ps < .03), and when around their friends, family, spouse/partner, or care recipient (i.e., person with cancer, ps < .02), relative to when not endorsing the context. Caregivers also reported lower state negative affect when eating/drinking or engaging in leisure (ps < .01; but no parallel effects for state positive affect). Caregivers reported higher state negative affect while working, when at their workplace, or when around work colleagues (ps < .001) and lower state positive affect when at home or alone (ps < .03). CONCLUSIONS: Results suggest the pertinence of a behavioral activation framework to mitigate the emotional strain of caregiving. Interventions that facilitate caregivers' ability to socialize with a range of friends and family, including their loved one with cancer, outside of the home may have the strongest positive emotional impact.

Assessing Emotion Polyregulation in Daily Life: Who Uses It, When Is It Used, and How Effective Is It?

Most research on emotion regulation has focused on understanding individual emotion regulation strategies. Preliminary research, however, suggests that people often use several strategies to regulate their emotions in a given emotional scenario (polyregulation). The present research examined who uses polyregulation, when polyregulation is used, and how effective polyregulation is when it is used. College students (N = 128; 65.6% female; 54.7% White) completed an in-person lab visit followed by a 2-week ecological momentary assessment protocol with six randomly timed survey prompts per day for up 2 weeks. At baseline, participants completed measures assessing past-week depression symptoms, social anxiety-related traits, and trait emotion dysregulation. During each randomly timed prompt, participants reported up to eight strategies used to change their thoughts or feelings, negative and positive affect, motivation to change emotions, their social context, and how well they felt they were managing their emotions. In pre-registered analyses examining the 1,423 survey responses collected, polyregulation was more likely when participants were feeling more intensely negative and when their motivation to change their emotions was stronger. Neither sex, psychopathology-related symptoms and traits, social context, nor subjective effectiveness was associated with polyregulation, and state affect did not moderate these associations. This study helps address a key gap in the literature by assessing emotion polyregulation in daily life. Supplementary Information: The online version contains supplementary material available at 10.1007/s42761-022-00166-x.

Improved Structural Order and Exciton Delocalization in High-Member Quasi-Two-Dimensional Tin Halide Perovskite Revealed by Electroabsorption Spectroscopy.

Engineering of quasi-two-dimensional (quasi-2D) tin halide perovskite structures is a promising pathway to achieve high-performance lead-free perovskite solar cells, with recently developed devices demonstrating over 14% efficiency. Despite the significant efficiency improvement over the bulk three-dimensional (3D) tin perovskite solar cells, the precise relationship between structural engineering and electron-hole (exciton) properties is not fully understood. Here, we study exciton properties in high-member quasi-2D tin perovskite (which is dominated by large n phases) and bulk 3D tin perovskite using electroabsorption (EA) spectroscopy. By numerically extracting the changes in polarizability and dipole moment between the excited and ground states, we show that more ordered and delocalized excitons are formed in the high-member quasi-2D film. This result indicates that the high-member quasi-2D tin perovskite film consists of more ordered crystal orientations and reduced defect density, which is in agreement with the over 5-fold increase in exciton lifetime and much improved solar cell efficiency in devices. Our results provide insights on the structure-property relationship of high-performance quasi-2D tin perovskite optoelectronic devices.

Evaluating the impact of patients' psychological and physical problems on their interest in participating in research at a cancer center with a rural catchment area.

BACKGROUND: Cancer patients' participation in research trials is essential to improving their care and treatment. In a large sample of adults recently diagnosed with cancer, the aim of the current study is to investigate the relationship between cancer patients' interest in research and the psychological and physical problems they experience resulting from their cancer diagnosis. METHOD: We analyzed data from 906 cancer patients collected during routine clinical care. Correlational analyses focused on the relationship between patients' psychological and physical problems and their interest in research. Hierarchical binary logistic regression analyses tested whether patients' psychological/physical problems as a block predicted their interest in research, above and beyond their sociodemographic characteristics. RESULTS: Higher levels of patients' anxiety, fear of cancer treatment, difficulty managing emotions, worry, suicidal/homicidal ideation, fatigue, problems related to physical appearance, sleep difficulty, and changes to weight/appetite, were associated with a greater interest in research. Patients' psychological/physical problems, as a block, incrementally predicted their interest in research (Δχ2 = 24.34, df = 14, p = .04, Δr2=0.05), though none of the individual psychological/physical problems were found to be significant predictors. A higher level of education was significantly positively associated with an increased likelihood of being interested in research (OR = 1.26, 95%CI = 1.09, 1.46, p = .001). CONCLUSION: Cancer patients' problems stemming from their diagnosis can be important factors in their decision to participate in research. Depending on the needs of the trial in question, researchers may want to account for patients' level of symptom burden in deciding who to approach for enrollment in a research trial.

Outcomes of a Caregiver-Focused Short Message Service (SMS) Intervention to Reduce Intake of Sugar-Sweetened Beverages in Rural Caregivers and Adolescents.

This study examined enrollment, retention, engagement, and behavior changes from a caregiver short message service (SMS) component of a larger school-based sugar-sweetened beverage (SSB) reduction intervention. Over 22 weeks, caregivers of seventh graders in 10 Appalachian middle schools received a two-way SMS Baseline Assessment and four monthly follow-up assessments to report their and their child's SSB intake and select a personalized strategy topic. Between assessments, caregivers received two weekly one-way messages: one information or infographic message and one strategy message. Of 1873 caregivers, 542 (29%) enrolled by completing the SMS Baseline Assessment. Three-quarters completed Assessments 2-5, with 84% retained at Assessment 5. Reminders, used to encourage adherence, improved completion by 19-40%, with 18-33% completing after the first two reminders. Most caregivers (72-93%) selected a personalized strategy and an average of 28% viewed infographic messages. Between Baseline and Assessment 5, daily SSB intake frequency significantly (p < 0.01) declined for caregivers (-0.32 (0.03), effect size (ES) = 0.51) and children (-0.26 (0.01), ES = 0.53). Effect sizes increased when limited to participants who consumed SSB twice or more per week (caregivers ES = 0.65, children ES = 0.67). Findings indicate that an SMS-delivered intervention is promising for engaging rural caregivers of middle school students and improving SSB behaviors.

Retention and engagement of rural caregivers of adolescents in a short message service intervention to reduce sugar-sweetened beverage intake.

Objective: This study investigates a 6-month short message service (SMS) intervention to reduce adolescent sugar-sweetened beverage (SSB) intake. The objectives are to describe caregiver retention and SMS engagement as well as explore differences by caregiver characteristics. Methods: Caregivers completed a baseline survey then messages were sent two times per week. Message types included the following: SSB intake assessments, educational information, infographic URLs, and strategies. Engagement was measured through interaction with these messages and included: assessment completion, reminders needed, number of strategies chosen, and URLs clicked. Results: Caregivers (n = 357) had an average baseline SSB intake of 23.9 (SD = 26.8) oz/day. Of those, 89% were retained. Caregivers with a greater income and education were retained at a higher rate. Average engagement included: 4.1 (SD = 1.3) of 5 assessments completed with few reminders needed [4.1 (SD = 3.7) of 14 possible], 3.2 (SD = 1.1) of 4 strategies selected, and 1.2 (SD = 1.6) of 5 URLs clicked. Overall, average engagement was relatively high, even where disparities were found. Demographic characteristics that were statistically related to lower engagement included younger age, lower income, lower educational attainment, single caregivers, lower health literacy. Furthermore, caregivers with a reduced intention to change SSB behaviors completed fewer assessments and needed more reminders. Higher baseline SSB intake was associated with lower engagement across all indicators except URL clicks. Conclusions: Results can be used to develop targeted retention and engagement strategies (e.g., just-in-time and/or adaptive interventions) in rural SMS interventions for identified demographic subsets. Trial registration: Clincialtrials.gov: NCT03740113.

Renewed Prospects for Organic Photovoltaics.

Organic photovoltaics (OPVs) have progressed steadily through three stages of photoactive materials development: (i) use of poly(3-hexylthiophene) and fullerene-based acceptors (FAs) for optimizing bulk heterojunctions; (ii) development of new donors to better match with FAs; (iii) development of non-fullerene acceptors (NFAs). The development and application of NFAs with an A-D-A configuration (where A = acceptor and D = donor) has enabled devices to have efficient charge generation and small energy losses (Eloss < 0.6 eV), resulting in substantially higher power conversion efficiencies (PCEs) than FA-based devices. The discovery of Y6-type acceptors (Y6 = 2,2'-((2Z,2'Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]-thiadiazolo[3,4-e]-thieno[2″,3″:4',5']thieno-[2',3':4,5]pyrrolo-[3,2-g]thieno-[2',3':4,5]thieno-[3,2-b]indole-2,10-diyl)bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile) with an A-DA' D-A configuration has further propelled the PCEs to go beyond 15% due to smaller Eloss values (∼0.5 eV) and higher external quantum efficiencies. Subsequently, the PCEs of Y6-series single-junction devices have increased to >19% and may soon approach 20%. This review provides an update of recent progress of OPV in the following aspects: developments of novel NFAs and donors, understanding of the structure-property relationships and underlying mechanisms of state-of-the-art OPVs, and tasks underpinning the commercialization of OPVs, such as device stability, module development, potential applications, and high-throughput manufacturing. Finally, an outlook and prospects section summarizes the remaining challenges for the further development of OPV technology.

Effects of an internet-delivered insomnia intervention for older adults: A secondary analysis on symptoms of depression and anxiety.

OBJECTIVE: To test whether an Internet-delivered cognitive behavioral therapy for insomnia (CBT-I) program for older adults attenuates symptoms of depression and anxiety. METHODS: Adults aged ≥ 55 with insomnia were randomized to SHUTi-OASIS (Sleep Healthy Using the Internet for Older Adult Sufferers of Insomnia and Sleeplessness; N = 207) or Patient Education (PE; N = 104). Depression and anxiety were assessed (HADS-D and HADS-A, respectively) at baseline, post-assessment, and 6- and 12-month follow-ups. RESULTS: Multilevel modeling of HADS-D showed a condition by time interaction (F[3,779] = 3.23, p = .02): SHUTi-OASIS participants reported lower symptoms than PE at post-assessment. There was no such interaction effect for HADS-A (F[3,779] = 2.12, p = .10). Generalized linear modeling showed no moderation of effects by baseline symptom severity. CONCLUSIONS: Participants randomized to Internet-delivered CBT-I showed stable depression and anxiety across time, while control participants' depressive symptoms briefly increased. CBT-I may help prevent development or worsening of psychological distress among older adults with insomnia. TRIAL REGISTRATION: [Registered at ClinicalTrials.gov; identifier removed for anonymity].

Understanding the Relationship Between Mood Symptoms and Mobile App Engagement Among Patients With Breast Cancer Using Machine Learning: Case Study.

BACKGROUND: Health interventions delivered via smart devices are increasingly being used to address mental health challenges associated with cancer treatment. Engagement with mobile interventions has been associated with treatment success; however, the relationship between mood and engagement among patients with cancer remains poorly understood. A reason for this is the lack of a data-driven process for analyzing mood and app engagement data for patients with cancer. OBJECTIVE: This study aimed to provide a step-by-step process for using app engagement metrics to predict continuously assessed mood outcomes in patients with breast cancer. METHODS: We described the steps involved in data preprocessing, feature extraction, and data modeling and prediction. We applied this process as a case study to data collected from patients with breast cancer who engaged with a mobile mental health app intervention (IntelliCare) over 7 weeks. We compared engagement patterns over time (eg, frequency and days of use) between participants with high and low anxiety and between participants with high and low depression. We then used a linear mixed model to identify significant effects and evaluate the performance of the random forest and XGBoost classifiers in predicting weekly mood from baseline affect and engagement features. RESULTS: We observed differences in engagement patterns between the participants with high and low levels of anxiety and depression. The linear mixed model results varied by the feature set; these results revealed weak effects for several features of engagement, including duration-based metrics and frequency. The accuracy of predicting depressed mood varied according to the feature set and classifier. The feature set containing survey features and overall app engagement features achieved the best performance (accuracy: 84.6%; precision: 82.5%; recall: 64.4%; F1 score: 67.8%) when used with a random forest classifier. CONCLUSIONS: The results from the case study support the feasibility and potential of our analytic process for understanding the relationship between app engagement and mood outcomes in patients with breast cancer. The ability to leverage both self-report and engagement features to analyze and predict mood during an intervention could be used to enhance decision-making for researchers and clinicians and assist in developing more personalized interventions for patients with breast cancer.