Testing pathways to scale: study protocol for a three-arm randomized controlled trial of a centralized and a decentralized ("Train the Trainers") dissemination of a mental health program for Kenyan adolescents.

BACKGROUND: Providing care in Kenya to all youth in need is difficult because of a shortage of professional providers and societal stigma. Previous trials of the Anansi model, which involves delivering low-touch mental health interventions through a tiered caregiving model (including lay-providers, supervisors, and clinical experts), have shown its effectiveness for reducing depression and anxiety symptoms in school-going Kenyan adolescents. In this trial, we aim to assess two different scale-up strategies by comparing centralized implementation (i.e., by the organization that designed the Anansi model) against implementation through an implementing partner. METHODS: In this three-arm trial, 1600 adolescents aged 13 to 20 years will be randomized to receive the Shamiri intervention from either the Shamiri Institute or an implementation partner or to be placed in the treatment as usual (TAU) control group. The implementation partner will be trained and supplied with protocols to ensure that the same procedures are followed by both implementors. Implementation activities will run concurrently for both implementors. The Shamiri intervention will be delivered by trained lay providers to groups of 10-15 adolescents over four weekly sessions which will take place in secondary schools in Machakos and Makueni counties in Kenya. The TAU group will receive the usual care offered by their respective schools. Outcomes will be assessed at baseline, midpoint (2 weeks), endpoint (4 weeks), and 1 month follow-up. The analysis will be based on an intent-to-treat approach. Mixed effects models will be used to assess trajectories over time of the primary outcomes (anxiety and depressive symptoms, mental well-being, perceived social support, and academic performance) and secondary outcomes for the intervention groups and the control group. Effect sizes will be computed for the mean differences of the intervention and control arms at midpoint, endpoint, and follow-up. DISCUSSION: This trial will provide insight into the comparative effectiveness of different strategies for scaling a school-based mental health care model. Findings will also indicate areas for improved efficiency of the model to enhance its replicability by other implementors. TRIAL REGISTRATION: Pan African Clinical Trials Registry (PACTR) (ID: PACTR202305589854478, Approved: 02/05/2023).

Using wearable activity trackers for research in the global south: Lessons learned from adolescent psychotherapy research in Kenya.

Wearable activity trackers have emerged as valuable tools for health research, providing high-resolution data on measures such as physical activity. While most research on these devices has been conducted in high-income countries, there is growing interest in their use in the global south. This perspective discusses the challenges faced and strategies employed when using wearable activity trackers to test the effects of a school-based intervention for depression and anxiety among Kenyan youth. Lessons learned include the importance of validating data output, establishing an internal procedure for international procurement, providing on-site support for participants, designating a full-time team member for wearable activity tracker operation, and issuing a paper-based information sheet to participants. The insights shared in this perspective serve as guidance for researchers undertaking studies with wearables in similar settings, contributing to the evidence base for mental health interventions targeting youth in the global south. Despite the challenges to set up, deploy and extract data from wearable activity trackers, we believe that wearables are a relatively economical approach to provide insight into the daily lives of research participants, and recommend their use to other researchers.

Long-term health outcomes of adolescent character strength interventions: 3- to 4-year outcomes of three randomized controlled trials of the Shamiri program.

BACKGROUND: Adolescents in low- and middle-income countries in need of mental health care often do not receive it due to stigma, cost, and lack of mental health professionals. Culturally appropriate, brief, and low-cost interventions delivered by lay-providers can help overcome these barriers and appear effective at reducing symptoms of depression and anxiety until several months post-intervention. However, little is known about whether these interventions may have long-term effects on health, mental health, social, or academic outcomes. METHODS: Three previous randomized controlled trials of the Shamiri intervention, a 4-week, group-delivered, lay-provider-led intervention, have been conducted in Kenyan high schools. Shamiri teaches positively focused intervention elements (i.e., growth mindset and strategies for growth, gratitude, and value affirmation) to target symptoms of depression and anxiety and to improve academic performance and social relationships, by fostering character strengths. In this long-term follow-up study, we will test whether these mental health, academic, social, and character-strength outcomes, along with related health outcomes (e.g., sleep quality, heart-rate variability and activity level measured via wearables, HIV risk behaviors, alcohol and substance use), differ between the intervention and control group at 3-4-year follow-up. For primary analyses (Nanticipated = 432), youths who participated in the three previous trials will be contacted again to assess whether outcomes at 3-4-year-follow-up differ for those in the Shamiri Intervention group compared to those in the study-skills active control group. Multi-level models will be used to model trajectories over time of primary outcomes and secondary outcomes that were collected in previous trials. For outcomes only collected at 3-4-year follow-up, tests of location difference (e.g., t-tests) will be used to assess group differences in metric outcomes and difference tests (e.g., odds ratios) will be used to assess differences in categorical outcomes. Finally, standardized effect sizes will be used to compare groups on all measures. DISCUSSION: This follow-up study of participants from three randomized controlled trials of the Shamiri intervention will provide evidence bearing on the long-term and health and mental health effects of brief, lay-provider-delivered character strength interventions for youth in low- and middle-income countries. TRIAL REGISTRATION: PACTR Trial ID: PACTR202201600200783 . Approved on January 21, 2022.

Effect of Shamiri Layperson-Provided Intervention vs Study Skills Control Intervention for Depression and Anxiety Symptoms in Adolescents in Kenya: A Randomized Clinical Trial.

Importance: Low-cost interventions for adolescent depression and anxiety are needed in low-resource countries such as those in Sub-Saharan Africa. Objective: To assess whether Shamiri, a 4-week layperson-delivered group intervention that teaches growth mindset, gratitude, and value affirmation, can alleviate depression and anxiety symptoms in symptomatic Kenyan adolescents. Design, Setting, and Participants: This school-based randomized clinical trial included outcomes assessed at baseline, posttreatment, and 2-week and 7-month follow-up from 4 secondary schools in Nairobi and Kiambu County, Kenya. Adolescents aged 13 to 18 years with elevated symptoms on standardized depression or anxiety measures were eligible. Intent-to-treat analyses were used to analyze effects. Recruitment took place in June 2019; follow-up data were collected in August 2019 and February 2020. Intervention: Adolescents were randomized to the Shamiri intervention or to a study skills control. All adolescents in both conditions met in groups (mean group size, 9) for 60 minutes per week for 4 weeks. Main Outcomes and Measures: Primary outcomes were depression (Patient Health Questionnaire-8 item) and anxiety (Generalized Anxiety Disorder-7 item) symptoms. Analyses of imputed data were hypothesized to reveal significant reductions in depression and anxiety symptoms for adolescents assigned to Shamiri compared with those in the study skills group. Results: Of 413 adolescents, 205 (49.6%) were randomized to Shamiri and 208 (50.4%) to study skills. The mean (SD) age was 15.5 (1.2) years, and 268 (65.21%) were female. A total of 307 youths completed the 4-week intervention. Both Shamiri and study skills were rated highly useful (4.8/5.0) and reduced symptoms of depression and anxiety, but analyses with imputed data revealed that youths receiving Shamiri showed greater reductions in depressive symptoms at posttreatment (Cohen d = 0.35 [95% CI, 0.09-0.60]), 2-week follow-up (Cohen d = 0.28 [95% CI, 0.04-0.54]), and 7-month follow-up (Cohen d = 0.45 [95% CI, 0.19-0.71]) and greater reductions in anxiety symptoms at posttreatment (Cohen d = 0.37 [95% CI, 0.11-0.63]), 2-week follow-up (Cohen d = 0.26 [95% CI, -0.01 to 0.53]), and 7-month follow-up (Cohen d = 0.44 [95% CI, 0.18-0.71]). Conclusions and Relevance: Both the Shamiri intervention and a study skills control group reduced depression and anxiety symptoms; the low-cost Shamiri intervention had a greater effect, with effects lasting at least 7 months. If attrition is reduced and the clinical significance of outcome differences is established, this kind of intervention may prove useful in other global settings where there are limited resources, mental illness stigma, or a shortage of professionals and limited access to mental health care. Trial Registration: Pan-African Clinical Trials Registry Identifier: PACTR201906525818462.

Goodness-of-Fit Assessment in Multidimensional Scaling and Unfolding.

Judging goodness of fit in multidimensional scaling requires a comprehensive set of diagnostic tools instead of relying on stress rules of thumb. This article elaborates on corresponding strategies and gives practical guidelines for researchers to obtain a clear picture of the goodness of fit of a solution. Special emphasis will be placed on the use of permutation tests. The second part of the article focuses on goodness-of-fit assessment of an important variant of multidimensional scaling called unfolding, which can be applied to a broad range of psychological data settings. Two real-life data sets are presented in order to walk the reader through the entire set of diagnostic measures, tests, and plots. R code is provided as supplementary information that makes the whole goodness-of-fit assessment workflow, as presented in this article, fully reproducible.

Guidelines by the AAPM and GEC-ESTRO on the use of innovative brachytherapy devices and applications: Report of Task Group 167.

Although a multicenter, Phase III, prospective, randomized trial is the gold standard for evidence-based medicine, it is rarely used in the evaluation of innovative devices because of many practical and ethical reasons. It is usually sufficient to compare the dose distributions and dose rates for determining the equivalence of the innovative treatment modality to an existing one. Thus, quantitative evaluation of the dosimetric characteristics of innovative radiotherapy devices or applications is a critical part in which physicists should be actively involved. The physicist's role, along with physician colleagues, in this process is highlighted for innovative brachytherapy devices and applications and includes evaluation of (1) dosimetric considerations for clinical implementation (including calibrations, dose calculations, and radiobiological aspects) to comply with existing societal dosimetric prerequisites for sources in routine clinical use, (2) risks and benefits from a regulatory and safety perspective, and (3) resource assessment and preparedness. Further, it is suggested that any developed calibration methods be traceable to a primary standards dosimetry laboratory (PSDL) such as the National Institute of Standards and Technology in the U.S. or to other PSDLs located elsewhere such as in Europe. Clinical users should follow standards as approved by their country's regulatory agencies that approved such a brachytherapy device. Integration of this system into the medical source calibration infrastructure of secondary standard dosimetry laboratories such as the Accredited Dosimetry Calibration Laboratories in the U.S. is encouraged before a source is introduced into widespread routine clinical use. The American Association of Physicists in Medicine and the Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO) have developed guidelines for the safe and consistent application of brachytherapy using innovative devices and applications. The current report covers regulatory approvals, calibration, dose calculations, radiobiological issues, and overall safety concerns that should be addressed during the commissioning stage preceding clinical use. These guidelines are based on review of requirements of the U.S. Nuclear Regulatory Commission, U.S. Department of Transportation, International Electrotechnical Commission Medical Electrical Equipment Standard 60601, U.S. Food and Drug Administration, European Commission for CE Marking (Conformité Européenne), and institutional review boards and radiation safety committees.

A comparison of the relative biological effectiveness of low energy electronic brachytherapy sources in breast tissue: a Monte Carlo study.

Electronic brachytherapy sources use low energy photons to treat the tumor bed during or after breast-conserving surgery. The relative biological effectiveness of two electronic brachytherapy sources was explored to determine if spectral differences due to source design influenced radiation quality and if radiation quality decreased with distance in the breast. The RBE was calculated through the number of DNA double strand breaks (RBEDSB) using the Monte Carlo damage simulator (MCDS) in combination with other Monte Carlo electron/photon spectrum calculations. 50kVp photons from the Intrabeam (Carl Zeiss Surgical) and Axxent (Xoft) through 40-mm spherical applicators were simulated to account for applicator and tissue attenuation in a variety of breast tissue compositions. 40kVp Axxent photons were also simulated. Secondary electrons (known to be responsible for most DNA damage) spectra at different distance were inputted into MCDS to calculate the RBEDSB. All RBEDSB used a cobalt-60 reference. RBEDSB data was combined with corresponding average photon spectrum energy for the Axxent and applied to model-based average photon energy distributions to produce an RBEDSB map of an accelerated partial breast irradiation (APBI) patient. Both Axxent and Intrabeam 50kVp spectra were shown to have a comparable RBEDSB of between 1.4 and 1.6 at all distances in spite of progressive beam hardening. The Axxent 40kVp also demonstrated a similar RBEDSB at distances. Most RBEDSB variability was dependent on the tissue type as was seen in rib (RBEDSB ≈ 1.4), gland (≈1.55), adipose (≈1.59), skin (≈1.52) and lung (≈1.50). RBEDSB variability between both sources was within 2%. A correlation was shown between RBEDSB and average photon energy and used to produce an RBEDSB map of a dose distribution in an APBI patient dataset. Radiation quality is very similar between electronic brachytherapy sources studied. No significant reductions in RBEDSB were observed with increasing distance from the source.

The grand old party - a party of values?

In this article we explore the semantic space spanned by self-reported statements of Republican voters. Our semantic structure analysis uses multidimensional scaling and social network analysis to extract, explore, and visualize word patterns and word associations in response to the stimulus statement "I'm a Republican, because …" which were collected from the official website of the Republican Party. With psychological value theory as our backdrop, we examine the association of specific keywords within and across the statements, compute clusters of statements based on these associations, and explore common word sequences Republican voters use to characterize their political association with the Party.

Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source.

PURPOSE: The recently updated guidelines for dosimetry in brachytherapy in TG-186 have recommended the use of model-based dosimetry calculations as a replacement for TG-43. TG-186 highlights shortcomings in the water-based approach in TG-43, particularly for low energy brachytherapy sources. The Xoft Axxent is a low energy (<50 kV) brachytherapy system used in accelerated partial breast irradiation (APBI). Breast tissue is a heterogeneous tissue in terms of density and composition. Dosimetric calculations of seven APBI patients treated with Axxent were made using a model-based Monte Carlo platform for a number of tissue models and dose reporting methods and compared to TG-43 based plans. METHODS: A model of the Axxent source, the S700, was created and validated against experimental data. CT scans of the patients were used to create realistic multi-tissue/heterogeneous models with breast tissue segmented using a published technique. Alternative water models were used to isolate the influence of tissue heterogeneity and backscatter on the dose distribution. Dose calculations were performed using Geant4 according to the original treatment parameters. The effect of the Axxent balloon applicator used in APBI which could not be modeled in the CT-based model, was modeled using a novel technique that utilizes CAD-based geometries. These techniques were validated experimentally. Results were calculated using two dose reporting methods, dose to water (Dw,m) and dose to medium (Dm,m), for the heterogeneous simulations. All results were compared against TG-43-based dose distributions and evaluated using dose ratio maps and DVH metrics. Changes in skin and PTV dose were highlighted. RESULTS: All simulated heterogeneous models showed a reduced dose to the DVH metrics that is dependent on the method of dose reporting and patient geometry. Based on a prescription dose of 34 Gy, the average D90 to PTV was reduced by between ~4% and ~40%, depending on the scoring method, compared to the TG-43 result. Peak skin dose is also reduced by 10%-15% due to the absence of backscatter not accounted for in TG-43. The balloon applicator also contributed to the reduced dose. Other ROIs showed a difference depending on the method of dose reporting. CONCLUSIONS: TG-186-based calculations produce results that are different from TG-43 for the Axxent source. The differences depend strongly on the method of dose reporting. This study highlights the importance of backscatter to peak skin dose. Tissue heterogeneities, applicator, and patient geometries demonstrate the need for a more robust dose calculation method for low energy brachytherapy sources.

Experience with an electronic brachytherapy technique for intracavitary accelerated partial breast irradiation.

OBJECTIVES: Phase IV study evaluated the safety and device performance of an electronic brachytherapy system (Axxent Electronic Brachytherapy System) as adjuvant therapy for early-stage breast cancer. METHODS: Patients were > or =50 years of age and had completely resected invasive ductal carcinoma or ductal carcinoma in situ (<2.0 cm), with N0 M0 and negative microscopic margins of > or =1 mm. The balloon applicator was placed in a closed cavity with a balloon surface to skin distance of > or =7 mm. The prescribed dose was 3.4 Gy/fraction prescribed to 1 cm beyond the balloon surface twice daily (BID) for 10 fractions. RESULTS: Of 65 patients consented, 21 (32%) were not eligible for treatment, and 44 (68%) were treated, with 6-months follow-up in 43 and 1-year follow-up in 36. The prescribed radiation treatment was successfully delivered in 42/44 (95.4%) patients; one was unsuccessful due to a controller issue and the other declined the final fraction following a balloon deflation. Side effects were as anticipated and generally manageable. Four CTCAE v3 grade 3 toxicities were reported: blistering (1), breast tenderness (1), and moist desquamation (2); all have resolved. The most common grade 2 toxicity was erythema. There were no device-related serious adverse events. CONCLUSIONS: Early experience demonstrates that the electronic brachytherapy system performed as expected. Electronic brachytherapy has similar acute toxicity profiles to other high dose rate approaches for accelerated partial breast irradiation and offers the convenience of having the treatment in an unshielded room.

Calculation of relative biological effectiveness of a low-energy electronic brachytherapy source.

Low-energy x-rays are known to have a higher relative biological effectiveness (RBE) than higher energy photons such as the gamma rays from 192Ir and 60Co. In this work the initial yield of single- and double-strand DNA breaks (SSB and DSB) and the RBE was estimated for a novel electronic brachytherapy source (EBS), emitting 40-50 kVp photons. An EGSnrc Monte Carlo model of the source was used in combination with the 'Monte Carlo damage simulation' program (Semenenko and Stewart 2004 Radiat. Res. 161 451-57; 2006 Phys. Med. Biol. 51 1693-706). The results indicate a substantially reduced SSB yield and increased DSB yield for the EBS compared to 60Co or 192Ir, leading to an enhanced RBE by 40-50%. The RBE estimate for the low-energy x-ray EBS was found to be very similar to the low-energy gamma ray brachytherapy isotope 125I. Biological damage was estimated in several human tissues: muscle, breast, calcified breast and cortical bone. SSB and DSB yields were similar in all media, except in bone. These findings should be taken into account if the EBS is intended to replace brachytherapy with the commonly used 192Ir isotope.

Spectroscopic characterization of a novel electronic brachytherapy system.

The Axxent developed by Xoft Inc. is a novel electronic brachytherapy system capable of generating x-rays up to 50 keV. These low energy photon-emitting sources merit attention not only because of their ability to vary the dosimetric properties of the radiation, but also because of the radiobiological effects of low energy x-rays. The objective of this study is to characterize the x-ray source and to model it using the Geant4 Monte Carlo code. Spectral and attenuation curve measurements are performed at various peak voltages and angles and the source is characterized in terms of spectrum and half-value layers (HVLs). Also, the effects of source variation and source aging are quantified. Bremsstrahlung splitting, phase-space scoring and particle-tagging features are implemented in the Geant4 code, which is bench-marked against BEAMnrc simulations. HVLs from spectral measurements, attenuation curve measurements and Geant4 simulations mostly agree within uncertainty. However, there are discrepancies between measurements and simulations for photons emitted on the source transverse plane (90 degrees).

Calculated and measured brachytherapy dosimetry parameters in water for the Xoft Axxent X-Ray Source: an electronic brachytherapy source.

A new x-ray source, the model S700 Axxent X-Ray Source (Source), has been developed by Xoft Inc. for electronic brachytherapy. Unlike brachytherapy sources containing radionuclides, this Source may be turned on and off at will and may be operated at variable currents and voltages to change the dose rate and penetration properties. The in-water dosimetry parameters for this electronic brachytherapy source have been determined from measurements and calculations at 40, 45, and 50 kV settings. Monte Carlo simulations of radiation transport utilized the MCNP5 code and the EPDL97-based mcplib04 cross-section library. Inter-tube consistency was assessed for 20 different Sources, measured with a PTW 34013 ionization chamber. As the Source is intended to be used for a maximum of ten treatment fractions, tube stability was also assessed. Photon spectra were measured using a high-purity germanium (HPGe) detector, and calculated using MCNP. Parameters used in the two-dimensional (2D) brachytherapy dosimetry formalism were determined. While the Source was characterized as a point due to the small anode size, < 1 mm, use of the one-dimensional (1D) brachytherapy dosimetry formalism is not recommended due to polar anisotropy. Consequently, 1D brachytherapy dosimetry parameters were not sought. Calculated point-source model radial dose functions at gP(5) were 0.20, 0.24, and 0.29 for the 40, 45, and 50 kV voltage settings, respectively. For 1