Psychometric properties of two implementation measures: Normalization MeAsure Development questionnaire (NoMAD) and organizational readiness for implementing change (ORIC)

Background

Effective interventions need to be implemented successfully to achieve impact. Two theory-based measures exist for measuring the effectiveness of implementation strategies and monitor implementation progress. The Normalization MeAsure Development questionnaire (NoMAD) explores the four core concepts (Coherence, Cognitive Participation, Collective Action, Reflexive Monitoring) of the Normalization Process Theory. The Organizational Readiness for Implementing Change (ORIC) is based on the theory of Organizational Readiness for Change, measuring organization members' psychological and behavioral preparedness for implementing a change. We examined the measurement properties of the NoMAD and ORIC in a multi-national implementation effectiveness study.

Method

Twelve mental health organizations in nine countries implemented Internet-based cognitive behavioral therapy (iCBT) for common mental disorders. Staff involved in iCBT service delivery (n = 318) participated in the study. Both measures were translated into eight languages using a standardized forward-backward translation procedure. Correlations between measures and subscales were estimated to examine convergent validity. The theoretical factor structures of the scales were tested using confirmatory factor analysis (CFA). Test-retest reliability was based on the correlation between scores at two time points 3 months apart. Internal consistency was assessed using Cronbach's alpha. Floor and ceiling effects were quantified using the proportion of zero and maximum scores.

Results

NoMAD and ORIC measure related but distinct latent constructs. The CFA showed that the use of a total score for each measure is appropriate. The theoretical subscales of the NoMAD had adequate internal consistency. The total scale had high internal consistency. The total ORIC scale and subscales demonstrated high internal consistency. Test-retest reliability was suboptimal for both measures and floor and ceiling effects were absent.

Conclusions

This study confirmed the psychometric properties of the NoMAD and ORIC in multi-national mental health care settings. While measuring on different but related aspects of implementation processes, the NoMAD and ORIC prove to be valid and reliable across different language settings.

How to promote usage of telehealth interventions for farmers' mental health? A qualitative study on supporting and hindering aspects for acceptance and satisfaction with a personalized telephone coaching for depression prevention

Low-threshold and remotely delivered preventive interventions, like telephone coaching, are warranted for farmers who experience multiple risk factors for depression, live in underserved areas, and show low help-seeking behavior. Factors facilitating uptake and actual use of effective remote interventions are important to reduce depression disease burden. This study aimed at identifying factors that potentially can influence acceptance of and satisfaction with a telephone coaching in this occupational group.Semi-structured interviews were based on the 'Unified Theory of Acceptance and Use of Technology', the 'Evaluation', and 'Discrepancy' models for satisfaction. Interviews were conducted with 20 of 66 invited participants of a 6-months telephone coaching during an effectiveness or implementation study. Audio-recorded interviews were transcribed and analyzed (deductive-inductive qualitative content analysis). Independent coding by two persons resulted in good agreement (Κ = 0.80). Participants validated results via questionnaire.Overall, 32 supporting (SF) and 14 hindering factors (HF) for acceptance and satisfaction were identified and organized into five dimensions: Coaching result (SF = 9, HF = 3), coach (SF = 9, HF = 1), organization (SF = 5, HF = 2), the telephone as communication medium (SF = 4, HF = 5) and participant characteristics (SF = 5, HF = 3). Most named SFs were 'Flexible appointment arrangement' (n = 19/95 %) and 'low effort' (n = 17/85 %), while most reported HFs were 'lack of visual cues' (n = 12/60 %) and 'social/professional involvement restricts change process' (n = 10/50 %).The perceived changes initiated by coaching, a low effort through telephone conduct, and the indicated personalization were identified as important influencing factors on acceptance and satisfaction based on interviewees' statements. Both may be further enhanced by offering choice and advice for delivery formats (e.g., video-calls) and training of coaches in farm-related issues.

Study registration

German Clinical Trial Registrations: DRKS00017078 and DRKS00015655.

Validation of the German Normalisation Process Theory Measure G-NoMAD: translation, adaptation, and pilot testing

BACKGROUND

Implementing evidence-based healthcare practices (EBPs) is a complex endeavour and often lags behind research-informed decision processes. Understanding and systematically improving implementation using implementation theory can help bridge the gap between research findings and practice. This study aims to translate, pilot, and validate a German version of the English NoMAD questionnaire (G-NoMAD), an instrument derived from the Normalisation Process Theory, to explore the implementation of EBPs.

METHODS

Survey data has been collected in four German research projects and subsequently combined into a validation data set. Two versions of the G-NoMAD existed, independently translated from the original English version by two research groups. A measurement invariance analysis was conducted, comparing latent scale structures between groups of respondents to both versions. After determining the baseline model, the questionnaire was tested for different degrees of invariance (configural, metric, scalar, and uniqueness) across samples. A confirmatory factor analysis for three models (a four-factor, a unidimensional, and a hierarchical model) was used to examine the theoretical structure of the G-NoMAD. Finally, psychometric results were discussed in a consensus meeting, and the final instructions, items, and scale format were consented to.

RESULTS

A total of 539 health care professionals completed the questionnaire. The results of the measurement invariance analysis showed configural, partial metric, and partial scalar invariance indicating that the questionnaire versions are comparable. Internal consistency ranged from acceptable to good (0.79 ≤ α ≤ 0.85) per subscale. Both the four factor and the hierarchical model achieved a better fit than the unidimensional model, with indices from acceptable (SRMR = 0.08) to good (CFI = 0.97; TLI = 0.96). However, the RMSEA values were only close to acceptable (four-factor model: χ2164 = 1029.84, RMSEA = 0.10; hierarchical model: χ2166 = 1073.43, RMSEA = 0.10).

CONCLUSIONS

The G-NoMAD provides a reliable and promising tool to measure the degree of normalisation among individuals involved in implementation activities. Since the fit was similar in the four-factor and the hierarchical model, priority should be given to the practical relevance of the hierarchical model, including a total score and four subscale scores. The findings of this study support the further usage of the G-NoMAD in German implementation settings.

TRIAL REGISTRATION

Both the AdAM project (No. NCT03430336, 06/02/2018) and the EU-project ImpleMentAll (No. NCT03652883, 29/08/2018) were registered on ClinicalTrials.gov. The ImplementIT study was registered at the German Clinical Trial Registration (No. DRKS00017078, 18/04/2019). The G-NoMAD validation study was registered at the Open Science Framework (No7u9ab, 17/04/2023).

Using the Consolidated Framework for Implementation Research to evaluate a nationwide depression prevention project (ImplementIT) from the perspective of health care workers and implementers: Results on the implementation of digital interventions for farmers

Introduction

Depression has a significant impact on individuals and society, which is why preventive measures are important. Farmers represent an occupational group exposed to many risk factors for depression. The potential of guided, tailored internet-based interventions and a personalized telephone coaching is evaluated in a German project of the Social Insurance for Agriculture, Forestry and Horticulture (SVLFG). While user outcomes are promising, not much is known about actual routine care use and implementation of the two digital health interventions. This study evaluates the implementation from the perspective of social insurance employees to understand determinants influencing the uptake and implementation of digital interventions to prevent depression in farmers.

Methods

The data collection and analysis are based on the Consolidated Framework for Implementation Research (CFIR). Health care workers (n = 86) and implementers (n = 7) completed online surveys and/or participated in focus groups. The surveys consisted of validated questionnaires used in implementation research, adapted items from the CFIR guide or from other CFIR studies. In addition, we used reporting data to map implementation based on selected CFIR constructs.

Results

Within the five CFIR dimensions, many facilitating factors emerged in relation to intervention characteristics (e.g., relative advantage compared to existing services, evidence and quality) and the inner setting of the SVLFG (e.g., tension for change, compatibility with values and existing working processes). In addition, barriers to implementation were identified in relation to the outer setting (patient needs and resources), inner setting (e.g., available resources, access to knowledge and information) and characteristics of individuals (e.g., self-efficacy). With regard to the implementation process, facilitating factors (formal implementation leaders) as well as hindering factors (reflecting and evaluating) were identified.

Discussion

The findings shed light on the implementation of two digital prevention services in an agricultural setting. While both offerings seem to be widely accepted by health care workers, the results also point to revealed barriers and contribute to recommendations for further service implementation. For instance, special attention should be given to "patient needs and resources" by raising awareness of mental health issues among the target population as well as barriers regarding the inner setting.

Clinical Trial Registration

German Clinical Trial Registration: [DRKS00017078]. Registered on 18.04.2019.

Barriers to and Facilitators of Engaging With and Adhering to Guided Internet-Based Interventions for Depression Prevention and Reduction of Pain-Related Disability in Green Professions: Mixed Methods Study

BACKGROUND

Internet-based interventions (IBIs) are effective for the prevention and treatment of mental disorders and are valuable additions for improving routine care. However, the uptake of and adherence to IBIs are often limited. To increase the actual use of IBIs, it is important to identify factors for engaging with and adhering to IBIs.

OBJECTIVE

We qualitatively evaluated barriers and facilitators regarding a portfolio of guided IBIs in green professions (farmers, gardeners, and foresters).

METHODS

Interview participants were selected from 2 randomized controlled trials for either the prevention of depression (Prevention of Depression in Agriculturists [PROD-A]) or the reduction of pain interference (Preventive Acceptance and Commitment Therapy for Chronic Pain in Agriculturists [PACT-A]) in green professions. The intervention group in PROD-A (N=180) participated in an IBI program, receiving access to 1 of 6 symptom-tailored IBIs. The intervention group in PACT-A (N=44) received access to an IBI for chronic pain. Overall, 41 semistructured qualitative interviews were conducted and transcribed verbatim. Barriers and facilitators were identified via inductive qualitative content analysis, with 2 independent coders reaching almost perfect intercoder reliability (Cohen κ=0.92). A quantitative follow-up survey (30/41, 73%) was conducted to validate the results. Subgroup analyses were performed based on intervention characteristics.

RESULTS

We identified 42 barriers and 26 facilitators, which we assigned to 4 superordinate categories related to the intervention (20 barriers; 17 facilitators), work (4 barriers; 1 facilitator), individual (13 barriers; 8 facilitators), and technical (5 barriers; 0 facilitators) aspects. Key barriers (identified by at least 50% of the interviewees) were time-consuming work life (29/40, 73%) and time-consuming private life (23/40, 58%). Similarly, the most frequently identified facilitators included presence of motivation, curiosity, interest and perseverance (30/40, 75%), flexible time management at work (25/40, 63%), and support from family and friends (20/40, 50%). Although agreement with barriers in the quantitative follow-up survey was rather low (mean 24%, SD 11%), agreement with facilitators was substantially higher (mean 80%, SD 13%). Differences in agreement rates were found particularly between intervention completers and noncompleters. Completers agreed significantly more often that perceived IBI success; being motivated, curious, interested, and perseverant; and having a persisting level of psychological strain have been facilitating. Noncompleters agreed more often with experiencing the e-coach contact as insufficient and technical problems as hindering for intervention completion.

CONCLUSIONS

Based on these results, strategies such as customization of modules for more flexible and adaptive use; video chat options with the e-coach; options to facilitate social support by family, friends, or other participants; or using prompts to facilitate training completion can be derived. These approaches could be evaluated in further quantitative research designs in terms of their potential to enhance intervention use in this occupational group.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00014000, https://tinyurl.com/3bukfr48; German Clinical Trials Register DRKS0001461, https://tinyurl.com/ebsn4sns.

Lessons Learned from an Attempted Pragmatic Randomized Controlled Trial for Improvement of Chronic Pain-Associated Disability in Green Professions: Long-Term Effectiveness of a Guided Online-Based Acceptance and Commitment Therapy  (PACT-A)

Musculoskeletal symptoms are increased in farmers, whereas the prevalence of chronified pain is unknown. Online interventions based on acceptance and commitment therapy (ACT) have shown encouraging results in the general population, representing a promising approach for reducing pain interference in green professions (i.e., farmers, foresters, gardeners). We conducted a pragmatic RCT comparing a guided ACT-based online intervention to enhanced treatment-as-usual in entrepreneurs, contributing spouses, family members and pensioners in green professions with chronic pain (CPG: ≥grade II, ≥6 months). Recruitment was terminated prematurely after 2.5 years at N = 89 (of planned N = 286). Assessments were conducted at 9 weeks (T1), 6 months (T2) and 12 months (T3) post-randomization. The primary outcome was pain interference (T1). The secondary outcomes encompassed pain-, health- and intervention-related variables. No treatment effect for reduction of pain interference was found at T1 (β = -0.16, 95%CI: -0.64-0.32, p = 0.256). Improvements in cognitive fusion, pain acceptance, anxiety, perceived stress and quality of life were found only at T3. Intervention satisfaction as well as therapeutic and technological alliances were moderate, and uptake and adherence were low. Results are restricted by low statistical power due to recruitment issues, high study attrition and low intervention adherence, standing in contrast to previous studies. Further research is warranted regarding the use of ACT-based online interventions for chronic pain in this occupational group. Trial registration: German Clinical Trial Registration: DRKS00014619. Registered: 16 April 2018.

Digital prevention of depression for farmers? A qualitative study on participants' experiences regarding determinants of acceptance and satisfaction with a tailored guided internet intervention program

INTRODUCTION

Farmers, forest workers and gardeners have a higher risk of developing depression compared to other occupational populations. As part of the German pilot project "With us in balance", the potential of six guided internet- and mobile-based interventions (IMIs) to prevent depression among their insurants is examined. The IMI program is tailored to various risk factors of depression, individual symptoms, and needs. Although IMIs have been shown to be effective in reducing depressive symptoms, there is little qualitative research about the acceptance of digital preventive IMIs. The aim of this qualitative study is to gain insights into participants' experiences with the guided IMIs by focusing on determinants for acceptance and satisfaction.

METHODS

Semi-structured interviews were conducted with 22/171 (13 %) intervention group (IG) participants of a randomized controlled trial. The interview guide was developed based on theoretical models of user acceptance (Unified Theory of Acceptance and Use of Technology) and patient satisfaction (evaluation model, discrepancy theory). The interviews were evaluated independently by two coders performing a deductive-inductive content analysis and attaining a substantial level of agreement (K = 0.73).

RESULTS

The qualitative analysis revealed 71 determinants for acceptance and satisfaction across ten dimensions: performance expectancy, organisation, e-coach, usability, training content and structure, training usage, training outcome, financing, social influence, and behavioural intention. The most frequently identified drivers for the IMI use include "location independence", "positive relationship to the e-coach" (each n = 19, 86 %), "personal e-coach guidance", "expertise of the e-coach", "target group specific adaptation" (each n = 18, 82 %), "flexibility", "high willingness for renewed participation" (each n = 17, 77 %), "fast and easy availability", "training of health enhancing attitudes and behaviours" and "content with figurative expressions" (each n = 16, 73 %).

DISCUSSION

The qualitative findings predominantly suggest the acceptance of and satisfaction with the IMI program for the prevention of depression in famers and related lines of work. Many identified positive drivers are related to the e-coach guidance, which emphasizes its importance in the preventive setting from the perspective of the participants. Nevertheless, some negative aspects have been identified which help to understand potential weaknesses of the IMI program. Participants indicated different needs in terms of IMI content and usage, which points towards the potential benefit of individualisation. The possibility of being able to use IMIs anonymously, flexibly and independently of location might be highly relevant for this specific target group.

Telephone coaching for the prevention of depression in farmers: Results from a pragmatic randomized controlled trial

INTRODUCTION

Farmers have a high risk for depression (MDD). Preventive measures targeting this often remotely living population might reduce depression burden. The study aimed to evaluate the effectiveness of personalized telephone coaching in reducing depressive symptom severity and preventing MDD in farmers compared to enhanced treatment as usual (TAU + ).

METHODS

In a two-armed, pragmatic randomized controlled trial (N = 314) with post-treatment at 6 months, farming entrepreneurs, collaborating family members and pensioners with elevated depressive symptoms (PHQ-9 ≥ 5) were randomized to personalized telephone coaching or TAU + . The coaching was provided by psychologists and consists on average of 13 (±7) sessions a 48 min (±15) over 6 months. The primary outcome was depressive symptom severity (QIDS-SR16).

RESULTS

Coaching participants showed a significantly greater reduction in depressive symptom severity compared to TAU + (d = 0.39). Whereas reliable symptom deterioration was significantly lower in the intervention group compared to TAU + , no significant group differences were found for reliable improvement and in depression onset. Further significant effects in favor of the intervention group were found for stress (d = 0.34), anxiety (d = 0.30), somatic symptoms (d = 0.39), burnout risk (d = 0.24-0.40) and quality of life (d = 0.28).

DISCUSSION

Limiting, we did not apply an upper cutoff score for depressive symptom severity or controlled for previous MDD episodes, leaving open whether the coaching was recurrence/relapse prevention or early treatment. Nevertheless, personalized telephone coaching can effectively improve mental health in farmers. It could play an important role in intervening at an early stage of mental health problems and reducing disease burden related to MDD.

TRIAL REGISTRATION NUMBER AND TRIAL REGISTER

German Clinical Trial Registration: DRKS00015655.

Reducing problematic alcohol use in employees: economic evaluation of guided and unguided web-based interventions alongside a three-arm randomized controlled trial

AIMS

To perform an economic evaluation of guided and unguided internet-based interventions to reduce problematic alcohol consumption in employees compared with a waiting-list control condition (WLC) with unrestricted access to treatment-as-usual.

DESIGN

A cost-effectiveness analysis (CEA) and cost-utility analysis (CUA) from a societal and a cost-benefit analysis from the employer's perspective with a 6-month time horizon.

SETTING

Open recruitment in the German working population.

PARTICIPANTS

Employees (178 males, 256 females, mean age 47 years) consuming at least 14 (women) or 21 (men) standard units of alcohol (SUAs) per week and scoring ≥ 8 (men) or 6 (women) on the Alcohol Use Disorders Identification Test.

MEASUREMENTS

On-line questionnaires administered to assess SUAs and assess quality of life (AQoL-8D) and resource use. Outcome measure was responder (≤ 14/≤ 21 SUAs) for the CEA and quality-adjusted life years (QALYs) for the CUA. Net benefit regression was used to estimate cost-effectiveness for each study arm. Bootstrapping and sensitivity analyses were performed to account for uncertainty.

INTERVENTIONS

Five weekly modules including personalized normative feedback, motivational interviewing, goal setting, problem-solving and emotion regulation, provided with adherence-focused guidance [n = 142; responders: n = 73 (51.4%); QALYs = 0.364, standard error (SE) = 0.006] or without guidance [n = 146; n = 66 (45.2%); 0.359, 0.007]. Controls were on a waiting-list [n = 144; n = 38 (26.4%); 0.342, 0.007].

FINDINGS

From a societal perspective, the guided intervention had a probability of 55% (54%) of being the most efficient strategy at a willingness-to-pay (WTP) of €0 per responder (QALY) gained, compared with the unguided intervention and the control condition. At a WTP of €20 000 per QALY gained, the probability was 78%. From an employer's perspective, the guided intervention had a higher probability of a positive return on investment (81%) compared with the unguided intervention (58%).

CONCLUSION

A guided internet-based intervention to reduce problematic alcohol consumption in employees appears to be both cost-beneficial and cost-effective.

Are guided internet-based interventions for the indicated prevention of depression in green professions effective in the long run? Longitudinal analysis of the 6- and 12-month follow-up of a pragmatic randomized controlled trial (PROD-A)

OBJECTIVE

Evidence of long-term stability for positive mental health effects of internet-based interventions (IBIs) for depression prevention is still scarce. We evaluate long-term effectiveness of a depression prevention program in green professions (i.e. agriculture, horticulture, forestry).

METHODS

This pragmatic RCT (n = 360) compares a tailored IBI program to enhanced treatment as usual (TAU+) in green professions with at least subthreshold depression (PHQ ≥ 5). Intervention group (IG) received one of six IBIs shown previously to efficaciously reduce depressive symptoms. We report 6- and 12-month follow-up measures for depression, mental health and intervention-related outcomes. Intention-to-treat and per-protocol regression analyses were conducted for each measurement point and complemented by latent growth modeling.

RESULTS

After 6 months, depression severity (β = -0.30, 95%-CI: -0.52; -0.07), insomnia (β = -0.22, 95%-CI: -0.41; -0.02), pain-associated disability (β = -0.26, 95%-CI: -0.48; -0.04) and quality of life (β = 0.29, 95%-CI: 0.13; 0.45) in IG were superior to TAU+. Onset of possible depression was not reduced. After 12 months, no intervention effects were found. Longitudinal modeling confirmed group effects attenuating over 12 months for most outcomes. After 12 months, 55.56% of IG had completed at least 80% of their IBI.

CONCLUSIONS

Stability of intervention effects along with intervention adherence was restricted. Measures enhancing long-term effectiveness of IBIs for depression health promotion are indicated in green professions.

TRIAL REGISTRATION

German Clinical Trial Registration: DRKS00014000. Registered: 09 April 2018.

Effectiveness of guided internet-based interventions in the indicated prevention of depression in green professions (PROD-A): Results of a pragmatic randomized controlled trial

BACKGROUND

Major Depressive Disorder (MDD) has a major impact on public health. Reduction of depression burden in general population is of greatest importance and might be achieved by implementation of depression prevention measures into routine care. We evaluate an online prevention measure as part of a national project aiming to reduce depression in the occupational group of green professions.

METHODS

This two-armed pragmatic RCT (n = 360) evaluates the effectiveness of a tailored internet-based intervention (IMI) program compared to enhanced treatment as usual. The IMI program entailed access to one of six guided IMIs each focusing on different symptom areas (depressive mood with optional comorbid diabetes, perceived stress, insomnia, panic and agoraphobia and harmful alcohol consumption). Eligible were entrepreneurs, spouses, family members and pensioners in green professions with adequate insurance status and at least subthreshold depression (PHQ≥5). Primary outcome was depressive symptom severity (QIDS-SR16) at 9-weeks post-treatment (T1). Various secondary outcomes were assessed at T1.

RESULTS

A small effect of depression reduction (d=-0.28, 95%-CI: -0.50 to -0.07) was found at T1 favouring the IMI program (β=-0.22, 95%-CI: -0.41 to -0.02, p=.033). Categorical analysis indicated a reduced risk of potential MDD with NNTB=28.11. Adherence to the IMI program at T1 was exceptionally low.

LIMITATIONS

Results are limited to green professions and representativeness might be restricted by self-selection of participants.

CONCLUSION

Depression burden in green professions can be reduced by this online prevention measure. Yet, short-term effectiveness is restricted by low adherence rates.

TRIAL REGISTRATION

German Clinical Trial Registration: DRKS00014000. Registered: 09 April 2018.

Clinical and cost-effectiveness of a guided internet-based Acceptance and Commitment Therapy to improve chronic pain-related disability in green professions (PACT-A): study protocol of a pragmatic randomised controlled trial

INTRODUCTION

Chronic pain is highly prevalent, associated with substantial personal and economic burdens, and increased risk for mental disorders. Individuals in green professions (agriculturists, horticulturists, foresters) show increased prevalence of chronic pain and other risk factors for mental disorders. Available healthcare services in rural areas are limited. Acceptance towards face-to-face therapy is low. Internet and mobile-based interventions (IMIs) based on Acceptance and Commitment Therapy (ACT) might be a promising alternative for this population and may enable effective treatment of chronic pain. The present study aims to evaluate the clinical and cost-effectiveness of an ACT-based IMI for chronic pain in green professions in comparison with enhanced treatment as usual (TAU+).

METHODS AND ANALYSIS

A two-armed pragmatic randomised controlled trial will be conducted. Two hundred eighty-six participants will be randomised and allocated to either an intervention or TAU+ group. Entrepreneurs in green professions, collaborating spouses, family members and pensioners with chronic pain are eligible for inclusion. The intervention group receives an internet-based intervention based on ACT (7 modules, over 7 weeks) guided by a trained e-coach to support adherence (eg, by positive reinforcement). Primary outcome is pain interference (Multidimensional Pain Interference scale; MPI) at 9 weeks post-randomisation. Secondary outcomes are depression severity (Quick Inventory Depressive Symptomology; QIDS-SR16), incidence of major depressive disorder, quality of life (Assessment of Quality of Life; AQoL-8D) and possible side effects associated with the treatment (Inventory for the Assessment of Negative Effects of Psychotherapy; INEP). Psychological flexibility (Chronic Pain Acceptance Questionnaire, Committed Action Questionnaire, Cognitive Fusion Questionnaire) will be evaluated as a potential mediator of the treatment effect. Furthermore, mediation, moderation and health-economic analyses from a societal perspective will be performed. Outcomes will be measured using online self-report questionnaires at baseline, 9-week, 6-month, 12-month, 24-month and 36-month follow-ups.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of the University of Ulm, Germany (file no. 453/17-FSt/Sta; 22 February 2018). Results will be submitted for publication in peer-reviewed journals and presented at conferences.

TRIAL REGISTRATION NUMBER

German Clinical Trial Registration: DRKS00014619. Registered on 16 April 2018.

Implementing internet- and tele-based interventions to prevent mental health disorders in farmers, foresters and gardeners (ImplementIT): study protocol for the multi-level evaluation of a nationwide project

BACKGROUND

Farmers are a vulnerable population for developing depression or other mental health disorders due to a variety of risk factors in their work context. Beyond face-to-face resources, preventive internet- and tele-based interventions could extend available treatment options to overcome barriers to care. The German Social Insurance Company for Agriculture, Forestry and Horticulture (SVLFG) implements several guided internet- and mobile-based interventions and personalised tele-based coaching for this specific target group provided by external companies within a nation-wide prevention project for their insured members. The current study aims to evaluate the implementation process and to identify determinants of successful implementation on various individual and organisational levels.

METHODS

The current study includes two groups of participants: 1) insured persons with an observable need for prevention services, and 2) staff-participants who are involved in the implementation process. The Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) framework and the Consolidated Framework for Implementation Research (CFIR) will be used to track and evaluate the implementation process. A mixed-method approach will provide insights on individual and organizational level (e.g. degree of normalization, readiness for change) and helps to identify determinants of successful implementation. In-depth insights on experiences of the participants (e.g. acceptance, satisfaction, barriers and facilitating factors of intervention use) will be yielded through qualitative interviews. Focus groups with field workers provide insights into barriers and facilitators perceived during their consultations. Furthermore, intervention as well as implementation costs will be evaluated. According to the stepwise, national rollout, data collection will occur at baseline and continuously across 24 months.

DISCUSSION

The results will show to what extent the implementation of the internet- and tele-based services as a preventive offer will be accepted by the participants and involved employees and which critical implementation aspects will occur within the process. If the implementation of the internet- and tele-based services succeeds, these services may be feasible in the long-term.

TRIAL REGISTRATION

German Clinical Trial Registration: DRKS00017078 . Registered on 18.04.2019.

Clinical and Cost-Effectiveness of Personalized Tele-Based Coaching for Farmers, Foresters and Gardeners to Prevent Depression: Study Protocol of an 18-Month Follow-Up Pragmatic Randomized Controlled Trial (TEC-A)

Background: Farmers show high levels of depressive symptoms and mental health problems in various studies. This study is part of a nationwide prevention project carried out by a German social insurance company for farmers, foresters, and gardeners (SVLFG) to implement internet- and tele-based services among others to improve mental health in this population. The aim of the present study is to evaluate the (cost-)effectiveness of personalized tele-based coaching for reducing depressive symptom severity and preventing the onset of clinical depression, compared to enhanced treatment as usual. Methods: In a two-armed, pragmatic randomized controlled trial (N = 312) with follow-ups at post-treatment (6 months), 12 and 18 months, insured farmers, foresters, and gardeners, collaborating family members and pensioners with elevated depressive symptoms (PHQ-9 ≥ 5) will be randomly allocated to personalized tele-based coaching or enhanced treatment as usual. The coaching is provided by psychologists and consists of up to 34 tele-based sessions for 25-50 min delivered over 6 months. Primary outcome is depressive symptom severity at post-treatment. Secondary outcomes include depression onset, anxiety, stress, and quality of life. A health-economic evaluation will be conducted from a societal perspective. Discussion: This study is the first pragmatic randomized controlled trial evaluating the (cost-)effectiveness of a nationwide tele-based preventive service for farmers. If proven effective, the implementation of personalized tele-based coaching has the potential to reduce disease burden and health care costs both at an individual and societal level. Clinical Trial Registration: German Clinical Trial Registration: DRKS00015655.

Clinical and cost-effectiveness of guided internet-based interventions in the indicated prevention of depression in green professions (PROD-A): study protocol of a 36-month follow-up pragmatic randomized controlled trial

BACKGROUND

People in green professions are exposed to a variety of risk factors, which could possibly enhance the development of depression. Amongst possible prevention approaches, internet- and mobile-based interventions (IMIs) have been shown to be effective and scalable. However, little is known about the effectiveness in green professions. The aim of the present study is to examine the (cost-)effectiveness of a tailored IMI program for reducing depressive symptoms and preventing the onset of clinical depression compared to enhanced treatment as usual (TAU+).

METHODS

A pragmatic randomized controlled trial (RCT) will be conducted to evaluate a tailored and therapeutically guided preventive IMI program in comparison to TAU+ with follow-ups at post-treatment (9 weeks), 6-, 12-, 24-, and 36-months. Entrepreneurs in green professions, collaborating spouses, family members and pensioners (N = 360) with sufficient insurance status and at least subthreshold depression (PHQ-9 ≥ 5) are eligible for inclusion. Primary outcome is depressive symptom severity (QIDS-SR16). Secondary outcomes include incidence of depression (QIDS-SR16), quality of life (AQoL-8D) and negative treatment effects (INEP). A health-economic evaluation will be conducted from a societal perspective. The IMI program is provided by psychologists of an external service company and consists of six guided IMIs (6-8 modules, duration: 6-8 weeks) targeting different symptoms (depressive mood, depressive mood with comorbid diabetes, perceived stress, insomnia, panic and agoraphobic symptoms or harmful alcohol use). Intervention choice depends on a screening of participants' symptoms and individual preferences. The intervention phase is followed by a 12-months consolidating phase with monthly contact to the e-coach.

DISCUSSION

This is the first pragmatic RCT investigating long-term effectiveness of a tailored guided IMI program for depression prevention in green professions. The present trial builds on a large-scale strategy for depression prevention in green professions. The intended implementation of the IMI program with a nationwide rollout has the potential to reduce overall depression burden and associated health care costs in case of given effectiveness.

TRIAL REGISTRATION

German Clinical Trial Registration: DRKS00014000 . Registered on 09 April 2018.

Assessing Communication Skills in Real Medical Encounters in Oncology: Development and Validation of the ComOn-Coaching Rating Scales

One of the challenges in research on teaching physician-patient communication is how to assess communication, necessary for evaluating training, the learning process, and for feedback. Few instruments have been validated for real physician-patient consultations. Real consultations involve unique contexts, different persons, and topics, and are difficult to compare. The aim of this study is to develop and validate a rating scale for assessment of such consultations. For the evaluation study of a communication skills training for physicians in oncology, real consultations were recorded in three assessment points. Based on earlier work and on current studies, a new instrument was developed for assessment of these consultations. Two psychologists were trained in using the instrument and assessed 42 consultations. For inter-rater reliability, interclass correlation (ICC) was calculated. The final version of the rating scales consists of 13 items evaluated on a 5-point scale. The items are grouped in seven areas: "Start of conversation," "assessment of the patient's perspective," "structure of conversation," "emotional issues," "end of conversation," "general communication skills," and "overall evaluation." ICC coefficients for the domains ranged from .44 to .77. An overall coefficient of all items resulted in an ICC of .66. The ComOn-Coaching Rating Scales are a short, reliable, and applicable instrument for the assessment of real physician-patient consultations in oncology. If adapted, they could be used in other areas. They were developed for research and teaching purposes and meet the required methodological criteria. Rater training should be considered more deeply by further research.

Exploring urban health in Cape Town, South Africa: an interdisciplinary analysis of secondary data

BACKGROUND

With modern information technology, an overwhelming amount of data is available on different aspects of societies. Our research investigated the feasibility of using secondary data sources to get an overview of determinants of health and health outcomes in different population strata of Cape Town, a large city of South Africa.

METHODS

The methodological approach of secondary-data analysis was similar in the different disciplines: Biological Anthropology, Public Health, Environmental Health, Mental Health, Palliative Care, Medical Psychology and Sociology at the University of Freiburg and Public Health at the University of Cape Town. The teams collected information on Cape Town through Internet searches and published articles. The information was extracted, analyzed, condensed, and jointly interpreted.

RESULTS

Data show the typical picture of a population in epidemiological and demographic transition exposed to often difficult social, mental, and physical environmental conditions. Comparison between low and higher socioeconomic districts demonstrated that the former had higher air pollution, poorer water quality, and deficient sanitary conditions in addition to sub-optimal mental health services and palliative care.

CONCLUSION

Although important information gaps were identified, the data draw attention to critical public health interventions required in poor health districts, and to motivate for pro-equity policies.

How to assess communication skills? Development of the rating scale ComOn Check

BACKGROUND

Good communication is a core competency for all physicians. Thus, medical students require adequate preparation in communication skills. For research purposes, as well as for evaluation in teaching, there is a clear need for reliable assessment tools. We analyzed the shortcomings of existing instruments and saw a need for a new rating scale. The aim of this publication is to describe the development process for, and evaluation of, a new rating scale.

METHODS

First, we developed the rating scale in 10 steps. Then, two raters evaluated the newly developed rating scale by rating 135 videotaped consultations of medical students with standardized patients. Additionally, standardized patients evaluated students' performance, which was used as an outside criterion to validate ratings.

RESULTS

Our rating scale comprises six domains with 13 specific items evaluated on a five-point Likert scale: initiating conversation, patient's perception, structure of conversation, patient's emotions, end of conversation, and general communication skills. Item-total correlation coefficients between the checklist items ranged from 0.15 to 0.78. Subscale consistency was calculated for domains comprised of more than one item and Cronbach's α ≥ 0.77, indicating acceptable consistency. Standardized patients' global evaluation correlated moderately with overall expert ratings (Spearman's ρ = .40, p < .001).

CONCLUSION

Our rating scale is a reliable and applicable assessment tool. The rating scale focuses on the evaluation of general communication skills and can be applied in research as well as in evaluations, such as objective structured clinical examinations (OSCE).

ABBREVIATIONS

CST: Communication skills training; ICC: Intra-class correlation coefficient; OSCE: Objective structured clinical examination; SP: Standardized patients; SD: Standard deviation; M: Mean.

Association between exploratory activity and social individuality in genetically identical mice living in the same enriched environment

We previously reported that inbred, genetically identical mice living in one enriched environment develop individual behavioral trajectories, indicating increasingly different levels of spatial exploratory behavior as quantified by roaming entropy. Cumulative roaming entropy (cRE) correlated positively with adult hippocampal neurogenesis, a type of plasticity involved in the flexible integration of new information into existing contexts (Freund et al., 2013). The study on which we report here was done in parallel to that first experiment, but here we acquired detailed observational data on the behavior of individual mice. Roaming entropy (RE) was again assessed in real-time with an antenna-based system over the entire experimental period of 3months. Compared to the least active mice in the enclosure (low number of antenna contacts), the most active animals showed tendencies of increased socially interactive behavior in the final observation block whereas least active mice displayed more self-related behavior (non-social local exploration and play). When looking at roaming behavior, we discovered that RE correlated negatively with latent factors representing social exploratory and non-social exploratory and play behavior. Adult neurogenesis could not be studied in the present cohort but we do know that under identical conditions, cumulative RE correlated positively with adult hippocampal neurogenesis. We can thus hypothesize that the mice with more exploratory experience in terms of areal coverage (as quantified by RE) and related greater levels of adult hippocampal plasticity, might also be the ones that were less involved in interactions within the group and, hence, more individualistic. While this remains to be confirmed experimentally, the present data suggest that the described mechanism of individualization, which has previously been shown to be hippocampus-dependent, has a social component.

The effect of high-intensity intermittent exercise on body composition of overweight young males

To determine the effect of a 12-week high intensity intermittent exercise (HIIE) intervention on total body, abdominal, trunk, visceral fat mass, and fat free mass of young overweight males. Participants were randomly assigned to either exercise or control group. The intervention group received HIIE three times per week, 20 min per session, for 12 weeks. Aerobic power improved significantly (P < 0.001) by 15% for the exercising group. Exercisers compared to controls experienced significant weight loss of 1.5 kg (P < 0.005) and a significant reduction in total fat mass of 2 kg (P < 0.001). Abdominal and trunk adiposity was also significantly reduced in the exercising group by 0.1 kg (P < 0.05) and 1.5 kg (P < 0.001). Also the exercise group had a significant (P < 0.01) 17% reduction in visceral fat after 12 weeks of HIIE, whereas waist circumference was significantly decreased by week six (P < 0.001). Fat free mass was significantly increased (P < 0.05) in the exercising group by 0.4 kg for the leg and 0.7 kg for the trunk. No significant change (P > 0.05) occurred in levels of insulin, HOMA-IR, and blood lipids. Twelve weeks of HIIE resulted in significant reductions in total, abdominal, trunk, and visceral fat and significant increases in fat free mass and aerobic power.

A family history of type 2 diabetes increases risk factors associated with overfeeding

AIMS/HYPOTHESIS

The purpose of the study was to test prospectively whether healthy individuals with a family history of type 2 diabetes are more susceptible to adverse metabolic effects during experimental overfeeding.

METHODS

We studied the effects of 3 and 28 days of overfeeding by 5,200 kJ/day in 41 sedentary individuals with and without a family history of type 2 diabetes (FH+ and FH- respectively). Measures included body weight, fat distribution (computed tomography) and insulin sensitivity (hyperinsulinaemic-euglycaemic clamp).

RESULTS

Body weight was increased compared with baseline at 3 and 28 days in both groups (p < 0.001), FH+ individuals having gained significantly more weight than FH- individuals at 28 days (3.4 +/- 1.6 vs 2.2 +/- 1.4 kg, p < 0.05). Fasting serum insulin and C-peptide were increased at 3 and 28 days compared with baseline in both groups, with greater increases in FH+ than in FH- for insulin at +3 and +28 days (p < 0.01) and C-peptide at +28 days (p < 0.05). Fasting glucose also increased at both time points, but without a significant group effect (p = 0.1). Peripheral insulin sensitivity decreased in the whole cohort at +28 days (54.8 +/- 17.7 to 50.3 +/- 15.6 micromol min(-1) [kg fat-free mass](-1), p = 0.03), and insulin sensitivity by HOMA-IR decreased at both time points (p < 0.001) and to a greater extent in FH+ than in FH- (p = 0.008). Liver fat, subcutaneous and visceral fat increased similarly in the two groups (p < 0.001).

CONCLUSIONS

Overfeeding induced weight and fat gain, insulin resistance and hepatic fat deposition in healthy individuals. However, individuals with a family history of type 2 diabetes gained more weight and greater insulin resistance by HOMA-IR. The results of this study suggest that healthy individuals with a family history of type 2 diabetes are predisposed to adverse effects of overfeeding.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00562393

FUNDING

The study was funded by the National Health and Medical Research Council (NHMRC), Australia (no. #427639).

IMMUNIZATION AGAINST MALARIA: VACCINATION OF DUCKS WITH KILLED PARASITES INCORPORATED WITH ADJUVANTS

When ducks are injected with formalin-inactivated P. lophurae in combination with a lanolin-like substance, paraffin oil and killed tubercle bacilli, they develop considerable resistance to subsequent infection with P. lophurae.

THE AGGLUTINATION OF RED BLOOD CELLS

1. Unsensitized sheep cells suspended in sugar solutions are agglutinated by electrolytes whenever the potential is depressed to 6 millivolts or less, except in the case of MgCl(2) or CaCl(2). 2. With these salts no agglutination occurs although there is practically no potential. The presence of these salts prevents acid agglutination. This is presumably due to a decrease in the "cohesion" between the cells. 3. Cells which have been sensitized with specific antibody, ricin, colloidal stannic hydroxide, or paraffin oil, are agglutinated whenever the potential is decreased below about 12 millivolts. 4. The agglutination by electrolytes is therefore primarily due to a decrease in the potential whereas agglutination by immune serum, ricin, etc., is due primarily to an increase in the critical potential.

HEMORRHAGES IN TUBERCULOUS GUINEA PIGS AT THE SITE OF INJECTION OF IRRITANTS FOLLOWING INTRAVASCULAR INJECTIONS OF INJURIOUS SUBSTANCES (SHWARTZMAN PHENOMENON)

1. When toxic filtrates from cultures of B coli, B. typhosus, or meningococci are injected into the blood stream, peritoneal cavity, or subcutaneous tissue of tuberculous guinea pigs, the skin at the site of a tuberculin reaction becomes hemorrhagic. The extent of the hemorrhage is proportional to the severity of the tuberculin reaction demonstrable by tests with various dilutions of tuberculin. 2. Tuberculin does not prepare the skin of non-tuberculous guinea pigs for this hemorrhagic reaction. 3. Tuberculin does not produce an intense or necrotic inflammation in the skin of tuberculous rabbits and fails to prepare the skin for the hemorrhagic reaction. 4. Tuberculin injected into the peritoneal cavities of tuberculous guinea pigs causes a hemorrhage in the skin at the site of a tuberculin reaction. 5. All guinea pigs infected with B.C.G., and most of those infected with a virulent strain of tubercle bacilli, when sensitized to horse serum and injected intracutaneously with 0.1 cc. of horse serum, react with redness, edema, and necrosis; and in some instances the necrosis is preceded by hemorrhage. When horse serum is injected into the skin of these guinea pigs in such dilution that only redness and edema result, the subsequent intravascular injection of typhoid filtrate produces hemorrhage at the site of reaction regularly in those infected with B.C.G. and frequently in those infected with a virulent strain. 6. Filtrates from B. coli, B. typhosus, or meningococci injected into the skin of tuberculous guinea pigs do not produce visible inflammation. When these injections are followed by intravascular injections of the same material hemorrhages do not occur in the skin. 7. When concentrated broth or turpentine is introduced into the skin of tuberculous guinea pigs and later typhoid filtrate is injected into the vascular system, hemorrhages do not occur in the skin at the site of inflammation. 8. The majority of guinea pigs that receive an intravascular injection of typhoid filtrate react with hemorrhage at the site of the injection of the silver nitrate. The incidence of hemorrhagic reaction in tuberculous guinea pigs is higher than in non-tuberculous guinea pigs that received similar injections of silver nitrate and typhoid toxin. 9. In tuberculous guinea pigs the skin can be prepared for the hemorrhagic reaction not only by bacterial toxins but also by tuberculin, horse serum, and an inorganic chemical, silver nitrate. 10. In the guinea pig the skin preparatory agents, i.e. tuberculin in the tuberculous guinea pig, diphtheria toxin and silver nitrate in both tuberculous and non-tuberculous guinea pigs, tend to produce hemorrhages in the skin even without subsequent injection of a toxic bacterial product. This property of the skin preparatory agents may be essential in their action. 11. Hemorrhages occur in the skin at the site of tuberculin reaction not only after the intravascular injection of bacterial toxins or tuberculin, but also after the injection of substances of non-bacterial origin; namely, peptone or soluble starch.

AN EXPERIMENTAL STUDY OF PROTECTIVE INOCULATION WITH HEAT KILLED TUBERCLE BACILLI

Heat killed tubercle bacilli repeatedly injected into or below the skin of rabbits increase conspicuously their resistance against infection with virulent tubercle bacilli. Protection against tuberculous infection following the administration of heat killed tubercle bacilli to rabbits is only slightly less than that given by BCG. Addition of certain antigens, notably heated horse serum, increases the protection given by heat killed tubercle bacilli so that it is approximately the same as that afforded by BCG. These experiments and tentative observations of persons exposed to tuberculous infection indicate that heat killed tubercle bacilli may be substituted for the living attenuated microorganism in the attempt to increase resistance against tuberculous infection and to influence favorably the delicate balance between asymptomatic or latent infection and progressive manifest disease that is characteristic of human tuberculosis.

HYPERSENSITIVENESS AND ANTIBODY FORMATION IN TUBERCULOUS RABBITS

1. Rabbits infected with bovine tubercle bacilli develop hyper-sensitiveness to an intracutaneous injection of tuberculin. This sensitiveness appears from the 2nd to the 6th week after infection and increases rapidly thereafter. Tests, as a rule, show fluctuation in the intensity of the sensitization. Sensitization is followed by an interval of several weeks preceding death during which the animals fail to react. 2. Rabbits infected with bovine tubercle bacilli form antibodies that fix complement in the presence of tubercle bacilli. The antibodies appear after 2 weeks, increase during 6 to 10 weeks, and persist until the animals die. 3. In the later period of infection the skin fails to react to tuberculin at a time when the serum contains complement fixing antibodies.

HEMORRHAGES IN SKIN LESIONS OF GUINEA PIGS FOLLOWING INTRAVASCULAR INJECTION OF TOXINS (SHWARTZMAN PHENOMENON)

1. Filtrates from B. coli, B. typhosus, or meningococci injected into the skin of guinea pigs do not produce visible inflammation. When these injections are followed by intravascular injections of the same material, hemorrhages do not occur in the skin. 2. Guinea pigs sensitized to horse serum react with redness and edema to 0.1 or 0.01 cc. of horse serum injected into the skin, and subsequent intravascular injection of typhoid filtrate does not produce hemorrhage at the site of the reaction to horse serum. 3. When guinea pigs are injected into the skin with diphtheria toxin and these injections are followed by intravascular injection of filtrates from B. typhosus, hemorrhage occurs in the skin at the site of the reaction to diphtheria toxin. 4. When silver nitrate is injected into the skin of guinea pigs, redness, edema, and necrosis follow, and in a few guinea pigs small areas of hemorrhage can also be noticed. About half of the guinea pigs that have received an intravascular injection of typhoid filtrate react with hemorrhage at the site of the injection of silver nitrate.

ACCUMULATION OF ANTIBODIES IN THE CENTRAL NERVOUS SYSTEM

1. Antibodies can be extracted from the brain and spinal cord of rabbits actively or passively immunized with typhoid bacilli. 2. The titers of the antibodies in the extracts of brain and cord depend upon the titer of the blood serum. In actively immunized rabbits the following numerical relationships exist between the titers of the serum and of these organ extracts: The ratio of the titer of the serum is to the titers of extract of brain and of the spinal cord about as 100 is to 0.8; the titer of the serum is to the titer of the cerebrospinal fluid as 100 is to 0.3. In passively immunized rabbits the titer of the serum is to the titer of brain and spinal-cord extract as 100 is to 0.7. 3. The antibodies recovered from the brain are not due to the presence of blood in it for perfusion of the brain does not reduce its antibody content appreciably. 4. Antibodies penetrate into the spinal fluid from the blood even in the absence of inflammation of the meninges. When the penetration is completed the following numerical relationship exists between the titer of the serum and that of the cerebrospinal fluid: 100 to 0.25. 5. The penetration into the cerebrospinal fluid of antibodies injected intravenously proceeds at a slow rate, being completed only several hours after the immune serum has been injected. The penetration of antibodies into the tissue of the brain occurs at a very rapid rate. It is completed within 15 minutes. 6. It is very unlikely that when the immune serum is injected intravenously the antibodies reach the brain tissue by way of the cerebrospinal fluid, for (1) the antibody titer of the cerebrospinal fluid is lower than that of the brain extract, and (2) antibodies penetrate faster into the tissue of the brain than into the cerebrospinal fluid.

ANTIPROTEINS IN HORSE SERA : III. ANTIBODIES TO RABBIT SERUM ALBUMIN AND THEIR REACTION WITH ANTIGEN

1. Two horses were injected subcutaneously with alum-precipitated rabbit serum albumin. 2. The resulting antibody resembled diphtheria antitoxin and anti-egg albumin in the horse in giving a sharp zone of flocculation with antigen, in being water-soluble, in reactivity toward an anti-antibody rabbit serum, and in its electrophoretic properties. 3. The effect of continued immunization, and of variation in volume and temperature on the reactivity of the antibody are discussed. 4. Intravenous injection of the same antigen into horses did not give rise to detectable amounts of antibody of the same type.

ANTIPROTEINS IN HORSE SERA : IV. ANTIBODIES TO RABBIT SERUM GLOBULIN AND THEIR INTERACTION WITH ANTIGEN

1. The intravenous injection of two horses with alum-precipitated rabbit serum globulin resulted in the production of antibody which gave a typical precipitin reaction without a prezone in the region of antibody excess. 2. The chemical, physical, and serological properties of this antibody are comparable to those of the more familiar anticarbohydrate antibodies. 3. The subcutaneous injection of horses with the globulin antigen gave rise to low grade "univalent" antibody which did not precipitate with soluble antigen. 4. The low grade antibody could be removed from solution by attachment to preformed specific precipitates, or by coprecipitation in the presence of "multivalent" precipitating antibody. 5. It is concluded that the familiar antitoxin type of antibody is not the only form of antiprotein response in horses but that precipitating and low grade non-precipitating antibodies may also be formed. 6. The nature of the antigen and the route of injection are demonstrated to be important factors in determining the characteristics of the antibody formed.

TOXIN-ANTITOXIN REACTION WITHOUT NEUTRALIZATION

1. Collodion particles adsorb diphtheria or tetanus or botulinus toxins. These toxins are retained on the particles when washed but are at least in part released in the animal. 2. The adsorbed toxins are neutralized by adsorption of the corresponding antitoxins but are unaffected by other serums. 3. When collodion particles are treated first with tetanus antitoxin, then with diphtheria toxin, they are not toxic, but they become toxic when they are treated first with diphtheria antitoxin, then with the diphtheria toxin. Similarly when collodion particles are treated first with diphtheria antitoxin and then with tetanus toxin, they do not become toxic, but they become toxic when they are treated with tetanus antitoxin and tetanus toxin.

REACTION OF YOUNG AND ADULT RABBITS TO PNEUMOCOCCI INJECTED INTO THE SKIN

1. Young and adult rabbits react differently to intracutaneous injection of virulent pneumococci. In adult rabbits a very extensive inflammation develops at the site of infection and bacteriemia and death occur only in a relatively few rabbits. Young rabbits fail to develop extensive inflammation and die with bacteriemia. 2. It is probable that the fate of the animals is influenced by the capacity to develop inflammation at the site of injection of pneumococci.

SENSITIZATION AND ANTIBODY FORMATION WITH INCREASED RESISTANCE TO TUBERCULOUS INFECTION INDUCED BY HEAT KILLED TUBERCLE BACILLI

Rabbits (and human beings) differ widely in the rapidity with which they undergo sensitization with heat killed tubercle bacilli, but after repeated injections all animals become sensitized. Intracutaneous injection of a small quantity of heat killed tubercle bacilli into a previously normal animal produces a nodule which persists from 8 to 12 weeks; the same injection into well sensitized animals produces a lesion which ulcerates within from 1 to 3 weeks and is completely healed after about 5 weeks. Complete healing is functional evidence of the disappearance of the antigen. Intracutaneous injection of heat killed tubercle bacilli induces more rapid sensitization than subcutaneous or intravenous injection, but after repeated injections the difference disappears. Increasing quantities of heat killed tubercle bacilli or the same quantity divided into several simultaneous injections accelerates sensitization. The rapidity of antibody formation measured by complement fixation varies in different rabbits under the same conditions but complement fixation is always demonstrable after repeated injections of heat killed tubercle bacilli. Antibody formation is more rapid and reaches higher titers with intravenous than with intracutaneous or with subcutaneous injections. It is accelerated by division of the injected antigen into multiple simultaneous injections. Small quantities of BCG induce rapid sensitization and more abundant antibody formation measured by complement fixation than heat killed tubercle bacilli but with repeated injections the difference disappears. Animals that are sensitized and immunized (allergic) before infection are in most instances more resistant to infection than previously normal animals, but there is no correlation between the intensity of sensitization or the titer of antibodies, on the one hand, and resistance to infection on the other. A previously normal animal subjected to infection differs essentially from a sensitized and immunized animal during the first few weeks of infection when sensitization and immunity are developing as the result of infection, but subsequently the progress of sensitization and antibody formation measured by the means at our disposal follows for a time the same course in both. Sensitization diminishes and in most instances disappears, whereas the titer of complement fixation remains elevated. When infection pursues a fatal course sensitization permanently disappears, but in animals that proceed toward recovery sensitization measured by injection of tuberculin into the skin repeatedly diminishes, usually to complete disappearance, and then increases in successive waves which tend to diminish in height with recovery from infection. The titer of complement fixation gradually diminishes with recovery from infection. It is probable that the skin test for sensitization and complement fixation applied to the blood serum measure antibodies or other factors determining sensitization and immunity that are in excess of those actively concerned in the maintenance of resistance.

Fat oxidation, body composition and insulin sensitivity in diabetic and normoglycaemic obese adults 5 years after weight loss

OBJECTIVE

To investigate whether normal glucose-tolerant and type II diabetic overweight adults differ in response to weight regain with regard to substrate oxidation and metabolic parameters.

METHODS

A total of 15 overweight-obese subjects: seven normal glucose tolerant (NGT) and eight with type II diabetes (DM) were restudied 5 y after significant weight loss. Prediet, after 28 days calorie restriction and at 5 y, subjects were characterised for weight, height, waist-to-hip ratio (WHR) and body composition by dual-energy X-ray absorptiometry. Fasting glucose, insulin, leptin and lipid levels were measured and subjects underwent euglycaemic-hyperinsulinaemic clamp (insulin 0.25 U/kg/h for 150 min). Indirect calorimetry was performed resting and in the final 30 min of the clamp. Dietary assessment was by 4-day diet-diary.

RESULTS

Both NGT and DM groups regained weight at 5 y and were not different to prediet. Total body fat (%) and WHR were higher at 5 y compared to prediet in both groups. Fasting glucose was increased in NGT subjects at 5 y, and fasting insulin was higher in both groups at 5 y compared to prediet. Insulin sensitivity (GIR) was similar at 5 y compared to prediet, but at 5 y DM subjects were more insulin resistant than NGT subjects. At 5 y, both DM and NGT groups had significantly reduced basal fat oxidation and no significant suppression of fat oxidation with insulin. Clamp respiratory quotient levels at 5 y were significantly higher in NGT compared to DM subjects.

CONCLUSION

Reduced basal fat oxidation, and reduced variation in substrate oxidation in response to insulin develop with fat regain and fasting hyperinsulinaemia in both NGT and DM obese adults.

Analysis of gene expression in carbon tetrachloride-treated rat livers using a novel bioarray technology

The present study successfully utilizes a new ADME Rat Expression Bioarray, containing 1040 metabolism- and toxicology-linked genes, to monitor gene expression from the livers of rats treated with carbon tetrachloride (CCl(4)). Histopathological analysis, hierarchical clustering methods, and gene expression profiling are compared between the control and CCl(4)-treated animals. A total of 44 transcripts were found to be altered in response to the hepatotoxin, 19 of which were upregulated and 25 were downregulated. Some of these gene expression changes were expected and concurred with previously published data while others were novel findings.

BMI inaccurately reflects total body and abdominal fat in Tongans

It has been noted since the earliest European contact that Polynesian body shape and size differ from those of Europeans. The muscular build of Polynesians, such as Tongans, raises questions as to the accuracy of simple anthropometric indicators, validated for use in European populations, in Polynesians. Body mass index (BMI), total body fat and an abdominal fat window were measured in a sample of Tongan [28 male (M), 28 female (F)] and Australian Caucasian adults (39 M, 46 F), with standard anthropometric and densitometric methods. Tongan males (BMI, 32.8+/-4.6 kg/m(2)) were heavier than Australian males (BMI, 27.1+/-3.7 kg/m(2)); but differences in total body percent fat (28.9+/-8.3 vs. 25.9+/-8.1, p=0.15), abdominal fat (1.84+/-0.69 vs. 1.55+/-0.60 kg, p=0.07) and abdominal percent fat (30.3+/-8.6 vs. 28.5+/-8.3, p=0.40) were non-significant. Tongan females (BMI, 34.3+/-5.5 kg/m(2)) were also heavier than their Australian counterparts (BMI, 26.2+/-6.3 kg/m(2)); with the difference in total body percent fat (41.9+/-5.2 vs. 38.7+/-8.9, p=0.05) and abdominal percent fat (39.3+/-4.8 vs. 33.6+/-8.9, p=0.001) less than expected, given the difference in BMI. This study demonstrates significant body composition variations between Tongans and Caucasians.

First in vivo optical coherence tomography in the human bile duct

BACKGROUND AND STUDY AIMS

Optical coherence tomography (OCT) is a novel technique for performing high-resolution, cross-sectional tomographic imaging in human tissue, which allows resolution of up to 10 microm. The short depth of penetration allows assessment of the superficial 2 mm of the gastrointestinal tract, an area that is difficult to appraise even with high-frequency ultrasound. This is the first report on in vivo OCT of the human biliary system. The aim was to assess the feasibility of the technique.

PATIENTS AND METHODS

Four cases of intraductal OCT are presented. The probe was inserted through the working channel of a duodenoscope.

RESULTS

The connective tissue layer and the underlying retroperitoneal tissue, with less backscattering, could be clearly demonstrated. The images showed a layer architecture which was similar to that found histologically.

CONCLUSIONS

OCT of the biliary system is feasible in patients with biliary pathology. Interpretable images were obtained, and clinical use needs further assessment. As current OCT probes and processors do not yet provide optimal resolution, further generations of equipment with improved image quality are required.

Coincidence detection FDG PET in the management of oncological patients: attenuation correction versus non-attenuation correction

The aim of this study was to determine if attenuation correction (AC) in a dual-head, coincidence, positron emission tomography imaging system (Co-PET) improved image quality, lesion detection, patient staging and management of various malignant neoplasms, compared to non-attenuation corrected (NAC) images. Thirty patients with known or suspected malignant neoplasms underwent fluorodeoxyglucose (FDG) Co-PET, which was correlated with histopathology, computed tomography (CT) and other conventional imaging modalities and clinical follow-up. The number and location of FDG avid lesions detected on the AC images and NAC Co-PET images were blindly assessed by two independent observers. Semi-quantitative grading of image clarity and lesion-to-background quality was performed. This revealed markedly improved image clarity and lesion-to-background quality in the AC versus NAC Co-PET images. AC Co-PET was statistically superior to NAC Co-PET in relation to lesion detection (P<0.01) and tumour staging (P<0.01). NAC Co-PET demonstrated 51 of the 65 lesions (78%) detected by AC Co-PET. AC Co-PET altered tumour staging in five additional patients (16%) compared to NAC Co-PET. Management was altered in two of these five patients.

A dynamic model of the forearm including fatigue

A biomechanical model of the forearm, consisting of 61 muscle-tendon systems or tendons and 8 sections, is presented. The model can be used to calculate the muscle forces when resultant of the external forces and the motion is known. Calculations are based on constraints of muscle forces, joint forces, contact forces, and tendon junctions, and a load sharing principle telling which of the feasible solutions are likely and which are not. Fatigue is accounted for by updating the upper limits of the muscle forces according to the loading history. As an example, the model is used to predict the load sharing between the fingers when they are pressed against a table with a given total force.