Optimizing placebo effects in medical contexts: utilizing learning theories and exploring communication strategies

This dissertation covered several relevant cycles of placebo research with the main aim to optimize placebo effects in medical contexts. Firstly, a literature review described how the immune system can be impacted by placebo effects and their underlying learning theories. In the following chapter, these learning theories were integrated to form an optimal research design by means of pharmacological conditioning to fit a specific patient group: children with juvenile idiopathic arthritis. Secondly, this dissertation focused on developing placebo information strategies to harness placebo beliefs and educate persons about the relevancy of placebo effects in practice. These insights are valuable because treatment expectations can have a positive or negative effect on treatment outcomes. Finally, insights from placebo learning theories and placebo information strategies were combined in an integrative experimental research design. This research design employed a more ethical form of placebo use because participants were made aware of placebos, called open-label placebos. In this last study we demonstrated that open-label placebo analgesia can be induced by combining learning theories and placebo information strategies. Altogether, this dissertation provided insights in learning mechanisms, communication strategies, and research paradigms that involve the optimization of placebo effects in medical context.Health and self-regulatio

Pharmacological conditioning for juvenile idiopathic arthritis: a potential solution to reduce methotrexate intolerance

Background Methotrexate (MTX) therapy has proven to be a successful and safe treatment for Juvenile Idiopathic Arthritis (JIA). Despite the high efficacy rates of MTX, treatment outcomes are often complicated by burdensome gastro-intestinal side effects. Intolerance rates for MTX in children are high (approximately 50%) and thus far no conclusive effective treatment strategies to control for side effects have been found. To address this need, this article proposes an innovative research approach based on pharmacological conditioning, to reduce MTX intolerance. Presentation of the hypothesis A collaboration between medical psychologists, pediatric rheumatologists, pharmacologists and patient groups was set up to develop an innovative research design that may be implemented to study potential improved control of side effects in JIA, by making use of the psychobiological principles of pharmacological conditioning. In pharmacological conditioning designs, learned positive associations from drug therapies (conditioning effects) are integrated in regular treatment regimens to maximize treatment outcomes. Medication regimens with immunosuppressant drugs that made use of pharmacological conditioning principles have been shown to lead to optimized therapeutic effects with reduced drug dosing, which might ultimately cause a reduction in side effects. Testing the hypothesis This research design is tailored to serve the needs of the JIA patient group. We developed a research design in collaboration with an interdisciplinary research group consisting of patient representatives, pediatric rheumatologists, pharmacologists, and medical psychologists

Pharmacological conditioning for juvenile idiopathic arthritis: a potential solution to reduce methotrexate intolerance

Background Methotrexate (MTX) therapy has proven to be a successful and safe treatment for Juvenile Idiopathic Arthritis (JIA). Despite the high efficacy rates of MTX, treatment outcomes are often complicated by burdensome gastro-intestinal side effects. Intolerance rates for MTX in children are high (approximately 50%) and thus far no conclusive effective treatment strategies to control for side effects have been found. To address this need, this article proposes an innovative research approach based on pharmacological conditioning, to reduce MTX intolerance. Presentation of the hypothesis A collaboration between medical psychologists, pediatric rheumatologists, pharmacologists and patient groups was set up to develop an innovative research design that may be implemented to study potential improved control of side effects in JIA, by making use of the psychobiological principles of pharmacological conditioning. In pharmacological conditioning designs, learned positive associations from drug therapies (conditioning effects) are integrated in regular treatment regimens to maximize treatment outcomes. Medication regimens with immunosuppressant drugs that made use of pharmacological conditioning principles have been shown to lead to optimized therapeutic effects with reduced drug dosing, which might ultimately cause a reduction in side effects. Testing the hypothesis This research design is tailored to serve the needs of the JIA patient group. We developed a research design in collaboration with an interdisciplinary research group consisting of patient representatives, pediatric rheumatologists, pharmacologists, and medical psychologists

Pharmacological conditioning for juvenile idiopathic arthritis: a potential solution to reduce methotrexate intolerance

Background Methotrexate (MTX) therapy has proven to be a successful and safe treatment for Juvenile Idiopathic Arthritis (JIA). Despite the high efficacy rates of MTX, treatment outcomes are often complicated by burdensome gastro-intestinal side effects. Intolerance rates for MTX in children are high (approximately 50%) and thus far no conclusive effective treatment strategies to control for side effects have been found. To address this need, this article proposes an innovative research approach based on pharmacological conditioning, to reduce MTX intolerance. Presentation of the hypothesis A collaboration between medical psychologists, pediatric rheumatologists, pharmacologists and patient groups was set up to develop an innovative research design that may be implemented to study potential improved control of side effects in JIA, by making use of the psychobiological principles of pharmacological conditioning. In pharmacological conditioning designs, learned positive associations from drug therapies (conditioning effects) are integrated in regular treatment regimens to maximize treatment outcomes. Medication regimens with immunosuppressant drugs that made use of pharmacological conditioning principles have been shown to lead to optimized therapeutic effects with reduced drug dosing, which might ultimately cause a reduction in side effects. Testing the hypothesis This research design is tailored to serve the needs of the JIA patient group. We developed a research design in collaboration with an interdisciplinary research group consisting of patient representatives, pediatric rheumatologists, pharmacologists, and medical psychologists

Pharmacological conditioning for juvenile idiopathic arthritis: a potential solution to reduce methotrexate intolerance

Background Methotrexate (MTX) therapy has proven to be a successful and safe treatment for Juvenile Idiopathic Arthritis (JIA). Despite the high efficacy rates of MTX, treatment outcomes are often complicated by burdensome gastro-intestinal side effects. Intolerance rates for MTX in children are high (approximately 50%) and thus far no conclusive effective treatment strategies to control for side effects have been found. To address this need, this article proposes an innovative research approach based on pharmacological conditioning, to reduce MTX intolerance. Presentation of the hypothesis A collaboration between medical psychologists, pediatric rheumatologists, pharmacologists and patient groups was set up to develop an innovative research design that may be implemented to study potential improved control of side effects in JIA, by making use of the psychobiological principles of pharmacological conditioning. In pharmacological conditioning designs, learned positive associations from drug therapies (conditioning effects) are integrated in regular treatment regimens to maximize treatment outcomes. Medication regimens with immunosuppressant drugs that made use of pharmacological conditioning principles have been shown to lead to optimized therapeutic effects with reduced drug dosing, which might ultimately cause a reduction in side effects. Testing the hypothesis This research design is tailored to serve the needs of the JIA patient group. We developed a research design in collaboration with an interdisciplinary research group consisting of patient representatives, pediatric rheumatologists, pharmacologists, and medical psychologists

Entebbe Mother and Baby Study - Data at one year

Dataset and supporting documentation collected as part of the Entebbe Mother and Baby Study (EMaBS), a clinical trial that investigated potential benefits of treating worm infections during pregnancy and early childhood. The dataset contains variables collected from mothers (at registration) and infants (when the child was one-year of age), including maternal age, education, parity and infection status (malaria, S. mansoni, hookworm, filariasis), and infant sex and immune responses (to HiB, diphtheria, Hepatitis B, pertussis, FHA, pertactin)

Neonatal critical illness and development: white matter and hippocampus alterations in school-age neonatal ECMO survivors

Aim: Examine the neurobiology of long-term neuropsychological deficits following neonatal extracorporeal membrane oxygenation (ECMO). Method: This cross-sectional study assessed white matter integrity and hippocampal volume of ECMO survivors (8-15yrs) and healthy controls (8-17yrs) using Diffusion Tensor Imaging and structural MRI, respectively. Neuropsychological outcome was evaluated in patients. Included clinical predictors of white matter integrity: age start ECMO, ECMO duration, highest oxygenation index before ECMO, highest mean airway pressure and mechanical ventilation duration. Results: Patients (n=23) had lower global fractional anisotropy than controls (n=54)(patients=.368; controls=.381; p=.02), but similar global mean diffusivity (p=.41). Patients had lower fractional anisotropy in the left cingulum bundle (patients=.345; controls=.399; p<.001) and higher mean diffusivity in a region of the left parahippocampal cingulum (patients=.916; controls=.871; p<.001). Higher global mean diffusivity predicted worse verbal memory in patients (n=17)(β=-.74, p=.01). Patients (n=23) had smaller bilateral hippocampal volume than controls (n=43)(left: p< .001; right: p< .001). In patients, this was related to worse verbal memory (left: β=.65, p=.02; right: β=.71, p=.01). Interpretation: Neonatal ECMO survivors are at risk for long-term brain alterations, which may partly explain long-term neuropsychological impairments. Neuroimaging may contribute to better risk stratification of long-term impairments

External validation and updating of prediction models for estimating the 1-year risk of low health-related quality of life in colorectal cancer survivors

Objectives Timely identification of colorectal cancer (CRC) survivors at risk of experiencing low health-related quality of life (HRQoL) in the near future is important for enabling appropriately tailored preventive actions. We previously developed and internally validated risk prediction models to estimate the 1-year risk of low HRQoL in long-term CRC survivors. In this article, we aim to externally validate and update these models in a population of short-term CRC survivors. Study Design and Setting In a pooled cohort of 1,596 CRC survivors, seven HRQoL domains (global QoL, cognitive/emotional/physical/role/social functioning, and fatigue) were measured prospectively at approximately 5 months postdiagnosis (baseline for prediction) and approximately 1 year later by a validated patient-reported outcome measure (European Organization for Research and Treatment of Cancer Quality of life Questionnaire–Core 30). For each HRQoL domain, 1-year scores were dichotomized into low vs. normal/high HRQoL. Performance of the previously developed multivariable logistic prediction models was evaluated (calibration and discrimination). Models were updated to create a more parsimonious predictor set for all HRQoL domains. Results Updated models showed good calibration and discrimination (AUC ≥0.75), containing a single set of 15 predictors, including nonmodifiable (age, sex, education, time since diagnosis, chemotherapy, radiotherapy, stoma, and comorbidities) and modifiable predictors (body mass index, physical activity, smoking, anxiety/depression, and baseline fatigue and HRQoL domain scores). Conclusion Externally validated and updated prediction models performed well for estimating the 1-year risk of low HRQoL in CRC survivors within 6 months postdiagnosis. The impact of implementing the models in oncology practice to improve HRQoL outcomes in CRC survivors needs to be evaluated