Medication regimens using conditioning via variable reinforcement have shown similar or improved therapeutic effects as full pharmacological treatment, but evidence in patient populations is scarce... Show moreMedication regimens using conditioning via variable reinforcement have shown similar or improved therapeutic effects as full pharmacological treatment, but evidence in patient populations is scarce. This proof-of-principle double-blind randomized clinical trial examined whether treatment effects in recent-onset rheumatoid arthritis (RA) can be optimized through pharmacological conditioning. After four months of standardized treatment (n = 46), patients in clinical remission (n = 19) were randomized to the Control group (C), continuing standardized treatment (n = 8), or the Pharmacological Conditioning (PC) group, receiving variable treatment according to conditioning principles (n = 11). After eight months, treatment was tapered and discontinued linearly (C) or variably (PC). Standard treatment led to large improvements in disease activity and HRQoL in both groups. The groups did not differ in the percentage of drug-free clinical remission obtained after conditioning or continued standard treatment. The PC group did show a larger decrease in self-reported disease activity (Cohen's d = 0.9) and a smaller increase in TNF-alpha levels (Cohen's d = 0.7) than the C group. During all phases, more differences between groups were found for the patients who followed protocol than for the intention-to-treat sample. Although the results are not conclusive, pharmacological conditioning may have some advantages in terms of disease progression and stability, especially during the conditioning phase, compared with standard clinical treatment. The effects may be particularly beneficial for patients who show a good initial response to increased medication dosages. Show less
Objectives:The current paper explores the psychological predictors of nocebo hyperalgesia and whether the reduction of nocebo hyperalgesia can be predicted by susceptibility to nocebo hyperalgesia... Show moreObjectives:The current paper explores the psychological predictors of nocebo hyperalgesia and whether the reduction of nocebo hyperalgesia can be predicted by susceptibility to nocebo hyperalgesia and psychological characteristics. Methods:Nocebo effects on pressure pain were first experimentally induced in 83 healthy female participants through conditioning with open-label instructions about the pain-worsening function of a sham TENS device to assess susceptibility to nocebo hyperalgesia. Participants were then randomized to 1 out of 2 nocebo-reduction conditions (counterconditioning/extinction) or to continued nocebo-conditioning (control), each combined with open-label instructions about the new sham device function. Dispositional optimism, trait and state anxiety, pain catastrophizing, fear of pain, and body vigilance were assessed at baseline. Results:The results showed that lower optimism and higher trait anxiety were related to a stronger induction of nocebo hyperalgesia. Moreover, a stronger induction of nocebo hyperalgesia and higher trait anxiety predicted a larger nocebo reduction across interventions. Also, nocebo hyperalgesia and optimism moderated the effects of the nocebo-reduction interventions, whereby larger nocebo hyperalgesia and lower optimism were associated with a larger nocebo reduction after counterconditioning, compared with control, and also extinction for larger nocebo hyperalgesia. Discussion:Our findings suggest that open-label conditioning leads to stronger nocebo hyperalgesia when trait anxiety is high and dispositional optimism is low, while these psychological characteristics, along with larger nocebo hyperalgesia, also predict open-label counterconditioning to be an effective nocebo-reduction strategy. Susceptibility to nocebo hyperalgesia, trait anxiety, and dispositional optimism might be indicators of a flexible pain regulatory system. Show less
Cardol, C.K.; Middendorp, H. van; Dusseldorp, E.; Boog, P.J.M. van der; Hilbrands, L.B.; Navis, G.; ... ; E GOAL Study Grp 2023
Objective: Psychological distress is common among patients with chronic kidney disease and can interfere with disease self-management. We assessed the effectiveness of the personalized E-GOAL... Show moreObjective: Psychological distress is common among patients with chronic kidney disease and can interfere with disease self-management. We assessed the effectiveness of the personalized E-GOAL electronic health care pathway with screening and cognitive-behavioral therapy including self-management support, aimed to treat psychological distress and facilitate self-management among people with chronic kidney disease not on dialysis (N = 121). Methods: Primary outcome of the open two-arm parallel randomized controlled trial in four Dutch hospitals was psychological distress at posttest directly after the intervention and at 3-month follow-up. Secondary outcomes were physical and mental health-related quality of life, self-efficacy, chronic disease self-management, and personalized outcomes, that is, perceived progress compared with the previous time point on functioning (e.g., mood or social functioning) and self-management (e.g., dietary or medication adherence) outcomes that were prioritized by each individual. Results: Linear mixed-effects analyses showed no significant time-by-group interaction effects for psychological distress, health-related quality of life, self-efficacy, and chronic condition self-management, whereas analyses of covariance showed significantly more perceived progress in the intervention group at posttest on personally prioritized areas of functioning (b = 0.46, 95% confidence interval = 0.07-0.85) and self-management (b = 0.55, 95% confidence interval = 0.16-0.95), with Cohen d values of 0.46 and 0.54 (medium effects), respectively. Effects on personalized outcomes were maintained at follow-up. Conclusions: Compared with regular care only, the electronic health intervention did not reduce psychological distress, whereas personalized outcomes did improve significantly after intervention. Future studies could consider personalized outcomes that reflect individually relevant areas and treatment goals, matching person-tailored treatments. Show less
Pratiwi Bunga, C.; Dusseldorp, E.; Karch, J.D.; de Rooij, M. 2023
Moderation analysis is an integral part of precision medicine research. Concerning moderation analysis with categorical outcomes, we start with an interesting observation, which shows that... Show moreModeration analysis is an integral part of precision medicine research. Concerning moderation analysis with categorical outcomes, we start with an interesting observation, which shows that heterogeneous treatment effects could be equivalently estimated via a role exchange between the outcome and the treatment variable in logistic regression models. Hence two estimators of moderating effects can be obtained. We then established the joint asymptotic normality for the two estimators, on which basis refined inference can be made for moderation analysis. The improved precision is helpful in addressing the lack-of-power problem that is common in search of moderators. The above-mentioned results hold for both experimental and observational data. We investigate the proposed method by simulation and provide an illustration with data from a randomized trial on wart treatment. Show less
Witlox, M.; Garnefski, N.; Kraaij, V.; Simou, M.; Dusseldorp, E.; Bohlmeijer, E.; Spinhoven, P. 2021
This systematic review and meta-analysis compared prevalence rates for subthreshold anxiety and anxiety disorders in adults aged 55 degrees and examined if these rates were associated with age. A... Show moreThis systematic review and meta-analysis compared prevalence rates for subthreshold anxiety and anxiety disorders in adults aged 55 degrees and examined if these rates were associated with age. A systematic search and screening procedure resulted in 46 included articles. First, prevalence rates for subthreshold anxiety and anxiety disorders were statistically compared. Subthreshold panic, generalized anxiety and specific phobia were significantly more prevalent than the corresponding clinical disorders. In general, subthreshold anxiety appeared to be at least similarly prevalent to anxiety disorders, although firm conclusions are precluded due to the small number of samples that could be included in the analyses and the large heterogeneity between the reported prevalence rates. Second, using subgroup analyses, pooled prevalence rates for four age groups of older adults (55-64, 65-74, 75-84, 85 degrees) were compared. For specific phobia, the 75-84 and 85 degrees groups had significantly lower prevalence rates than the 55-64 and 65-74 groups. Posttraumatic stress disorder was significantly more prevalent in the 55-64 group than in the other age groups, and lowest in the 85 degrees group. No other significant differences between age groups were found. The association between later life subthreshold anxiety and age could not be examined due to a lack of reported information. The main limitation of this study is the small number of samples in the analyses, which limits their power and generalizability. Show less
Witlox, M.; Garnefski, N.; Kraaij, V.; Simou, M.; Dusseldorp, E.; Bohlmeijer, E.; Spinhoven, P. 2021
This systematic review and meta-analysis compared prevalence rates for subthreshold anxiety and anxiety disorders in adults aged 55 degrees and examined if these rates were associated with age. A... Show moreThis systematic review and meta-analysis compared prevalence rates for subthreshold anxiety and anxiety disorders in adults aged 55 degrees and examined if these rates were associated with age. A systematic search and screening procedure resulted in 46 included articles. First, prevalence rates for subthreshold anxiety and anxiety disorders were statistically compared. Subthreshold panic, generalized anxiety and specific phobia were significantly more prevalent than the corresponding clinical disorders. In general, subthreshold anxiety appeared to be at least similarly prevalent to anxiety disorders, although firm conclusions are precluded due to the small number of samples that could be included in the analyses and the large heterogeneity between the reported prevalence rates. Second, using subgroup analyses, pooled prevalence rates for four age groups of older adults (55-64, 65-74, 75-84, 85 degrees) were compared. For specific phobia, the 75-84 and 85 degrees groups had significantly lower prevalence rates than the 55-64 and 65-74 groups. Posttraumatic stress disorder was significantly more prevalent in the 55-64 group than in the other age groups, and lowest in the 85 degrees group. No other significant differences between age groups were found. The association between later life subthreshold anxiety and age could not be examined due to a lack of reported information. The main limitation of this study is the small number of samples in the analyses, which limits their power and generalizability. Show less
Ter Avest, M.J.; Dusseldorp, E.; Huijbers, M.J.; Van Aalderen, J.R.; Cladder-Micus, M.B.; Spinhoven, P.; ... ; Speckens, A.E.M. 2019
Aim: To identify moderators of treatment effect for Mindfulness-Based Cognitive Therapy (MBCT) versus Treatment As Usual (TAU) in depressed patients.Methods: An individual patient data-analysis was... Show moreAim: To identify moderators of treatment effect for Mindfulness-Based Cognitive Therapy (MBCT) versus Treatment As Usual (TAU) in depressed patients.Methods: An individual patient data-analysis was performed on three randomized-controlled trials, investigating the effect of MBCT + TAU versus TAU alone (N = 292). Patients were either in (partial) remission, currently depressed or had chronic, treatment-resistant depression. Outcomes were depressive symptoms and quality of life. The Qualitative INteraction Trees (QUINT) method was used to identify subgroups that benefited more from either condition.Results: MBCT + TAU outperformed TAU in reducing depressive symptoms. For both conditions, the effect of baseline depressive symptoms on post-treatment depressive symptoms was curvilinear. QUINT analyses revealed that MBCT + TAU was more beneficial than TAU for patients with an earlier onset and higher rumination levels in terms of depressive symptom reduction and for patients with a lower quality of life in terms of improving quality of life.Conclusions: The results suggest that MBCT might be more beneficial for those with earlier onset and higher levels of rumination and for patients with a lower quality of life. Sophisticated analytical techniques such as QUINT can be used in future research to improve personalized assignment of MBCT to patients. Long-term outcome could also be integrated in this. Show less
In meta‐analytic studies, there are often multiple moderators available (eg, study characteristics). In such cases, traditional meta‐analysis methods often lack sufficient power to investigate... Show moreIn meta‐analytic studies, there are often multiple moderators available (eg, study characteristics). In such cases, traditional meta‐analysis methods often lack sufficient power to investigate interaction effects between moderators, especially high‐order interactions. To overcome this problem, meta‐CART was proposed: an approach that applies classification and regression trees (CART) to identify interactions, and then subgroup meta‐analysis to test the significance of moderator effects. The aim of this study is to improve meta‐CART upon two aspects: 1) to integrate the two steps of the approach into one and 2) to consistently take into account the fixed‐effect or random‐effects assumption in both the the interaction identification and testing process. For fixed effect meta‐CART, weights are applied, and subgroup analysis is adapted. For random effects meta‐CART, a new algorithm has been developed. The performance of the improved meta‐CART was investigated via an extensive simulation study on different types of moderator variables (ie, dichotomous, nominal, ordinal, and continuous variables). The simulation results revealed that the new method can achieve satisfactory performance (power greater than 0.80 and Type I error less than 0.05) if appropriate pruning rule is applied and the number of studies is large enough. The required minimum number of studies ranges from 40 to 120 depending on the complexity and strength of the interaction effects, the within‐study sample size, the type of moderators, and the residual heterogeneity. Show less
BackgroundSupport staff of adults with intellectual disability (ID) play an important role in promoting independence in home and community settings. However, little is known about the types of... Show moreBackgroundSupport staff of adults with intellectual disability (ID) play an important role in promoting independence in home and community settings. However, little is known about the types of behaviours staff should use to promote independence and instruments that assess such behaviour do not yet exist. The aim of this study was therefore to develop and initially validate a reliable questionnaire that measures the degree to which support staff display behaviours that promote independence in people with ID. MethodThe Leiden Independence Questionnaire for Support Staff (LIQSS) was constructed to measure the extent to which support staff promote independence in people with ID. The LIQSS was completed by 142 staff members working with people with ID. For the psychometric evaluation of the LIQSS, a principal component analysis was performed with an oblique rotation in all items. Next, the principal component analysis was performed with a forced three‐component extraction, and three sub‐scales were computed. To assess internal consistency, Cronbach's α was calculated for each of the sub‐scales. ResultsThe LIQSS was found to consist of three internally consistent (Cronbach's α was respectively 0.92, 0.79 and 0.76) and meaningful components: (1) communication, agreements and coordination; (2) positive encouragement and tailoring; and (3) supporting independent performance. The final 22 items had factor loadings between 0.44 and 0.91 on their corresponding component and a minimal difference in loading to the other factors of 0.20. ConclusionsThe LIQSS appears to be an instrument with positive face validity and reliability (internal consistency) that assesses the degree to which support staff promote independence in people with ID. To increase the instrument's value for both scientific research and clinical practice, studies should focus on the further validation of the LIQSS. Show less
PurposeHealthy eating, physical activity and smoking interventions for low-income groups may have small, positive effects. Identifying effective intervention components could guide intervention... Show morePurposeHealthy eating, physical activity and smoking interventions for low-income groups may have small, positive effects. Identifying effective intervention components could guide intervention development. This study investigated which content and delivery components of interventions were associated with increased healthy behavior in randomised controlled trials (RCTs) for low-income adults.MethodData from a review showing intervention effects in 35 RCTs containing 45 interventions with 17,000 participants were analysed to assess associations with behavior change techniques (BCTs) and delivery/context components from the template for intervention description and replication (TIDieR) checklist. The associations of 46 BCTs and 14 delivery/context components with behavior change (measures of healthy eating, physical activity and smoking cessation) were examined using random effects subgroup meta-analyses. Synergistic effects of components were examined using classification and regression trees (meta-CART) analyses based on both fixed and random effects assumptions.ResultsFor healthy eating, self-monitoring, delivery through personal contact, and targeting multiple behaviors were associated with increased effectiveness. Providing feedback, information about emotional consequences, or using prompts and cues were associated with reduced effectiveness. In synergistic analyses, interventions were most effective without feedback, or with self-monitoring excluding feedback. More effective physical activity interventions included behavioral practice/rehearsal or instruction, focussed solely on physical activity or took place in home/community settings. Information about antecedents was associated with reduced effectiveness. In synergistic analyses, interventions were most effective in home/community settings with instruction. No associations were identified for smoking.ConclusionThis study identified BCTs and delivery/context components, individually and synergistically, linked to increased and reduced effectiveness of healthy eating and physical activity interventions. The identified components should be subject to further experimental study to help inform the development effective behavior change interventions for low-income groups to reduce health inequalities. Show less
Luenen, S. van; Garnefski, N.; Spinhoven, P.; Spaan, P.; Dusseldorp, E.; Kraaij, V. 2018
