Heike Gerger

Researcher allegiance in psychotherapy outcome research: An overview of reviews

Researcher allegiance (RA) is widely discussed as a risk of bias in psychotherapy outcome research. The relevance attached to RA bias is related to meta-analyses demonstrating an association of RA with treatment effects. However, recent meta-analyses have yielded mixed results. To provide more clarity on the magnitude and robustness of the RA-outcome association this article reports on a meta-meta-analysis summarizing all available meta-analytic estimates of the RA-outcome association. Random-effects methods were used. Primary study overlap was controlled. Thirty meta-analyses were included. The mean RA-outcome association was r=.262 (p=.002, I(2)=28.98%), corresponding to a moderate effect size. The RA-outcome association was robust across several moderating variables including characteristics of treatment, population, and the type of RA assessment. Allegiance towards the RA bias hypothesis moderated the RA-outcome association. The findings of this meta-meta-analysis suggest that the RA-outcome association is substantial and robust. Implications for psychotherapy outcome research are discussed.

Testing the allegiance bias hypothesis: a meta-analysis

Abstract This meta-analysis investigated whether the association between researcher allegiance (RA) and the relative effect of two psychotherapies can be explained through the methodological weaknesses of the treatment comparisons. Seventy-nine comparisons of psychotherapies for depression or posttraumatic stress disorder (PTSD) were included. Methodological quality (MQ) was investigated as both a moderator and a mediator of the RA-outcome association. MQ included balanced nonspecific factors, balanced specific factors, conceptual quality, patients-per-therapist ratio, randomization to conditions and outcome assessment. The RA-outcome association was stronger when the MQ was low, suggesting a buffering effect of MQ. In addition, differences in the conceptual quality of treatments mediated the effect of RA on outcome. The results support the view that RA acts as a bias in treatment comparisons.

Is the allegiance effect an epiphenomenon of true efficacy differences between treatments? a meta-analysis

Many meta-analyses of comparative outcome studies found a substantial association of researcher allegiance (RA) and relative treatment effects. Therefore, RA is regarded as a biasing factor in comparative outcome research (RA bias hypothesis). However, the RA bias hypothesis has been criticized as causality might be reversed. That is, RA might be a reflection of true efficacy differences between treatments (true efficacy hypothesis). Consequently, the RA-outcome association would not be indicative of bias but an epiphenomenon of true efficacy differences. This meta-analysis tested the validity of the true efficacy hypothesis. This was done by controlling the RA-outcome association for true efficacy differences by restricting analysis to direct comparisons of treatments with equivalent efficacy. We included direct comparisons of different versions of trauma-focused therapy (TFT) in the treatment of posttraumatic stress disorder (PTSD). RA was measured from the research reports. Relative effect sizes for symptoms of PTSD were calculated. Random effects meta-regression was conducted. Twenty-nine comparisons of TFTs from 20 studies were identified. Initial heterogeneity among relative effect sizes was low. RA was a significant predictor of outcome and explained 12% of the variance in outcomes. The true efficacy hypothesis predicted the RA-outcome association to be zero; however, a substantial association was found. Thus, this study does not support the true efficacy hypothesis. Given findings from psychotherapy research and other fields that support a biasing influence of researcher preferences, RA should be regarded as a causal factor and conceptualized as a threat to the validity of conclusions from comparative outcome studies.

Combination of Psychological Intervention and Phosphodiesterase‐5 Inhibitors for Erectile Dysfunction: A Narrative Review and Meta‐Analysis

INTRODUCTION Erectile dysfunction (ED) is an increasing health problem that demands effective treatment. There is evidence that phosphodiesterase-5 inhibitors (PDE5-Is) and psychological intervention (PI) are effective treatment options; however, little is known about their comparative efficacy and the efficacy of combined treatments. AIM The aim of this systematic review and meta-analysis is to evaluate the comparative efficacy of PI, PDE5-Is, and their combination in the treatment of ED. MAIN OUTCOME MEASURES Primary outcome was ED symptoms, and secondary outcome was sexual satisfaction of the patient. METHODS A systematic literature search was conducted in order to identify relevant articles published between 1998 and 2012. We included randomized controlled trials and controlled trials comparing PI with PDE5-I treatment or one of them against a combination of both. RESULTS Eight studies with a total number of 562 patients were included in the meta-analysis. The results of the included studies are inconclusive, though they show a trend towards a larger effect of combined treatment compared with PI or PDE5-I treatment alone. The meta-analysis found that, overall, combined treatment was more efficacious for ED symptoms than PDE5-I treatment or PI alone. Combined treatment was more efficacious than PDE5-I use alone on sexual satisfaction. No differences were found between PDE5-Is and PI as stand-alone treatments. None of the moderators (treatment duration, methodological quality, or researcher allegiance) altered the effects. CONCLUSIONS The combination of PI and PDE5-Is is a promising strategy for a favorable outcome in ED and can be considered as a first-choice option for ED patients. Stronger RCTs are required to confirm this initial finding.

Oxytocin and Autism Spectrum Disorders: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Aim: Oxytocin presents an exciting potential to target the core symptoms of autism spectrum disorder (ASD) pharmacologically in an easily administered, cost-effective form with possibly minimal adverse effects. But, there are still major gaps in this area of research. This paper reviewed randomized controlled trials (RCTs) examining the effects of oxytocin administration on social cognition and restricted, repetitive behaviors in individuals with an ASD. Method: Electronic literature searches were conducted from PsycINFO, PubMed, Web of Knowledge, and EMBASE for RCTs published through June 2015. Results: 12 RCTs were included in this review. 7 out of the 11 studies that examined social cognition reported improvements. Additionally, one out of the 4 studies on restricted, repetitive behaviors, reported improvements following oxytocin administration. However, results from our meta-analyses suggest that oxytocin has no significant effect on these 2 domains. Conclusion: Previous evidence revealed mixed findings about the effects of oxytocin on ASD. Given the limited number of RCTs, our summary of findings on the effectiveness of oxytocin on ASD should still be considered tentative.

Specific and Nonspecific Psychological Interventions for PTSD Symptoms: A Meta‐Analysis With Problem Complexity as a Moderator

CONTEXT The necessity of specific intervention components for the successful treatment of patients with posttraumatic stress disorder is the subject of controversy. OBJECTIVE To investigate the complexity of clinical problems as a moderator of relative effects between specific and nonspecific psychological interventions. METHODS We included 18 randomized controlled trials, directly comparing specific and nonspecific psychological interventions. We conducted moderator analyses, including the complexity of clinical problems as predictor. RESULTS Our results have confirmed the moderate superiority of specific over nonspecific psychological interventions; however, the superiority was small in studies with complex clinical problems and large in studies with noncomplex clinical problems. CONCLUSIONS For patients with complex clinical problems, our results suggest that particular nonspecific psychological interventions may be offered as an alternative to specific psychological interventions. In contrast, for patients with noncomplex clinical problems, specific psychological interventions are the best treatment option.

Trust in the health care professional and health outcome: A meta-analysis

Objective To examine whether patients’ trust in the health care professional is associated with health outcomes. Study selection We searched 4 major electronic databases for studies that reported quantitative data on the association between trust in the health care professional and health outcome. We screened the full-texts of 400 publications and included 47 studies in our meta-analysis. Data extraction and data synthesis We conducted random effects meta-analyses and meta-regressions and calculated correlation coefficients with corresponding 95% confidence intervals. Two interdependent researchers assessed the quality of the included studies using the Strengthening the Reporting of Observational Studies in Epidemiology guidelines. Results Overall, we found a small to moderate correlation between trust and health outcomes (r = 0.24, 95% CI: 0.19–0.29). Subgroup analyses revealed a moderate correlation between trust and self-rated subjective health outcomes (r = 0.30, 0.24–0.35). Correlations between trust and objective (r = -0.02, -0.08–0.03) as well as observer-rated outcomes (r = 0.10, -0.16–0.36) were non-significant. Exploratory analyses showed a large correlation between trust and patient satisfaction and somewhat smaller correlations with health behaviours, quality of life and symptom severity. Heterogeneity was small to moderate across the analyses. Conclusions From a clinical perspective, patients reported more beneficial health behaviours, less symptoms and higher quality of life and to be more satisfied with treatment when they had higher trust in their health care professional. There was evidence for upward bias in the summarized results. Prospective studies are required to deepen our understanding of the complex interplay between trust and health outcomes.

Integrating fragmented evidence by network meta-analysis: relative effectiveness of psychological interventions for adults with post-traumatic stress disorder.

BACKGROUND To summarize the available evidence on the effectiveness of psychological interventions for patients with post-traumatic stress disorder (PTSD). METHOD We searched bibliographic databases and reference lists of relevant systematic reviews and meta-analyses for randomized controlled trials that compared specific psychological interventions for adults with PTSD symptoms either head-to-head or against control interventions using non-specific intervention components, or against wait-list control. Two investigators independently extracted the data and assessed trial characteristics. RESULTS The analyses included 4190 patients in 66 trials. An initial network meta-analysis showed large effect sizes (ESs) for all specific psychological interventions (ESs between -1.10 and -1.37) and moderate effects of psychological interventions that were used to control for non-specific intervention effects (ESs -0.58 and -0.62). ES differences between various types of specific psychological interventions were absent to small (ES differences between 0.00 and 0.27). Considerable between-trial heterogeneity occurred (τ²= 0.30). Stratified analyses revealed that trials that adhered to DSM-III/IV criteria for PTSD were associated with larger ESs. However, considerable heterogeneity remained. Heterogeneity was reduced in trials with adequate concealment of allocation and in large-sized trials. We found evidence for small-study bias. CONCLUSIONS Our findings show that patients with a formal diagnosis of PTSD and those with subclinical PTSD symptoms benefit from different psychological interventions. We did not identify any intervention that was consistently superior to other specific psychological interventions. However, the robustness of evidence varies considerably between different psychological interventions for PTSD, with most robust evidence for cognitive behavioral and exposure therapies.

Does It Matter Who Provides Psychological Interventions for Medically Unexplained Symptoms? A Meta-Analysis

Background: Patients with medically unexplained symptoms (MUS) are difficult to treat and cause high health-care costs. Psychological interventions might be a beneficial option for treating patients with MUS, but evidence is inconsistent. This meta-analysis compares the effectiveness of psychological interventions for MUS - delivered either by psychotherapists (PTs) or by general practitioners (GPs) - with that of usual care. Method: We conducted a systematic review and meta-analysis on randomised controlled trials of psychological interventions for MUS. Physical symptoms were the primary outcome, and physical functioning and psychological symptoms were the secondary outcomes. We pooled between-group effect sizes (ESs) after the treatment and at the follow-up in random-effects meta-regressions and stratified meta-analyses. We repeated these analyses with the intervention provider, intervention dose, MUS severity and methodological quality as predictors of relative intervention effects. Results: A total of 3,225 patients in 20 studies were analysed. After the treatment, small and significant ESs were found for all 3 outcome domains (ES range: 0.13-0.19, all p < 0.05). Psychological interventions were more beneficial for physical symptoms when delivered by PTs than by GPs (p = 0.02). There was no difference between PTs and GPs in terms of physical functioning and psychological symptoms. Conclusion: Psychological interventions are effective for patients with MUS, but the effects are small and most likely of short duration. Interventions that are delivered by PTs appear to have larger effects on unexplained physical symptoms than those delivered by GPs. Whether this superiority is due to a larger number of sessions of PT interventions remains unclear from our findings.

Die Allegianz von Forschenden als versteckter Moderator in der Psychotherapieforschung

Der direkte randomisierte Vergleich zwischen Behandlungen gilt als Standarddesign zur Ermittlung derjenigen Bestandteile komplexer psychotherapeutischer Behandlungen, die die Symptomverbesserung entscheidend beeinflussen. Die vorliegende Arbeit untersucht den Einfluss einseitiger Allegianz von Forschenden - d.h. deren Präferenz für eine bestimmte Behandlung - als extra-therapeutischen Moderator des Behandlungseffekts. Da die Allegianz von Forschenden nur auf Studienebene gemessen werden kann, sind metaanalytische Strategien erforderlich, um mögliche Zusammenhänge zwischen einseitiger Allegianz und Studienergebnissen zu untersuchen. In der Übersichtsarbeit soll gezeigt werden, dass eine einseitige Allegianz von Forschenden bedeutsam mit Studienergebnissen korreliert. Auch wenn dieser Zusammenhang bei verschiedenen Behandlungsansätzen und Störungen beobachtet werden kann, sind die Ursachen und verantwortlichen Prozesse noch nicht weitgehend bekannt. Aufgrund der Vielfalt an potenziellen kausalen Erklärungen für den beobachteten Zusammenhang zwischen Allegianz und Studienergebnissen schlussfolgern wir, dass die explizite Nennung der Allegianz ein möglicher und sinnvoller Schritt zur besseren Beurteilung von Schlussfolgerungen in der Psychotherapieforschung sein kann.