How Confidence in Prior Attitudes, Social Tag Popularity, and Source Credibility Shape Confirmation Bias Toward Antidepressants and Psychotherapy in a Representative German Sample: Randomized Controlled Web-Based Study.

BACKGROUND: In health-related, Web-based information search, people should select information in line with expert (vs nonexpert) information, independent of their prior attitudes and consequent confirmation bias. OBJECTIVE: This study aimed to investigate confirmation bias in mental health-related information search, particularly (1) if high confidence worsens confirmation bias, (2) if social tags eliminate the influence of prior attitudes, and (3) if people successfully distinguish high and low source credibility. METHODS: In total, 520 participants of a representative sample of the German Web-based population were recruited via a panel company. Among them, 48.1% (250/520) participants completed the fully automated study. Participants provided prior attitudes about antidepressants and psychotherapy. We manipulated (1) confidence in prior attitudes when participants searched for blog posts about the treatment of depression, (2) tag popularity -either psychotherapy or antidepressant tags were more popular, and (3) source credibility with banners indicating high or low expertise of the tagging community. We measured tag and blog post selection, and treatmentefficacy ratings after navigation. RESULTS: Tag popularity predicted the proportion of selected antidepressant tags (beta=.44, SE 0.11; P<.001) and blog posts (beta=.46, SE 0.11; P<.001). When confidence was low (-1 SD), participants selected more blog posts consistent with prior attitudes (beta=-.26, SE 0.05; P<.001). Moreover, when confidence was low (-1 SD) and source credibility was high (+1 SD), the efficacy ratings of attitude-consistent treatments increased (beta=.34, SE 0.13; P=.01). CONCLUSIONS: We found correlational support for defense motivation account underlying confirmation bias in the mental health-related search context. That is, participants tended to select information that supported their prior attitudes, which is not in line with the current scientific evidence. Implications for presenting persuasive Web-based information are also discussed. TRIAL REGISTRATION: ClinicalTrials.gov NCT03899168; https://clinicaltrials.gov/ct2/show/NCT03899168 (Archived by WebCite at http://www.webcitation.org/77Nyot3Do).

Attitude confidence and source credibility in information foraging with social tags.

There is growing concern that online information searchers are overconfident and therefore largely search for information which reinforces their prior attitudes, blinded by confirmation bias. This study tests if this effect can be reduced in content aggregation platforms, when social tag clouds show popular topics among experts. We manipulated (1) confidence in prior attitudes, and (2) the credibility of the expert community that tagged the content. We found that both factors influence navigation in different ways. First, attitude confidence moderated the influence of prior attitudes when choosing how much attitude-consistent content in blog posts to read. When attitude confidence was high, prior attitudes were positively associated with selection of blog posts, when low, not positively associated. After navigation, when confidence was high, the content of attitude-consistent blog posts was more favourably evaluated, whereas when confidence was low, attitude inconsistent blog posts were more favourably evaluated. Second, source credibility moderated the influence of prior attitudes on tag selection. When source credibility was low, prior attitudes did guide tag selection, when high, they did not. With low source credibility, people selected more attitude-consistent content. The findings advance social tagging theories by showing that not only semantic associations, but also attitudes play a role when people select and process tags and related content. The findings also show that credibility and confidence have a different impact on different stages of information selection and evaluation. Whereas credibility is more important when switching among pages, attitude confidence is more important when reading and evaluating the content of one page.

The DNA methylation landscape of glioblastoma disease progression shows extensive heterogeneity in time and space.

Glioblastoma is characterized by widespread genetic and transcriptional heterogeneity, yet little is known about the role of the epigenome in glioblastoma disease progression. Here, we present genome-scale maps of DNA methylation in matched primary and recurring glioblastoma tumors, using data from a highly annotated clinical cohort that was selected through a national patient registry. We demonstrate the feasibility of DNA methylation mapping in a large set of routinely collected FFPE samples, and we validate bisulfite sequencing as a multipurpose assay that allowed us to infer a range of different genetic, epigenetic, and transcriptional characteristics of the profiled tumor samples. On the basis of these data, we identified subtle differences between primary and recurring tumors, links between DNA methylation and the tumor microenvironment, and an association of epigenetic tumor heterogeneity with patient survival. In summary, this study establishes an open resource for dissecting DNA methylation heterogeneity in a genetically diverse and heterogeneous cancer, and it demonstrates the feasibility of integrating epigenomics, radiology, and digital pathology for a national cohort, thereby leveraging existing samples and data collected as part of routine clinical practice.

Confirmation bias in web-based search: a randomized online study on the effects of expert information and social tags on information search and evaluation.

BACKGROUND: The public typically believes psychotherapy to be more effective than pharmacotherapy for depression treatments. This is not consistent with current scientific evidence, which shows that both types of treatment are about equally effective. OBJECTIVE: The study investigates whether this bias towards psychotherapy guides online information search and whether the bias can be reduced by explicitly providing expert information (in a blog entry) and by providing tag clouds that implicitly reveal experts' evaluations. METHODS: A total of 174 participants completed a fully automated Web-based study after we invited them via mailing lists. First, participants read two blog posts by experts that either challenged or supported the bias towards psychotherapy. Subsequently, participants searched for information about depression treatment in an online environment that provided more experts' blog posts about the effectiveness of treatments based on alleged research findings. These blogs were organized in a tag cloud; both psychotherapy tags and pharmacotherapy tags were popular. We measured tag and blog post selection, efficacy ratings of the presented treatments, and participants' treatment recommendation after information search. RESULTS: Participants demonstrated a clear bias towards psychotherapy (mean 4.53, SD 1.99) compared to pharmacotherapy (mean 2.73, SD 2.41; t173=7.67, P<.001, d=0.81) when rating treatment efficacy prior to the experiment. Accordingly, participants exhibited biased information search and evaluation. This bias was significantly reduced, however, when participants were exposed to tag clouds with challenging popular tags. Participants facing popular tags challenging their bias (n=61) showed significantly less biased tag selection (F2,168=10.61, P<.001, partial eta squared=0.112), blog post selection (F2,168=6.55, P=.002, partial eta squared=0.072), and treatment efficacy ratings (F2,168=8.48, P<.001, partial eta squared=0.092), compared to bias-supporting tag clouds (n=56) and balanced tag clouds (n=57). Challenging (n=93) explicit expert information as presented in blog posts, compared to supporting expert information (n=81), decreased the bias in information search with regard to blog post selection (F1,168=4.32, P=.04, partial eta squared=0.025). No significant effects were found for treatment recommendation (Ps>.33). CONCLUSIONS: We conclude that the psychotherapy bias is most effectively attenuated-and even eliminated-when popular tags implicitly point to blog posts that challenge the widespread view. Explicit expert information (in a blog entry) was less successful in reducing biased information search and evaluation. Since tag clouds have the potential to counter biased information processing, we recommend their insertion.

Evaluation of a new arterial pressure-based cardiac output device requiring no external calibration.

BACKGROUND: Several techniques have been discussed as alternatives to the intermittent bolus thermodilution cardiac output (COPAC) measurement by the pulmonary artery catheter (PAC). However, these techniques usually require a central venous line, an additional catheter, or a special calibration procedure. A new arterial pressure-based cardiac output (COAP) device (FloTractrade mark, Vigileotrade mark; Edwards Lifesciences, Irvine, CA, USA) only requires access to the radial or femoral artery using a standard arterial catheter and does not need an external calibration. We validated this technique in critically ill patients in the intensive care unit (ICU) using COPAC as the method of reference. METHODS: We studied 20 critically ill patients, aged 16 to 74 years (mean, 55.5 +/- 18.8 years), who required both arterial and pulmonary artery pressure monitoring. COPAC measurements were performed at least every 4 hours and calculated as the average of 3 measurements, while COAP values were taken immediately at the end of bolus determinations. Accuracy of measurements was assessed by calculating the bias and limits of agreement using the method described by Bland and Altman. RESULTS: A total of 164 coupled measurements were obtained. Absolute values of COPAC ranged from 2.80 to 10.80 l/min (mean 5.93 +/- 1.55 l/min). The bias and limits of agreement between COPAC and COAP for unequal numbers of replicates was 0.02 +/- 2.92 l/min. The percentage error between COPAC and COAP was 49.3%. The bias between percentage changes in COPAC (DeltaCOPAC) and percentage changes in COAP (DeltaCOAP) for consecutive measurements was -0.70% +/- 32.28%. COPAC and COAP showed a Pearson correlation coefficient of 0.58 (p < 0.01), while the correlation coefficient between DeltaCOPAC and DeltaCOAP was 0.46 (p < 0.01). CONCLUSION: Although the COAP algorithm shows a minimal bias with COPAC over a wide range of values in an inhomogeneous group of critically ill patients, the scattering of the data remains relative wide. Therefore, the used algorithm (V 1.03) failed to demonstrate an acceptable accuracy in comparison to the clinical standard of cardiac output determination.

Influence of patient-related and surgery-related risk factors on cognitive performance, emotional state, and convalescence after cardiac surgery.

BACKGROUND: Cardiac surgery may account for complications such as cognitive impairment, depression, and delay of convalescence. This study investigated the influence of different risk factors on cognitive performance, emotional state, and convalescence. METHODS: We included 83 patients undergoing cardiac surgery who had no indication of postoperative delirium. Psychometric testing was performed 1 day before and 7 days after surgery. Neuron-specific enolase (NSE) levels were measured 1 day before and 36 h after surgery. RESULTS: Depression score increased after surgery, but patients showed no clinically significant depression. Postoperative cognitive performance correlated with postoperative depression level and preoperative cognitive performance. Forty-three percent of patients showed postoperative decline. Older patients exhibited a higher postoperative increase in NSE concentrations. Patients undergoing coronary artery bypass grafts or combined procedures exhibited more medical risk factors than those undergoing valve surgery alone. The number of bypass grafts was associated with time of hospitalization, and the number of patient-related risk factors correlated with stay in intensive care unit. CONCLUSIONS: For elderly patients undergoing cardiac surgery, older age, total preexisting medical risk factors, and surgery duration seem to be the most important factors influencing cognitive outcome and convalescence. Results show that, also for patients without postoperative delirium, medical risk factors and intraoperative parameters can result in delay of convalescence.

Double proton transfer reactions with plateau-like transition state regions: pyrazole-trifluoroacetic acid clusters.

The double proton transfer reactions between carboxylic acids and pyrazole were studied by computational methods up to the coupled-cluster level. Introduction of substituents allowed for a systematic modulation of the reaction profile, resulting in imaginary frequencies of the associated transition states between -1180 and -45 cm(-1). In the latter case, a local transition state is replaced by an extremely flat (plateaulike) transition region, which constitutes the transition from a concerted toward a stepwise mechanism. Vertical excitation energies along the reaction path reveal that the feature of a plateau in the ground state is mirrored in the excited states.