Interpreting response time effects in functional imaging studies

It has been suggested that differential neural activity in imaging studies is most informative if it is independent of response time (RT) differences. However, others view RT as a behavioural index of key cognitive processes, which is likely linked to underlying neural activity. Here, we reconcile these views using the effort and engagement framework developed by Taylor, Rastle, and Davis (2013) and data from the domain of reading aloud. We propose that differences in neural engagement should be independent of RT, whereas, differences in neural effort should co-vary with RT. We illustrate these different mechanisms using data from an fMRI study of neural activity during reading aloud of regular words, irregular words, and pseudowords. In line with our proposals, activation revealed by contrasts designed to tap differences in neural engagement (e.g., words are meaningful and therefore engage semantic representations more than pseudowords) survived correction for RT, whereas activation for contrasts designed to tap differences in neural effort (e.g., it is more difficult to generate the pronunciation of pseudowords than words) correlated with RT. However, even for contrasts designed to tap neural effort, activity remained after factoring out the RT-BOLD response correlation. This may reveal unpredicted differences in neural engagement (e.g., learning phonological forms for pseudowords. >. words) that could further the development of cognitive models of reading aloud. Our framework provides a theoretically well-grounded and easily implemented method for analysing and interpreting RT effects in neuroimaging studies of cognitive processes

Eosinophilic Esophagitis in Two Patients with Systemic Sclerosis

The gastrointestinal tract (GIT) is the most common extracutaneous organ system damaged in systemic sclerosis (SSc) and is the presenting feature in 10% of patients. The esophagus as the portion of the GIT is the most commonly affected and there is an association of gastroesophageal reflux (GER) with SSc interstitial lung disease (ILD). Thus, an aggressive treatment for GER is recommended in all SSc patients with ILD; however, it is recognized that a long-term benefit to this treatment is needed to understand its impact. In this case report we discuss the presence of eosinophilic esophagitis (EoE) in two SSc patients and discuss the role for early EGD in SSc patients with moderate-severe GER symptoms for tissue study. Assessment of esophageal biopsy specimens for the presence of eosinophils and possibly ANA can help elucidate disease pathogenesis and direct therapy, as the presence of EoE in SSc has important management considerations, particularly with regards to dietary modification strategies

Discord among Performance Measures for Central Line—Associated Bloodstream Infection

BackgroundCentral line-associated bloodstream infection (CLABSI) is a national target for mandatory reporting and a Centers for Medicare and Medicaid Services target for value-based purchasing. Differences in chart review versus claims-based metrics used by national agencies and groups raise concerns about the validity of these measures.ObjectiveEvaluate consistency and reasons for discordance among chart review and claims-based CLABSI events.MethodsWe conducted 2 multicenter retrospective cohort studies within 6 academic institutions. A total of 150 consecutive patients were identified with CLABSI on the basis of National Healthcare Safety Network (NHSN) criteria (NHSN cohort), and an additional 150 consecutive patients were identified with CLABSI on the basis of claims codes (claims cohort). All events had full-text medical record reviews and were identified as concordant or discordant with the other metric.ResultsIn the NHSN cohort, there were 152 CLABSIs among 150 patients, and 73.0% of these cases were discordant with claims data. Common reasons for the lack of associated claims codes included coding omission and lack of physician documentation of bacteremia cause. In the claims cohort, there were 150 CLABSIs among 150 patients, and 65.3% of these cases were discordant with NHSN criteria. Common reasons for the lack of NHSN reporting were identification of non-CLABSI with bacteremia meeting Centers for Disease Control and Prevention (CDC) criteria for an alternative infection source.ConclusionSubstantial discordance between NHSN and claims-based CLABSI indicators persists. Compared with standardized CDC chart review criteria, claims data often had both coding omissions and misclassification of non-CLABSI infections as CLABSI. Additionally, claims did not identify any additional CLABSIs for CDC reporting. NHSN criteria are a more consistent interhospital standard for CLABSI reporting