Error Rates In Patients Research Articles

1108: Secondary Analysis of Diagnostic Error Rate in Patients Requiring Rapid Response Team Activation

Pinevich, Yuliya1; Soleimani, Jalal1; Huang, Chanyan1; Herasevich, Svetlana1; Barwise, Amelia1; Dong, Yue1; Herasevich, Vitaly1; Gajic, Ognjen1; Pickering, Brian1 Author Information

Working Memory and Attention Influence Antisaccade Error Rate in Schizophrenia.

Objectives: Antisaccade error rate has been proposed to be one of the most promising endophenotypes for schizophrenia. Increased error rate in patients has been associated with working memory, attention and other executive function impairments. The relationship between antisaccade error rate and other neuropsychological processes in patients compared to healthy controls has not been explored in depth. This study aimed to replicate the finding of heightened antisaccade error rate in patients and determine which cognitive processes were most strongly associated with antisaccade error rate in both patients and controls. In addition, the study investigated whether different antisaccade task paradigms engage different cognitive processes. Methods: One hundred and ninety-one participants (54 patients with schizophrenia/schizoaffective disorder and 137 controls) completed the antisaccade task, which included both gap and step task parameters. Neuropsychological measures were obtained using the MCCB and the Stroop task. Results: The current study replicated a pronounced antisaccade error rate deficit in patients. In patients, working memory variance was most significantly associated with antisaccade errors made during the step condition, while attentional processes were most associated with errors made during the gap condition. In controls, overall global cognitive performance was most associated with antisaccade rates for both gap and step conditions. Conclusions: The current study demonstrates that in schizophrenia patients, but not controls, elevated antisaccade error rate is associated with attention and working memory, but not with global cognitive impairment or psychopathological processes. Our novel findings demonstrate that the gap and step conditions of the antisaccade task engage different cognitive processes. (JINS, 2019, 25, 174-183).

Alterations in intrinsic fronto-thalamo-parietal connectivity are associated with cognitive control deficits in psychotic disorders.

Despite a growing number of reports about alterations in intrinsic/resting brain activity observed in patients with psychotic disorders, their relevance to well-established cognitive control deficits in this patient group is not well understood. Totally 88 clinically stabilized patients with a psychotic disorder and 50 healthy controls participated in a resting-state magnetic resonance imaging study (rs-MRI) and performed an antisaccade task in the laboratory to assess voluntary inhibitory control ability. Deficits on this task are a well-established biomarker across psychotic disorders as we found in the present patient sample. First, regional cerebral function was evaluated by measuring the amplitude of low frequency fluctuations (ALFF) in rs-MRI BOLD signals. We found reduced ALFF in patients in regions known to be relevant to antisaccade task performance including bilateral frontal eye fields (FEF), supplementary eye fields (SEF) and thalamus. Second, areas with ALFF alterations were used as seed areas in whole-brain functional connectivity (FC) analysis. Altered FC was observed in a fronto-thalamo-parietal network that was associated with inhibition error rate in patients but not in controls. In contrast, faster time to generate a correct antisaccade was associated with FC in FEF and SEF in controls but this effect was not seen in patients. These findings establish a behavioral relevance of resting-state fMRI findings in psychotic disorders, and extend previous reports of alterations in fronto-thalamo-parietal network activation during antisaccade performance seen in task-based fMRI studies.

A Comprehensive Quality Assurance Program for Personnel and Procedures in Radiation Oncology: Value of Voluntary Error Reporting and Checklists

This report describes the value of a voluntary error reporting system and the impact of a series of quality assurance (QA) measures including checklists and timeouts on reported error rates in patients receiving radiation therapy. A voluntary error reporting system was instituted with the goal of recording errors, analyzing their clinical impact, and guiding the implementation of targeted QA measures. In response to errors committed in relation to treatment of the wrong patient, wrong treatment site, and wrong dose, a novel initiative involving the use of checklists and timeouts for all staff was implemented. The impact of these and other QA initiatives was analyzed. From 2001 to 2011, a total of 256 errors in 139 patients after 284,810 external radiation treatments (0.09% per treatment) were recorded in our voluntary error database. The incidence of errors related to patient/tumor site, treatment planning/data transfer, and patient setup/treatment delivery was 9%, 40.2%, and 50.8%, respectively. The compliance rate for the checklists and timeouts initiative was 97% (P<.001). These and other QA measures resulted in a significant reduction in many categories of errors. The introduction of checklists and timeouts has been successful in eliminating errors related to wrong patient, wrong site, and wrong dose. A comprehensive QA program that regularly monitors staff compliance together with a robust voluntary error reporting system can reduce or eliminate errors that could result in serious patient injury. We recommend the adoption of these relatively simple QA initiatives including the use of checklists and timeouts for all staff to improve the safety of patients undergoing radiation therapy in the modern era.

Combined visual and motor disorganization in patients with schizophrenia

Cognitive impairments are difficult to relate to clinical symptoms in schizophrenia, partly due to insufficient knowledge on how cognitive impairments interact with one another. Here, we devised a new sequential pointing task requiring both visual organization and motor sequencing. Six circles were presented simultaneously on a touch screen around a fixation point. Participants pointed with the finger each circle one after the other, in synchrony with auditory tones. We used an alternating rhythmic 300/600 ms pattern so that participants performed pairs of taps separated by short intervals of 300 ms. Visual organization was manipulated by using line-segments that grouped the circles two by two, yielding three pairs of connected circles, and three pairs of unconnected circles that belonged to different pairs. This led to three experimental conditions. In the “congruent condition,” the pairs of taps had to be executed on circles grouped by connecters. In the “non congruent condition,” they were to be executed on the unconnected circles that belonged to different pairs. In a neutral condition, there were no connecters. Twenty two patients with schizophrenia with mild symptoms and 22 control participants performed a series of 30 taps in each condition. Tap pairs were counted as errors when the produced rhythm was inverted (expected rhythm 600/300 = 2; inversed rhythm <1). Error rates in patients with a high level of clinical disorganization were significantly higher in the non-congruent condition than in the two other conditions, contrary to controls and the remaining patients. The tap-tone asynchrony increased in the presence of connecters in both patient groups, but not in the controls. Patients appeared not to integrate the visual organization during the planning phase of action, leading to a large difficulty during motor execution, especially in those patients revealing difficulties in visual organization. Visual motor tapping tasks may help detect those subgroups of patients.

Medicine administration errors in patients with dysphagia in secondary care: a multi-centre observational study

The aim of this study was to describe the interventions used by nurses when administering oral medicines to patients with and without dysphagia, to quantify the appropriateness of these interventions and the medicine administration error rate. The administration of medicines to patients with dysphagia is complex and potentially more error prone because of the need to match the medication's formulation to the swallowing ability of the patient. Data was collected on the preparation and administration of oral medicines to patients with and without dysphagia, including those with enteral feeding tubes, using undisguised direct observation of 65 nurse-led medicine administration rounds on stroke and care-of-the-elderly wards at four acute general hospitals in East of England between 1 March and 30 June 2008. Of the 2129 medicine administrations observed, 817 involved an error, and of these 313 involved patients with dysphagia. Excluding time errors, the normalized frequency of medicine administration errors for patients with dysphagia was 21.1% compared with 5.9% for patients without. Using a mixed effects model and excluding time errors, there is a higher risk of errors for patients with dysphagia (excluding patients with enteral tubes) compared with those without (P < 0.001) and a further increase in risk of error for patients with enteral tubes compared with dysphagic patients without tubes (P < 0.001). The increased medicine administration error rate in patients with dysphagia requires healthcare professionals to take extra care when prescribing, dispensing and administering medicines to this group.

Chemotherapy safety and severe adverse events in cancer patients: Strategies to efficiently avoid chemotherapy errors in in‐ and outpatient treatment

To enhance the quality and safety in cancer treatment, and in acknowledgement that medical errors occur, we have established 2 error management systems: one monitors chemotherapy errors, the other records all severe adverse events occurring in chemotherapy-treated cancer patients (SAECTx) in in- and outpatient treatment. These error systems have been implemented by our departmental "Clinical Service Center," a multidisciplinary team which controls all chemotherapy protocols and orders prior to the medication reaching the patient. We performed a prospective cohort study in consecutive cancer patients who received chemotherapies in our department between January 2005 and December 2006. Over this 2-year period, 2,337 patients were treated, with an equal distribution as in- and outpatients: 22,216 consecutive chemotherapy orders were analyzed, of which 83.5% were completely flawless, whereas we detected and corrected medical and administrative errors in 17.1%: in 3.8%, these errors involved the chemotherapy itself, in 4.5% the patient data and in 8.7% missing written informed consent forms. Chemotherapy errors were less frequent in outpatients than inpatients (3.3 vs. 4.5%, respectively). In outpatients, the rate of chemotherapy errors decreased from 4% in 2005 to 2.8% in 2006, but remained stable for inpatients (4.4% 2005 vs. 4.7% 2006). Among a total of 3,792 detected errors, only 3 reached the patient, resulting in an error rate in patients of 0.079%. Therefore, since we detected a substantial number of chemotherapy-related errors and intercepted 99.9%, we recommend our efficient surveillance system as an important safety check, thereby ensuring that chemotherapies are delivered error-free to cancer patients.

Syllable frequency and syllable structure in the spontaneous speech production of patients with apraxia of speech

Background: The sublexical factors syllable frequency and syllable structure are known to influence error rates in patients with apraxia of speech (e.g., Aichert & Ziegler, 2004; Romani & Galluzzi, 2005). To our knowledge, these factors have almost exclusively been examined by single‐word production paradigms. However, performance on single‐word tasks is not necessarily a good predictor of spontaneous speech production, since the generation of conversational speech involves specific conditions and additional demands. This might influence the weights of syllable frequency and syllable structure in explanations of the accuracy of speech production in apraxic speakers. Aims: Our aim was to determine if the spontaneous speech production of patients with apraxia of speech (AOS) is influenced by the factors syllable frequency and syllable structure. The two research questions that guided our investigation were: (1) Are the distribution properties of syllables in spontaneous speech different in patients with AOS compared to unimpaired speakers? (2) Do the factors syllable frequency and syllable structure affect articulatory accuracy in the spontaneous speech of patients with AOS? Methods & Procedures: Three patients with AOS and 15 neurologically unimpaired control persons produced samples of spontaneous speech with a minimum of 1000 syllables each. Structure and frequency counts were made on the basis of the German CELEX database. Outcomes & Results: The distribution properties of the spontaneous speech samples were similar in the apraxic speakers and the unimpaired controls. In all three patients the proportion of errors was significantly higher on low‐ than on high‐frequency syllables. In two patients a significant effect even persisted when any confound with syllable structure was ruled out. Syllable structure effects were only found within the low‐frequency syllables. Conclusions: Syllable frequency and syllable structure play a decisive role with respect to articulatory accuracy in the spontaneous speech production of patients with AOS. The first author of this study was supported by a grant from the DFG ‐ German research council (ZI 469/10‐2). We would also like to thank the ReHa‐Hilfe e.V. for their support. We are grateful to our colleagues from the Neuropsychological Clinic, Munich‐Bogenhausen Hospital, Munich, and to the staff from the speech therapy departments at the Rehabilitation Hospitals Bad Heilbrunn and Bad Aibling for their collaboration on clinical issues. We would also like to express our gratitude to all participants.

Schizophrenia patients show impaired response switching in saccade tasks

Action control deficits of schizophrenia patients result from frontostriatal brain abnormalities and presumably reflect an impairment of selective cognitive processes. This study aimed at dissociating two different levels of action control in saccades toward and away from visual stimuli (pro- and antisaccades). Results of previous studies suggested that task switch effects (between pro- and antisaccades) reflect the persistence of a task-specific production rule and refer to the level of task selection, whereas response switch effects (between leftward and rightward saccades) point to the persistence of a specific response program, referring to the level of response selection. In the present study, task switching and response switching were investigated in 20 schizophrenia patients and 20 control subjects. Groups did not differ concerning task switch effects. In contrast, response switching entailed a stronger enhancement of error rates in patients, suggesting a specific deficit on the level of response selection in schizophrenia. The deficit was associated with spatial working memory capacities, confirming and specifying existing hypotheses on a relationship between working memory and action control.

The Prefrontal Substrate of Reflexive Saccade Inhibition in Humans

Prefrontal dysfunction in neuropsychiatric disorders such as schizophrenia has been shown to impair inhibition of reflexive saccadic eye movements; however, it is unclear whether reflexive saccade inhibition can be attributed to a distinct subregion of the human prefrontal cortex. We tested 15 patients with acute unilateral ischemic lesions of the prefrontal cortex and 20 control subjects with an antisaccade task. Lesions were reconstructed using Talairach coordinates, and possible candidate regions for reflexive saccade inhibition were identified. Significantly increased antisaccade error rates were observed in patients with lesions affecting a region in mid-dorsolateral prefrontal cortex or the white matter between this region and the anterior portions of the internal capsule. Antisaccade error rates of patients with lesions outside this region were normal. These findings were largely independent of lesion volume, postlesion delay, and subject age. Our findings suggest that inhibition of reflexive saccades depends on a circumscribed subregion of the human dorsolateral prefrontal cortex. This region closely corresponds to Brodmann area 46 as defined by recent cytoarchitectonic studies. Increased antisaccade error rates in patients with prefrontal pathology may be explained by dysfunction of this region.

Frontal and striatal brain lesions increase susceptibility to masking in perceptual decisions

Recent data suggest that perceptual decisions on masked stimuli involve neural activity in frontal cortex. We examined the effect of damage to frontal and striatal brain regions in man on the susceptibility to backward masking in rapid stimulus streams. Patients with unilateral frontal excisions and patients with early Huntington’s disease were compared to controls in the identification of a brief white letter embedded in short streams of black letters at two presentation rates: (a) 9 letters/s; (b) 12.5 letters/s and also in a control condition in which the first post-target masking letter was absent. Patients could identify the target when the post-target mask was absent, but reducing the delay between stimuli significantly increased the error rates in patients. Intrusion errors often involved reporting post-target or pre-target distractors instead of the target. These results suggest that fronto-striatal lesions increase the period during which perceptual decisions are susceptible to perturbation. This deficit is compatible with a functional role of frontal systems in the cognitive control of brief perceptual decisions.