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Background: The use of larger femoral heads in total hip replacement (THR) has increased over the last decade. While the relationship between increasing head size and increased stability is well known, the risk of revision with increasing head size remains poorly understood. The aim of this study was to compare the outcome of total hip joint replacement with 32-mm and 36-mm heads.Methods: We carried out a 20-year retrospective analysis of prospective data from the New Zealand Joint Registry (NZJR). All primary total hip replacements registered between January 1999 and December 2018 were included. We compared the rate of revision of 32-mm and 36-mm heads in THR. Sub-group analysis included comparisons of bearing type and all-cause revision.Results: 60,051 primary THRs met our inclusion criteria. The revision rate per 100 component years was significantly higher with a 36-mm head than with a 32-mm head (0.649 vs. 0.534, p<0.001). Subgroup analysis of bearing type showed no significant differences in revision rates for all combinations of 36-mm heads when compared to 32-mm (p=0.074–0.92), with the exception of metal-on-metal (MoM); p=0.038. When MoM was removed there was no significant difference in revision rates per 100 component years between 32-mm and 36-mm heads, 0.528 versus 0.578 (p=0.099).Conclusions: Increasing head size from 32 mm to 36 mm results in no significant increase in revision in all bearing combinations except MoM.

IMPORTANCE: Chimeric antigen receptor (CAR) T-cell therapy for relapsed or refractory hematologic malignant neoplasm causes severe neurologic adverse events ranging from encephalopathy and aphasia to cerebral edema and death. The cause of neurotoxicity is incompletely understood, and its unpredictability is a reason for prolonged hospitalization after CAR T-cell infusion. OBJECTIVE: To identify clinical and laboratory parameters predictive of neurotoxicity and to develop a prognostic score associated with its risk. DESIGN, SETTING, AND PARTICIPANTS: This single-center diagnostic/prognostic accuracy study was conducted at Brigham and Women’s Hospital/Dana Farber Cancer Institute from April 2015 to February 2020. A consecutive sample of all patients undergoing CAR T-cell therapy with axicabtagene ciloleucel for relapsed or refractory lymphoma were assessed for inclusion (n = 213). Patients who had previously received CAR T cells or who were treated for mantle cell lymphoma were excluded (n = 9). Patients were followed up for a minimum of 30 days from the date of CAR T-cell infusion. MAIN OUTCOMES AND MEASURES: The primary outcomes were measures of performance (accuracy, sensitivity, specificity, area under the curve) of a diagnostic tool to predict the occurrence of CAR-associated neurotoxicity, as graded by the Common Terminology Criteria for Adverse Events criteria. RESULTS: Two hundred four patients (127 men [62.2%]; mean [SD] age, 60.0 [12.1] years) were included in the analysis, of which 126 (61.8%) comprised a derivation cohort and 78 (38.2%), an internal validation cohort. Seventy-three patients (57.9%) in the derivation cohort and 45 patients (57.7%) in the validation cohort experienced neurotoxicity. Clinical and laboratory values obtained early in admission were used to develop a multivariable score that can predict the subsequent development of neurotoxicity; when tested on an internal validation cohort, this score had an area under the curve of 74%, an accuracy of 77%, a sensitivity of 82%, and a specificity of 70% (positive:negative likelihood ratio, 2.71:0.26). CONCLUSIONS AND RELEVANCE: The score developed in this study may help predict which patients are likely to experience CAR T-cell–associated neurotoxicity. The score can be used for triaging and resource allocation and may allow a large proportion of patients to be discharged from the hospital early.

ObjectiveTo assess the benefit of arthroscopic partial meniscectomy (APM) in adults with a meniscal tear and knee pain in three defined populations (taking account of the comparison intervention): (A) all patients (any type of meniscal tear with or without radiographic osteoarthritis); (B) patients with any type of meniscal tear in a non-osteoarthritic knee; and (C) patients with an unstable meniscal tear in a non-osteoarthritic knee.DesignSystematic review and meta-analysis.DatasourcesA search of MEDLINE, Embase, CENTRAL, Scopus, Web of Science, Clinicaltrials.gov and ISRCTN was performed, unlimited by language or publication date (inception to 18 October 2018).EligibilitycriteriaRandomised controlled trials performed in adults with meniscal tears, comparing APM versus (1) non-surgical intervention; (2) pharmacological intervention; (3) surgical intervention; and (4) no intervention.ResultsTen trials were identified: seven compared with non-surgery, one pharmacological and two surgical. Findings were limited by small sample size, small number of trials and cross-over of participants to APM from comparator interventions. In group A (all patients) receiving APM versus non-surgical intervention (physiotherapy), at 6–12 months, there was a small mean improvement in knee pain (standardised mean difference [SMD] 0.22 [95% CI 0.03 to 0.40]; five trials, 943 patients; I248%; Grading of Recommendations Assessment, Development and Evaluation [GRADE]: low), knee-specific quality of life (SMD 0.43 [95% CI 0.10 to 0.75]; three trials, 350 patients; I256%; GRADE: low) and knee function (SMD 0.18 [95% CI 0.04 to 0.33]; six trials, 1050 patients; I227%; GRADE: low). When the analysis was restricted to people without osteoarthritis (group B), there was a small to moderate improvement in knee pain (SMD 0.35 [95% CI 0.04 to 0.66]; three trials, 402 patients; I258%; GRADE: very low), knee-specific quality of life (SMD 0.59 [95% CI 0.11 to 1.07]; two trials, 244 patients; I271%; GRADE: low) and knee function (SMD 0.30 [95% CI 0.06 to 0.53]; four trials, 507 patients; I244%; GRADE: very low). There was no improvement in knee pain, function or quality of life in patients receiving APM compared with placebo surgery at 6–12 months in group A or B (pain: SMD 0.08 [95% CI −0.24 to 0.41]; one trial, 146 patients; GRADE: low; function: SMD −0.08 [95% CI −0.41 to 0.24]; one trial, 146 patients; GRADE: high; quality of life: SMD 0.05 [95% CI −0.27 to 0.38]; one trial; 146 patients; GRADE: high). No trials were identified for people in group C.ConclusionPerforming APM in all patients with knee pain and a meniscal tear is not appropriate, and surgical treatment should not be considered the first-line intervention. There may, however, be a small-to-moderate benefit from APM compared with physiotherapy for patients without osteoarthritis. No trial has been limited to patients failing non-operative treatment or patients with an unstable meniscal tear in a non-arthritic joint; research is needed to establish the value of APM in this population.Protocol registration numberPROSPERO CRD42017056844.

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The ratio of healthcare professionals to care recipients is dropping at an alarming rate, particularly for the older population. It is estimated that the number of persons with Alzheimer's disease, for example, will top 100 million worldwide by the year 2050 [Alzheimer's Disease International 2009]. It will become harder and harder to provide needed health services to this population of older adults. Further, patients are becoming more aware and involved in their own healthcare decisions. This is creating a void in which technology has an increasingly important role to play as a tool to connect providers with recipients. Examples of interactive technologies range from telecare for remote regions to computer games promoting fitness in the home. Currently, such technologies are developed for specific applications and are difficult to modify to suit individual user needs. The future potential economic and social impact of technology in the healthcare field therefore lies in our ability to make intelligent devices that are customizable by healthcare professionals and their clients, that are adaptive to users over time, and that generalize across tasks and environments. A wide application area for technology in healthcare is for assistance and monitoring in the home. As the population ages, it becomes increasingly dependent on chronic healthcare, such as assistance for tasks of everyday life (washing, cooking, dressing), medication taking, nutrition, and fitness. This article will present a summary of work over the past decade on the development of intelligent systems that provide assistance to persons with cognitive disabilities. These systems are unique in that they are all built using a common framework, a decision-theoretic model for general-purpose assistance in the home. In this article, we will show how this type of general model can be applied to a range of assistance tasks, including prompting for activities of daily living, assistance for art therapists, and stroke rehabilitation. This model is a Partially Observable Markov Decision Process (POMDP) that can be customized by end-users, that can integrate complex sensor information, and that can adapt over time. These three characteristics of the POMDP model will allow for increasing uptake and long-term efficiency and robustness of technology for assistance.

Introduction: Many health technologies exhibit some form of learning effect, and this represents a barrier to rigorous assessment. It has been shown that the statistical methods used are relatively crude. Methods to describe learning curves in fields outside medicine, for example, psychology and engineering, may be better. Methods: To systematically search non–health technology assessment literature (for example, PsycLit and Econlit databases) to identify novel statistical techniques applied to learning curves. Results: The search retrieved 9,431 abstracts for assessment, of which 18 used a statistical technique for analyzing learning effects that had not previously been identified in the clinical literature. The newly identified methods were combined with those previously used in health technology assessment, and categorized into four groups of increasing complexity: a) exploratory data analysis; b) simple data analysis; c) complex data analysis; and d) generic methods. All the complex structured data techniques for analyzing learning effects were identified in the nonclinical literature, and these emphasized the importance of estimating intra- and interindividual learning effects. Conclusion: A good dividend of more sophisticated methods was obtained by searching in nonclinical fields. These methods now require formal testing on health technology data sets.

Objective: We reviewed and appraised the methods by which the issue of the learning curve has been addressed during health technology assessment in the past. Method: We performed a systematic review of papers in clinical databases (BIOSIS, CINAHL, Cochrane Library, EMBASE, HealthSTAR, MEDLINE, Science Citation Index, and Social Science Citation Index) using the search term “learning curve.” Results: The clinical search retrieved 4,571 abstracts for assessment, of which 559 (12%) published articles were eligible for review. Of these, 272 were judged to have formally assessed a learning curve. The procedures assessed were minimal access (51%), other surgical (41%), and diagnostic (8%). The majority of the studies were case series (95%). Some 47% of studies addressed only individual operator performance and 52% addressed institutional performance. The data were collected prospectively in 40%, retrospectively in 26%, and the method was unclear for 31%. The statistical methods used were simple graphs (44%), splitting the data chronologically and performing a t test or chi-squared test (60%), curve fitting (12%), and other model fitting (5%). Conclusions: Learning curves are rarely considered formally in health technology assessment. Where they are, the reporting of the studies and the statistical methods used are weak. As a minimum, reporting of learning should include the number and experience of the operators and a detailed description of data collection. Improved statistical methods would enhance the assessment of health technologies that require learning.

The importance of overhearing, and other ways of monitoring communicative behaviour not explicitly directed at oneself, has been illustrated in numerous ethnographic studies of computer-supported cooperative work. This paper is concerned with a particular form of monitoring. A “peripheral participant” is defined as someone who has a legitimate interest in monitoring a joint task (being carried out by some “primary participants”) but who is not actively involved in carrying out the task themselves. The concept is illustrated through field studies of telemedical consultation and related to other analyses of overhearing. Two experiments are reported where participatory status was manipulated using a role-play task. Ratings of interpersonal awareness, measures of gaze direction and recall of the conversation all indicate that the task successfully operationalized the distinction between primary and peripheral participation. In addition, the experiment manipulated the visibility of the peripheral participant to a remote primary participant. This was shown to have an effect on the remote primary participant's interpersonal awareness of the peripheral participant. Potential mechanisms for this effect are considered. It is concluded that peripheral participation is a potentially important form of involvement that needs to be considered when designing and configuring equipment for video-mediated cooperative work.

Abstract: Participants worked in pairs, with one person gazing at a flat horizontal stimulus between them. The other participant estimated where the gazer was looking. Experiment 1 used linear scales as gaze targets. The mean root mean square error of estimation equates to 3.8° of head-and-eye pan and 2.6° of tilt. This small error of estimation was essentially the same in a video-mediated condition and in one in which a procedure that did not allow the estimator to see the head-and-eye movement to the target position was used. Experiment 2 obtained comparable gaze estimation performance in face-to-face and video-mediated conditions, using a combined pan-and-tilt grid. It is concluded that people are very good at estimating what someone else is looking at and that such estimations should be practical during video-mediated conversation.

The results of a field study of three sites that used video to link primary care medical centers to hospitals are reported. The analysis was concerned with identifying the people involved, the tasks carried out in collaboration at each end of the link, and how the different communications facilities helped or hindered. The results are summarized as six task characteristics and their design implications for this model of telemedical consultation are discussed.

How may we discriminate between the multitude of point-to-point communication facilities currently available? To take just one aspect of communication, how can we assess the fluency of coordination that results from using some communication technology? This paper describes two groups of measures with this general purpose. The measures described have been devised to be used in a particular approach to evaluation for the design of communication systems that borrows from experimental and ethnographic methods. This approach is promoted as a practical and rigorous way of assessing design alternatives.The first group of measures are subjective ratings that assess someone's awareness of the attentional status of their conversational partner, such awareness is necessary for the successful coordination of conversation. The rating scales are shown to be sensitive in that they distinguish between video and audio mediated conversation in a short experiment.The second group are measures derived from video records of communicative behaviour using “activity set” analysis. This can be used to assess coordination in communication directly. An activity set is a mutually exclusive and exhaustive set of behavioural states. A publicly available tool, Action Recorder, makes it possible to score the tapes in near real time. “Simple statistics” are extracted from a single activity set, examples are: the proportion of time spent looking towards the video monitor and the average duration of these glances. “Contingent statistics” are extracted from two or more activity sets, for example, the proportion of time both members of a pair are looking towards their video monitors. A way of assessing the synchronization evident in two people's behaviour is presented that makes use of these contingent statistics. Inter-observer reliabilities are given for all the measures generated.

The technique described here involves generating a user-centred specification of the system in terms of 'action-effect rules'. This specification is then examined for violations of principles. In this paper we consider hard to reverse effects and ambiguous displays. Additional principles which might be used are also discussed. The technique is demonstrated with an example which also shows how it can be incorporated, with user testing, into an iterative design methodology. Action-effect rules are easier to generate than many of the alternative schemes. They can be extracted from the functional specification a designer will have to produce anyway. Specifying the user interface of a system with action-effect rules encourages the designer to think about the problems of the user from the earliest stages of design.

There are many commercial systems capable of transmitting a video image of parties in a conversation over a digital network. Typically, these have been used to provide facial images of the participants. Experimental evidence for the advantages of such a capability has been hard to find. This paper describes two experiments that demonstrate significant advantages for video conferencing over audio-only conferencing, in the context of a negotiation task using electronically shared data. In the video condition there was a large, high-quality image of the head and upper torso of the participant(s) at the other end of the link and high-quality sound. For the audio-alone condition the sound was the same but there was no video image. The criteria by which these two communication conditions were compared were not the conventional measures of task outcome. Rather, measures relating to conversational fluency and interpersonal awareness were applied. In each of the two experiments, participants completed the same task with data presented by a shared editor. In Experiment 1, they worked in pairs and in Experiment 2 they worked at quartets with two people at each end of the link. Fluency was assessed from transcripts in terms of length of utterance, overlapping speech and explicit questions. Only the latter measure discriminated between the two communication conditions in both experiments. The other measures showed significant effects in Experiment 2 but not in Experiment 1. Given this pattern of results it is concluded that video can result in more fluent conversation, particularly where there are more than two discussants. However, in the case of dyadic conversation auditory cues to turn taking, etc., would seem to suffice. In both experiments there was a large and significant effect on interpersonal awareness as assessed by ratings of the illusion of presence, and most clearly, awareness of the attentional focus of the remote partner (s). In Experiment 2, the ratings for the remote partners were similar to those for the co-located discussants, demonstrating the effectiveness of the video link with regard to these subjective scales.

In systems development it is essential for a piece of software to be able effectively to incorporate the requirements of the particular task domain that it is intended to address. This paper describes an approach that uses dialogue modelling to carry the requirements derived from task analysis through to the implementation phase of development. A notation based on production systems is used to develop an abstract specification of user and system behaviour which can subsequently be used as the basis for the implementation. The requirements for a computer-based tool are also discussed, with particular attention being given to ways in which the communication and reasoning about such a dialogue design can be supported.

Analyses of the costs and benefits of asynchronous communication, and the complementary properties of writing and speech, are used to predict that messages containing both writing and speech will be more communicative than either medium alone. Two experimental studies of asynchronous messaging are presented. Both experiments examine the use of pen-and-voice messages, that is voice messages attached to ‘scribbled’, i.e., uninterpreted text. The control conditions were voice messages alone, equivalent to an answerphone, and scribbled messages alone, equivalent to a fax. In Experiment 1 the visual component of the pen-and-voice messages was static, in Experiment 2 users could record short ‘movies’ including speech and pen movements over a document surface. Users showed a significant preference for the pen-and-voice messages in both experiments. In Experiment 2 half the number of pen-and-voice messages were required to achieve the same task performance as in the control conditions. It is concluded that dynamic pen-and-voice messages have considerable potential advantages over current single medium asynchronous communication facilities such as fax, answerphone, voicemail and e-mail.

Marr and Nishihara (1978) have made certain recommendations about how representations postulated in a theory of visual information processing should be specified. Using this scheme the paper discusses representations which might be postulated in a model of visual word recognition. A representation is specified in terms of a set of primitives (e.g., word identities or visual features) in combination with a coordinate system. The coordinate systems considered are retinal, spatial (e.g., position on page) word-centred (position in word) and sentence-centred (position in sentence).Various combinations of primitives and coordinate systems are considered along with how to decide which combinations are actually generated in the process of fluent reading. A tentative model is put forward in which a single processing stage, which starts anew after each saccade, generates a representation with word identities as its primitives and sentence-centred coordinates. Evidence to support such a model which has no intermediate representation with spatial coordinates is briefly reviewed.

There is a growing literature of experiments whose purpose is to compare different configurations for computer-mediated communication. If the results of these experiments are to be useful they must: ( i ) use the right experimental tasks; and ( ii ) measure the right dependent variables. This paper is concerned with the latter problem which is illustrated using data collected in experimental comparisons of three configurations of a text-based conferencing system. No significant differences were found using a measure of task outcome. This accords with numerous previous findings. However, a numberof process-related dependent variables were devised that did show significant effects. These included common ground, as measured by shared recall, and references to the topic of one message in the next available turn. Another, the use of first and second person pronouns in conversation approached significance. Finally, an approach to the selection of measures for use in studies of computer-mediated communication is commended.

The article explains the advantages of a carbon trading scheme in the organic farming industry. Organic wines are already recognized by wine connoisseurs in Australia and overseas because of organic farming's focus on soil health and related ecological approach to the farming system. There are producers in the organic industry who ask for carbon in the form the humus, the building block of a biologically active soil. Also discussed are the soil related clauses in the Australian Organic Standard and biodiversity in organic farms.

It is well known that schizophrenics have difficulty in effectively encoding verbal materials into their long-term memories and consequently show a deficit in recall. Recently, orienting tasks were introduced as a method for achieving equivalent to normal encoding and mnemonic organization in schizophrenics; consequently, their deficit in recall disappeared. A detailed review of the literature, however, showed that such effective orienting tasks had only been applied to mildly disturbed schizophrenics (nonchronic, in a good condition). This report presents three experiments which show that more severey disturbed (chronic, hospitalized) schizophrenics, unlike mildly disturbed patients, have memory deficits that cannot be located at the encoding stage. Severely disturbed schizophrenics show (1) a recall deficit, even after effective encoding and mnemonic organization are induced; (2) excessive forgetting over 24- and 48-hour periods; and (3) a recognition memory deficit. These deficits are in addition to their encoding deficit. The use of a matched tasks check in experiments 2 and 3 suggests that this postencoding deficit is a differential deficit and does not simply reflect the schizophrenic generalized deficit. Theoretical implications, also supported by the use of various organizational indices (e.g., clustering, hierarchical clustering schemes, and hierarchical grouping analysis), are discussed.

Apparatus to close a circuit when a subject writes can be assembled using an ordinary wooden pencil and baking foil. Problems encountered in the construction of similar systems using internal contacts are thus avoided.

Abstract: Assistive systems for persons with cognitive disabilities (e.g., dementia) are difficult to build due to the wide range of different approaches people can take to accomplishing the same task, and the significant uncertainties that arise from both the unpredictability of client’s behaviours and from noise in sensor readings. Partially observable Markov decision process (POMDP) models have been used successfully as the reasoning engine behind such assistive systems for small multi-step tasks such as hand washing. POMDP models are a powerful, yet flexible framework for modelling assistance that can deal with uncertainty and utility. Unfortunately, POMDPs usually require a very labour intensive, manual procedure for their definition and construction. Our previous work has described a knowledge driven method for automatically generating POMDP activity recognition and context sensitive prompting systems for complex tasks. We call the resulting POMDP a SNAP (SyNdetic Assistance Process). The spreadsheet-like result of the analysis does not correspond to the POMDP model directly and the translation to a formal POMDP representation is required. To date, this translation had to be performed manually by a trained POMDP expert. In this paper, we formalise and automate this translation process using a probabilistic relational model (PRM) encoded in a relational database. The database encodes the relational skeleton of the PRM, and includes the goals, action preconditions, environment states, cognitive model, client and system actions (i.e., the outcome of the SNAP analysis), as well as relevant sensor models. The database is easy to approach for someone who is not an expert in POMDPs, allowing them to fill in the necessary details of a task using a simple and intuitive procedure. The database, when filled, implicitly defines a ground instance of the relational skeleton, which we extract using an automated procedure, thus generating a POMDP model of the assistance task. A strength of the database is that it allows constraints to be specified, such that we can verify the POMDP model is, indeed, valid for the task given the analysis. We demonstrate the method by eliciting three assistance tasks from non-experts: handwashing, and toothbrushing for elderly persons with dementia, and on a factory assembly task for persons with a cognitive disability. We validate the resulting POMDP models using case-based simulations to show that they are reasonable for the domains. We also show a complete case study of a designer specifying one database, including an evaluation in a real-life experiment with a human actor. [Copyright &y& Elsevier]