The AMC Linear Disability Score project in a population requiring residential care: psychometric properties

BACKGROUND: Currently there is a lot of interest in the flexible framework offered by item banks for measuring patient relevant outcomes, including functional status. However, there are few item banks, which have been developed to quantify functional status, as expressed by the ability to perform activities of daily life. METHOD: This paper examines the psychometric properties of the AMC Linear Disability Score (ALDS) project item bank using an item response theory model and full information factor analysis. Data were collected from 555 respondents on a total of 160 items. RESULTS: Following the analysis, 79 items remained in the item bank. The remaining 81 items were excluded because of: difficulties in presentation (1 item); low levels of variation in response pattern (28 items); significant differences in measurement characteristics for males and females or for respondents under or over 85 years old (26 items); or lack of model fit to the data at item level (26 items). CONCLUSIONS: It is conceivable that the item bank will have different measurement characteristics for other patient or demographic populations. However, these results indicate that the ALDS item bank has sound psychometric properties for respondents in residential care settings and could form a stable base for measuring functional status in a range of situations, including the implementation of computerised adaptive testing of functional status

Practical methods for dealing with 'not applicable' item responses in the AMC Linear Disability Score project

Background:\ud Whenever questionnaires are used to collect data on constructs, such as functional status or health related quality of life, it is unlikely that all respondents will respond to all items. This paper examines ways of dealing with responses in a 'not applicable' category to items included in the AMC Linear Disability Score (ALDS) project item bank. \ud \ud Methods:\ud The data examined in this paper come from the responses of 392 respondents to 32 items and form part of the calibration sample for the ALDS item bank. The data are analysed using the one-parameter logistic item response theory model. The four practical strategies for dealing with this type of response are: cold deck imputation; hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the 'tendency to respond to items'. \ud \ud Results:\ud The item and respondent population parameter estimates were very similar for the strategies involving hot deck imputation; treating the missing responses as if these items had never been offered to those individual patients; and using a model which takes account of the 'tendency to respond to items'. The estimates obtained using the cold deck imputation method were substantially different. \ud \ud Conclusions:\ud The cold deck imputation method was not considered suitable for use in the ALDS item bank. The other three methods described can be usefully implemented in the ALDS item bank, depending on the purpose of the data analysis to be carried out. These three methods may be useful for other data sets examining similar constructs, when item response theory based methods are used

Towards sideband-separation for ALMA's highest bands

Over the last few years, we developed high-performance sideband- separating (2SB) mixers for 600-720 GHz (Band 9) and 790-950 GHz (Band 10). The former have successfully been commissioned in the SEPIA front- end at APEX. On-sky image rejection ratios in excess of 24dB have been recorded for the CO(6-5) line at 691 GHz and the water maser line at 658 GHz, while lab testing shows 15dB or better over an extended RF band of about 580-740GHz. Noise temperature is better than 200K (SSB) over most of the band. The receiver cartridge has four 4-12 GHz IF outputs and is fully ALMA-frontend compatible. We intend to extend the IF bandwidth even further in the near future. The new Band 790-950 GHz 2SB mixer (intended for the FLASH front-end at APEX) has been tested in the lab recently and shows comparable performance characteristics. We see these mixers, with circulator-less wideband IF infrastructure, as an attractive upgrade for the highest ALMA bands

The Academic Medical Center Linear Disability Score (ALDS) item bank: item response theory analysis in a mixed patient population

BACKGROUND: Currently, there is a lot of interest in the flexible framework offered by item banks for measuring patient relevant outcomes. However, there are few item banks, which have been developed to quantify functional status, as expressed by the ability to perform activities of daily life. This paper examines the measurement properties of the Academic Medical Center linear disability score item bank in a mixed population. METHODS: This paper uses item response theory to analyse data on 115 of 170 items from a total of 1002 respondents. These were: 551 (55%) residents of supported housing, residential care or nursing homes; 235 (23%) patients with chronic pain; 127 (13%) inpatients on a neurology ward following a stroke; and 89 (9%) patients suffering from Parkinson's disease. RESULTS: Of the 170 items, 115 were judged to be clinically relevant. Of these 115 items, 77 were retained in the item bank following the item response theory analysis. Of the 38 items that were excluded from the item bank, 24 had either been presented to fewer than 200 respondents or had fewer than 10% or more than 90% of responses in the category 'can carry out'. A further 11 items had different measurement properties for younger and older or for male and female respondents. Finally, 3 items were excluded because the item response theory model did not fit the data. CONCLUSION: The Academic Medical Center linear disability score item bank has promising measurement characteristics for the mixed patient population described in this paper. Further studies will be needed to examine the measurement properties of the item bank in other populations

Cost-Effectiveness and Cost-Utility of Early Levodopa in Parkinson's Disease

Background: In the Levodopa in EArly Parkinson's disease (LEAP) study, 445 patients were randomized to levodopa/carbidopa 100/25 mg three times per day for 80 weeks (early-start) or placebo for 40 weeks followed by levodopa/carbidopa 100/25 mg three times per day for 40 weeks (delayed-start).Objective: This paper reports the results of the economic evaluation performed alongside the LEAP-study.Methods: Early-start treatment was evaluated versus delayed-start treatment, in which the cost-effectiveness analysis (CEA) and the cost-utility analysis (CUA) were performed from the societal perspective, including health care costs among providers, non-reimbursable out-of-pocket expenses of patients, employer costs of sick leave, and lowered productivity while at work. The outcome measure for the CEA was the extra cost per unit decrease on the Unified Parkinson's Disease Rating Scale 80 weeks after baseline. The outcome measure for the CUA was the extra costs per additional quality adjusted life year (QALY) during follow-up.Results: 212 patients in the early-start and 219 patients in the delayed-start group reported use of health care resources. With savings of D 59 per patient (BCa 95% CI: -829, 788) in the early-start compared to the delayed-start group, societal costs were balanced. The early-start group showed a mean of 1.30 QALYs (BCa 95% CI: 1.26, 1.33) versus 1.30 QALYs (BCa 95% CI: 1.27, 1.33) for the delayed-start group. Because of this negligible difference, incremental cost-effectiveness and cost-utility ratios were not calculated.Conclusion: From an economic point of view, this study suggests that early treatment with levodopa is not more expensive than delayed treatment with levodopa.Neurological Motor Disorder

Call-duration and triage decisions in out of hours cooperatives with and without the use of an expert system

<p>Abstract</p> <p>Background</p> <p>Cooperatives delivering out of hours care in the Netherlands are hesitant about the use of expert systems during triage. Apart from the extra costs, cooperatives are not sure that quality of triage is sufficiently enhanced by these systems and believe that call duration will be prolonged drastically. No figures about the influence of the use of an expert system during triage on call duration and triage decisions in out of hours care in the Netherlands are available.</p> <p>Methods</p> <p>Electronically registered data concerning call duration and triage decisions were collected in two cooperatives. One in Tilburg, a cooperative in a Southern city of the Netherlands using an expert system, and one in Groningen, a cooperative in a Northern city not using an expert system. Some other relevant information about the care process was collected additionally. Data about call duration was compared using an independent sample t-test. Data about call decisions was compared using Chi Square.</p> <p>Results</p> <p>The mean call time in the cooperative using the TAS expert system is 4.6 minutes, in the cooperative not using the expert system 3.9 minutes. A significant difference of 0.7 minutes (0.4 – 1.0, 95% CI) minutes. In the cooperative with an expert system a larger percentage of patients is handled by the assistant, patients are less often referred to a telephone consultation with the GP and are less likely to be offered a visit by the GP.</p> <p>A quick interpretation of the impact of the difference in triage decisions, show that these may be large enough to support the hypothesis that longer call duration is compensated for by less contacts with the GP (by telephone or face-to-face). There is no proof, however, that these differences are caused by the use of the triage system. The larger amount of calls handled by the assistant may be partly caused by the fact that the assistants in the cooperative with an expert system more often consult the GP during triage. And it is not likely that the larger amount of home visits in Groningen can be attributed to the absence of an expert system. The expert system only offers advice whether a GP should be seen, not in which way (by consultation in the office or by home visit).</p> <p>Conclusion</p> <p>The differences in call times between a cooperative using an expert system and a cooperative not using an expert system are small; 0.4 – 1.0 min. Differences in triage decisions were found, but it is not proven that these can be contributed to the use of an expert system.</p

Neuropsychological deficits in Posterior Cortical Atrophy and typical Alzheimer's disease:A meta-analytic review

Aims: To identify cognitive tests that best differentiate between Posterior Cortical Atrophy (PCA) and typical Alzheimer's Disease (tAD), as well as PCA and healthy control (HC) participants. Method: Medline, PsycInfo and Web of Science were systematically searched using terms related to PCA, tAD, and cognitive testing. Seventeen studies were identified, including 441 PCA, 391 tAD, and 284 HC participants. Standardised effect sizes of mean scores were calculated to measure performance differences on cognitive tests for PCA versus tAD and PCA versus HC groups. Meta-analyses used a random effects model. Results: The most discriminating cognitive tests for PCA and tAD presentations were measures of visuospatial function and verbal memory. Large, significant effect sizes were produced for all measures of visuospatial function, most notably for Rey-Osterrieth Copy (Hedges' g =-2.79), VOSP Fragmented letters (Hedges' g =-1.73), VOSP Dot Counting (Hedges' g =-1.74), and VOSP Cube Analysis (Hedges' g =-1.98). For measures of verbal memory, the RAVLT delay and Digit Span Backwards produced significant medium effects (Hedges' g = .62 and-.56, respectively). Conclusion: Establishing a common framework for testing individuals with PCA has important implications for diagnosis and treatment, and forms a practical objective for future research. Findings from this meta-analysis suggest that measures of visuospatial function and verbal memory would form an important part of this framework. Crown Copyright (c) 2021 Published by Elsevier Ltd. All rights reserved

Math saves the forest

Wireless sensor networks are decentralised networks consisting of sensors that can detect events and transmit data to neighbouring sensors. Ideally, this data is eventually gathered in a central base station. Wireless sensor networks have many possible applications. For example, they can be used to detect gas leaks in houses or fires in a forest.\ud In this report, we study data gathering in wireless sensor networks with the objective of minimising the time to send event data to the base station. We focus on sensors with a limited cache and take into account both node and transmission failures. We present two cache strategies and analyse the performance of these strategies for specific networks. For the case without node failures we give the expected arrival time of event data at the base station for both a line and a 2D grid network. For the case with node failures we study the expected arrival time on two-dimensional networks through simulation, as well as the influence of the broadcast range

The frontotemporal syndrome of ALS is associated with poor survival

Thirty percent of ALS patients have a frontotemporal syndrome (FS), defined as behavioral changes or cognitive impairment. Despite previous studies, there are no firm conclusions on the effect of the FS on survival and the use of non-invasive ventilation (NIV) in ALS. We examined the effect of the FS on survival and the start and duration of NIV in ALS. Behavioral changes were defined as >22 points on the ALS-Frontotemporal-Dementia-Questionnaire or ≥3 points on ≥2 items of the Neuropsychiatric Inventory. Cognitive impairment was defined as below the fifth percentile on ≥2 tests of executive function, memory or language. Classic ALS was defined as ALS without the frontotemporal syndrome. We performed survival analyses from symptom ons

Unscheduled return visits to a Dutch inner-city emergency department

Background Unscheduled return visits to the emergency department (ED) may reflect shortcomings in care. This study characterized ED return visits with respect to incidence, risk factors, reasons and post-ED disposition. We hypothesized that risk factors for unscheduled return and reasons for returning would differ from previous studies, due to differences in health care systems. Methods All unscheduled return visits occurring within 1 week and related to the initial ED visit were selected. Multivariable logistic regression was conducted to determine independent factors associated with unscheduled return, using patient information available at the initial visit. Reasons for returning unscheduled were categorized into illness-, patient- or physician-related. Post-ED disposition was compared between patients with unscheduled return visits and the patients who did not return. Results Five percent (n = 2,492) of total ED visits (n = 49,341) were unscheduled return visits. Patients with an urgent triage level, patients presenting during the night shift, with a wound or local infection, abdominal pain or urinary problems were more likely to return unscheduled. Reasons to revisit unscheduled were mostly illness-related (49%) or patient-related (41%). Admission rates for returning patients (16%) were the same as for the patients who did not return (17%). Conclusions Apart from abdominal complaints, risk factors for unscheduled return differ from previous studies. Short-term follow-up at the outpatient clinic or general practitioner for patients with urgent triage levels and suffering from wounds or local infections, abdominal pain or urinary problem might prevent unscheduled return