An administrative data validation study of the accuracy of algorithms for identifying rheumatoid arthritis: the influence of the reference standard on algorithm performance

BACKGROUND: We have previously validated administrative data algorithms to identify patients with rheumatoid arthritis (RA) using rheumatology clinic records as the reference standard. Here we reassessed the accuracy of the algorithms using primary care records as the reference standard. METHODS: We performed a retrospective chart abstraction study using a random sample of 7500 adult patients under the care of 83 family physicians contributing to the Electronic Medical Record Administrative data Linked Database (EMRALD) in Ontario, Canada. Using physician-reported diagnoses as the reference standard, we computed and compared the sensitivity, specificity, and predictive values for over 100 administrative data algorithms for RA case ascertainment. RESULTS: We identified 69 patients with RA for a lifetime RA prevalence of 0.9%. All algorithms had excellent specificity (>97%). However, sensitivity varied (75-90%) among physician billing algorithms. Despite the low prevalence of RA, most algorithms had adequate positive predictive value (PPV; 51-83%). The algorithm of “[1 hospitalization RA diagnosis code] or [3 physician RA diagnosis codes with ≥1 by a specialist over 2 years]” had a sensitivity of 78% (95% CI 69–88), specificity of 100% (95% CI 100–100), PPV of 78% (95% CI 69–88) and NPV of 100% (95% CI 100–100). CONCLUSIONS: Administrative data algorithms for detecting RA patients achieved a high degree of accuracy amongst the general population. However, results varied slightly from our previous report, which can be attributed to differences in the reference standards with respect to disease prevalence, spectrum of disease, and type of comparator group

Experimental evaluation of mechanical properties of the metal of pipeline of steel 17G1S-U after long-term operation

Наведено результати експериментального визначення характеристик короткочасної статичної міцності та пластичності металу трубопроводу з поздовжнім заводським зварним швом. Встановлено, що характеристики міцності та пластичності основного металу трубопроводу та металу зварного шва залежать від напрямку прокату та форми лабораторних зразків. Визначення характеристик міцності металу трубопроводу неруйнівним методом інструментованого індентування добре узгоджуються з даними механічних випробувань.The results are presented for the experimental determination of the short-term static strength and ductility of the metal in the longitudinal and transverse directions of the pipe of steel 17G1S-U with a factory-made longitudinal welded joint after a long operation. Specimen blanks were cut out of a piece of the pipe of 530 x 8 mm in diameter. The mechanical properties of the base metal (BM) and the metal in the specific areas of the welded joint: weld metal (WM) and the metal of the heat-affected zone (HAZ) were determined in the transverse direction of the pipe. The mechanical properties of the BM and WM were determined in the longitudinal direction of the pipe. The strength and plasticity characteristics of the pipe metal were determined by conventional tensile testing of laboratory specimens and a nondestructive instrumented indentation technique. For conventional tensile tests, flat specimens (with a treated and untreated test portion), both full-sized cylindrical specimens and those with a shortened test portion (for weld zones) were used. The strength characteristics of the BM were determined by a nondestructive instrumented indentation technique, whereas the strength of the specific areas of the welded joint was determined under static and cyclic loading conditions using a ball indenter of D = 2.5 mm. It is found that the mechanical treatment of both surfaces of the flat specimen of the BM increases the ultimate strength by 4.8%, the offset yield stress by 7.6% and the reduction of area by 16% as compared to the specimen with an untreated surface. The machining of the external or internal surface of the flat specimen increases the ultimate strength only by 1.2% as compared to that with an untreated surface. Tensile tests of specimens with a treated surface (flat and cylindrical specimens) of the BM and WM give a higher ultimate strength (by 6.3-7.6%) as compared to the similar data obtained for flat specimens having the BM without surface treatment, regardless of the rolling direction. The data obtained in testing of cylindrical specimens cut out in the transverse direction of the pipe and having a shortened test portion for the BM and WM exhibit higher ultimate strength and offset yield stress (by 5.46% and 2.86% and 8.7% and 9.05%) and lower reduction of area by 11.42% and 14.42% as compared to the corresponding characteristics obtained for full-sized cylindrical specimens in the longitudinal direction of the pipe. The determination of the strength characteristics of the pipeline metal by a nondestructive instrumented indentation technique agrees well with the data of conventional mechanical tests

MicroPulse DIAL (MPD) – a diode-laser-based lidar architecture for quantitative atmospheric profiling

Continuous water vapor and temperature profiles are critically needed for improved understanding of the lower atmosphere and potential advances in weather forecasting skill. Ground-based, national-scale profiling networks are part of a suite of instruments to provide such observations; however, the technological method must be cost-effective and quantitative. We have been developing an active remote sensing technology based on a diode-laser-based lidar technology to address this observational need. Narrowband, high-spectral-fidelity diode lasers enable accurate and calibration-free measurements requiring a minimal set of assumptions based on direct absorption (Beer–Lambert law) and a ratio of two signals. These well-proven quantitative methods are known as differential absorption lidar (DIAL) and high-spectral-resolution lidar (HSRL). This diode-laser-based architecture, characterized by less powerful laser transmitters than those historically used for atmospheric studies, can be made eye-safe and robust. Nevertheless, it also requires solar background suppression techniques such as narrow-field-of-view receivers with an ultra-narrow bandpass to observe individual photons backscattered from the atmosphere. We discuss this diode-laser-based lidar architecture's latest generation and analyze how it addresses a national-scale profiling network's need to provide continuous thermodynamic observations. The work presented focuses on general architecture changes that pertain to both the water vapor and the temperature profiling capabilities of the MicroPulse DIAL (MPD). However, the specific subcomponent testing and instrument validation presented are for the water vapor measurements only. A fiber-coupled seed laser transmitter optimization is performed and shown to meet all of the requirements for the DIAL technique. Further improvements – such as a fiber-coupled near-range receiver, the ability to perform quality control via automatic receiver scanning, advanced multi-channel scalar capabilities, and advanced processing techniques – are discussed. These new developments increase narrowband DIAL technology readiness and are shown to allow higher-quality water vapor measurements closer to the surface via preliminary intercomparisons within the MPD network itself and with radiosondes.</p

Personal non-commercial use only

ABSTRACT. Objective. We describe the pattern of incidence of thrombovascular events after diagnosis of systemic lupus erythematosus (SLE) in a cohort of lupus patients. Methods. Descriptive study of prospectively collected data using incidence rates of thrombovascular events and 95% confidence intervals (CI) calculated for predetermined periods of observation. KaplanMeier survival curves were plotted to estimate thrombovascular event-free survival. Results. Among 426 individuals, person-years contributed were as follows: 399 persons and 4356.0 person-years for all events; 417 persons and 4691.9 person-years for arterial events; and 408 persons and 4846.6 person-years for venous events. The incidence of thrombovascular events was highest during the first year after SLE diagnosis (4.00, 95% CI 2.24-6.59) and after 20 years (ranging from 3.32, 95% CI 1.52-6.30, to 4.99, 95% CI 0.60-18.01), and was lowest between 1 and 5 years after SLE diagnosis (1.00, 95% CI 0.53-1.72). A similar pattern was observed for arterial events, while venous events showed a higher incidence rate only in the first 30 days after SLE diagnosis (12.06, 95% CI 3.29-30.87) and remained low afterwards. The probabilities of remaining event-free at 5, 10, and 15 years were as follows: 0.92, 0.85, and 0.78, respectively, for all thrombovascular events; 0.95, 0.88, and 0.82, respectively, for arterial events; and 0.98, 0.95, and 0.94, respectively, for venous events. Conclusion. Thrombovascular events occur throughout the course of lupus, with the highest risk of arterial or venous events in the first year after diagnosis, and the pattern of occurrence varying there

An exploration of parents’ preferences for foot care in juvenile idiopathic arthritis: a possible role for the discrete choice experiment

Background: An increased awareness of patients’ and parents’ care preferences regarding foot care is desirable from a clinical perspective as such information may be utilised to optimise care delivery. The aim of this study was to examine parents’ preferences for, and valuations of foot care and foot-related outcomes in juvenile idiopathic arthritis (JIA).&lt;p&gt;&lt;/p&gt; Methods: A discrete choice experiment (DCE) incorporating willingness-to-pay (WTP) questions was conducted by surveying 42 parents of children with JIA who were enrolled in a randomised-controlled trial of multidisciplinary foot care at a single UK paediatric rheumatology outpatients department. Attributes explored were: levels of pain; mobility; ability to perform activities of daily living (ADL); waiting time; referral route; and footwear. The DCE was administered at trial baseline. DCE data were analysed using a multinomial-logit-regression model to estimate preferences and relative importance of attributes of foot care. A stated-preference WTP question was presented to estimate parents’ monetary valuation of health and service improvements.&lt;p&gt;&lt;/p&gt; Results: Every attribute in the DCE was statistically significant (p &#60; 0.01) except that of cost (p = 0.118), suggesting that all attributes, except cost, have an impact on parents’ preferences for foot care for their child. The magnitudes of the coefficients indicate that the strength of preference for each attribute was (in descending order): improved ability to perform ADL, reductions in foot pain, improved mobility, improved ability to wear desired footwear, multidisciplinary foot care route, and reduced waiting time. Parents’ estimated mean annual WTP for a multidisciplinary foot care service was £1,119.05.&lt;p&gt;&lt;/p&gt; Conclusions: In terms of foot care service provision for children with JIA, parents appear to prefer improvements in health outcomes over non-health outcomes and service process attributes. Cost was relatively less important than other attributes suggesting that it does not appear to impact on parents’ preferences.&lt;p&gt;&lt;/p&gt

Primary vs. Secondary Antibody Deficiency: Clinical Features and Infection Outcomes of Immunoglobulin Replacement

<div><p>Secondary antibody deficiency can occur as a result of haematological malignancies or certain medications, but not much is known about the clinical and immunological features of this group of patients as a whole. Here we describe a cohort of 167 patients with primary or secondary antibody deficiencies on immunoglobulin (Ig)-replacement treatment. The demographics, causes of immunodeficiency, diagnostic delay, clinical and laboratory features, and infection frequency were analysed retrospectively. Chemotherapy for B cell lymphoma and the use of Rituximab, corticosteroids or immunosuppressive medications were the most common causes of secondary antibody deficiency in this cohort. There was no difference in diagnostic delay or bronchiectasis between primary and secondary antibody deficiency patients, and both groups experienced disorders associated with immune dysregulation. Secondary antibody deficiency patients had similar baseline levels of serum IgG, but higher IgM and IgA, and a higher frequency of switched memory B cells than primary antibody deficiency patients. Serious and non-serious infections before and after Ig-replacement were also compared in both groups. Although secondary antibody deficiency patients had more serious infections before initiation of Ig-replacement, treatment resulted in a significant reduction of serious and non-serious infections in both primary and secondary antibody deficiency patients. Patients with secondary antibody deficiency experience similar delays in diagnosis as primary antibody deficiency patients and can also benefit from immunoglobulin-replacement treatment.</p></div

Costing juvenile idiopathic arthritis: examining patient-based costs during the first year after diagnosis

Objectives. There are few data on the treatment patterns and associated cost of treating children with inflammatory arthritis including juvenile idiopathic arthritis (JIA), in the short or long term. The aim of this study was to obtain patient-based costs for treating children with JIA in the UK, in the first year from diagnosis and from the secondary health care payer perspective

Breast cancer in systemic lupus

OBJECTIVE: There is a decreased breast cancer risk in SLE versus the general population. We assessed a large sample of SLE patients, evaluating demographic and clinical characteristics and breast cancer risk. METHODS: We performed case-cohort analyses within a multi-centre international SLE sample. We calculated the breast cancer hazard ratio (HR) in female SLE patients, relative to demographics, reproductive history, family history of breast cancer, and time-dependent measures of anti-dsDNA positivity, cumulative disease activity, and drugs, adjusted for SLE duration. RESULTS: There were 86 SLE breast cancers and 4,498 female SLE cancer-free controls. Patients were followed on average for 7.6 years. Versus controls, SLE breast cancer cases tended to be white and older. Breast cancer cases were similar to controls regarding anti-dsDNA positivity, disease activity and most drug exposures over time. In univariate and multivariate models, the principal factor associated with breast cancers was older age at cohort entry. CONCLUSIONS: There was little evidence that breast cancer risk in this SLE sample was strongly driven by any of the clinical factors that we studied. Further search for factors that determine the lower risk of breast cancer in SLE may be warranted

Study of Flare Assessment in Systemic Lupus Erythematosus Based on Paper Patients.

OBJECTIVE: To determine the level of agreement of disease flare severity (distinguishing severe, moderate, and mild flare and persistent disease activity) in a large paper-patient exercise involving 988 individual cases of systemic lupus erythematosus. METHODS: A total of 988 individual lupus case histories were assessed by 3 individual physicians. Complete agreement about the degree of flare (or persistent disease activity) was obtained in 451 cases (46%), and these provided the reference standard for the second part of the study. This component used 3 flare activity instruments (the British Isles Lupus Assessment Group [BILAG] 2004, Safety of Estrogens in Lupus Erythematosus National Assessment [SELENA] flare index [SFI] and the revised SELENA flare index [rSFI]). The 451 patient case histories were distributed to 18 pairs of physicians, carefully randomized in a manner designed to ensure a fair case mix and equal distribution of flare according to severity. RESULTS: The 3-physician assessment of flare matched the level of flare using the 3 indices, with 67% for BILAG 2004, 72% for SFI, and 70% for rSFI. The corresponding weighted kappa coefficients for each instrument were 0.82, 0.59, and 0.74, respectively. We undertook a detailed analysis of the discrepant cases and several factors emerged, including a tendency to score moderate flares as severe and persistent activity as flare, especially when the SFI and rSFI instruments were used. Overscoring was also driven by scoring treatment change as flare, even if there were no new or worsening clinical features. CONCLUSION: Given the complexity of assessing lupus flare, we were encouraged by the overall results reported. However, the problem of capturing lupus flare accurately is not completely solved