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Results for “Dual Data Collection”

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PubMed2000

A comparison of trends in problematic drug misuse from two reporting systems.

BACKGROUND: Regional Drug Misuse Databases (RDMDs) are considered the main source of intelligence on problem drug takers in England. Originally intended to provide trend data on visible drug use, a recent strategic review concluded that their purpose should be to monitor treatment targets for the Government's latest 10 year strategy to tackle drug misuse. The aim of this analysis was to explore whether the General Practice Research Database (GPRD) could supplement RDMDs. METHODS: A retrospective analysis was carried out using the GPRD and the RDMD in the West Midlands from 1993 to 1997. RESULTS: Extrapolation of GPRD data indicates 6,574 drug misusing or dependent diagnosed patients in primary care in 1997 compared with 3,643 clients reported by all agencies including general practitioners (GPs) to the RDMD. From 1993 to 1997, the RDMD notification rate fluctuated whereas the GPRD rate has increased steadily since 1995. Half of all drug misusing or dependent patients recorded on the GPRD had psychiatric co-morbidity and 10 per cent had been referred to hospital for a drug overdose. CONCLUSIONS: As the GPRD has been unaffected by the demise of statutory notification of drug dependence in 1997, interpretation of trends may be more reliable than on the RDMD. There is also considerable potential for analysis of prescribing patterns, co-morbidity and drug-related hospitalization. As the Department of Health's Strategic Review of RDMDs recommends GPs as 'core reporters' for providing data to the national system, there is a need for a strategy to ensure valid and comprehensive reporting from GPs.

Data Collection↗

PubMed2001

Factors associated with low bone mineral density in female patients with systemic lupus erythematosus.

OBJECTIVE: To study risk factors for low bone mineral density (BMD, g/cm) in patients with systemic lupus erythematosus (SLE). METHODS: Ninety-two consecutive patients with SLE followed by rheumatology faculty between 1997 and 1999 completed a questionnaire regarding lifestyle during the clinic visit, a chart review was performed, and data were collected for the time of the first dual energy x-ray absorptiometry (DXA) examination. Univariate and multivariate statistical analyses were used to assess relationships between various risk factors and BMD. RESULTS: Ninety-eight percent of patients had received prednisone, 51% were postmenopausal (9 of whom received hormone replacement therapy), 68% had received hydroxychloroquine, and 15% were osteoporotic. The following factors were found to be significantly related to lower BMD by univariate analysis: Caucasian race, older age at diagnosis, higher age at the time of the first DXA, longer disease duration, higher cumulative corticosteroid dose, higher SLE Damage Index score, and postmenopausal status. In the multivariate analysis only the following factors were significant: Caucasian race, increased number of pregnancies, postmenopausal status, higher SLE Damage Index, and higher cumulative corticosteroid dose. An unexpected finding was that taking hydroxychloroquine was the only factor associated with higher BMD of the hip and spine in the univariate analysis, and it remained predictive of higher BMD of the hip and spine in the multivariate analysis. CONCLUSION: Hydroxychloroquine appears to protect against low BMD in corticosteroid treated patients with SLE.

Absorptiometry, Photon↗

PubMed1988

Determination of the critical O2 delivery from experimental data: sensitivity to error.

Normally, metabolic need determines tissue O2 consumption (VO2). In states of reduced supply, VO2 declines sharply below a critical level of O2 delivery (QO2 = blood flow X arterial O2 content). Although several investigators have measured a critical O2 delivery in whole animals or in isolated tissues, there is no general agreement over how to determine the critical point from a collection of real data. In this study, we compare three algorithms for finding the critical O2 delivery from a set of experimental data. We also present a technique for estimating the effect of experimental error on the precision of these algorithms. Using 16 data sets collected in normal dogs, we compare single-line, dual-line, and polynomial regression algorithms for identifying the critical O2 delivery. The dual-line and polynomial regression techniques fit the data better (mean residual square deviation 0.024 and 0.031, respectively) than the single-regression line approach (0.110). To investigate the influence of experimental error on the derived critical QO2, we used a Monte Carlo technique, repeatedly perturbing the experimental data to simulate experimental error. We then calculated the variance of the critical QO2 frequency distribution obtained when the three algorithms were applied to the perturbed data. By this analysis, the dual-line regression technique was less sensitive to experimental error than the polynomial technique.

Algorithms↗

PubMed2025

Integrated Seroprevalence and Genome-Based Study of SARS-CoV-2 Viral Strains in N'Djamena: Insights Into Chad's COVID-19 Epicenter.

The COVID-19 epidemic has shown regional variations in transmission and outcomes. As a primary hotspot in Chad, N'Djamena is crucial for comprehensive epidemiological investigation. Our study employed two methodologies: seroprevalence data collection and whole-genome sequencing of SARS-CoV-2 strains. This dual approach assessed population exposure and virus genetic diversity. Seroprevalence data indicated broader exposure than confirmed cases suggested, and genome sequencing identified multiple strains, including globally recognized variants of concern. Integrating these data provided insights into transmission dynamics, potential herd immunity thresholds, and the impact of specific variants on disease progression. Our findings underscore the importance of integrated, multidisciplinary research in infectious disease epidemiology and inform targeted public health strategies, including social measures and vaccination, to combat infectious diseases in N'Djamena.

Humans↗

PubMed2003

Radiographic damage associated with low bone mineral density and vertebral deformities in rheumatoid arthritis: the Oslo-Truro-Amsterdam (OSTRA) collaborative study.

OBJECTIVE: To examine variables associated with bone mineral density (BMD) and vertebral deformities in women with rheumatoid arthritis (RA) from 3 northwest European countries. METHODS: Female patients were recruited from rheumatology clinics in Oslo, Norway; Truro, UK; and Amsterdam, The Netherlands (150 total, 50 per center, age 50-70 years, disease duration > or = 5 years). Demographic and clinical data were collected and BMD was measured by means of dual energy x-ray absorptiometry. Associations between demographic and clinical measures on the one hand and BMD and vertebral deformities on the other were investigated by single and multiple regression analyses. RESULTS: Body mass index (BMI), medication use, RA damage measures, and BMD differed significantly between the 3 centers. Overall, Norwegian patients had the lowest BMI, used more corticosteroids and anti-osteoporotic drugs, had lower joint damage measured by Larsen score, and lower BMD at both spine and hip. High age, low BMI, and high cumulative dose of corticosteroids (last 2 years) are related to low BMD. A high Larsen score was associated with low BMD at the hip. Larsen score was the independent determinant of vertebral deformities after correction for center, age, BMI, and BMD. CONCLUSION: Data from 3 countries on BMD and vertebral deformities in female patients aged 50-70 years with longstanding RA are presented, demonstrating an association between radiographic RA damage and low BMD and between radiographic RA damage and vertebral deformities.

Absorptiometry, Photon↗

PubMed1988

The transition to parenthood in dual-earner couples.

The impact of the transition to parenthood for dual-earner couples was examined in a longitudinal study. Data were collected by questionnaire from couples expecting their first child, during pregnancy and after maternity leave, and from childless couples at two separate time points. The impact of the transition was minimal overall, although women experienced more pressure than men and there were some cases of extreme stress. New single-earner parents reported a greater decline in life satisfaction than dual-earners.

Adaptation, Psychological↗

PubMed2002

Past and present habitual physical activity and its relationship with bone mineral density in men aged 50 years and older in Brazil.

BACKGROUND: The aim of this study was to determine the relationship between habitual physical activity (HPA) during life and bone mineral density (BMD) in men aged 50 years and older. METHODS: A total of 326 men aged 50 years and older, volunteers living in São Paulo city, Brazil, were studied. BMD was measured in the whole body, femoral neck, Ward's triangle, trochanter, and lumbar spine (L2-L4) with a dual-energy x-ray absorptiometer. The HPA data were collected with questionnaires inquiring about physical exercise and occupational physical activity in the past and during the past 12 months and leisure and locomotor physical activity in the preceding 12 months. The relationship between BMD and HPA was analyzed using multiple linear regression models adjusted for age and body mass index (BMI). RESULTS: Practice of physical exercise in the past 10-20 years and leisure and locomotor physical activity in the preceding 12 months showed a significant positive correlation with BMD of whole body, femoral neck, trochanter, and lumbar spine, and this association was independent of age and BMI. CONCLUSIONS: HPA can contribute to preserving BMD in men aged 50 years and older in Brazil, when it is practiced in the past 10-20 years and even in the present.

Age Factors↗

PubMedDate not supplied

A dual frame design for sampling elderly minorities and persons with disabilities.

Multiple data sources are sometimes available as potential sampling frames for population surveys, and in some situations the use of a multiple frame sample design is more advantageous than using a single sampling frame. The use of multiple sampling frames, however, has variance and bias implications, as well as sampling, data collection, and logistical considerations. These issues are addressed for a proposed dual frame sampling approach in the National Health Interview Survey (NHIS). The results of an investigation of the sampling efficiencies and operational issues in supplementing the NHIS area frame sample with a sample of elderly African and Hispanic Americans and persons with disabilities selected from Social Security Administration files are presented.

Adolescent↗

PubMed1995

Comparison of single-injection multisample renal clearance methods with and without urine collection.

UNLABELLED: Single-injection renal clearance methods based on plasma clearance alone, without urine collection, are sometimes met with skepticism. They require data extrapolation to infinite time, which is hard to justify a priori. It has been asserted that they are less accurate for rapidly cleared tubular agents than for slowly cleared glomerular filtration rate agents. In this study, we compare urine-based and urine-free methods for the tubular agents 99mTc-MAG3 and 131I-OIH. METHODS: In 18 patients, dual-tracer plasma data were obtained from 4 to 90 min after injection (nine samples). Urine was also collected for 90 min (in two voidings). The urine counts wre corrected for residual bladder activity by pre- and postvoid dual-channel gamma camera images. RESULTS: When comparing the two methods of clearance calculations, the difference between urine-based and urine-free measurements 1 +/- 5 ml/min for 99mTc-MAG3 and 23 +/- 8 for 131I-OIH (mean +/- s.e. of the mean). For 99mTc-MAG3, the regression line did not differ significantly from the line of identity. The correlation coefficient was 0.94 for both agents. CONCLUSION: Urine collection is not necessary to measure renal clearance, even for the rapidly cleared tubular agents, except at low clearance levels (when the small absolute error corresponds to a large percentage error).

Glomerular Filtration Rate↗

PubMed1999

High-speed data acquisition system and receiver configurations for time-domain radiofrequency electron paramagnetic resonance spectroscopy and imaging.

Design strategies, system configuration, and operation of a dual-channel data acquisition system for a radiofrequency (RF) time-domain electron paramagnetic resonance (EPR) spectrometer/imager operating at 300 MHz are described. This system wasconfigured to incorporate high-speed analog-to-digital conversion (ADC) and summation capabilities with both internal and external triggering via GPIB interface. The sampling rate of the ADC is programmable up to a maximum of 1 GS/s when operating in a dual-channel mode or 2 GS/s when the EPR data are collected in a single-channel mode. By using high-speed flash ADCs, a pipelined 8-bit adder, and a 24-bit accumulator, a repetition rate of 230 kHz is realized to sum FIDs of 4096 points. The record length is programmable up to a maximum of 8K points and a large number of FIDs (2(24)) can be summed without overflow before the data can be transferred to a host computer via GPIB interface for further processing. The data acquisition system can operate in a two-channel (quadrature) receiver mode for the conventional mixing to baseband. For detection using the single-channel mode, the resonance signals around the center frequency of 300 MHz were mixed with a synchronized local oscillator of appropriate frequency leading to an intermediate frequency (IF) which is sampled at a rate of 2 GS/s. Comparison of quadrature-mode and an IF-mode operation for EPR detection is presented by studying the FID signal intensity across a bandwidth of 10 MHz and as a function of transmit RF power. Imaging of large-sized phantoms accommodated in appropriately sized resonators indicates that IF-mode operation can be used to obtain distortion-free images in resonators of size 50 mm diameter and 50 mm length.

Data Collection↗

PubMed1998

Dispositional effects on job and life satisfaction: the role of core evaluations.

Past research has suggested that dispositional sources of job satisfaction can be traced to measures of affective temperament. The present research focused on another concept, core self-evaluations, which were hypothesized to comprise self-esteem, generalized self-efficacy, locus of control, and nonneuroticism. A model hypothesized that core self-evaluations would have direct effects on job and life satisfaction. It also was hypothesized that core self-evaluations would have indirect effects on job satisfaction. Data were collected from 3 independent samples in 2 countries, using dual source methodology. Results indicated that core self-evaluations had direct and indirect effects on job and life satisfaction. The statistical and logical relationship among core evaluations, affective disposition, and satisfaction was explored.

Adult↗

PubMed1996

Correction for scatter in 3D brain PET using a dual energy window method.

A method for scatter correction using dual energy window acquisition has been developed and implemented on data collected with a brain-PET tomograph operated in the septa retracted, 3D mode. Coincidence events are assigned to (i) an upper energy window where both photons deposit energy between 380 keV and 850 keV or (ii) a lower energy window where one or both photons deposit within 200 keV and 380 keV. Scaling parameters are derived from measurements of the ratios of counts from line sources due to scattered and unscattered events in the two energy windows in head-sized phantoms. A scaled subtraction of the two energy windows produces a distribution of scatter which is smoothed prior to subtraction from the upper energy window. In phantoms, the correction was found to restore the uniformity, contrast and linearity of activity concentration. Relative activity concentrations were restored to within 7% of their true values in a multicompartment phantom. The method was found to provide accurate correction for scattered events arising from activity outside the direct detector field of view. In a three-compartment phantom containing water, 18F and 11C scanned in dynamic, multiframe mode, the half-lives of the two isotopes were restored to within 2% of their true value.

Brain↗

PubMed2001

Influence of bone densitometry results on the treatment of osteoporosis.

BACKGROUND: Measurement of bone mineral density is widely used to diagnose osteoporosis. The objectives of this study are to determine how bone densitometry affects subsequent treatment of osteopenia and osteoporosis with either hormone replacement therapy or bisphosphonates and to examine clinical factors associated with starting either therapy after bone densitometry. METHODS: We conducted a prospective study involving women over 50 years of age who were referred to a tertiary care hospital for the first time to undergo bone density measurement using dual-energy x-ray absorptiometry (DXA). Baseline clinical data were collected through face-to-face interviews before the test. Subsequently, the scans were reviewed and categorized as showing no bone loss, osteopenia or osteoporosis, based on World Health Organization criteria. Three months after DXA, subjects were contacted by telephone to determine their understanding of the test results and any new treatments started or recommended since the scan. RESULTS: Of 383 women recruited at the time of their DXA, 335 (87.5%) completed the 3-month follow-up. Among those reached at follow-up, DXA results showed no bone loss in 119 (35.5%), osteopenia in 137 (40.9%) and osteoporosis in 79 (23.6%). The proportion of subjects with osteoporosis receiving either hormone replacement therapy or bisphosphonate therapy was 15.2% before the test, increasing to 63.3% after the scan. The following factors were independently associated with the initiation of either therapy: actual DXA result showing osteoporosis (odds ratio [OR] 7.2; 95% confidence interval [CI] 1.7-30.3), compared with a normal scan; subjects' perception that their scan showed bone loss (osteopenia, or osteoporosis) (OR 13.5; 95% CI 4.0-45.5) or that they were unclear about the results (OR 5.4; 95% CI 1.6-18.8), compared with the perception that the results were normal; and discussion of the DXA results with a physician (OR 5.5; 95% CI 1.9-16.0). INTERPRETATION: The proportion of women with osteoporosis receiving hormone replacement therapy or bisphosphonate therapy increases after diagnosis with densitometry. However, communication by physicians so that patients understand their test results is a critical component in the initiation of therapy after bone densitometry.

Absorptiometry, Photon↗

PubMed2001

A dual path programmable array microscope (PAM): simultaneous acquisition of conjugate and non-conjugate images.

A programmable array microscope (PAM) incorporates a spatial light modulator (SLM) placed in the primary image plane of a widefield microscope, where it is used to define patterns of illumination and/or detection. We describe the characteristics of a special type of PAM collecting two images simultaneously. The conjugate image (Ic) is formed by light originating from the object plane and returning along the optical path of the illumination light. The non-conjugate image (Inc) receives light from only those regions of the SLM that are not used for illuminating the sample. The dual-signal PAM provides much more time-efficient excitation than the confocal laser scanning microscope (CLSM) and greater utilization of the available emission light. It has superior noise characteristics in comparison to single-sided instruments. The axial responses of the system under a variety of conditions were measured and the behaviour of the novel Inc image characterized. As in systems in which only Ic images are collected (Nipkow-disc microscopes, and previously characterized PAMs), the axial response to thin fluorescent films showed a sharpening of the axial response as the unit cell of the repetitive patterns decreased in size. The dual-signal PAM can be adapted to a wide range of data analysis and collection strategies. We investigated systematically the effects of patterns and unit cell dimensions on the axial response. Sufficiently sparse patterns lead to an Ic image formed by the superposition of the many parallel beams, each of which is equivalent to the single scanning spot of a CLSM. The sectioning capabilities of the system, as given by its axial responses, were similar for a given scan pattern and for processed pseudorandom sequence (PRS) scans with the same size of the unit cell. For the PRS scans, optical sectioning was achieved by a subtraction of an Inc image or, alternatively, a scaled widefield image from the Ic image. Based on the comparative noise levels of the two methods, the non-conjugate subtraction was significantly superior. A point spread function for Ic and Inc was simulated and properties of the optical transfer functions (OTFs) were compared. Simulations of the OTF in non-conjugate imaging did not suffer from the missing cone problem, enabling a high quality deconvolution of the non-conjugate side alone. We also investigated the properties of images obtained by subjecting the Ic and Inc data to a combined maximum likelihood deconvolution.

Animals↗

PubMed1991

The experience of fathers in dual-earner families following the births of their first infants.

This study explores the experience of fathers in dual-earner families following the births of their first infants. The grounded theory method was used to collect, code, compare and contrast data gathered in interviews with 10 men. The fathers indicated that they viewed their return to a dual-earner lifestyle as a process of redefining roles. Redefining roles was influenced by four basic life resources and two sets of value systems and occurred in the context of needs which were either met or unmet. The basic life resources and value systems not only influenced family members' needs, but also the two basic strategies which the men used in redefining their roles. First, the men monitored role strain and, second, they limited role strain. Each of these strategies evolved from the central concept of redefining roles. The consequences of redefining roles included effects on marital intactness, family members' health and family members' satisfaction. Redefining roles has implications for nurses who work with men in dual-earner families. As first-time fathers assume multiple roles and struggle with redefining their roles, nurses can offer anticipative and concurrent guidance.

Adult↗

PubMed2000

High-sensitivity chromatographic detector incorporating three-dimensional charge coupled device fluorimetry.

This article describes a detector for liquid chromatography that provides three-dimensional, excitation-emission-intensity data of fluorescent compounds. The instrument achieves multi-wavelength excitation by employing a polychromator that disperses radiation along the vertical portion of a quartz capillary flow cell. The ensuing sample fluorescence is collected in the horizontal plane and dispersed using an emission polychromator to form a focused two-dimensional excitation-emission image at a charge coupled device (CCD) pixel array. Each vertical pixel equates to a narrowly defined excitation wavelength band, whilst horizontal pixels equate to corresponding emission wavelengths, with the intensity of light encroaching onto the CCD pixel elements providing the third-dimensional variable in the measurement. It is shown that the extreme sensitivity of CCD detection coupled to the dual polychromator arrangement makes possible the collection of fluorescence excitation-emission-intensity data of polycyclic aromatic hydrocarbons in a flow stream in less than 0.05 s with nanogram per millilitre limits of detection.

Anthracenes↗

PubMed2003

Factor structure of hypomania: interrelationships with cyclothymia and the soft bipolar spectrum.

BACKGROUND: No systematic data exists on the phenomenology and psychometric aspects of hypomania. In this report we focus on the factor structure of hypomania and its relationships with cyclothymic temperament in unipolar (UP) and bipolar II (BP-II) spectrum (soft bipolar) patients. METHOD: The combined sample of UP and BP-II spectrum patients (n=427) derives from the French National multi-center study (EPIDEP). The study involved training 48 psychiatrists at 15 sites in France in a protocol based on DSM-IV phenomenological criteria for major depressive disorder, hypomania, and BP-II, as well as a broadened definition of soft bipolarity. Psychometric measures included Angst's Hypomania Checklist (HCA) and Akiskal's Cyclothymic Temperament (CT) Questionnaires. RESULTS: In the combined sample of the UP and BP-II spectrum, the factor pattern based on the HCA was characterized by the presence of one hypomanic component. In the soft bipolar group (n=191), two components were identified before and after varimax rotation. The first factor (F-1) identified hypomania with positive (driven-euphoric) features, and the second factor (F-2) hypomania with greater irritability and risk-taking. In exploratory analyses, both factors of hypomania tentatively distinguished most soft BP subtypes from UP. However, F-1 was generic across the soft spectrum, whereas F-2 was rather specific for II-1/2 (i.e., BP-II arising from CT). CT, which was found to conform to a single factor among the soft bipolar patients, was significantly correlated only with irritable risk-taking hypomania (F-2). LIMITATION: In a study conducted in a clinical setting, psychiatrists cannot be kept blind of the data revealed in the various clinical evaluations and instruments. However, the systematic collection of all data tended to minimize biases. CONCLUSION: EPIDEP data revealed a dual structure of hypomania with 'classic' driven-euphoric contrasted with irritable risk-taking expressions distributed differentially across the soft bipolar spectrum. Only the latter correlated significantly with cyclothymic temperament, suggesting the hypothesis that repeated brief swings into hypomania tend to destabilize soft bipolar conditions.

Adolescent↗

PubMed2000

Association between breast cancer and bone mineral density: the Dubbo Osteoporosis Epidemiology Study.

BACKGROUND: The association between bone mineral density and breast cancer was investigated in a nested case-control study, involving 30 breast cancer cases and 120 controls, aged 68+/-6 (mean +/-S.D.) years, as part of the Dubbo Osteoporosis Epidemiology Study (Australia). METHODS: Bone mineral density (BMD, g/cm(2)) at the femoral neck and lumbar spine was measured by dual energy X-ray absorptiometry. Anthropometric data and reproductive history were collected by direct interview using a structured questionnaire. RESULTS: In univariate conditional logistic regression analysis, lower age at menarche, longer overall duration of lifetime ovulation and higher bone density were associated with higher risk of breast cancer. Among the breast cancer cases, 20% of subjects had lumbar spine BMD greater than 1.20 g/cm(2) (or 2.5 S.D. above the mean) compared with less than 1% of the controls. After adjusting for the effects of duration of lifetime ovulation and body mass index, each 0.1 g/cm(2) increase in lumbar spine and femoral neck BMD was associated with a 2.1-fold (95% CI: 1.3-3.4) and 1.5-fold (1.0-2.4) respectively, higher risk of breast cancer. Further adjustment for age at menarche, hormone replacement therapy, and parity did not alter the result. Thus, postmenopausal BMD, which is affected by lifetime exposure to estrogen, is also related to risk of breast cancer. Importantly, it is estimated that estrogen therapy in osteoporotic women, even if raising the risk of breast cancer by 70% as suggested by some studies, would not elevate their risk to the level experienced by their non-osteoporotic counterparts. CONCLUSION: While the mechanism of this relationship remains to be explored, these data support the concept that lifetime exposure to estrogen is an indicator of risk of both breast cancer and osteoporosis. However, the use of estrogen in osteoporosis treatment would not elevate the risk of breast cancer in osteoporotic women up to the level experienced by their non-osteoporotic counterparts.

Absorptiometry, Photon↗