In the 1980s and early 1990s, asthma prevalence increased significantly in most Westernized countries. In more recent years, asthma trends have been less clear, with some studies suggesting that they ...are still rising and others suggesting that they have stabilized or decreased. A population-based cohort study was conducted to estimate asthma prevalence and incidence trends in one large Canadian province, Ontario. All individuals with asthma living in Ontario, a province of Canada with a multicultural population of approximately 12 million, were identified in universal, population health administrative databases by using a validated health administrative case definition of asthma. Annual asthma prevalence, incidence, and all-cause mortality rates were estimated from 1996 to 2005. During this time, the prevalence of asthma increased by 70.5%. The age- and sex-standardized asthma prevalence increased from 8.5% in 1996 to 13.3% in 2005, a relative increase of 55.1% (P < 0.0001). Asthma incidence rates increased in children by 30.0% and were relatively stable in adults. Overall all-cause mortality decreased. Asthma prevalence in Ontario, Canada, has increased significantly. This is attributable, in part, to an increase in the incidence of asthma in children. Effective clinical and public health strategies are needed to prevent and manage asthma in the population.
Asthma imposes a heavy and expensive burden on individuals and populations. A population-based surveillance and research program based on health administrative data could measure and study the burden ...of asthma; however, the validity of a health administrative data diagnosis of asthma must first be confirmed.
To evaluate the accuracy of population-based provincial health administrative data in identifying adult patients with asthma for ongoing surveillance and research.
Patients from randomly selected primary care practices were assigned to four categories according to their previous diagnoses: asthma, chronic obstructive pulmonary disease, related respiratory conditions and nonasthma conditions. In each practice, 10 charts from each category were randomly selected, abstracted, then reviewed by a blinded expert panel who identified them as asthma or nonasthma. These reference standard diagnoses were then linked to the patients' provincial records and compared with health administrative algorithms designed to identify asthma. Analyses were performed using the concepts of diagnostic test evaluation.
A total of 518 charts, including 160 from individuals with asthma, were reviewed. The algorithm of two or more ambulatory care visits and/or one or more hospitalization(s) for asthma in two years had a sensitivity of 83.8% (95% CI 77.1% to 89.1%) and a specificity of 76.5% (95% CI 71.8% to 80.8%).
Definitions of adult asthma using health administrative data are sensitive and specific for identifying adults with asthma. Using these definitions, cohorts of adults with asthma for ongoing population-based surveillance and research can be developed.
Asthma comorbidity, such as depression and obesity, has been associated with greater healthcare use, decreased quality of life and poor asthma control. Treating this comorbidity has been shown to ...improve asthma outcomes as well as overall health. Despite this, asthma comorbidity remains relatively under-recognised and understudied-perhaps because most asthma occurs in young people who are believed to be healthy and relatively free of comorbidity. The aim of this study was to quantify empirically the amount of comorbidity associated with asthma.
A population-based cohort study was conducted using the health administrative data of the 12 million residents of Ontario, Canada in 2005. A validated health administrative algorithm was used to identify individuals with asthma.
The amount of comorbidity among individuals with asthma, as reflected in rates of hospitalisations, emergency department visits and ambulatory care claims, was found to be substantial and much greater than that observed among individuals without asthma. Together, asthma and asthma comorbidity (the extra comorbidity found in individuals with asthma compared with those without asthma) were associated with 6% of all hospitalisations, 9% of all emergency room visits and 6% of all ambulatory care visits that occurred in Ontario.
Asthma comorbidity places a significant burden on individuals and the healthcare system and should be considered in the management of asthma. Further research should focus on which types of asthma comorbidity are responsible for the greatest burden and how such comorbidity should be prevented and managed.
Asthma is the most common chronic respiratory disease in Canada. The estimates of risk of developing asthma may help researchers and health planners set research agendas, predict the burden of asthma ...on society, and target the at-risk population for asthma prevention, management, and control.
To estimate the lifetime risk of physician-diagnosed asthma.
All individuals aged 0-79 years living in Ontario, Canada on April 1, 1996 who had not been diagnosed with asthma were monitored for 11 years until March 31, 2007. They were censored when they were diagnosed with asthma, turned age 80 years, or died. The lifetime risk (from birth to age 79 yr) of physician-diagnosed asthma was calculated by a modified survival analysis technique. Results were stratified by sex, rurality, and neighborhood income.
Overall, the lifetime risk of physician-diagnosed asthma was 33.9%. Whereas the overall lifetime risk was higher in females (35.0 vs. 32.9%; P < 0.001), the cumulative risk was higher in males in early years. The lifetime risk was higher in individuals living in urban areas (34.5 vs. 30.1%; P < 0.001) or low-income neighborhoods (35.0% in the lowest income quintile vs. 32.2% in the highest; P < 0.001).
Our estimated overall lifetime risk indicates that one of every three individuals in Ontario, Canada has physician-diagnosed asthma during one's lifetime.
Resistive Random Access Memory (ReRAM) is promising to be employed as high density storage-class memory due to its crossbar array and Triple-Level Cell (TLC) structures. However, TLC crossbar ReRAM ...suffers from high write latency and energy due to three unique challenges: (1) The crossbar array structure incurs IR drop issues. (2) The TLC structure requires iterative program-and-verify (P&V) procedure. (3) The resistance drift problem needs short interval scrub to avoid uncorrectable soft errors. In this article, to overcome the challenges of TLC crossbar ReRAM, we propose an enhanced low latency and energy efficient TLC crossbar ReRAM architecture, called EnTiered-ReRAM. The proposed EnTiered-ReRAM is composed of four components, including EnTiered-crossbar design, Compression-based Incomplete Data Mapping (CIDM), Compression-based Flip Scheme (CFS), and Compression-based Error Correction Code (CECC). Specifically, based on the observation that our previously proposed Tiered-crossbar design still suffers from large IR drops along bitlines in the far segments due to the long length of bitlines, EnTiered-crossbar partitions each crossbar array into two halves along bitlines, and then splits each bitline of the half crossbar array into the near and far segments by an isolation transistor, which thoroughly mitigates the IR drop issues. Then we use our previously proposed CIDM and CFS in the near and far segments of EnTiered-crossbar arrays to further decreases the write latency and energy. In addition, CECC is deeply coupled with CIDM and CFS. CECC dynamically employs the most appropriate ECC capability according to the remaining space of each cache line after CIDM or CFS encoding, which effectively improves the scrub interval and performance/energy with insignificant space overhead. The evaluation results show that, compared with an aggressive baseline, EnTiered-ReRAM can improve the system performance by 56.3% and reduce the energy consumption by 60.6% on average.
The course of asthma activity: A population study Gershon, Andrea, MSc, MD; Guan, Jun, MSc; Victor, J. Charles, MSc ...
Journal of allergy and clinical immunology,
03/2012, Letnik:
129, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Background Unlike most chronic diseases, which tend to progress over time, asthma is known to persist, possibly resolve, and/or present with any combination of remissions and relapses. As a result, ...its course has been difficult to characterize and its prognosis difficult to predict. Objective To quantify the proportion of individuals with asthma who have active disease and, of those, the proportion who experience significant gaps in their asthma activity; and to determine factors associated with asthma activity. Methods Universal population health administrative databases were used to identify all individuals with asthma living in Ontario, Canada, in 1993 and follow them for 15 years. Active asthma was indicated by 1 or more physician claims for asthma. Results Of 613,394 individuals with asthma in 1993, 504,851 (82.3%) had active disease in subsequent years. Of those who had complete follow-up, 74.6% experienced a gap of 2 or more years in their asthma activity. Previous asthma claims, older and younger age, and a codiagnosis of chronic obstructive pulmonary disease correlated with greater asthma activity. Conclusion Over 15 years, most individuals with asthma in Ontario, Canada, had active disease that was interspersed by periods of inactivity when they did not require medical attention and were likely in remission. These analyses offer insight into the natural course of asthma activity that may help improve the ability to predict an individual’s course of disease.
Resistive random access memory (RRAM) is promising to be used as high density storage-class memory by employing crossbar structure. However, the wire resistance in crossbar array causes the IR drop ...problem, which makes nonuniformity of write latency throughout the array. In large crossbar array, the write latency differs greatly even in the same row. Since the write latency of a region is determined by its slowest write-unit, the conventional group-by-row region partition and addressing scheme is suboptimal for improving the overall performance of RRAM. In this work, we present DAWS, a novel RRAM architecture that exploits intrinsic features of crossbar structure. We first build a circuit model to analyze the voltage distribution and write latency distribution in a crossbar array. Then we propose a voltage bias scheme to optimize write latency via minimizing the IR drop path. We further present block diagonal partition to narrow the variance of write latency within each region, thus the write latency of each region is reduced. Moreover, we provide block diagonal addressing to make the write latency monotonically increase with the physical address, which is in favor of address mapping and memory allocation. We also design diagonal writing and diagonal swapping to overlap SET and RESET operations by applying a particular voltage bias pattern that can exploit row level parallelism, thus the number of write operations is halved. The experimental results show that DAWS can reduce memory access latency by 24.0% and improve system performance by 29.7% over an aggressive baseline.
BACKGROUND Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease with a prevalence of more than 10% worldwide among adults 40 years and older. Whether this amount has ...been increasing, decreasing, or stable over time remains unknown. METHODS A longitudinal cohort study using population-based, health administrative data from 1991 to 2007 was conducted in Ontario, Canada. Individuals with COPD were identified using a previously validated health administrative case definition of COPD. Annual COPD prevalence, incidence, and all-cause mortality rates were estimated from 1996 to 2007. RESULTS The prevalence of COPD increased by 64.8% between 1996 and 2007. The age- and sex-standardized COPD prevalence rate increased from 7.8% to 9.5%, representing a relative increase of 23.0% (P < .001). The age- and sex-standardized incidence decreased from 11.8 per 1000 adults to 8.5 per 1000 adults, representing a relative decrease of 28.3% (P < .001). Finally, the age- and sex-standardized all-cause mortality rate decreased from 5.7% to 4.3%, representing a relative decrease of 24.0% (P < .001). CONCLUSIONS Our findings indicate a substantial increase in COPD prevalence in the last decade, with more of the burden being shifted from men to women. Effective clinical and public health strategies are needed to prevent COPD and manage the increasing number of people living longer with this disease.Arch Intern Med. 2010;170(6):560-565-->
Objective To determine the association between large birth weight and the risk of developing asthma in early childhood. Methods All single live births (n=687 194) born in Ontario between 1 April 1995 ...and 31 March 2001 were followed until their sixth birthday. Their birth weight was categorised as low (<2.5 kg), normal (2.5–4.5 kg), large (4.6–6.5 kg) or extremely large (>6.5 kg). Poisson regression analysis was used. Results Compared with normal-birth-weight infants, large-birth-weight infants (2.3% of total) had a slightly lower risk of developing asthma by age 6 after adjusting for confounders (adjusted RR 0.90, 95% CI 0.86 to 0.93). There was a trend towards increased risk of asthma among extremely large-birth-weight infants (RR 1.21, 95% CI 0.67 to 2.19). Conclusions Contrary to previous reports, large birth weight was associated with a lower risk for asthma. Instead, a trend towards increased risk of asthma was observed among extremely large-birth-weight infants and interventions to reduce the incidence of extreme large birth weight may help reduce the risk of asthma.
To assess the intra- and inter-rater agreement of chart abstractors from multiple sites involved in the evaluation of an Asthma Care Program (ACP).
For intra-rater agreement, 110 charts randomly ...selected from 1,433 patients enrolled in the ACP across eight Ontario communities were re-abstracted by 10 abstractors. For inter-rater agreement, data abstractors reviewed a set of eight fictitious charts. Data abstraction involved information pertaining to six categories: physical assessment, asthma control, spirometry, asthma education, referral visits, and medication side effects. Percentage agreement and the kappa statistic (kappa) were used to measure agreement. Sensitivity and specificity estimates were calculated comparing results from all raters against the gold standard.
Intra-rater re-abstraction yielded an overall kappa of 0.81. Kappa values for the chart abstraction categories were: physical assessment (kappa 0.84), asthma control (kappa 0.83), spirometry (kappa 0.84), asthma education (kappa 0.72), referral visits (kappa 0.59) and medication side effects (kappa 0.51). Inter-rater abstraction of the fictitious charts produced an overall kappa of 0.75, sensitivity of 0.91 and specificity of 0.89. Abstractors demonstrated agreement for physical assessment (kappa 0.88, sensitivity and specificity 0.95), asthma control (kappa 0.68, sensitivity 0.89, specificity 0.85), referral visits (kappa 0.77, sensitivity 0.88, specificity 0.95), and asthma education (kappa 0.49, sensitivity 0.87, specificity 0.77).
Though collected by multiple abstractors, the results show high sensitivity and specificity and substantial to excellent inter- and intra-rater agreement, assuring confidence in the use of chart abstraction for evaluating the ACP.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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