Impact of a severe influenza vaccine shortage on primary care practice.
ABSTRACT Because of influenza vaccine shortages during the 2004-2005 influenza season, vaccine was targeted for high-risk priority groups.
To assess among primary care physicians: (1) ability to identify priority patients; (2) extent of shortages; and (3) effects of shortages on vaccine redistribution, patient referral and future plans for vaccine delivery.
Mailed surveys of pediatric (Peds), family medicine (FM), and general internal medicine (GIM) physicians randomly selected from the American Medical Association master file.
Response rate was 37% and the study population included 377 Peds, 319 FM, and 251 GIM physicians. Seventy-five percent of Peds, 58% of FM and 60% of GIM had some method to identify priority patients, although only 39%, 21%, and 18%, respectively, had a computerized method. Forty-five percent of Peds, 73% of FM, and 75% of GIM experienced shortages, for a median of 2-3 months. Approximately 48%-50% of Peds, FM, and GIM obtained additional influenza doses; among these, 53% received vaccine from a public health entity. Fifty-one percent of Peds, 79% of FM, and 80% of GIM referred high-risk patients for immunization, 94% of the time to a public health clinic. More than 95% planned to administer influenza vaccine next season.
The majority of physicians experienced influenza vaccine shortages for prioritized patients, especially those providers caring for adults. There was significant vaccine redistribution and patient referral, primarily involving the public health system. Enhancing methods of targeting priority patients and increasing cooperation with public health entities should be priorities in dealing with future influenza vaccine shortages.
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ABSTRACT: Adaptive array weight adjustment algorithms are described by time varying stochastic differential equations. A new method employing a two-variable perturbation analysis is used to investigate the effects of the weight fluctuations on the Applebaum algorithm performance in the presence of multiple jammers. An explicit solution of the directivity pattern in the direction of the jammers for the two-jammer problem is derived. An improved formula for the output signal-to-interference plus noise ratio (SINR) is obtained. It is shown as expected that the greater the number of signals at the array input the greater the degradation in the directivity pattern in the direction of the interfering signals and the greater the degradation in the output SINR. In addition, we show that the performance degrades uncontrollably when the number of independent jammers approaches the number of array elements. A comparison is made of the new results and those obtained using standard approximations. Substantial differences are caused by first-order terms in the perturbation.Military Communications Conference, 1985. MILCOM 1985. IEEE; 11/1985
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ABSTRACT: Recommendations for annual seasonal influenza vaccination have expanded to now include >300 million children and adults each year. Community settings have become increasingly important venues for influenza vaccination. We sought to identify barriers to and solutions for expanding influenza vaccination in community settings. Semi-structured telephone interviews were conducted from 01/09 to 06/10 with a range of stakeholders involved in influenza vaccination, including health plans, medical services firms, retail based clinics, pharmacies, schools, and state and local public health immunization programs. Participants (n=65) were asked about barriers and feasible solutions to influenza vaccine delivery to children and adults in community settings. Key themes were identified through iterative coding using a grounded theory approach. Stakeholders identified specific financial barriers to influenza vaccine delivery in 3 major areas: purchase and distribution, delivery, and reimbursement. Limited purchasing power, the uncertain nature of public demand, and unpredictable timing of influenza vaccine supply were important barriers to enhance delivery in community settings. Barriers to delivery included complexities in running off-site clinics, especially in school settings, the need to manage publicly vs. privately purchased vaccines separately, and state-to-state variability in requirements for credentialing, physician oversight, and reporting. Reimbursement barriers included a protracted credentialing process, the need to determine insurance eligibility at point-of-service, and lack of a billing infrastructure in off-site clinics. Opportunities to mitigate financial barriers to influenza vaccine delivery in community settings focused on coordination across providers and the role of public health as a "trusted broker" to overcome existing challenges. Financial and systems barriers hamper the optimal use of community settings to effectively deliver influenza vaccines. Public health partners at the federal, state, and local levels are well-positioned to facilitate the engagement of all stakeholders in this important and complex vaccine delivery system.Vaccine 12/2011; 29(52):9632-9. DOI:10.1016/j.vaccine.2011.10.041 · 3.49 Impact Factor
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ABSTRACT: This paper deals with the control and management of a hybrid power system composed of two clean generators connected to the load via a DC-Bus. The system configuration can solve certain problems inherent to reliability and power supply quality emanating from generators renewable energy resources based connected to the load. Since the primary natural energy resource cannot be easy to handle due to fluctuations appearing at the output. This can be solved by using an adequate control strategy including intermediate energy storage. The paper describes some research works achieved till now in hybrid energy system area, including the assessment of the modeling and control methods used and a survey of control problems which must be carried out. The main contribution in this paper focuses with modeling the hybrid PV/PEMFC energy system, using Matlab/Simulink, optimizing a hybrid system devices using artificial intelligence and carrying out simulation studies using a real climate data and practical load profile. A comprehensive results of simulation showed that the model is effective, operational and that backup system composed of PEM Fuel Cells and electrolyser can be integrated with photovoltaic power systems to provide uninterrupted high-quality power.Renewable and Sustainable Energy Reviews 12/2011; 15(9). DOI:10.1016/j.rser.2011.07.046 · 5.51 Impact Factor