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Biomedical subjects

David C Aron

Publications and source records attributed to David C Aron.

At least 19 recordsLinked to original sources
PubMed2006

Suppression of gastric acid production by proton pump inhibitor treatment facilitates colonization of the large intestine by vancomycin-resistant Enterococcus spp. and Klebsiella pneumoniae in clindamycin-treated mice.

Proton pump inhibitor treatment of clindamycin-treated mice elevated the gastric pH and facilitated the establishment of colonization of the large intestine by vancomycin-resistant Enterococcus spp. (75 to 80%, versus 20 to 25% for saline-treated controls) and Klebsiella pneumoniae (90%, versus 30% for saline-treated controls). These findings demonstrate a mechanism by which proton pump inhibitor therapy could contribute to the dissemination of nosocomial pathogens.

Animals↗
PubMed2006

Disparities among the disadvantaged: variation in lipid management in the Ohio Medicaid program.

BACKGROUND: Racial disparities exist in cardiovascular disease (CVD) prevention, but other non-clinical factors may influence treatment, further exacerbating disparities. METHODS: Using Ohio Medicaid data from 1992 to 1999, we identified a sample of 19,106 individuals with CVD-related diagnoses or procedures. A review of pharmacy claims identified previous, new, and long-term users of lipid-lowering agents, including statins, fibrates, and bile sequestrants. RESULTS: 3,934 (20.6%) Medicaid beneficiaries used lipid-lowering medications previously, 1,598 (10.5%) filed new claims, and 2,998 of 5,532 (54.2%) previous or new users filed >or=6 claims for refills. Minority adults <or=60 years were least likely to have been previous users (0.80 [0.67, 0.96]), new users (0.75 [0.58, 0.98]), or to use lipid-lowering agents long-term (0.65 [0.49, 0.84]). CONCLUSIONS: Targeted efforts to enhance younger minority adults' receipt and long-term use of lipid-lowering agents may reduce risks for subsequent morbidity and mortality related to CVD.

Adult↗
PubMed2006

Comparison of weighted performance measurement and dichotomous thresholds for glycemic control in the Veterans Health Administration.

OBJECTIVE: Quality measures of glycemic control using threshold values do not assess incremental quality improvement. We compared health care system performance using weighted continuous versus dichotomous measures for glycemic control. RESEARCH DESIGN AND METHODS: We performed retrospective cross-sectional analysis of chart abstraction data on 37,142 diabetic patients from 141 Veterans Health Administration medical centers in 2000-2001. RESULTS: Subjects per facility ranged from 163 to 740 (mean 263). Mean overall HbA(1c) (A1C) was 7.58%. A continuous measure for glycemic control was calculated based on percentage of maximal quality-adjusted life-years saved (QALYsS). Overall mean facility performance using the dichotomous measure was 62% <8% A1C (range 48-75%) and 39% <7% A1C (21-57%), in comparison with 45% maximal QALYsS (31-60%). Correlation between QALYsS and A1C thresholds of <8 (0.848) and <7 (0.838) for facility rankings was excellent; correlation between facility level performance using thresholds of <8 and 7% was poor (r = 0.13, P = 0.14). Comparison of facility rankings between the <7% dichotomous measure and the QALYsS-weighted measure showed that 22% changed their ranking by > or =2 deciles with marked changes in top and bottom deciles. CONCLUSIONS: Facility rankings vary by threshold or continuous methodology. However, because significant numbers of individuals are unable to reach "optimal" target goals (thresholds) even in clinical trials with extensive exclusion criteria, we propose that a continuous measure assessing improvement toward optimal A1C, rather than a pass/fail optimal target, is both a fairer assessment clinical practice and a more accurate reflection of population health improvement.

Aged↗
PubMed2005

The DNA damage response and patient safety: engaging our molecular biology-oriented colleagues.

The imperative to improve patient safety is clear. Biomedical scientists, who account for a large proportion of medical school faculty, and clinicians tend to speak different languages. Biological systems are remarkable for their high robustness, flexibility, and efficiency. Biomedical scientists possess a profound understanding of the complex mechanisms that govern organisms. Their insights may inform the design of safer health care systems. We propose a model to assist in bi-directional communication between these disciplines. We use the principles and mechanisms of the DNA damage response to describe the central concepts of safety science and discuss similarities and differences between the systems of DNA repair and organizational approaches to safety in health care. We suggest that such biomedical scientists can and should be engaged in the effort to bring education about patient safety management into the medical school curriculum and to make patient care safer.

Biomedical Research↗
PubMed2005

The outcomes card. Development of a systems-based practice educational tool.

INTRODUCTION: The Accreditation Council for Graduate Medical Education requires competence in systems-based practice (SBP) demonstrating understanding of complex interactions between systems of care and its impact upon care delivery. Patient safety is a useful vehicle to facilitate learning about these interactions. AIM: Develop an educational tool, Outcomes Card (OC), to reinforce core concepts of SBP. SETTING: Urgent Care Center at Louis Stokes Cleveland Department of Veterans Affairs Medical Center. PROGRAM DESCRIPTION: Pilot study of an educational intervention for residents that included patient safety didactic sessions and analysis of 2 self-identified clinical cases using the OC. Residents entered the following information on the OC: case description, type of event (error, near miss, and/or adverse event), error type(s), systems, and system failures. PROGRAM EVALUATION: Two reviewers independently analyzed 98 cards completed during 60 two-week trainee rotations (81.7% return rate). Interrater reliability for error types between residents and physician supervisor and between reviewers was excellent (kappa=0.88 and 0.95, respectively), and for system identification was good (kappa=0.66 and 0.68, respectively). The self-assessment survey (56.6% return rate) suggests that residents improved their knowledge of patient safety and had positive attitudes about the curriculum. DISCUSSION: This pilot study suggests that OCs are feasible and reliable educational tools for enhancing competence in SBP.

Adult↗
PubMed2004

Acquisition of nosocomial pathogens on hands after contact with environmental surfaces near hospitalized patients.

We examined the frequency of acquisition of bacterial pathogens on investigators' hands after contacting environmental surfaces near hospitalized patients. Hand imprint cultures were positive for one or more pathogens after contacting surfaces near 34 (53%) of 64 study patients, with Staphylococcus aureus and vancomycin-resistant Enterococcus being the most common isolates.

Bacteria↗
PubMed2004

Effect of the increasing use of piperacillin/tazobactam on the incidence of vancomycin-resistant enterococci in four academic medical centers.

BACKGROUND: The substitution of piperacillin/tazobactam, ampicillin/sulbactam, or both for third-generation cephalosporins has been associated with reduced vancomycin-resistant enterococci (VRE). However, piperacillin/tazobactam came into widespread use during a period in which the prevalence of VRE increased. We hypothesized that the increasing use of piperacillin/tazobactam and other agents with relatively enhanced anti-enterococcal activity (ie, piperacillin, ampicillin/sulbactam, and ampicillin) has been associated with increased or unchanged rates of VRE in some hospitals. DESIGN: We retrospectively evaluated the correlation between hospital antibiotic use (defined daily doses per 10,000 patient-days of care) and incidence of stool or non-stool VRE isolation. We assessed whether a high or increasing proportion of use of beta-lactam agents with relatively enhanced versus minimal (ie, third-generation cephalosporins and ticarcillin/clavulanate) anti-enterococcal activity would prevent increased VRE. SETTING: Four academic medical centers. RESULTS: With the increasing use of piperacillin/tazobactam, the use of beta-lactam agents with enhanced activity against enterococci surpassed the combined use of third-generation cephalosporins and ticarcillin/clavulanate in each hospital. In one hospital, the incidence of VRE was positively correlated with the use of piperacillin/tazobactam or beta-lactam agents with enhanced anti-enterococcal activity (P < .0001). The incidence of VRE rose steadily in another hospital despite relatively high use of beta-lactam agents with enhanced versus minimal anti-enterococcal activity. A negative correlation between VRE and piperacillin/tazobactam or beta-lactam agents with enhanced anti-enterococcal activity was observed in one hospital, but this correlation was not statistically significant. CONCLUSION: Increasing the hospital use of piperacillin/tazobactam and other beta-lactams with relatively enhanced anti-enterococcal activity may not be an effective control measure for VRE.

Academic Medical Centers↗
PubMed2004

Cavernous and inferior petrosal sinus sampling in the evaluation of ACTH-dependent Cushing's syndrome.

OBJECTIVE: Central venous sampling (CVS) is used frequently in the evaluation of ACTH-dependent Cushing's syndrome. However, several controversies exist including the diagnostic accuracy, the sampling site of choice (cavernous sinus vs. inferior petrosal sinus) and the use of lateralization data in tumour localization. We have analysed our experience with CVS to address these controversies. DESIGN: We retrospectively reviewed CVS data in patients with ACTH-dependent Cushing's syndrome, in whom cavernous sinus sampling (CSS), inferior petrosal sinus sampling (IPSS) and IPSS after administration of ovine corticotrophin releasing hormone (oCRH) were performed. PATIENTS: Data on 95 patients were analysed, including 79 patients with suspected Cushing's disease (CD) and 16 patients with suspected ectopic ACTH syndrome (EAS). RESULTS: For the differential diagnosis of ACTH-dependent Cushing's syndrome, the diagnostic accuracy of IPSS after oCRH stimulation was 97% compared to 86% for CSS. While no single sampling site was perfect in diagnostic accuracy, sampling both CS and IPS achieved a combined diagnostic accuracy of 100%. Lateralization data predicted tumour location in 62-68% of the patients with various central venous drainage patterns and in 77-80% of the patients with symmetrical drainage. CSS was not significantly superior to IPSS in tumour lateralization. In patients with suspected CD based on CVS and in whom an adenoma was not found on magnetic resonance imaging (MRI) and not located by the surgeon intraoperatively, hemihypophysectomy based on lateralization data was successful in only 10 of the 18 patients (56%) with various central venous drainage patterns and in 5 of 10 patients with symmetrical drainage. CONCLUSION: CVS is a powerful method for differentiating CD from the EAS. CSS without oCRH was not superior to IPSS after oCRH stimulation; however, we achieved a 100% diagnostic accuracy if at least two sites were sampled. Tumour localization by CVS did not accurately predict the tumour site at surgery and should not be used to guide surgical resection.

ACTH Syndrome, Ectopic↗
PubMed2004

The low-dose dexamethasone suppression test: a reevaluation in patients with Cushing's syndrome.

Low-dose dexamethasone suppression testing has been recommended for biochemical screening when Cushing's syndrome is suspected. The criterion for normal suppression of cortisol after dexamethasone is controversial. To assess diagnostic utility (sensitivity), we report the results of low-dose dexamethasone suppression testing in 103 patients with spontaneous Cushing's syndrome. There were 80 patients with Cushing's disease (78%), 13 with the ectopic ACTH syndrome (13%), and 10 with cortisol-producing adrenocortical adenomas (10%). Fourteen (18%) of 80 patients with Cushing's disease suppressed serum cortisol to less than 5 micro g/dl (<135 nmol/liter) after the overnight 1-mg test, whereas six patients (8%) actually showed suppression of serum cortisol to less than 2 micro g/dl (<54 nmol/liter). In addition, the 2-d, low-dose dexamethasone suppression test yielded false-negative results in 38% of patients when urine cortisol was used and 28% when urinary 17-hydroxycorticosteroids were used. Serum cortisol after the 1-mg test correlated with baseline urinary free cortisol (r = 0.705, P < 0.001), plasma ACTH level (r = 0.322, P = 0.001), and urinary free cortisol after the 2-d test (r = 0.709, P = 0.001). This study provides evidence that low-dose dexamethasone may suppress either plasma cortisol or urinary steroids to levels previously thought to exclude Cushing's syndrome and that these tests should not be used as the sole criterion to exclude the diagnosis of endogenous hypercortisolism.

17-Hydroxycorticosteroids↗
PubMed2003

Coexistence of vancomycin-resistant enterococci and Staphylococcus aureus in the intestinal tracts of hospitalized patients.

The potential for transfer of vancomycin-resistance genes from enterococci to Staphylococcus aureus exists when these organisms share an ecologic niche. We performed an 8-month prospective study to determine the frequency at which S. aureus and vancomycin-resistant enterococci (VRE) coexist in the intestinal tracts of VRE-colonized patients and evaluated whether antianaerobic antibiotic therapy promoted increased density of S. aureus colonization. Of 37 patients colonized with vancomycin-resistant Enterococcus faecium, 23 (62%) had S. aureus recovered from stool specimens and 20 (87%) had methicillin-resistant strains. There was no significant difference in the mean density (+/- standard deviation) of S. aureus during versus > or =1 month after discontinuation of antianaerobic antibiotic therapy (5.1+/-1.5 vs. 4.7+/-1.6 log10 colony-forming units per gram of stool; P=.34). No S. aureus isolates were resistant to vancomycin. S. aureus and VRE often coexist in the intestinal tract, providing a potential reservoir for the emergence of vancomycin-resistant S. aureus isolates.

Aged↗
PubMed2003

Unnecessary use of antimicrobials in hospitalized patients: current patterns of misuse with an emphasis on the antianaerobic spectrum of activity.

BACKGROUND: Unnecessary use of antimicrobials contributes to the emergence and dissemination of antimicrobial-resistant nosocomial pathogens in part through elimination of normal anaerobic bacterial flora that inhibit overgrowth of pathogenic microorganisms. METHODS: A prospective observational study was conducted in a 650-bed, university-affiliated hospital. All adult nonintensive care inpatients for whom new antimicrobials were prescribed during a 2-week period were monitored throughout their hospitalization. We examined how often antimicrobials, in particular those with antianaerobic activity, were used unnecessarily. The reasons for unnecessary therapy were assessed and common patterns of unnecessary use were identified. RESULTS: A total of 1941 antimicrobial days of therapy were prescribed for 129 patients. A total of 576 (30%) of the 1941 days of therapy were deemed unnecessary. The most common reasons for unnecessary therapy included administration of antimicrobials for longer than recommended durations (192 days of therapy), administration of antimicrobials for noninfectious or nonbacterial syndromes (187 days of therapy), and treatment of colonizing or contaminating microorganisms (94 days of therapy). Antianaerobic agents accounted for 203 (35%) of the 576 unnecessary antimicrobial days of therapy, and these agents were also frequently prescribed (98 days of therapy) when equally efficacious alternative regimens with minimal antianaerobic activity were available. CONCLUSIONS: In our institution, hospitalized patients frequently received unnecessary antimicrobial therapy, and antianaerobic agents were often prescribed when this spectrum of activity was not indicated.

Anti-Bacterial Agents↗
PubMed2003

Colonization and infection with multiple nosocomial pathogens among patients colonized with vancomycin-resistant Enterococcus.

OBJECTIVE: To test the hypothesis that patients colonized with vancomycin-resistant Enterococcus (VRE) have a higher frequency of colonization or infection with other nosocomial pathogens than do patients who are not colonized with VRE. DESIGN: A rectal swab culture survey was conducted to determine the point-prevalence of stool colonization with ceftazidime-resistant gram-negative bacilli in hospitalized patients with or without VRE stool colonization. For a 6-month period, the frequency of Clostridium difficile diarrhea and isolation of antibiotic-resistant (ie, ceftazidime-, piperacillin/tazobactam-, levofloxacin-, or trimethoprim/sulfamethoxazole-resistant) gram-negative bacilli, methicillin-resistant Staphylococcus aureus (MRSA), and non-albicans Candida species from clinical specimens other than stool was examined. SETTING: A Department of Veterans Affairs medical center. PATIENTS: All patients hospitalized in the acute care facility and one nursing home unit during a 1-week period in February 2001. RESULTS: VRE-colonized patients had a higher point-prevalence of rectal colonization with ceftazidime-resistant gram-negative bacilli than did patients not colonized with VRE (17% vs 4%; P = .026). During a 6-month period,the VRE-colonized patients were more likely to have Clostridium difficile-associated diarrhea (26% vs 2%; P = .001), MRSA infection (17% vs 4%; P = .017), or colonization or infection with gram-negative bacilli resistant to 4 different antibiotics. CONCLUSION: VRE-colonized patients in our institution have a higher frequency of colonization or infection with other nosocomial pathogens than do patients who are not colonized with VRE. This suggests that isolation measures implemented to control VRE could help limit the dissemination of other, coexisting pathogens.

Aged↗
PubMed2003

Effect of parenteral antibiotic administration on establishment of intestinal colonization in mice by Klebsiella pneumoniae strains producing extended-spectrum beta-lactamases.

A mouse model was used to test the hypothesis that antibiotics with activity against anaerobes promote overgrowth of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae strains in stool. Subcutaneous clindamycin consistently promoted establishment of high-density colonization, whereas piperacillin-tazobactam, ceftriaxone, and ceftazidime promoted colonization only when a large inoculum and/or more resistant strain was administered.

Animals↗
PubMed2002

Reliability of birth certificate data: a multi-hospital comparison to medical records information.

OBJECTIVE: To examine the reliability of birth certificate data and determine if reliability differs between teaching and nonteaching hospitals. METHODS: We compared information from birth certificates and medical records in 33,616 women admitted for labor and delivery in 1993-95 to 20 hospitals in Northeast Ohio. Analyses determined the agreement for 36 common data elements, and the sensitivity, specificity, and positive and negative predictive values of birth certificate data, using medical record data as a "gold standard." RESULTS: Sensitivity and positive predictive value varied widely (9-100% and 2-100%, respectively), as did agreement, which was "almost perfect" for measures of prior obstetrical history, delivery type, and infant Apgar score (K = 0.854-0.969) and "substantial" for several other variables (e.g., tobacco use (K = 0.766), gestational age (K = 0.726), prenatal care (K = 0.671)). However, agreement was only "slight" to "moderate" for most maternal risk factors and comorbidities (K = 0.085-0.545) and for several complications of pregnancy and/or labor and delivery (K = 0.285-0.734). Overall agreement was similar in teaching (mean K = 0.51) and nonteaching (K = 0.52) hospitals. Although agreement in teaching and nonteaching hospitals varied for some variables, no systematic differences were seen across types of variables. CONCLUSIONS: Our findings indicate that the reliability of birth certificate data vary for specific elements. Researchers and health policymakers need to be cognizant of the potential limitations of specific data elements.

Birth Certificates↗
PubMed2002

A curriculum for training quality scholars to improve the health and health care of veterans and the community at large.

In 1998, the Veterans Health Administration invested in the creation of the Veterans Administration National Quality Scholars Fellowship Program (VAQS) to train physicians in new ways to improve the quality of health care. We describe the curriculum for this program and the lessons learned from our experience to date. The VAQS Fellowship program has developed a core improvement curriculum to train postresidency physicians in the scholarship, research, and teaching of the improvement of health care. The curriculum covers seven domains of knowledge related to improvement: health care as a process; variation and measurement; customer/beneficiary knowledge; leading, following, and making changes in health care; collaboration; social context and accountability; and developing new, locally useful knowledge. We combine specific knowledge about the improvement of health care with the use of adult learning strategies, interactive video, and development of learner competencies. Our program provides insights for medical education to better prepare physicians to participate in and lead the improvement of health care.

Adult↗
PubMed2002

Applying the theory of constraints in health care: Part 1--The philosophy.

The imperative to improve both technical and service quality while simultaneously reducing costs is quite clear. The Theory of Constraints (TOC) is an emerging philosophy that rests on two assumptions: (1) systems thinking and (2) if a constraint "is anything that limits a system from achieving higher performance versus its goal," then every system must have at least one (and at most no more than a few) constraints or limiting factors. A constraint is neither good nor bad in itself. Rather, it just is. In fact, recognition of the existence of constraints represents an excellent opportunity for improvement because it allows one to focus ones efforts in the most productive area--identifying and managing the constraints. This is accomplished by using the five focusing steps of TOC: (1) identify the system's constraint; (2) decide how to exploit it; (3) subordinate/synchronize everything else to the above decisions; (4) elevate the system's constraint; and (5) if the constraint has shifted in the above steps, go back to step 1. Do not allow inertia to become the system's constraint. TOC also refers to a series of tools termed "thinking processes" and the sequence in which they are used.

Accounting↗
PubMed2002

Exploring the academic context for quality improvement: a scientific discipline in need of a career path.

Physician training typically occurs in an academic context. We examine whether improvement should be a central element in academe--specifically medical school. We observe that quality improvement meets the criteria for a discipline, but that there are many obstacles to career development in this field. Whether the research agenda of quality improvement can be accomplished within centers or institutes or whether this discipline needs its own department to ensure the nurturing of new faculty is still an open question. What is not open is the necessity for a career path in this discipline to exist and flourish.

Career Choice↗