PubMed Health⌕ Search

Biomedical subjects

John R Clarke

Publications and source records attributed to John R Clarke.

17 recordsLinked to original sources
PubMed2006

Translating patient safety legislation into health care practice.

BACKGROUND: An independent state agency, the Authority is charged with taking steps to reduce and eliminate medical errors by identifying problems and recommending solutions that promote patient safety. PENNSYLVANIA PATIENT SAFETY REPORTING SYSTEM (PA-PSRS): The Authority implemented PA-PSRS, a mandatory reporting and analysis system for both adverse events and near-misses, among 450 hospitals, birthing centers, and ambulatory surgical facilities. Pennsylvania is the only state to require the reporting of both adverse events and near-misses. THE PATIENT SAFETY ADVISORY: The Patient Safety Advisory is a quarterly publication containing articles about trends in reports submitted to PA-PSRS. The peer-reviewed articles include analysis of and lessons learned from PA-PSRS reports and evidence-based risk reduction strategies based on research in the clinical literature. To complement and reinforce the effectiveness of certain Advisory articles, the Authority has introduced electronic, educational tool kits on its Web site that can be downloaded. They include posters, draft policies, audio-slide presentations for staff training, and other materials related to clinical implementation of patient safety interventions and protocols. SUMMARY AND CONCLUSION: In just over two years, the Authority has developed a program that turns reports into actionable items through the analysis and research of adverse events and near-misses.

Awards and Prizes↗
PubMed2006

How a system for reporting medical errors can and cannot improve patient safety.

The Institute of Medicine has recommended systems for reporting medical errors. This article discusses the necessary components of patient safety databases, steps for implementing patient safety reporting systems, what systems can do, what they cannot do, and motivations for physician participation. An ideal system captures adverse events, when care harms patients, and near misses, when errors occur without any harm. Near misses signal system weaknesses and, because harm did not occur, may provide insight into solutions. With an integrated system, medical errors can be linked to patient and team characteristics. Confidentiality and ease of use are important incentives in reporting. Confidentiality is preferred to anonymity to allow follow-up. Analysis and feedback are critical. Reporting systems need to be linked to organizational leaders who can act on the conclusions of reports. The use of statistics is limited by the absence of reliable numerators and denominators. Solutions should focus on changing the cultural environment. Patient safety reporting systems can help bring to light, monitor, and correct systems of care that produces medical errors. They are useful components of the patient safety and quality improvement initiatives of healthcare systems and they warrant involvement by physicians.

Guidelines as Topic↗
PubMed2005

A surgeon who CARES can be safer.

The characteristics of a high-reliability organization are reviewed. Examples of how these characteristics relate to patient safety in surgical practice are illustrated by vignettes. The characteristics discussed include commitment to safety demonstrated to others by the conduct of one's practice; attention focused on one's own performance and the performance of others to the task at hand; rehearsal and proper preparation and contingency planning for procedures; effective communication so that information is accurate, adequate, unambiguous, and confirmed; and sense-making, or an understanding and verification of consistency between what is observed and expected and between what is planned and the premises for those plans.

Humans↗
PubMed2005

Representations of the cinaedus in Roman art: Evidence of "gay" subculture?

Whereas analysis of ancient Roman texts reveals signs of a possible homosexual subculture, their interpretation is difficult. This article analyzes the content and context of visual representations of male-male intercourse, including wall paintings at Pompeii, a silver cup, and an engraved agate gemstone. Whether presenting negative stereotypes (Tavern of Salvius, Pompeii; Suburban Baths, Pompeii), or positive ones (Warren Cup, British Museum; Leiden gemstone), these representations reveal the presence of well-developed social attitudes toward the practice ofmale-male sex and the practitioners themselves.

Adolescent↗
PubMed2005

Comparisons of survival predictions using survival risk ratios based on International Classification of Diseases, Ninth Revision and Abbreviated Injury Scale trauma diagnosis codes.

BACKGROUND: We conducted a comparison of methods for predicting survival using survival risk ratios (SRRs), including new comparisons based on International Classification of Diseases, Ninth Revision (ICD-9) versus Abbreviated Injury Scale (AIS) six-digit codes. METHODS: From the Pennsylvania trauma center's registry, all direct trauma admissions were collected through June 22, 1999. Patients with no comorbid medical diagnoses and both ICD-9 and AIS injury codes were used for comparisons based on a single set of data. SRRs for ICD-9 and then for AIS diagnostic codes were each calculated two ways: from the survival rate of patients with each diagnosis and when each diagnosis was an isolated diagnosis. Probabilities of survival for the cohort were calculated using each set of SRRs by the multiplicative ICISS method and, where appropriate, the minimum SRR method. These prediction sets were then internally validated against actual survival by the Hosmer-Lemeshow goodness-of-fit statistic. RESULTS: The 41,364 patients had 1,224 different ICD-9 injury diagnoses in 32,261 combinations and 1,263 corresponding AIS injury diagnoses in 31,755 combinations, ranging from 1 to 27 injuries per patient. All conventional ICD-9-based combinations of SRRs and methods had better Hosmer-Lemeshow goodness-of-fit statistic fits than their AIS-based counterparts. The minimum SRR method produced better calibration than the multiplicative methods, presumably because it did not magnify inaccuracies in the SRRs that might occur with multiplication. CONCLUSION: Predictions of survival based on anatomic injury alone can be performed using ICD-9 codes, with no advantage from extra coding of AIS diagnoses. Predictions based on the single worst SRR were closer to actual outcomes than those based on multiplying SRRs.

Abbreviated Injury Scale↗
PubMed2005

Evaluating the discriminatory power of a computer-based system for assessing penetrating trauma on retrospective multi-center data.

OBJECTIVE: To evaluate the discriminatory power of TraumaSCAN-Web, a system for assessing penetrating trauma, using retrospective multi-center case data for gunshot and stab wounds to the thorax and abdomen. METHODS: 80 gunshot and 114 stab cases were evaluated using TraumaSCAN-Web. Areas under the Receiver Operator Characteristic Curves (AUC) were calculated for each condition modeled in TraumaSCAN-Web. RESULTS: Of the 23 conditions modeled by TraumaSCAN-Web, 19 were present in either the gunshot or stab case data. The gunshot AUCs ranged from 0.519 (pericardial tamponade) to 0.975 (right renal injury). The stab AUCs ranged from 0.701 (intestinal injury) to 1.000 (tracheal injury).

Abdominal Injuries↗
PubMed2004

The impact of aging and habitual physical activity on static respiratory work at rest and during exercise.

We investigated the effects of aging on the elastic properties of lung tissue and the chest wall, simultaneously quantifying the contribution of each component to static inspiratory muscle work in resting and exercising adults. We further evaluated the interaction of aging and habitual physical activity on respiratory mechanics. Static lung volumes and elastic properties of the lung and chest wall (pressure-volume relaxation maneuvers) in 29 chronically sedentary and 29 habitually active subjects, grouped by age, were investigated: young (Y, 20-30 years), middle-aged (M, 40-50 years), and older (O, >60 years). Using static pressure-volume data, we computed the elastic work of breathing (joules per liter, J.l(-1)), including inspiratory muscle work, over resting and exercising tidal volume excursions. Elastic work of the lung (Y = 0.79 +/- 0.05; M = 0.47 +/- 0.05; O = 0.43 +/- 0.05 J.l(-1)) and chest wall (Y = -0.49 +/- 0.06; M = -0.12 +/- 0.07; O = 0.04 +/- 0.05 J.l(-1) ) changed significantly with age (P < 0.05). With aging, a parallel displacement of the chest wall pressure-volume curve resulted in a shift from energy being stored primarily during expiration to energy storage during inspiration, and driving expiration, both at rest and during exercise. Although deviating significantly from young adults, this did not significantly elevate static inspiratory muscle work but resulted in a redistribution of the tissues on which this work was performed and the phase of the respiratory cycle in which it occurred. Nevertheless, static inspiratory muscle work remained similar across age groups, at rest and during exercise, and habitual physical activity failed to influence these changes.

Adult↗
PubMed2004

Different resistance mutations can be detected simultaneously in the blood and the lung of HIV-1 infected individuals on antiretroviral therapy.

In this retrospective study, matched peripheral blood and lung samples from patients on antiretroviral therapy were studied in order to investigate whether differences in mutations associated with resistance to nucleoside analogues could be detected between the lung and blood. Discordant mutation patterns in the reverse transcriptase (RT) between plasma and cell free bronchoalveolar lavage fluid (BAL-fluid) HIV-1 genomic RNA was observed in five out of seven patients on nucleoside reverse transcriptase inhibitor (NRTI) monotherapy and six out of seven on combination therapy. In the cellular compartments, DNA recovered from peripheral blood mononuclear cells (PBMCs) and cells from BAL-cells discordant HIV-1 resistance genotypes were detected in 15 out of 44 matched samples. Differences in resistant genotypes between PBMCs and BAL-cells were most pronounced in patients receiving combination antiretroviral therapy. The pattern and number of mutations in RT associated with resistance differed in the BAL-cells compared to PBMCs in four out of 12 subjects not receiving antiretroviral therapy at the time of bronchoscopy, three from 14 patients on NRTI monotherapy, five out of nine on dual combination therapy and three out of nine on HAART. The differences in the detection of resistance mutations between blood and the lung suggest that the lung is a site of replication for HIV-1.

Anti-HIV Agents↗
PubMed2004

The optimal initial management of children with suspected appendicitis: a decision analysis.

BACKGROUND/PURPOSE: As abdominal imaging has improved, the use of computed tomography (CT) and ultrasonography (US) for evaluating children with suspected appendicitis has increased. The purpose of this study was to determine the optimal management strategy for evaluating children with suspected appendicitis given the current accuracy of abdominal imaging. METHODS: Decision analysis was used to evaluate 5 management strategies: discharge, observation, CT, US, and appendectomy. Probabilities and time variables were obtained from publications and a chart review. Each approach was evaluated for its impact on length of stay, hospital charges, cost effectiveness and its capacity to minimize perforation and avoid negative appendectomy (risk-benefit). RESULTS: Discharge was preferred when the probability of appendicitis was low (<0.09 to <0.47), imaging when in an intermediate range and surgery when high (>0.61 to >0.91). A role for observation was found only when the anticipated time of inpatient observation was brief (<9 hours). Although CT was more expensive than US, CT was more cost effective for preventing negative appendectomy and perforation and achieved a better risk-benefit. CONCLUSIONS: CT has an important role in the management of suspected appendicitis. Among children with a low or high likelihood of appendicitis, the cost of imaging tests required to prevent the complications of appendicitis is high.

Abdominal Pain↗
PubMed2004

Detection of HIV-1 antiretroviral resistance from patients with persistently low but detectable viraemia.

We modified the Abbott diagnostics HIV-1 Viroseq version 2 assay trade mark in order to detect the presence of HIV-1 drug resistance mutations in patients with viraemia below 1000 copies/ml of plasma. One hundred and forty-four patients with a detectable HIV-1 plasma viral load below 1000 copies/ml were selected and HIV-1 genetic analysis carried out using a modification of the Abbott Diagnostics Viroseq 2.0 assay trade mark. The procedure differs from the standard protocol in that a nested PCR amplification step was introduced. The oligonucleotide primers for the first round of PCR were those supplied in the RT-PCR module of the kit. The nested PCR primers were primers A and H taken from the sequencing module. One hundred and twenty-eight out of 144 (89%) plasma samples with an HIV-1 viral load of less than 1000 copies/ml (ranging from 54 to 992 copies) were successfully sequenced. HIV-1 genotypes were obtained from 68 out of 81 (84%) samples with a viral load of greater than 50 but less than 300 copies/ml and 60/63 (95%) of samples with a viral load of greater than 300 but less than 1000 copies/ml. Serial dilution of a sample with a high viral load did not affect the detection of resistance mutations. Multiple sequencing of samples with low viral load did not result in detection of additional mutations, although, in one sample the K103N mutation was detected in 3/6 replicates while wild-type was detected in 2/6 and a mixture of wild-type/mutant in 1/6. Samples from patients infected with both clade B and non-B clades of HIV-1 could be genotyped at low copy number. Modification of the Abbott Viroseq assay allows reproducible sequencing of the HIV-1 genome from patients with low, but detectable, plasma virus burden.

Anti-HIV Agents↗
PubMed2003

Discordant outcomes following failure of antiretroviral therapy are associated with substantial differences in human immunodeficiency virus-specific cellular immunity.

Many individuals chronically infected with human immunodeficiency virus type 1 (HIV-1) experience a recrudescence of plasma virus during continuous combination antiretroviral therapy (ART) due either to the emergence of drug-resistant viruses or to poor compliance. In most cases, virologic failure on ART is associated with a coincident decline in CD4(+) T lymphocyte levels. However, a proportion of discordant individuals retain a stable or even increasing CD4(+) T lymphocyte count despite virological failure. In order to address the nature of these different outcomes, we evaluated virologic and immunologic variables in a prospective, single-blinded, nonrandomized cohort of 53 subjects with chronic HIV-1 infection who had been treated with continuous ART and monitored intensively over a period of 19 months. In all individuals with detectable viremia on ART, multiple drug resistance mutations with similar impacts on viral growth kinetics were detected in the pol gene of circulating plasma virus. Further, C2V3 env gene analysis demonstrated sequences indicative of CCR5 coreceptor usage in the majority of those with detectable plasma viremia. In contrast to this homogeneous virologic pattern, comprehensive screening with a range of antigens derived from HIV-1 revealed substantial immunologic differences. Discordant subjects with stable CD4(+) T lymphocyte counts in the presence of recrudescent virus demonstrated potent virus-specific CD4(+) and CD8(+) T lymphocyte responses. In contrast, subjects with virologic failure associated with declining CD4(+) T lymphocyte counts had substantially weaker HIV-specific CD4(+) T lymphocyte responses and exhibited a trend towards weaker HIV-specific CD8(+) T lymphocyte responses. Importantly the CD4(+) response was sustained over periods as long as 11 months, confirming the stability of the phenomenon. These correlative data lead to the testable hypothesis that the consequences of viral recrudescence during continuous ART are modulated by the HIV-specific cellular immune response.

Adult↗
PubMed2002

Comparative response of African HIV-1-infected individuals to highly active antiretroviral therapy.

OBJECTIVE: Few data exist on the virological response to antiretroviral therapy of individuals infected with African HIV-1 subtypes. Our objective was to compare the response, in our clinic, of African HIV-1-infected patients with their British and European contemporaries treated with the same regimes. DESIGN: The St Mary's Hospital HIV database was used to identify drug-naive African and European patients starting a highly active antiretroviral therapy (HAART) regimen. METHODS: HIV-1 subtype was determined by phylogenetic analysis of pol sequences. Kaplan-Meier survival analysis was used to estimate the proportion of patients achieving undetectable viral loads (< 500 copies/ml). The longer-term response to therapy was assessed by changes in CD4 cell counts and viral loads from baseline. RESULTS: A total of 265 patients were classified as 'European' and 97 as 'African', confirmed by sequence. The time to first undetectable viral load was similar for the two groups (P = 0.9). Although there were no statistically significant differences in the CD4 cell count responses (P = 0.11), there was evidence of an increase in viral load after 9 months for the African group, resulting in a widening viral load gap between the two cohorts; the effect of ethnic group was statistically significant (P < 0.001). CONCLUSION: The initial virological and immunological responses of the African and European cohorts to HAART were similar; although the longer-term virological response was poorer in the African cohort, which may be related to adherence. On the basis of these findings, there is no justification for withholding HAART from Africa on virological grounds.

Adult↗
PubMed2002

Computer-generated trauma management plans: comparison with actual care.

TraumAID is a computer-based decision aid that uses decision rules and logical deduction to generate management plans for the initial definitive management of injured patients; its use is currently confined to assessing penetrating thoracoabdominal injuries in nonpregnant adults. These management plans were compared to trauma center care in an American urban medical school hospital. The TraumAID program was available to trauma chief residents for patient care during the "golden hour." Resulting changes in plans were documented by the residents. For 15 months the management plans for all applicable patients were documented serially, as were computer plans and outcomes. The sequential care and computer-generated care plans were then blinded and judged by three other trauma surgeons as to acceptability and preference. A consecutive series of 97 patients was evaluated. The residents used the computer for 40 cases during patient care. In 5 of the 40 cases, they altered their evaluation, diagnosis, or treatment; in none of these 5 was the alteration judged an error. Of the 97 patients, 10 had adverse outcomes, 2 of which were judged potentially avoidable, with unacceptable errors in management. TraumAID's plans were acceptable for both. In 31 cases previously managed by the judges themselves, the TraumAID plans were preferred by the judge to the care he or she had provided, by a ratio of 25:6 (p < 0.01). In a preliminary assessment, computer-generated, patient-specific protocols for the acute management of injuries were preferred to actual care previously given by the judges themselves and were associated with improved care and potential improvement in outcome.

Adult↗
PubMed2002

Time to laparotomy for intra-abdominal bleeding from trauma does affect survival for delays up to 90 minutes.

OBJECTIVE: We examined the relationship between survival and time in the emergency department (ED) before laparotomy for hypotensive patients bleeding from abdominal injuries. METHODS: Patients in the Pennsylvania Trauma Systems Foundation trauma registry with isolated abdominal vascular, solid organ, or wall injuries grade 3 to 6 and hypotension were identified. Deaths were predicted from the prehospital time, systolic blood pressure (SBP) on ED admission, and time in the ED before either laparotomy or ED death. RESULTS: Two-hundred forty-three patients met the criteria. SBP ranged from 30 to 90 mm Hg. Time to the ED ranged from 7 to 185 minutes. Time in the ED ranged from 7 to 915 minutes. Overall, 98 patients died (40%). The risk ratio for the SBP increased, as expected, as SBP dropped. The risk ratio for time spent in the ED before laparotomy increased until 90 minutes, then significantly decreased below all earlier values. Logistic regression on the 165 patients spending 90 minutes or less in the ED showed that the probability of death increased with time in the ED. The increase was as much as 0.35% per minute. CONCLUSION: Among patients in a trauma registry who were hypotensive on arrival in the ED and had major injuries isolated to the abdomen requiring emergency laparotomy, the probability of death showed a relationship to both the extent of hypotension and the length of time in the ED for patients who were in the ED for 90 minutes or less. The probability of death increased approximately 1% for each 3 minutes in the ED.

Abdominal Injuries↗
PubMed2002

Molecular diagnosis of HIV.

The development of molecular techniques that access viral load and the development of genotypic resistance have revolutionized the treatment of HIV disease. Commercially available viral load assays use a number of different approaches from reverse transcriptase PCR to amplification of branched chain DNA. The drawbacks of the assay are that there is no international standard that allows comparison of viral load between assays and the diversity of different clades of HIV results in the under or the nondetection of some patients samples. New real-time PCR assays are under development, including LightCycler- and TaqMan-based tests. The development of sequence-based genotyping assays for the detection of mutations associated with the development of the resistance to the 17 licensed drugs targeted against the pol gene of HIV have added to the improvements in patient management. However, next-generation assays must extend detection to include the gp41 fusion region and the integrase region of the genome as compounds directed against these targets move from clinical trails into licensed drugs. Also, genotypic assays must improve detection of minor species and detection of sequences from patients with low viral load number. Real-time sequence based-diagnostics remains a realistic target within the next 5 years.

Anti-HIV Agents↗
PubMedDate not supplied

Combining geometric and probabilistic reasoning for computer-based penetrating-trauma assessment.

OBJECTIVE: To ascertain whether three-dimensional geometric and probabilistic reasoning methods can be successfully combined for computer-based assessment of conditions arising from ballistic penetrating trauma to the chest and abdomen. DESIGN: The authors created a computer system (TraumaSCAN) that integrates three-dimensional geometric reasoning about anatomic likelihood of injury with probabilistic reasoning about injury consequences using Bayesian networks. Preliminary evaluation of TraumaSCAN was performed via a retrospective study testing performance of the system on data from 26 cases of actual gunshot wounds. MEASUREMENTS: Areas under the receiver operating characteristics (ROC) curve were calculated for each condition modeled in TraumaSCAN that was present in the 26 cases. The comprehensiveness and relevance of the TraumaSCAN diagnosis for the 26 cases were used to assess the overall performance of the system. To test the ability of TraumaSCAN to handle limited findings, these measurements were calculated both with and without input of observed findings into the Bayesian network. RESULTS: For the 11 conditions assessed, the worst area under the ROC curve with no observed findings input into the Bayesian network was 0.542 (95% CI, 0.146-0.937), the median was 0.883 (95% CI, 0.713-1.000), and the best was 1.00 (95% CI, 1.000-1.000). The worst area under the ROC curve with all observed findings input into the Bayesian network was 0.835 (95% CI, 0.602-1.000), the median was 0.941 (95% CI, 0.827-1.000), and the best was 0.992 (95% CI, 0.965-1.000). A comparison of the areas under the curve obtained with and without input of observed findings into the Bayesian network showed that there were significant differences for 2 of the 11 conditions assessed. CONCLUSION: A computer-based method that combines geometric and probabilistic reasoning shows promise as a tool for assessing ballistic penetrating trauma to the chest and abdomen.

Bayes Theorem↗