Demonstration of the safety and effectiveness of the RECELL® System combined with split-thickness meshed autografts for the reduction of donor skin to treat mixed-depth burn injuries.

INTRODUCTION: Split-thickness skin grafts (STSG) are the standard of care (SOC) for burns undergoing autografting but are associated with donor skin site morbidity and limited by the availability of uninjured skin. The RECELL® Autologous Cell Harvesting Device (RECELL® System, or RECELL) was developed for point-of-care preparation and application of a suspension of non-cultured, disaggregated, autologous skin cells, using 1cm2 of the patient's skin to treat up to 80cm2 of excised burn. METHODS: A multi-center, prospective, within-subject controlled, randomized, clinical trial was conducted with 30 subjects to evaluate RECELL in combination with a more widely meshed STSG than a pre-defined SOC meshed STSG (RECELL treatment) for the treatment of mixed-depth burns, including full-thickness. Treatment areas were randomized to receive standard meshed STSG (Control treatment) or RECELL treatment, such that each subject had 1 Control and 1 RECELL treatment area. Effectiveness measures were assessed and included complete wound closure, donor skin use, subject satisfaction, and scarring outcomes out to one year following treatment. RESULTS: At 8 weeks, 85% of the Control-treated wounds were healed compared with 92% of the RECELL-treated wounds, establishing the non-inferiority of RECELL treatment for wound healing. Control-treated and RECELL-treated wounds were similar in mean size; however, mean donor skin use was significantly reduced by 32% with the use of RECELL (p<0.001), establishing the superiority of RECELL treatment for reducing donor skin requirements. Secondary effectiveness and safety outcomes were similar between the treatments. CONCLUSIONS: In combination with widely meshed STSG, RECELL is a safe and effective point-of-care treatment for mixed-depth burns without confluent dermis, achieving short- and long-term healing comparable to standard STSG, while significantly decreasing donor skin use.

Transforming Data into Knowledge: How to Improve the Efficiency of Clinical Care?

Objectives: To provide an introduction to the 2017 IMIA Yearbook of Medical Informatics by the editors. Methods: We present a brief overview of the 2017 special topic "Learning from experience: Secondary use of patient data". We review our choice of special topic section editors, present the new section "Health Information Management", and discuss transitions in the editorial team. Results: In this edition of the Yearbook, we focused on one of the most important issues for the medical informatics community: The secondary use of clinical data. With the ubiquitous adoption of electronic health records (EHRs) and the increasing availability of genomic and environmental data, as well as the accessibility of unstructured data in social media, issues related to data integration, storage, and management, as well as the need for novel analytic approaches are clear challenges. The paradigm of Learning Health Systems (LHSs) is presented in the keynote paper and survey papers review the significant developments in allied fields such as clinical research, clinical systems, translational informatics, and public health over the past two years. IMIA Working Groups also contributed to this topic. Conclusion: The 2017 issue of the IMIA yearbook focuses on the secondary use of patient data and presents the difficulties that still need to be solved before witnessing the actual development of LHSs.

Temporal electronic phenotyping by mining careflows of breast cancer patients.

In this work we present a careflow mining approach designed to analyze heterogeneous longitudinal data and to identify phenotypes in a patient cohort. The main idea underlying our approach is to combine methods derived from sequential pattern mining and temporal data mining to derive frequent healthcare histories (careflows) in a population of patients. This approach was applied to an integrated data repository containing clinical and administrative data of more than 4000 breast cancer patients. We used the mined histories to identify sub-cohorts of patients grouped according to healthcare activities pathways, then we characterized these sub-cohorts with clinical data. In this way, we were able to perform temporal electronic phenotyping of electronic health records (EHR) data.

Progress in Biomedical Knowledge Discovery: A 25-year Retrospective.

OBJECTIVES: We sought to explore, via a systematic review of the literature, the state of the art of knowledge discovery in biomedical databases as it existed in 1992, and then now, 25 years later, mainly focused on supervised learning. METHODS: We performed a rigorous systematic search of PubMed and latent Dirichlet allocation to identify themes in the literature and trends in the science of knowledge discovery in and between time periods and compare these trends. We restricted the result set using a bracket of five years previous, such that the 1992 result set was restricted to articles published between 1987 and 1992, and the 2015 set between 2011 and 2015. This was to reflect the current literature available at the time to researchers and others at the target dates of 1992 and 2015. The search term was framed as: Knowledge Discovery OR Data Mining OR Pattern Discovery OR Pattern Recognition, Automated. RESULTS: A total 538 and 18,172 documents were retrieved for 1992 and 2015, respectively. The number and type of data sources increased dramatically over the observation period, primarily due to the advent of electronic clinical systems. The period 1992- 2015 saw the emergence of new areas of research in knowledge discovery, and the refinement and application of machine learning approaches that were nascent or unknown in 1992. CONCLUSIONS: Over the 25 years of the observation period, we identified numerous developments that impacted the science of knowledge discovery, including the availability of new forms of data, new machine learning algorithms, and new application domains. Through a bibliometric analysis we examine the striking changes in the availability of highly heterogeneous data resources, the evolution of new algorithmic approaches to knowledge discovery, and we consider from legal, social, and political perspectives possible explanations of the growth of the field. Finally, we reflect on the achievements of the past 25 years to consider what the next 25 years will bring with regard to the availability of even more complex data and to the methods that could be, and are being now developed for the discovery of new knowledge in biomedical data.

Technical challenges for big data in biomedicine and health: data sources, infrastructure, and analytics.

OBJECTIVES: To review technical and methodological challenges for big data research in biomedicine and health. METHODS: We discuss sources of big datasets, survey infrastructures for big data storage and big data processing, and describe the main challenges that arise when analyzing big data. RESULTS: The life and biomedical sciences are massively contributing to the big data revolution through secondary use of data that were collected during routine care and through new data sources such as social media. Efficient processing of big datasets is typically achieved by distributing computation over a cluster of computers. Data analysts should be aware of pitfalls related to big data such as bias in routine care data and the risk of false-positive findings in high-dimensional datasets. CONCLUSIONS: The major challenge for the near future is to transform analytical methods that are used in the biomedical and health domain, to fit the distributed storage and processing model that is required to handle big data, while ensuring confidentiality of the data being analyzed.

CAH to CAH: EHR implementation advice to critical access hospitals from peer experts and other key informants.

UNLABELLED: The US government allocated $30 billion to implement electronic health records (EHRs) in hospitals and provider practices through policy addressing Meaningful Use (MU). Most small, rural hospitals, particularly those designated as Critical Access Hospitals (CAHs), comprising nearly a quarter of US hospitals, had not implemented EHRs before. Little is known about implementation in this setting. Socio-technical factors differ between larger hospitals and CAHs, which continue to lag behind other hospitals in EHR adoption. OBJECTIVE: The main objective is to provide EHR implementation advice for CAHs from a spectrum of experts with an emphasis on recommendations from their peers at CAHs that have undertaken the process. The secondary objective is to begin to identify implementation process differences at CAHs v. larger hospitals. METHODS: We interviewed 41 experts, including 16 CAH staff members from EHR teams at 10 CAHs that recently implemented EHRs. We qualitatively analyzed the interviews to ascertain themes and implementation recommendations. RESULTS: Nineteen themes emerged. Under each theme, comments by experts provide in-depth advice on all implementation stages including ongoing optimization and use. We present comments for three top themes as ranked by number of CAH peer experts commenting - EHR System Selection, EHR Team, and Preparatory Work - and for two others, Outside Partners/Resources and Clinical Decision Support (CDS)/Knowledge Management (KM). Comments for remaining themes are included in tables. DISCUSSION: CAH experts rank the themes differently from all experts, a likely indication of the differences between hospitals. Comments for each theme indicate the specific difficulties CAHs encountered. CAH staffs have little or no EHR experience before implementation. A factor across themes is insufficient system and process knowledge, compounded by compressed implementation schedules. Increased, proactive self-education, via available outside partners and information resources, will mitigate difficulties and aid CAHs in meeting increased CDS requirements in MU Stages 2 and 3.

Burn injury: what's in a name? Labels used for burn injury classification: a review of the data from 2000-2012.

Through the years, the burn injury has been described using a variety of labels. These labels have ranged from one word terms to phrases including degrees of injury or more descriptive terms. A search was conducted relying on a common general internet search engine. After multiple searches varying the keywords, the top 100 searches identified the most prevalent terms or phrases, ranging from the common to the more obscure. The search was repeated using the most prevalent terms or phrases identified in the common internet search engine, focusing on either the title or abstract for all papers indexed in PubMed. This process narrowed the attention to the most common terms or phrases used by the academics in their published work. This work therefore focused on measuring the specific terms being used today and their frequency of use in the peer reviewed papers indexed in the PubMed system. It is difficult to focus on the unique aspects of any given profession when there is confusion surrounding a common vocabulary. By identifying and noting in the academic literature the most commonly used labels, a point of reference can be created for future work. Furthermore, having a common and accurate set of labels that are uniformly applied across the profession is critical for academia to include in training and education programs for physicians, nurses, and paramedical staff.

Au fil des ans, la brûlure a été décrite en utilisant une variété d'étiquettes. Ces étiquettes ont oscillé entre un seul mot et des phrases, y compris degrés de blessures ou de termes plus descriptifs. Une recherche a été menée en s'appuyant sur un moteur de recherche internet. Après de multiples recherches variant les mots-clés, le top 100 des termes de recherche identifié ou expressions les plus courantes, allant de la commune à la plus obscure. La recherche a été répétée en utilisant des termes ou des expressions les plus fréquentes identifiées dans le moteur de recherche internet, en mettant l'accent soit sur le titre ou le résumé de tous les articles indexés dans PubMed. Ce processus réduit l'attention de termes ou expressions les plus courantes utilisées par les professeurs dans leur travail publié. Par conséquent, ce travail a porté sur la mesure des termes spécifiques qui sont utilisées aujourd'hui et leur fréquence d'utilisation dans les journaux évalués par les pairs indexées dans le système PubMed. Il est difficile de se concentrer sur les aspects spécifiques de chaque profession donnée quand il y a confusion entourant un vocabulaire commun. En identifiant et en notant dans la littérature académique les étiquettes les plus couramment utilisées, un point de référence peut être créé pour les travaux futurs. En outre, un ensemble commun et précis des étiquettes qui sont appliqués uniformément à travers la profession est essentiel pour les universités à inclure dans les programmes de formation et d'éducation pour les médecins, les infirmières et le personnel paramédical.

Understanding behavioral intent to participate in shared decision-making in medically uncertain situations.

OBJECTIVE: This article describes the process undertaken to identify and validate behavioral and normative beliefs and behavioral intent based on the Theory of Reasoned Action (TRA) and applied to men between the ages of 45 and 70 in the context of their participation in shared decision-making (SDM) in medically uncertain situations. This article also discusses the preliminary results of the aforementioned processes and explores potential future uses of this information that may facilitate greater understanding, efficiency and effectiveness of clinician-patient consultations. MATERIALS AND METHODS: Twenty-five male subjects from the Philadelphia community participated in this study. Individual semi-structure patient interviews were conducted until data saturation was reached. Based on their review of the patient interview transcripts, researchers conducted a qualitative content analysis to identify prevalent themes and, subsequently, create a category framework. Qualitative indicators were used to evaluate respondents' experiences, beliefs, and behavioral intent relative to participation in shared decision-making during medical uncertainty. RESULTS: Based on the themes uncovered through the content analysis, a category framework was developed to facilitate understanding and increase the accuracy of predictions related to an individual's behavioral intent to participate in shared decision-making in medical uncertainty. The emerged themes included past experience with medical uncertainty, individual personality, and the relationship between the patient and his physician. The resulting three main framework categories include 1) an individual's Foundation for the concept of medical uncertainty, 2) how the individual Copes with medical uncertainty, and 3) the individual's Behavioral Intent to seek information and participate in shared decision-making during times of medically uncertain situations. DISCUSSION: The theme of Coping (with uncertainty) emerged as a particularly critical behavior/characteristic amongst the subjects. By understanding a subject's disposition with regard to coping, researchers were better able to make connections between a subject's prior experiences, their knowledge seeking activities, and their intent to participate in SDM. Despite having information and social support, the subjects still had to cope with the idea of uncertainty before determining how to proceed with regard to shared decision-making. In addition, the coping category reinforced the importance of information seeking behaviors and preferences for shared decision-making. CONCLUSIONS: This study applies and extends the field of behavioral and health informatics to assist medical practice and decision-making in situations of medical uncertainty. More specifically, this study led to the development of a category framework that facilitates the identification of an individual's needs and motivational factors with regard to their intent to participate in shared decision-making in situations of medical uncertainty.

medpie: an information extraction package for medical message board posts.

SUMMARY: We have developed medpie, a software package for preparing medical message board corpora and extracting patient mentions and statistics for drugs, herbs and adverse effects experienced from them. The package is divided into web-crawling, HTML-cleaning, de-identification and information extraction modules. It also includes a sample controlled vocabulary of drugs, herbs and adverse effect terms. AVAILABILITY: http://www.cis.upenn.edu/~ungar/medpie.zip. DEPENDENCIES: Python 2.6 or 2.7.

Magnitude of the inflammatory response to cardiopulmonary bypass and its relation to adverse clinical outcomes.

INTRODUCTION: Cardiopulmonary bypass (CPB) induces an inflammatory response believed to contribute to postoperative morbidity. We hypothesized that the magnitude of the inflammatory response following CPB would be associated with adverse clinical outcomes. METHODS: Twenty-nine patients had plasma TNF, IL-6, IL-8, elastase, histamine, complement C5a, and complement C3a measured by ELISA before, during, and after cardiac operations employing CPB. Inflammatory mediator levels were analyzed with respect to outcomes. RESULTS: Mediator levels peaked at 4 h post-CPB and either returned to baseline or substantially decreased by 24 h. Patients with peak mediator levels above the median for the group as a whole were classified as 'hyper-responders'; those with levels below the median were classified as 'normal responders'. While IL-8, C3a, and IL-6 levels were independently associated with adverse outcomes, TNF, histamine, and C5a levels were not. Elastase levels trended towards adverse outcomes. IL-8 'hyper-responders' experienced significantly greater postoperative weight gain and had higher IL-8 levels at 24 h (p<0.05), with trends towards renal impairment and protracted supplemental oxygen requirements. C3a 'hyper-responders' strongly trended towards increased bleeding, delayed extubation, greater postoperative weight gain, and decreased levels of independent functioning at discharge (p < or = 0.10). IL-6 'hyper-responders' experienced significantly more postoperative bleeding, delayed extubation, and higher IL-6 levels at 24 h compared to 'normal responders' (p < 0.05). They strongly trended towards greater postoperative weight gain and decreased levels of independent functioning at discharge (p < or = 0.10). CONCLUSIONS: Patients who have an exaggerated inflammatory response to CPB tend to bleed more, require more respiratory support, demonstrate greater capillary leak via weight gain, and display a decline in independent functioning relative to normal responders. Thus, it appears that the magnitude of the inflammatory response to CPB adversely influences clinical outcomes.

Elevated intestinal fatty acid binding protein and gastrointestinal complications following cardiopulmonary bypass: a preliminary analysis.

BACKGROUND: Cardiopulmonary bypass (CPB) is associated with poorly understood alterations in gastrointestinal (GI) perfusion. Intestinal fatty acid binding protein (IFABP), a cytosolic protein uniquely located in mature small-intestinal enterocytes, has been shown to be a sensitive biochemical marker of early intestinal ischemia when assayed in urine. We hypothesized that if significant small-intestinal ischemia occurs with CPB, then urine IFABP levels should be concomitantly elevated. METHODS: Twenty-nine patients (15 low risk and 14 high risk) undergoing cardiac surgery with CPB were studied prospectively. Serial urine IFABP levels were measured and results were correlated with clinical outcomes. RESULTS: None of the low-risk patients had IFABP elevations or experienced GI complications. Five of the high-risk patients had IFABP elevations, and three of the five developed GI complications. Within the high-risk cohort, the only significant difference between patients with or without IFABP elevations was the GI complication rate (P = 0.03). Overall, patients with IFABP elevations had a significantly higher mean ASA class and significant increases in mean CPB and aortic cross-clamp times, mean time to oral intake, median ICU and postoperative lengths of stay, and GI complications. CONCLUSIONS: In low-risk bypass patients, small-bowel mucosal perfusion appeared to be maintained, while in the high-risk population, 21% of the patients sustained clinically significant mucosal compromise. In this pilot study, urine IFABP was 100% sensitive and 92% specific with respect to GI complications. Since elevated urine IFABP concentrations appeared to correlate with clinical GI complications, urine IFABP may be a useful marker to identify the patient at risk for postbypass GI complications.

Effect of transdermal testosterone treatment on serum lipid and apolipoprotein levels in men more than 65 years of age.

PURPOSE: Because the effects of androgen replacement on lipoprotein levels are uncertain, we sought to determine the effect of transdermal testosterone treatment on serum lipid and apolipoprotein levels in elderly men. SUBJECTS AND METHODS: One hundred and eight healthy men more than 65 years of age who had serum testosterone concentrations >1 SD below the mean for young men were randomly assigned to receive either testosterone (54 men; 6 mg/day) or placebo (54 men) transdermally in a double-blind fashion for 36 months. Serum concentrations of lipids and apolipoproteins were measured, and cardiovascular events recorded. RESULTS: Serum total cholesterol concentrations decreased in both the testosterone-treated men and placebo-treated men, but the 3-year mean (+/- SD) decreases in the two groups (testosterone treated, -17 +/- 29 mg/dL; placebo treated, -12 +/- 38 mg/dL) were not significantly different from each other (P = 0.4). Similarly, serum low-density lipoprotein (LDL) cholesterol levels decreased in both treatment groups, but the decreases in the two groups (testosterone treated, -16 +/- 24 mg/dL; placebo treated, -16 +/- 33 mg/dL) were similar (P = 1.0). Levels of high-density lipoprotein (HDL) cholesterol, triglycerides, and apolipoproteins A-I and B did not change. Lipoprotein(a) levels increased in both groups by similar amounts (testosterone treated, 3 +/- 9 mg/dL; placebo treated, 4 +/- 6 mg/dL; P = 1.0). The number of cardiovascular events was small and did not differ significantly between the testosterone-treated men (9 events) and the placebo-treated men (5 events) during the 3-year study (relative risk = 1.8; 95% confidence interval: 0.7 to 5.0). CONCLUSIONS: As compared with placebo, transdermal testosterone treatment of healthy elderly men for 3 years did not affect any of the lipid or apolipoprotein parameters that we measured. The effect of testosterone treatment on cardiovascular events was unclear, because the number of events was small.

Management and long-term follow-up of hepatic cysts.

PURPOSE: To provide an algorithm for the management of hepatic cysts through an analysis of our series over 16 years. METHOD: We reviewed the surgical management and outcome of patients with hepatic cysts between 1984 and 2000 at a single institution. Data were collected by chart review, telephone interview, and follow-up hepatic ultrasonography. RESULTS: Forty-four patients (36 females, 8 males) underwent a total of 46 operations for hepatic cysts (mean size 12.0 +/- 5.2 cm) with a mean follow-up of 5.1 +/- 4.0 years. We treated 28 simple cysts, 4 polycystic liver disease (PCLD), 7 cystadenomas, 2 hydatid cysts, 1 cystadenocarcinoma, 1 endometrioma, and 1 hepatic foregut cyst. Operations included simple drainage, wide unroofing (open and laparoscopic), and hepatic resection. Four patients experienced a symptomatic recurrence after definitive treatment; 3 of these patients had PCLD. Four of the 7 patients with cystadenomas had undergone previous operations that required subsequent definitive resection without a recurrence. CONCLUSIONS: The preoperative distinction between simple cysts and cystadenomas/cystadenocarcinomas can be difficult, yet the management is different. Unroofing is a safe and effective operation for patients with simple cysts. Patients with PCLD frequently have recurrences. Cystadenomas should be completely resected owing to the likelihood of recurrence after partial excision and the risk of eventual cystadenocarcinoma. We present a treatment algorithm for the preoperative evaluation and management of hepatic cysts based on the largest number of patients with the longest follow-up reported to date.

Partners for child passenger safety: a unique child-specific crash surveillance system.

Insurance claims data were combined with telephone survey and on-site crash investigation data to create the first large scale, child-focused motor vehicle crash surveillance system in the US. Novel data management and transfer techniques were used to create a nearly real-time data collection system. In the first year of this on-going project, known as Partners for Child Passenger Safety, over 1200 children < or = 15 years of age per week were identified in crashes reported to State Farm Insurance Co. from 15 states and Washington, D.C. Partners for Child Passenger Safety is similar in its design and overall objectives to National Automotive Sampling System (NASS), the only other population-based crash surveillance system currently operating in the US.

Stat5 and Sp1 regulate transcription of the cyclin D2 gene in response to IL-2.

The IL-2R promotes rapid expansion of activated T cells through signals mediated by the adaptor protein Shc and the transcription factor Stat5. The mechanisms that engage the cell cycle are not well defined. We report on the transcriptional regulation of the cell cycle gene cyclin D2 by the IL-2R. IL-2-responsive induction of a luciferase reporter gene containing 1624 bp of the cyclin D2 promoter/enhancer was studied in the murine CD8(+) T cell line CTLL2. Reporter gene deletional analysis and EMSAs indicate an IL-2-regulated enhancer element flanks nucleotide -1204 and binds a complex of at least three proteins. The enhancer element is bound constitutively by Sp1 and an unknown factor(s) and inducibly by Stat5 in response to IL-2. The Stat5 binding site was essential for IL-2-mediated reporter gene activity, and maximum induction required the adjacent Sp1 binding site. Receptor mutagenesis studies in the pro-B cell line BA/FG (a derivative of the BA/F3 cell line) demonstrated a correlation between Stat5 activity and cyclin D2 mRNA levels when the Stat5 signal was isolated, disrupted, and then rescued. Further, a dominant-negative form of Stat5 lacking the trans-activation domain inhibited induction of cyclin D2 mRNA. We propose that the IL-2R regulates the cyclin D2 gene in part through formation of an enhancer complex containing Stat5 and Sp1.

Discovery of predictive models in an injury surveillance database: an application of data mining in clinical research.

A new, evolutionary computation-based approach to discovering prediction models in surveillance data was developed and evaluated. This approach was operationalized in EpiCS, a type of learning classifier system specially adapted to model clinical data. In applying EpiCS to a large, prospective injury surveillance database, EpiCS was found to create accurate predictive models quickly that were highly robust, being able to classify > 99% of cases early during training. After training, EpiCS classified novel data more accurately (p < 0.001) than either logistic regression or decision tree induction (C4.5), two traditional methods for discovering or building predictive models.

Effects of testosterone replacement in hypogonadal men.

Treatment of hypogonadal men with testosterone has been shown to ameliorate the effects of testosterone deficiency on bone, muscle, erythropoiesis, and the prostate. Most previous studies, however, have employed somewhat pharmacological doses of testosterone esters, which could result in exaggerated effects, and/or have been of relatively short duration or employed previously treated men, which could result in dampened effects. The goal of this study was to determine the magnitude and time course of the effects of physiological testosterone replacement for 3 yr on bone density, muscle mass and strength, erythropoiesis, prostate volume, energy, sexual function, and lipids in previously untreated hypogonadal men. We selected 18 men who were hypogonadal (mean serum testosterone +/- SD, 78 +/- 77 ng/dL; 2.7 +/- 2.7 nmol/L) due to organic disease and had never previously been treated for hypogonadism. We treated them with testosterone transdermally for 3 yr. Sixteen men completed 12 months of the protocol, and 14 men completed 36 months. The mean serum testosterone concentration reached the normal range by 3 months of treatment and remained there for the duration of treatment. Bone mineral density of the lumbar spine (L2-L4) increased by 7.7 +/- 7.6% (P < 0.001), and that of the femoral trochanter increased by 4.0 +/- 5.4% (P = 0.02); both reached maximum values by 24 months. Fat-free mass increased 3.1 kg (P = 0.004), and fat-free mass of the arms and legs individually increased, principally within the first 6 months. The decrease in fat mass was not statistically significant. Strength of knee flexion and extension did not change. Hematocrit increased dramatically, from mildly anemic (38.0 +/- 3.0%) to midnormal (43.1 +/- 4.0%; P = 0.002) within 3 months, and remained at that level for the duration of treatment. Prostate volume also increased dramatically, from subnormal (12.0 +/- 6.0 mL) before treatment to normal (22.4 +/- 8.4 mL; P = 0.004), principally during the first 6 months. Self-reported sense of energy (49 +/- 19% to 66 +/- 24%; P = 0.01) and sexual function (24 +/- 20% to 66 +/- 24%; P < 0.001) also increased, principally within the first 3 months. Lipids did not change. We conclude from this study that replacing testosterone in hypogonadal men increases bone mineral density of the spine and hip, fat-free mass, prostate volume, erythropoiesis, energy, and sexual function. The full effect of testosterone on bone mineral density took 24 months, but the full effects on the other tissues took only 3-6 months. These results provide the basis for monitoring the magnitude and the time course of the effects of testosterone replacement in hypogonadal men.

The learning classifier system: an evolutionary computation approach to knowledge discovery in epidemiologic surveillance.

The learning classifier system (LCS) integrates a rule-based system with reinforcement learning and genetic algorithm-based rule discovery. This investigation reports on the design, implementation, and evaluation of EpiCS, a LCS adapted for knowledge discovery in epidemiologic surveillance. Using data from a large, national child automobile passenger protection program, EpiCS was compared with C4. 5 and logistic regression to evaluate its ability to induce rules from data that could be used to classify cases and to derive estimates of outcome risk, respectively. The rules induced by EpiCS were less parsimonious than those induced by C4.5, but were potentially more useful to investigators in hypothesis generation. Classification performance of C4.5 was superior to that of EpiCS (P<0.05). However, risk estimates derived by EpiCS were significantly more accurate than those derived by logistic regression (P<0.05).

Association of dialyzer reuse and hospitalization rates among hemodialysis patients in the US.

OBJECTIVES: To determine if reuse of hemodialyzers is associated with higher rates of hospitalization and their resulting costs among end-stage renal disease (ESRD) patients. METHODS: Noncurrent cohort study of hospitalization rates among 27,264 ESRD patients beginning hemodialysis in the United States in 1986 and 1987. RESULTS: Dialysis in free-standing facilities reprocessing dialyzers was associated with a greater rate of hospitalization than in facilities not reprocessing (relative rate (RR) = 1.08, 95% confidence interval (CI), 1.02-1.14). This higher rate of hospitalization was observed with dialyzer reuse using peracetic/acetic acids (RR = 1.11, CI 1. 04-1.18) and formaldehyde (RR = 1.07, CI 1.00-1.14), but not glutaraldehyde (p = 0.97). There was no difference among hospitalization rates in hospital-based facilities reprocessing dialyzers with any sterilant and those not reprocessing. Hospitalization for causes other than vascular access morbidity in free-standing facilities reusing dialyzers with formaldehyde was not different from hospitalization in facilities not reusing. However, reuse with peracetic/acetic acids was associated with higher rates of hospitalization than formaldehyde (RR = 1.08, CI 1.03-1.15). CONCLUSIONS: Dialysis in free-standing facilities reprocessing dialyzers with peracetic/acetic acids or formaldehyde was associated with greater hospitalization than dialysis without dialyzer reprocessing. This greater hospitalization accounts for a large increment in inpatient stays in the USA. These findings raise important concerns about potentially avoidable morbidity among hemodialysis patients.

The use of micro-dose aprotinin with continuous infusion in coronary artery bypass surgery.

BACKGROUND: To evaluate the efficacy of aprotinin at a dose far less than standard. EXPERIMENTAL DESIGN: Retrospective, case-control study. SETTING: community-based, teaching hospital PATIENTS: one hundred one patients undergoing primary, non-emergent, coronary artery bypass during two, six-month periods were studied. INTERVENTIONS: during the first period aprotinin was not administered, and these patients served as controls (n = 52). During the second period all patients received aprotinin via a micro-dose regimen (n = 49). MEASURES: postoperative bleeding and blood product usage served as determinants of efficacy. RESULTS: A significant difference existed in postoperative bleeding with the mean thoracic drain outputs being reduced in the aprotinin group both at 6 hours (p = 0.0003) and in total (p = 0.0004). This was further supported by significantly higher hematocrits (p = 0.03) on the first postoperative day in patients receiving aprotinin. Likewise, there was a significant reduction in total blood product exposures (p = 0.04) and platelet usage (p = 0.02) in the aprotinin group with a tendency towards decreased red cell usage. Further, when all patients with a hematocrit < or =30% prior to bypass were excluded, the significant reduction in total blood product exposures persisted (p = 0.04), and there was a significant reduction in red cell usage (p = 0.04) with a trend towards decreased platelet usage (p = 0.06) in the aprotinin group. CONCLUSIONS: Micro-dose aprotinin significantly reduces postoperative bleeding and blood product usage in primary, non-emergent, CABG patients.