Illness severity scores in veterinary medicine: what can we learn?

Illness severity scores are gaining increasing popularity in veterinary medicine. This article discusses their applications in both clinical medicine and research, reviews the caveats pertaining to their use, and discusses some of the issues that arise in appropriate construction of a score. Illness severity scores can be used to decrease bias and confounding and add important contextual information to research by providing a quantitative and objective measure of patient illness. In addition, illness severity scores can be used to benchmark performance, and establish protocols for triage and therapeutic management. Many diagnosis-specific and diagnosis-independent veterinary scores have been developed in recent years. Although score use in veterinary research is increasing, the scores available are currently underutilized, particularly in the context of observational studies. Analysis of treatment effect while controlling for illness severity by an objective measure can improve the validity of the conclusions of observational studies. In randomized trials, illness severity scores can be used to demonstrate effective randomization, which is of particular utility when group sizes are small. The quality of veterinary scoring systems can be improved by prospective multicenter validation. The prevalence of euthanasia in companion animal medicine poses a unique challenge to scores based on a mortality outcome.

The acute patient physiologic and laboratory evaluation (APPLE) score: a severity of illness stratification system for hospitalized dogs.

BACKGROUND: Objective risk stratification models are used routinely in human critical care medicine. Applications include quantitative and objective delineation of illness severity for patients enrolled in clinical research, performance benchmarking, and protocol development for triage and therapeutic management. OBJECTIVE: To develop an accurate, validated, and user-friendly model to stratify illness severity by mortality risk in hospitalized dogs. ANIMALS: Eight hundred and ten consecutive intensive care unit (ICU) admissions of dogs at a veterinary teaching hospital. METHODS: Prospective census cohort study. Data on 55 management, physiological, and biochemical variables were collected within 24 hours of admission. Data were randomly divided, with 598 patient records used for logistic regression model construction and 212 for model validation. RESULTS: Patient mortality was 18.4%. Ten-variable and 5-variable models were developed to provide both a high-performance model and model maximizing accessibility, while maintaining good performance. The 10-variable model contained creatinine, WBC count, albumin, SpO(2) , total bilirubin, mentation score, respiratory rate, age, lactate, and presence of free fluid in a body cavity. Area under the receiver operator characteristic (AUROC) on the construction data set was 0.93, and on the validation data set was 0.91. The 5-variable model contained glucose, albumin, mentation score, platelet count, and lactate. AUROC on the construction data set was 0.87, and on the validation data set was 0.85. CONCLUSIONS AND CLINICAL IMPORTANCE: Two models are presented that enable allocation of an accurate and user-friendly illness severity index for dogs admitted to an ICU. These models operate independent of primary diagnosis, and have been independently validated.

The investigation of bronchospasm during induction of anaesthesia.

BACKGROUND: The aim of this study was to ascertain whether anaesthetic induction-related anaphylactic bronchospasm could be distinguished from other types of bronchospasm by clinical features and response to treatment. Such features could then be used to identify a group of patients in whom skin testing is indicated. METHODS: We retrospectively studied data from 183 patients referred to an anaesthetic allergy clinic because of bronchospasm during induction. For the analysis, the patients were divided into two groups depending on whether there was evidence suggesting immunological anaphylaxis. RESULTS: When the patients in whom intradermal tests were positive were compared with those in whom intradermal tests were negative, the skin test-positive patients had significantly more severe reactions, and they were more commonly associated with other clinical signs. Mast cell tryptase (MCT) was an excellent discriminator between reactions likely to be allergic and those unlikely to be allergic. CONCLUSIONS: Anaphylactic bronchospasm related to induction of anaesthesia is more likely to be severe than bronchospasm due to non-immune causes. An allergic cause is more likely if there are associated features of anaphylaxis (skin changes, hypotension, angioedema) or elevated MCT. Patients with any of these features should undergo immuno-allergolical investigation.

Pulmonary artery catheters for adult patients in intensive care.

BACKGROUND: Pulmonary artery catheterization was adopted about 30 years ago and widely disseminated without rigorous evaluation as to whether it benefited critically ill patients. The technique is used to measure cardiac output and pressures in the pulmonary circulation to guide diagnosis and treatment. Clinicians believe these data can improve patients' outcomes, even in the absence of consensus about the specific interpretation of the data. OBJECTIVES: To assess the effect of pulmonary artery catheterization on mortality and cost of care in adult intensive care patients. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 2, 2006); MEDLINE (all records to April 2006); EMBASE (all records to April 2006); CINAHL (all records to April 2006) and reference lists of articles. We contacted manufacturers and researchers in the field. SELECTION CRITERIA: We included all randomized controlled trials in adults, comparing management with and without a pulmonary artery catheter (PAC). DATA COLLECTION AND ANALYSIS: We screened the titles and abstracts of the electronic search results and obtained the full text of studies of possible relevance for independent review. We determined the final results of the literature search by consensus between the authors. We did not contact study authors for additional information. MAIN RESULTS: We identified 12 studies. Mortality was reported as hospital, 28-day, 30-day, or intensive care unit. We considered studies of high-risk surgery patients (eight studies) and general intensive care patients (four studies) separately for the meta-analysis. The pooled odds ratio for the studies of general intensive care patients was 1.05 (95% confidence interval (CI) 0.87 to 1.26) and for the studies of high-risk surgery patients 0.99 (95% CI 0.73 to 1.24). Of the eight studies of high-risk surgery patients, five evaluated the effectiveness of pre-operative optimization but there was no difference in mortality when these studies were examined separately. Pulmonary artery catheterization did not affect intensive care unit (reported by 10 studies) or hospital (reported by nine studies) length of stay. Four studies, conducted in the United States, measured costs based on hospital charges billed to patients, which on average were higher in the PAC groups. AUTHORS' CONCLUSIONS: To date, there have been two multi-centre trials of the effectiveness of PACs for managing critically ill patients admitted to intensive care, although only one was adequately powered. Efficacy studies are needed to determine optimal management protocols and patient groups who could benefit from management with a PAC.

Lipids and stroke: a paradox resolved.

BACKGROUND: Although dyslipidemia is a well established risk factor for coronary artery disease, its relationship to ischemic cerebrovascular disease has remained unclear, perhaps because of the heterogeneous nature of strokes. METHODS: In a case-control study, we measured the serum concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, serum triglycerides, and lipoprotein(a) levels and determined the apolipoprotein E phenotype and serum ferritin level in 90 consecutive systematically investigated patients with stroke or transient ischemic attack of atherothrombotic origin. Ninety age-, sex-, and community-matched subjects served as controls. RESULTS: Plasma total cholesterol (5.99 vs 5.45 mmol/L [232 vs 211 mg/dL], P=.003), low-density lipoprotein cholesterol (3.96 vs 3.45 mmol/L [153 vs 133 mg/dL], P=.004), and serum triglyceride (2.09 vs 1.82 mmol/L [8] vs 70 mg/dL], P=.03) levels were significantly higher among the patients with atherothrombotic strokes and transient ischemic attacks than among the control subjects. The inverse was true for high-density lipoprotein cholesterol (1.07 vs 1.18 mmol/L [41 vs 46 mg/dL], P=.02) levels. No significant differences were found in lipoprotein(a) levels or in the distribution of apolipoprotein E phenotypes or allele frequency. Serum ferritin levels did not differ significantly between patients and control subjects. CONCLUSIONS: Elevated low-density lipoprotein cholesterol and triglyceride levels are significant independent risk factors in patients with proven atherothrombotic cerebrovascular disease manifesting as stroke or transient ischemic attack. The level of stored serum iron, as reflected by serum ferritin levels, does not correlate with the presence of atherothrombotic cerebrovascular or coronary disease.

An assessment of nonconvulsive seizures in the intensive care unit using continuous EEG monitoring: an investigation of variables associated with mortality.

Of 49 patients with nonconvulsive seizures studied with continuous EEG monitoring, the overall mortality was 33% (16/49). Of the 23 patients with nonconvulsive status epilepticus (NCSE), 13 died (mortality 57%). Individual variables significantly associated with mortality were age, presence of NCSE, seizure duration, hospital and NICU length of stay, and delay to diagnosis and etiology (acute illness versus remote symptomatic). With multivariate logistic regression, only seizure duration (p = 0.0057, OR = 1.131/hour) and delay to diagnosis (p = 0.0351, OR = 1.039/hour) were associated with increased mortality. Acute symptomatic cases could not be adequately classified as either absence, simple, or complex partial status epilepticus when the impairment of consciousness arose form the initial illness. Current classifications of status epilepticus are inadequate for such cases.

Tumor angiogenesis predicts recurrence in invasive colorectal cancer when controlled for Dukes staging.

Tumor angiogenesis is associated with metastasis in several types of solid tumors, including melanoma, breast, prostate, lung, bladder, and oral-cavity tumors. The purpose of this study was to determine whether tumor angiogenesis could predict recurrence following curative surgery for colorectal cancer. Thirty-five patients were studied, including 13 patients with recurrent tumor and 22 without. Representative formalin-fixed, paraffin-embedded sections of invasive colorectal cancers from these patients were sectioned. The endothelial cells of microvessels within the tumors were highlighted by immunohistochemical staining for CD31. The most active areas were identified and the microvessels counted in a x 400 field (0.152 mm2) by two observers in a blinded fashion. Tumor microvessel count (p = 0.0062). Dukes' staging (p = 0.0004), vascular invasion (p = 0.0280), and tumor grade (p = 0.0559) were all significantly associated with tumor recurrence. Tumor microvessel counts > or = 65 per x 400 field were associated with tumor recurrence (p = 0.0035, relative risk [RR] = 11.3). Controlling for Dukes' stage, a multivariate logistic regression model revealed that a tumor microvessel count > or = 65 is an important predictor of tumor recurrence (p = 0.0783, RR = 6.0). A backwards elimination proportional hazards model revealed that a microvessel count > or = 65 shows a trend toward independent prediction of time to tumor recurrence (p = 0.1203, RR = 2.967) when controlled for Dukes' staging (p = 0.0029, RR = 9.089). Despite the small number of patients studied, these results suggest that the number of microvessels in sections of invasive colorectal adenocarcinoma immunohistochemically stained with CD31 may be an important independent predictor of tumor recurrence and time to recurrence.

Relationship of a new histological categorization of ductal carcinoma in situ of the breast with size and the immunohistochemical expression of p53, c-erb B2, bcl-2, and ki-67.

Ductal carcinoma in situ (DCIS) represents a heterogeneous group of diseases. There is no generally accepted classification for the different cytological and architectural types of DCIS. A recent study (Scott et al, 1995) indicates that over 90% of DCIS can be easily classified into the following five categories: high grade (HG), intermediate grade (IG), low grade (LG), pure micropapillary (M), and pure apocrine (A). The aim of this study was to determine if there is a relationship between lesion size and the immunohistochemical expression of p53, c-erb B2, bcl-2, and ki67 with this reproducible categorization of DCIS. Seventy cases of DCIS diagnosed between 1984 and 1995 were obtained from the Departments of Pathology at two teaching hospitals in London, Ontario. The original sections were reviewed, classified according to Scott et al (1995), and representative sections were cut for immunohistochemical (IHC) studies. IHC stains were scored using a previously described semiquantitative scoring system (Allred et al, 1993). Size was taken from the gross measurement if the lesion was palpable or recorded as the largest dimension, as measured on the histological slide, for nonpalpable cases. Of the 70 DCIS cases, 17 (24.3%) were HG, 23 (32.9%) were IG, 21 (30%) were LG, seven (10%) were pure micropapillary cases, and two (2.9%) were pure apocrine DCIS. The mean size of the DCIS for each subcategory was statistically significantly different (P = .008). In particular, the micropapillary DCIS cases were largest (mean size, 17 mm). The mean immunohistochemical scores for c-erb B2 for each category were also statistically different (P = .007), whereas the mean scores for p53 and ki67 for each category trended toward significance (P = .073, P = .062, respectively). There were no significant differences between bcl-2 mean scores and each subcategory. Size of DCIS and c-erb B2 positivity are known to be associated with more aggressive clinical behavior and more advanced histologic features, respectively. Because this combined histological cytological classification system is predictive of size and c-erb B2 positivity, our results support the clinical relevance of this classification system.

The predictive power of semiquantitative immunohistochemical assessment of p53 and c-erb B-2 in lymph node-negative breast cancer.

A series of 107 lymph node-negative (LNN) breast cancers was stained immunohistochemically with a combination of p53 and c-erb B-2. The immunohistochemical results were semiquantitated using a previously described system by Allred et al. p53 immunopositive cases were further screened for DNA mutations by the polymerase chain reaction-single-strand conformation polymorphism method (PCR-SSCP). Three representative cases showing mobility shifts were directly sequenced. One hundred of 103 invasive carcinomas were of no special type (infiltrating ductal carcinomas not otherwise specified). The three special type carcinomas included a tubular carcinoma, a classic infiltrating lobular carcinoma, and a mucinous carcinoma. Twenty-six patients (25.2%) had grade I carcinomas, and 77 patients (75%) had grade 2 or 3 carcinomas. There were four cases composed predominantly of ductal carcinoma in situ (DCIS) with foci of microinvasion. Twenty-seven of 107 patients (25%) died of disease. All those who died had grade 2 or 3 tumors. Univariate analysis showed that p53 and c-erb B-2 positivity (score > 6) were associated with a decreased overall survival (OS) (P = .0012 and P = .010, respectively), and a decreased disease-free survival (DFS) (P = .0009 and P = .027, respectively). The multivariate model selected these two variables as the best predictors of both OS and DFS (all P = or < .01). These results suggest that semiquantitative immunohistochemical analysis of p53 and c-erb B-2 provides prognostic information in LNN disease.

Assessing the efficiency of the admission process to a critical care unit: does the literature allow the use of benchmarking?

OBJECTIVES: To determine the ability of the current literature to supply appropriate data for benchmarking admission practice to a multidisciplinary critical care unit. DESIGN: Retrospective review of data collected prospectively on a cohort of 614 patients and a systematic review of the literature. SETTING: A 30-bed multidisciplinary critical care unit at a university teaching hospital. PATIENTS: Consecutive admissions to the critical care unit over a 6-month period. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: For each patient, demographic data and admitting diagnosis were recorded on admission. Information necessary to calculate the Acute Physiology and Chronic Health Evaluation II and Therapeutic Intervention Scoring System (TISS) scores were collected daily. TISS variables were categorized as "active" or "non-active" treatment variables. Patients were then identified on a daily basis as receiving or not receiving active treatment. A review of the literature, using MEDLINE and the search term "Therapeutic Intervention Scoring Index" (as a textword), was conducted to identify studies that had similarly divided their patients. Using the method of benchmarking, the proportion of patients admitted who received active treatment during their stay in the critical care units was compared between the index critical care unit and those in the literature. A greater proportion of the patients admitted to our unit received active treatment (97.7%) when compared to other studies in the literature (20-66%). However, a number of potential confounding factors were present, such as the availability of intermediate care units, overnight recovery room ventilation, and critical care bed availability between the index critical care unit and those described in the literature. CONCLUSIONS: The current literature does not provide adequate data on critical care unit admission practices to allow useful application of the method of benchmarking. There is a need for publicly accessible large databases to allow individual critical care units to determine their level of efficiency when compared to similar institutions.

Hyperdynamic sepsis depresses circulatory compensation to normovolemic anemia in conscious rats.

This study was designed to determine whether sepsis modifies the ability to preserve vital organ O2 delivery (QO2) across a clinically relevant range of hematocrits. Ninety rats were randomly allocated to cecal ligation and perforation (CLP) or a sham (Sham) procedure. With the use of rat plasma, rat whole blood, or packed rat red blood cells, respectively, randomization into three different hematocrit subgroups followed: low (21-28%), middle (33-40%), and high (45-52%). Organ blood flow values (Q) were measured by the radioactive microsphere technique, and organ QO2 values were calculated. Twenty-four hours after laparotomy, the hematocrit grouping had not modified the interorgan distribution of Q or QO2 in either the CLP or Sham rats. To characterize overall metabolic O2 reserve, rats were then exposed to hypoxia (inspired O2 fraction, 0.08) for 20 min. Whereas cardiac output increased significantly during hypoxia in all experimental groups, myocardial QO2 failed to increase in the low hematocrit Sham subgroup and fell significantly in both the middle- and low-hematocrit CLP subgroups. There was also a lesser redistribution of QO2 away from the small intestine in the low-hematocrit compared with the high-hematocrit CLP subgroup. We conclude that myocardial QO2 is more effectively maintained in septic hypoxic rats if the hematocrit is maintained at levels >45%.

Metallothionein expression in renal cancer.

OBJECTIVES: To assess metallothionein (MT) expression with immunohistochemical localization in human renal cell carcinoma and to determine whether a possible relationship with the histopathologic findings, tumor grade, or pathologic tumor stage is demonstrable, because MT may have a role in carcinogenesis. METHODS: Archival pathologic specimens and medical records were reviewed for 28 patients with renal cell carcinoma. Immunohistochemical localization of MT was performed with a polyclonal-antibody-to-rat-liver MT, an anti-rabbit IgG linking antibody, and an avidin-biotin horseradish peroxidase complex. Correlation was sought between immunohistochemical data (MT staining intensity, extension, and subcellular site) and clinical data (histologic cell type, tumor grade, and pathologic stage). RESULTS: The mean patient age was 61.7 years (range 42 to 86). The predominant histologic cell type was the clear cell variant. Three, sixteen, and nine tumors were pathologically staged as 1, 2, and 3, respectively. There were 1, 13, 10, and 4 tumors with grades 1, 2, 3, and 4, respectively. Among the independent variables, greater immunoreactivity was observed in Stage 2 tumors (P = 0.028). A significant inverse relationship between tumor grade and MT staining intensity was also observed (P = 0.007). CONCLUSIONS: The inverse relationship in renal cell carcinoma between MT immunoreactivity and tumor grade may indicate a role for MT in tumor growth and dedifferentiation. Increased MT immunoreactivity in lower stage tumors may be related to rapid tumor growth during their growth cycle. Further study is required to elucidate the role of MT in renal cell carcinoma oncogenesis and its possible use as a clinical prognostic parameter.

Interpreting and using clinical trials.

In 1754, aboard HMS Salisbury, James Lind conducted a simple, controlled clinical trial. He took 12 patients with "pale and bloated skin, listlessness, an aversion to exercise, swollen gums, halitosis, ecchymotic mucous membranes, and limb edema" and allocated them to receive treatment with one of six different therapies. Since the patients receiving two of his six chosen interventions had such a dramatic recovery, he felt ethically obligated to end his trial and administer these treatments to all the remaining sailors. Today we fully recognize the impact that the controlled clinical trial can have on the development of new interventions. Unfortunately, very few of these interventions are likely to have as dramatic an impact on outcomes as lemons and oranges did on scurvy. Because the interventions we study tend to have relatively small treatment effects, and because the design and reporting of published RCTs has consistently been documented to be less than perfect, there is a real need for us to develop critical appraisal skills. This article is by no means the only approach to critical appraisal, but hopefully it serves as an adequate starting point for the journey.

Pulmonary artery catheters in the critically ill. An overview using the methodology of evidence-based medicine.

Evidence-based approaches to assessing the clinical literature are used increasingly in issues relating to critical care medicine. As we discussed previously, this approach attempts to provide a logical and convenient framework from which the quality and relevance of clinical studies may be assessed in an unbiased manner. An evidence-based approach also allows the reader to differentiate between solid evidence and evidence that is based on a presumed mechanism, standard practice, or conventional wisdom. Evidence-based medicine that deemphasizes intuition, unsystemic clinical experience, and pathophysiologic rationale is sufficient grounds for clinical decision making and stresses the examination of evidence from clinical research. Importantly, it is the objective nature by which the evidence-based medicine paradigm approaches the questions of "What are we doing" and "How can we do better," that causes health care providers and funding agencies to increasingly adopt this paradigm as a primary principle. The role of evidence-based medicine, therefore, is not to discount expert opinion but, wherever possible, to require that recommendations be based on the results of rigorous and controlled scientific study. We introduced this article by highlighting the growing imbalance between resources and patient needs in the critical care environment. At the level of diagnostic technology and therapeutic care plans, critical care professionals increasingly are asked to identify strategies to improve efficiencies-approaches with rigorous costs that at the same time promote better patient care. Formalized technology assessment is one of the mechanisms to accomplish this. Using critical appraisal within the context of evidence-based medicine is one of the mechanisms by which data can be synthesized to describe technology assessment. In this example, we used controversies surrounding use of pulmonary artery catheterization in critically ill patients to highlight some of the principles of evidence-based medicine at the bedside. We introduced how a particular case example can be used to ask the question, "What is the evidence that a particular diagnostic technology or therapeutic modality improves outcome?" In the case of PACs, no one would argue that a diagnostic technology a priori leads to improved outcome; rather, we have to presume that given good data, the care provider will apply the most appropriate management strategy. In this case example, however, we demonstrate how the critical appraisal process should identify a search strategy to find the most appropriate evidence to support the questioning process. From this, the evidence can be critically appraised and tabulated. In the case of the PAC, Table 13 demonstrates that there are few data to identify a grade A recommendation that the PAC should be used as part of the care process in critically ill patients. Finding that there is little evidence to support the use of pulmonary artery catheterization in the clinical literature does not mean that this diagnostic technology is neither efficacious nor effective. It might well be that information provided by PACs is important in the care process. However, what this exercise has taught us is that there is little objective evidence to support this conclusion. The challenge to critical care practitioners is not only to apply the evidence-based processes more frequently to our environment but also to use the information to separate out clearly what is fact versus opinion. Where there is little evidence to support a particular clinical practice, as we have demonstrated with the PAC review earlier, the challenge to the clinician should be the design and conduct of clinical trials clarifying debate between opinion and evidence.

Trauma outcome analysis and the development of regional norms.

Early attempts to assess patient outcomes in trauma hospitals included morality reviews and expert panel chart audits. More recently, a statistical methodology combining the Revised Trauma Score and Injury Severity Score has been developed (TRISS). A modification of this methodology--TRISS-like analysis--allows the inclusion of patients who have required endotracheal intubation prior to the time of arrival at the trauma hospital. This study was undertaken to further improve this TRISS-like methodology by developing statistical coefficients based on regional data. It was hypothesized that his would allow the analysis to better identify those hospitals with significantly better worse outcomes than their peers. The Comprehensive Data Set of the Ontario Trauma Registry was accessed, which contains data on severely injured patients from all 11 lead trauma hospitals in the province. Three years' data were obtained, and checked for accuracy and completeness. Analysis was performed using the previously published coefficients. New coefficients were then derived, using regression analysis on the Ontario patient data. 5,258 of 6,389 files were complete and eligible for analysis. TRISS-like analysis resulted in an expected mortality of 21.2% (1115.6/5258) with a z score for the entire province of -14.102. Individual hospital scores were all negative (fewer deaths than expected), and 9/11 hospital scores were < -1.96 (statistically significant). The new coefficients were markedly different from those previously published, and their application resulted in an overall z score of 0.000. Institutional scores ranged from -3.309 to +4.686, with two hospitals < -1.96 and one > +1.96. The old coefficients predicted many more deaths than occurred in all of the hospitals. The new coefficients proved quite accurate overall in predicting outcomes, and identified one institution with significantly more deaths than would have been predicted for other hospitals in the province. Subsequently, a fourth year's data files were obtained, and used as a validation data set. The new coefficients again proved more useful than the original ones.

Using the Vista 350 telephone to communicate the results of home monitoring of diabetes mellitus to a central database and to provide feedback.

PURPOSE: Self-monitoring of blood glucose has become routine practice in the management of diabetes mellitus. When all the data is complete, however, the amount of information to be taken into account when making therapeutic decisions becomes overwhelming not only for the patient but for the healthcare provider. Computers excel at processing large amounts of information quickly and impassively, which makes them potentially helpful for collating and communicating the data in a manner that facilitates decision-making by patient and healthcare provider. This should in turn improve control and help prevent acute and chronic complications. METHOD: Using the Vista 350 telephone, we have developed a system that enables patients with diabetes to record home monitoring data to a central database and receive feedback summaries. A small trial was conducted to determine if the Vista 350 telephone is an acceptable and feasible method to communicate the results of home monitoring of diabetes mellitus to a central database and receive feedback summaries. A total of 35 volunteers with insulin-requiring diabetes mellitus in the London area were randomly allocated to either use the Vista 350 phone for 6 months, or to a control group that continued to use traditional methods for recording home monitoring data. RESULTS: 33 of the 35 patients enrolled completed the trial. All 16 patients who began using the phone continued to do so for 6 months confirming the feasibility of the system. Questionnaires completed at 3 and 6 months confirmed the Vista 350 telephone system to be acceptable to the subjects. The results will enable some minor modifications to be made to the telephone system before a larger definitive trial, designed to determine the effect on diabetes control, is conducted later this year.

Evidence-based veterinary medicine: what it is, what it isn't and how to do it.

EBM represents a more formal process for considering the merits of published research in the context of clinical decision making. By combining the application of formal rules of evidence in evaluating the clinical literature (critical appraisal) with the ability to conduct efficient and effective literature searches, any clinician is able to keep current on topics of interest. Learning the core skills that enable the practice of EBM is easier than expected. The EBM Working Group published a series of Users' Guides to enable clinicians to learn critical appraisal of the primary literature in a systematic fashion. The complete series of Users' Guides is available free of charge over the web (www. CCHE.net). Similarly, PubMed, which contains a number of easy to use search filters (Clinical Queries) that can identify high-quality papers published in key veterinary journals, is also available free of charge over the web (www.PubMed.org). How ever one obtains the core skills, an efficient, structured approach to the practice of EBM can actually reduce the amount of time one requires to keep current by helping the user locate and identify methodologically rigorous research. Although the entire process can be self-taught, as with any new technique, other effective ways to bring these new skills into your practice setting include attending a conference workshop or even hiring a new graduate who has already been trained in the process.

Cesarean section in the sow: A retrospective analysis of litter size and stillbirth rate.

The purpose of this study was to examine the litter size and stillbirth rate associated with cesarean-derived litters and to examine the relationship between the number of previous cesarean sections a sow had experienced and litter size. The records of 856 cesarean sections during a ten-year period from 1978 to 1988 were examined. The mean litter size was 10.6 +/- 3.2 and the mean number of stillborn pigs per litter was 0.2 +/- 0.8. The low level of stillbirth observed in this study provides supportive evidence to many earlier publications suggesting that the majority of stillborn pigs die during the birth process itself.A negative correlation between the number of previous cesarean sections a sow had experienced and litter size (r(2) = 0.015, p < 0.001) was observed. The slope of the regression line was -0.55, suggesting that litter size is reduced by approximately one-half a piglet for each cesarean section the sow has previously experienced. There are many factors which influence the variation in litter size. The small correlation coefficient (r(2) = 0.015) observed in this study indicates that only 1.5% of the variation in litter size can be explained by the number of previous cesarean sections that the sow has experienced.

Potential savings involved in the purchase of low-cost, high-volume medical commodities as established from a community hospital survey.

Health technology refers to the instruments, equipment, drugs and procedures used in health care delivery, as well as the organizations supporting it. Health technology assessment, which is the process of conducting investigations to establish the criteria for efficacious, effective and efficient patient care, is becoming increasingly important in an era of diminishing resources. This survey of 39 community hospitals in southwestern Ontario found that improved purchasing strategies can result in substantial cost savings which can in turn be used to improve patient care. The study shows that optimizing the price of basic hospital commodities could save an average community hospital as much as $625,000 per year.