David Butler-Jones

Bio: David Butler-Jones is an academic researcher from Saskatchewan Health. The author has contributed to research in topics: Public health & Health promotion. The author has an hindex of 7, co-authored 15 publications receiving 509 citations. Previous affiliations of David Butler-Jones include University of Saskatchewan.

Incidence of lactic acidosis in metformin users.

Abstract: OBJECTIVE: The purpose of this study was to determine the incidence of lactic acidosis in a geographically defined population of metformin users. RESEARCH DESIGN AND METHODS: The study was based on a historical cohort from the Saskatchewan Health administrative databases. Individuals with a metformin prescription dispensed between 1980 and 1995 inclusive were eligible for the cohort. Person-years of exposure were calculated. Cases were defined by hospital discharge with a diagnosis of acidosis (International Classification of Diseases, Ninth Revision code: 276.2) and confirmation by chart review of a blood lactate level > or = 5 mmol/l. Death registrations of individuals dying within 120 days of a metformin prescription were also reviewed. RESULTS: During the study period, 11,797 residents received one or more metformin prescriptions, resulting in 22,296 person-years of exposure. There were 10 subjects who had hospital discharges with a diagnosis of acidosis. However, primary record review revealed only two cases with laboratory findings of elevated blood lactate levels, for an incidence rate of 9 cases per 100,000 person-years of metformin exposure. In both cases, other factors besides metformin could have contributed to the lactic acidosis. No additional cases were found on review of death registrations. CONCLUSIONS: From 1980 through 1995, the incidence rate of lactic acidosis was 9 per 100,000 person-years (95% CI 0-21) in patients dispensed metformin in Saskatchewan, Canada. This incidence rate was derived from a population with complete ascertainment of hospitalizations and deaths associated with lactic acidosis in metformin users. It is similar to previously published rates based on passive reporting of cases, and it is well below the lactic acidosis rate of 40-64 per 100,000 patient-years in patients prescribed phenformin.

Managing the microbiological risks of drinking water.

Abstract: The microbiological contamination of drinking water supplies can have serious health consequences for consumers, and this has been dramatically illustrated in recent years by two disease outbreaks in Canada. In this paper, some factors that can influence the microbiological quality of drinking water and its management are examined. Frameworks have been proposed that help to clarify the main elements of health risk assessment and risk management, and, in accordance with these, risks can be logically characterized, evaluated and controlled. A protocol has been developed for microbiological risk assessment and a risk management framework now guides the development of Canada's national guidelines for drinking-water quality. Monitoring of indicator organisms and the application of adequate water treatment are the primary means recommended in the Canadian guidelines to safeguard health from the presence of water-borne pathogens. Understanding the biological characteristics of microbial pathogens is necessary for assessing their impact on community health and appraising the rationale behind drinking-water testing methods and their limitations. Improvements in health surveillance, monitoring, and risk characterization and application of concepts such as multiple barriers (source-to-tap) and total quality management should contribute to better management of the microbiological quality of drinking water.

Capacity for Community Development: An Approach to Conceptualization and Measurement

Abstract: The concept of "capacity" has generated substantial interest among community development practitioners and scholars. This article describes our efforts to understand and measure health promotion capacity in Saskatchewan, and encourages readers to think about the usefulness of this concept in other community development contexts. We conceptualize capacity as a set of knowledge, skills, commitments, and resources required by individuals and organizations to effectively plan, implement, and evaluate health promotion activities. We initially operationalized and measured capacity through survey instruments designed to elicit responses from health promotion practitioners and leaders of regional health care organizations. After the initial administration of these two surveys, and following additional qualitative consultations with respondents to the surveys, we developed "capacity checklists" as practical tools to help practitioners and leaders assess their individual and organizational capacity for health promo...

Grounded Theory and Sensitizing Concepts

Abstract: Grounded theory is a qualitative research approach that uses inductive analysis as a principal technique. Yet, researchers who embrace this approach often use sensitizing concepts to guide their analysis. In this article, the author examines the relationship between sensitizing concepts and grounded theory. Furthermore, he illustrates the application of sensitizing concepts in a study of community-based antipoverty projects in Jamaica. The article contains commentary about trustworthiness techniques, the coding process, and the constant comparative method of analysis, as well as a synopsis of study findings.

Risk of fatal and nonfatal lactic acidosis with metformin use in type 2 diabetes mellitus

Abstract: Background Metformin is an oral anti-hyperglycemic agent that has been shown to reduce total mortality compared to other anti-hyperglycemic agents, in the treatment of type 2 diabetes mellitus. Metformin, however, is thought to increase the risk of lactic acidosis, and has been considered to be contraindicated in many chronic hypoxemic conditions that may be associated with lactic acidosis, such as cardiovascular, renal, hepatic and pulmonary disease, and advancing age. Objectives To assess the incidence of fatal and nonfatal lactic acidosis, and to evaluate blood lactate levels, for those on metformin treatment compared to placebo or non-metformin therapies. Search strategy A comprehensive search was performed of electronic databases to identify studies of metformin treatment. The search was augmented by scanning references of identified articles, and by contacting principal investigators. Selection criteria Prospective trials and observational cohort studies in patients with type 2 diabetes of least one month duration were included if they evaluated metformin, alone or in combination with other treatments, compared to placebo or any other glucose-lowering therapy. Data collection and analysis The incidence of fatal and nonfatal lactic acidosis was recorded as cases per patient-years, for metformin treatment and for non-metformin treatments. The upper limit for the true incidence of cases was calculated using Poisson statistics. In a second analysis lactate levels were measured as a net change from baseline or as mean treatment values (basal and stimulated by food or exercise) for treatment and comparison groups. The pooled results were recorded as a weighted mean difference (WMD) in mmol/L, using the fixed-effect model for continuous data. Main results Pooled data from 347 comparative trials and cohort studies revealed no cases of fatal or nonfatal lactic acidosis in 70,490 patient-years of metformin use or in 55,451 patients-years in the non-metformin group. Using Poisson statistics the upper limit for the true incidence of lactic acidosis per 100,000 patient-years was 4.3 cases in the metformin group and 5.4 cases in the non-metformin group. There was no difference in lactate levels, either as mean treatment levels or as a net change from baseline, for metformin compared to non-metformin therapies. Authors' conclusions There is no evidence from prospective comparative trials or from observational cohort studies that metformin is associated with an increased risk of lactic acidosis, or with increased levels of lactate, compared to other anti-hyperglycemic treatments.

Contrast induced nephropathy: updated ESUR Contrast Media Safety Committee guidelines.

Abstract: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN). Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic measures used to reduce the incidence of CIN, and the management of patients receiving metformin. Key Points • Definition, risk factors and prevention of contrast medium induced nephropathy are reviewed. • CIN risk is lower with intravenous than intra-arterial iodinated contrast medium. • eGFR of 45 ml/min/1.73 m 2 is CIN risk threshold for intravenous contrast medium. • Hydration with either saline or sodium bicarbonate reduces CIN incidence. • Patients with eGFR ≥60 ml/min/1.73 m 2 receiving contrast medium can continue metformin normally.

Statins and cancer prevention

Abstract: Randomized controlled trials for preventing cardiovascular disease indicated that statins had provocative and unexpected benefits for reducing colorectal cancer and melanoma. These findings have led to the intensive study of statins in cancer prevention, including recent, large population-based studies showing statin-associated reductions in overall, colorectal and prostate cancer. Understanding the complex cellular effects (for example, on angiogenesis and inflammation) and the underlying molecular mechanisms of statins (for example, 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA) reductase-dependent processes that involve geranylgeranylation of Rho proteins, and HMG-CoA-independent processes that involve lymphocyte-function-associated antigen 1) will advance the development of molecularly targeted agents for preventing cancer. This understanding might also help the development of drugs for other ageing-related diseases with interrelated molecular pathways.