Search PubMed⌕ Search

Biomedical subjects

J W Frank

Publications and source records attributed to J W Frank.

At least 37 records · Page 2Linked to original sources
PubMed1996

Using Labour Force Survey and census data to generate denominators for occupational injury rates: an application and expansion of Haggar-Guénette's method.

The calculation of rates of occupational injury claims is essential to identify groups at high risk, yet limitations of denominator data have often restricted our capacity to do this. Haggar-Guénette's method of using Statistics Canada's data on paid workers from the Labour Force Survey as denominators has been expanded by incorporating information from the Census. The method is illustrated by calculating denominators for male construction industry workers within the province of Ontario. Information for paid workers employed in construction occupations was derived from the Labour Force Survey to produce denominators for those aged 15-64, overall and by 10-year age groups. Census data on the distribution of construction occupational roles were applied to produce denominators both overall, then simultaneously by age and by occupational role. Advantages and disadvantages, including the limitations or biases due to the differing sources for denominators and numerators are identified.

Accidents, Occupational↗
PubMed1995

Mechanism of accelerated gastric emptying of liquids and hyperglycemia in patients with type II diabetes mellitus.

BACKGROUND & AIMS: The roles of hyperglycemia in diabetic gastroparesis and gastric delivery in postprandial hyperglycemia of diabetic patients are unclear. The aims of this study were to assess gastric emptying and its relation to postprandial glucose metabolism in patients with asymptomatic non-insulin-dependent diabetes mellitus (NIDDM) and no autonomic neuropathy and to identify motor mechanisms responsible for any accelerated gastric emptying. METHODS: Autonomic function, gastric emptying, postprandial glucose metabolism, and hormone levels (glucagon, insulin, cholecystokinin, glucose-dependent insulinotropic polypeptide, neurotensin, and peptide YY) were assessed in healthy volunteers and patients with NIDDM. In a second study, gastric tone and motility were measured in patients with accelerated gastric emptying and in controls. RESULTS: Gastric emptying of solids did not differ in the two groups, but liquids emptied faster in patients with NIDDM (P < 0.02). The rate of entry of ingested glucose into the systemic circulation was similar, but higher postprandial glucagon and lower insulin concentrations led to greater (P < 0.01) postprandial hepatic glucose release. Levels of other enteropeptides, gastric accommodation, and antral motility were similar, but patients with NIDDM had greater proximal gastric phasic contractions than controls (P < 0.05). CONCLUSIONS: Excessive hepatic glucose release, not rapid entry of ingested glucose, is the primary cause of postprandial hyperglycemia in patients with NIDDM. Accelerated gastric emptying in patients with nonneuropathic NIDDM is associated with increased proximal stomach phasic contractions.

Autonomic Nervous System↗
PubMed1995

Methodological issues in assessing reproducibility--a comparative study of various indices of reproducibility applied to repeat ELISA serologic tests for Lyme disease.

This study applies and evaluates a variety of different measures of reproducibility. As an example, repeat enzyme-linked immunosorbent assays (ELISA) for antibodies to Borrelia burgdorferi, the etiologic agent of Lyme disease, are used. These repeat tests were part of the 1991 Quality Control Assessment of provincial laboratories that was carried out by the Laboratory Centre for Disease Control (Ottawa). Twenty-seven sera from cases and non-cases were tested by three laboratories, and two laboratories repeated the tests once. Methodological issues discussed include: different methods of assessing reproducibility in the continuous scale; whether reproducibility should be assessed with data in continuous or categorical form; problems assessing the reproducibility of data that has been standardized using a calibration-regression line; and problems with external generalizability of reproducibility studies of rare diseases. The authors conclude that the statistical method used to assess the reproducibility of a test must be adjusted to suit individual study designs and data, and the usage of the test.

Antibodies, Bacterial↗
PubMed1995

Quantitative measures of human immunodeficiency virus-specific antibodies predict progression to AIDS.

Studies examining specific antibodies directed against antigenic components of human immunodeficiency virus (HIV), as potential markers of progression to AIDS, have reported inconsistent results. We used reflectance densitometry and survival analysis to determine whether single quantitative measures of HIV-specific antibodies predicted progression to AIDS in a prospective cohort of 159 HIV-infected homosexual men. Lowered baseline levels of p24 antibody and p24/gp41 antibody ratio were independent predictors of progression to AIDS and retained statistical significance after simultaneously controlling for CD4:CD8 ratio, age, use of zidovudine, and clinical symptoms. Quantitative measures of p24 antibody and p24/gp41 antibody ratio warrant further study with regards to their clinical application as markers of HIV disease progression.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Occupational back pain--an unhelpful polemic.

In most industrialized countries, disability and work absence due to occupational back pain have risen steadily in recent decades. Conventional views of the causes of this slow epidemic tend to fall into one of the following three areas: (i) the clinical pathology view, which attributes the level of pain and disability to either the severity of the initial injury or to psychosomatic conditions; (ii) the biomechanical exposures view, which attributes the problem to hazardous and preventable conditions of work; and (iii) the perverse incentives view, which suggests that reporting and disability are influenced by a combination of work dissatisfaction and accessible disability benefits. This paper reviews, from an epidemiologic perspective, the specific methodological hurdles faced during investigations of the etiology of occupational back pain. It is argued that methodological issues have contributed to the perpetuation of the three distinct but incomplete views of the problem. New research directions are suggested and a broader interdisciplinary perspective is proposed to help resolve the existing polemic.

Back Pain↗
PubMed1995

Patient consent to observation. Responses to requests for written consent in an academic family practice unit.

OBJECTIVE: To examine patient rates of consent to observation and response to being asked for written consent. DESIGN: Patients were asked to provide written consent for a supervising physician to observe a resident performing a physical examination, or for both direct observation and videotaping of the visit. After the visit, all patients were interviewed, and patients who had given written consent completed a questionnaire. SETTING: The family practice unit at a teaching hospital affiliated with the University of Toronto. PARTICIPANTS: A representative sample of new and returning patients. MAIN OUTCOME MEASURES: Patient consent to observation or videotaping. RESULTS: Most patients (92.2%) agreed to be observed. Of those asked only for consent to observe, 97.3% agreed. Of those asked for consent to observe and videotape, 85.2% agreed. When specifically asked, 22% of patients who agreed to observation expressed concerns. CONCLUSION: We must devise clear policies and procedures for obtaining patient consent that are both sensitive to patients' concerns and administratively effective.

Adult↗
PubMed1994

A guide to interpreting epidemiologic studies on the etiology of back pain.

Understanding disease etiology is key for effective preventive or therapeutic interventions. Knowledge about risk factors is useful to the clinician to answer patients' questions about the possible cause(s) of their presenting disorders. This article describes the three most common types of etiologic studies using examples from the published literature on the risk factors for back pain. Cohort studies typically follow a group of "healthy" people forward in time to assess disease outcome after risk factors have already been measured. Case-control studies use people selected on the basis of outcome status; risk factors are assessed after the fact. Although more prone to bias than cohort studies, case control studies are more common in back pain research because of the ease of examining several risk factors simultaneously and the expense of cohort studies. Prevalence studies use a random sample of people collected at a single point in time; consequently there is no predetermined number of "cases" and "controls," their numbers depending on the prevalence of disease and exposures in the samples. To assist in the interpretation of research findings this paper presents a general framework for assessing the strengths and weaknesses of an individual study. Case-control studies are discussed in more detail because they are so commonly encountered in the etiologic literature. Finally, because the evidence from a single study, no matter how well designed and executed, is never enough on its own to decide if a risk factor is causal or not, the paper concludes by briefly summarizing the criteria for inferring causation using the full body of available biologic and epidemiologic literature.

Back Pain↗
PubMed1994

Group education interventions for people with low back pain. An overview of the literature.

STUDY DESIGN: This study systematically reviewed the literature on group education for people with low back pain. Findings are considered in relation to parameters such as the characteristics of the study participants, the intervention, and the setting. OBJECTIVE: To make a recommendation regarding the effectiveness of group education as an intervention for people with low back pain. RESULTS: Based on a systematic search of the literature, 13 primary studies are cited; 6 of these were sufficiently well designed and executed for their findings to be considered. Of the four quality studies with chronic back pain subjects, only one found a positive short-term effect on one of the outcome measures considered (pain intensity). In the two studies with acute cases, group education was found by one of the studies to reduce pain duration and initial sick leave duration in the short term, but the intervention also included work-site visits. At 1 year of follow-up, there was no evidence in the six studies of clinically important benefits on any of the outcome measures. CONCLUSIONS: There is insufficient evidence to recommend group education for people with low back pain.

Adult↗
PubMed1994

Budd-Chiari syndrome: early intervention with angioplasty and thrombolytic therapy.

We present a complex case of the Budd-Chiari syndrome due to thrombosis of the hepatic veins in the presence of stenosis of the left hepatic vein and membranous obstruction of the inferior vena cava. The acute thrombosis occurred after laparoscopic surgical removal of the gallbladder. Because we strongly suspected the Budd-Chiari syndrome, hepatic venography was performed. The hepatic venous outflow obstruction was relieved by angioplasty and thrombolytic therapy with use of local infusions of urokinase into the clot. We propose that angiography be performed in patients in whom the Budd-Chiari syndrome is suspected and that angioplasty and thrombolytic therapy be initiated early.

Adult↗
PubMed1994

Predicting risk of back injuries, work absenteeism, and chronic disability. The shortcomings of preplacement screening.

Preplacement screening is put forth by some as an effective method for preventing low back disability at the workplace. Although there are still large gaps in knowledge regarding the natural history of and risk factors for back disability, it is clear that the majority of costs are derived from the small proportion of those that will suffer with back symptoms for 6 months or more. Thus, if preplacement screening is to have an impact on health care spending and compensation costs, the screening test will have to be predictive not so much of all back injuries, but rather of work absenteeism and especially chronic disability. This paper presents some criteria for evaluating a screening program and explores the effect of choosing different outcomes for evaluation. The literature on the effectiveness of a number of preplacement screening techniques is examined. Current legislation related to preplacement screening is also described. The natural history, etiologic factors, and prognostic markers for back injuries need to be elucidated further before effective screening strategies can be developed to reduce the incidence of back injuries and back disability in the population.

Absenteeism↗
PubMed1994

Use of gastroduodenal manometry to differentiate mechanical and functional intestinal obstruction: an analysis of clinical outcome.

OBJECTIVES: Our aim was to assess the outcome of patients whose gastrointestinal motility recording suggested intestinal mechanical obstruction. METHODS: Medical records were reviewed for operative reports and alternative diagnoses during at least 1-yr follow-up. RESULTS: During 1988-1992, 27 of 890 consecutive manometric recordings suggested mechanical obstruction: 20 with non-propagated, prolonged contractions, seven with a pattern of non-propagated clustered contractions that lasted > 30 min. Obstruction was confirmed at laparotomy in 17 (including two with progressive systemic sclerosis) and by radiology in one. In confirmed obstruction, 12 of 18 contrast radiographs performed prior to manometry were either normal or nondiagnostic. One laparotomy was negative for obstruction; nine patients who did not undergo laparotomy were classified as unobstructed. Manometric recordings showed prolonged contractions in two, clustered contractions in three, and a mixed pattern in four. Positive predictive values of these patterns for obstruction were: prolonged contractions, 82%; clustered contractions, 57%; and mixed pattern, 56%. CONCLUSIONS: Thus, non-propagated, prolonged contractions in small bowel should prompt a search for obstruction, even when this is equivocal on barium small bowel radiography.

Adolescent↗
PubMed1993

Potentially undesirable prescribing and drug use among the elderly. Measurable and remediable.

Forty-seven patients older than 65 years were randomly selected for structured chart review of all long-term medications documented during the prior year and the number of instances of potentially undesirable prescribing for each patient. A trained nurse subsequently made home visits to assess all long-term medications used regularly during the same period. Forty-five percent of elderly patients had one or more instances of potentially undesirable drug use, all of which appeared to be readily remediable. Commercial drug interaction software identified less than half of the potentially undesirable instances.

Aged↗
PubMed1992

Will lowering population levels of serum cholesterol affect total mortality? Expectations from the Honolulu Heart Program.

Major campaigns now underway to reduce the serum cholesterol levels of entire national populations have not given serious consideration to the high rates of noncardiovascular disease and death associated with low cholesterol levels (less than 190 mg/dl). To explore this problem, the relationships between serum cholesterol levels, measured in 1965-1968 in 7478 Japanese American men in Hawaii, and subsequent total and cause-specific mortality through 1985, were analyzed by multivariate Cox regression to control for potential confounders. Total mortality rates for 1648 deaths showed a U-shaped curve by baseline cholesterol level, with significant inverse trends (p less than 0.03) for deaths due to hemorrhagic stroke, all cancer, benign liver disease, chronic obstructive lung disease and "unknown cause". Only the inverse trends for cancer and benign liver disease showed flattening when 227 deaths in the first 5 years of follow-up were deleted from the analysis. Simulation models using three different strategies of cholesterol reduction in this cohort revealed that none of these approaches had any substantial impact on predicted total mortality over 15 years. However, the population-based approach might theoretically increase mortality for 60% of the cohort with baseline cholesterol levels less than 225 mg/dl.

Aged↗
PubMed1992

The Ontario HIV seroprevalence study of childbearing women: results from the first year of testing.

The Ontario HIV Seroprevalence Study of Childbearing Women is an unliked anonymous seroprevalence study designed according to the well-established ethical and legal guidelines for such studies. Commencing in November, 1989, randomly selected neonatal heelprick specimens were tested for the presence of HIV antibodies after all identifying information had been permanently and irrevocably unlinked from the specimens. During the first year of the study 94,119 (approximately 60% of all submitted specimens) were tested. Twenty-six specimens which were repeatedly reactive by EIA were confirmed as positive for an overall crude seroprevalence rate of 2.8 per 10,000 women having live births (95% CI: 1.8-4.1). Twenty-five of the 26 confirmed seropositive results came from babies born in hospitals in the Metropolitan Toronto, Ottawa-Carlton, or Hamilton-Peel-Halton regions.

Adult↗