Laboratory survey of prostate specific antigen testing in Ontario.
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Follow-Up Studies↗
Biomedical subjects
V Goel
Publications and source records attributed to V Goel.
Prostate-specific antigen utilization in Ontario: extent of testing in patients with and without cancer.
OBJECTIVES: To ascertain the extent of prostate-specific antigen (PSA) testing in patients with prostate cancer (PC), with other cancers (OC), and with no cancer (NC) in two clinical laboratory databases. DESIGN AND METHODS: PSA test records were obtained from a tertiary care hospital, Sunnybrook Health Science Centre (SHSC) and from a private laboratory, Gamma-Dynacare Medical Laboratories (GDL), during the period 1988 to 1995. These records were linked with the Ontario Cancer Registry (OCR) to establish a diagnosis of PC, OC, or NC. Trends in PSA testing according to diagnostic category, testing laboratory, patient age (by decade), and PSA value (in microgram/L) were determined. RESULTS: Major cancer sites identified in the patients tested for PSA were prostate (60%), bladder and colon (7% each), lung (5%), kidney (3%), and rectum (3%). There were 11,867 patients (8.5%) with PC, 8,002 (5.9%) with OC, and 118,954 (86%) with NC. The total number of PSA tests performed on these patients was 230,756, of which 21% were on PC, 5% on OC, and 74% on NC; of these tests, 64% were performed through GDL and 36% through SHSC. The mean (median) number of tests per patient was: PC, 4.0 (2); OC, 1.4 (1); and NC, 1.5 (1). For PC 89% and for OC 72% of all tests occurred after diagnosis. Between 1990 and 1995 the number of PSA tests increased two-fold in PC and OC, and 20-fold in NC. We estimate that about one-half of the PSA tests in the NC group were for screening purposes. The proportion of PSA tests occurring in PC, OC, and NC for patients 50 to 70 years of age was 41%, 50%, and 63%, respectively; for patients over 70 years of age, this proportion was 58%, 46%, and 22% respectively; and for patients under 50 it was 1%, 4%, and 15%, respectively. Between 1990 and 1995, the largest increase in testing frequency was in the NC group, particularly in patients 50 to 70 years of age, which was accompanied by a decrease in patients over 70. Less than 10% of testing occurred in patients under 50 in all diagnostic groups. We estimate that about 26% of PSA screening tests in NC occurred outside the guidelines for patient age. Between 1988 and 1995, the proportion of PSA results below our detection limit (< 0.2 micrograms/L) showed a steady rise in the PC group, as did the proportion between 0.2 and 3.9 micrograms/L; these were accompanied by a fall in the proportion > 20.0 micrograms/L. However, the proportion of PSA results within these ranges did not change much during the same time period for the OC and NC groups. At cutoffs of PSA = 4.0 micrograms/L (or PSA = 10.0 micrograms/L), estimates of clinical specificity were 84.0% (or 96.3%), and of clinical sensitivity were 83.4% (or 47.1%). CONCLUSIONS: Most (86%) PSA testing occurred in men with NC, consistent with diagnosis or screening. There were more PSA tests per patient in PC than in OC, and most testing occurred after diagnosis. PSA testing in the NC group continues to increase rapidly. The proportion of PSA tests in patients over age 70 decreased in the order of PC > NC > OC. Between 1990 and 1995, there was an increase in the proportion of patients tested who were between 50 and 70 in the NC group, which may suggest more screening in this group. Over this same time period, there was an increase in the proportion of undetectable PSA values, possibly suggesting increased use of radical therapy; there was also a decrease in the proportion of PSA > 20 micrograms/L, possibly suggesting a decrease in the prevalence of advanced stage PC.
Age Factors↗
Assessing the extent of contamination in the Canadian National Breast Screening Study.
OBJECTIVE: To estimate the proportion of Canadian National Breast Screening Study (NBSS) participants who went outside the trial for a mammogram, based on health insurance claims data. METHOD: Prospective cohort study linking trial subjects with population-based administrative data. SUBJECTS: All NBSS participants enrolled in the Winnipeg screening center who had health insurance claims to Manitoba Health (n = 9,780). ANALYSIS: Claims for bilateral mammograms were compared by screening arm allocation and age group at enrollment. Mammograms likely to be "screening" were defined based on prior claim history. RESULTS: For women aged 40 to 49 at enrollment, 5.3% in the intervention group and 21.8% in the control group had a claim for at least one bilateral mammogram. After excluding nonscreening mammograms these proportions fell to 2.2% and 14.1% (P < 0.0001). For women aged 50 to 59, 4.5% in the intervention group and 16.7% of the control group had at least one claim for a bilateral mammogram. These proportions were 2.1% and 10.5% for screening (P < 0.0001). CONCLUSION: Health care utilization data can be used to estimate contamination in a screening trial. The levels of contamination resulting from participants going outside the study for a screening test can have an impact on the power of the study and need to be considered when interpreting results and planning future screening studies.
Adult↗
Sex differences in the factors related to hospital utilization: results from the 1990 Ontario Health Survey.
We assessed the factors associated with hospital admission in Ontario, Canada, across age-specific and sex-specific groups. Data from the cross-sectional, population-based 1990 Ontario Health Survey (OHS) were used to examine the relationships between hospital admission and sociodemographic, health care need, psychosocial, and lifestyle factors. The OHS sample of 42,698 adults aged > or = 16 years, weighted to represent more than 7 million Ontarians, was used. Hospitalization rates per 1000 in the prior year were 130 for men and 203 for women. The higher rates for women are attributed in part to admissions related to childbearing. Women who delivered a child in the year before the OHS were excluded from subsequent analyses. Multivariate logistic regression models revealed that health care need (increasing number of health problems, fair/poor health status, older age) was the most important factor associated with higher hospitalization rates for men. For women, in addition to health care need, psychosocial (low/average well-being) and sociodemographic factors (married, low income, unemployed, English/French spoken in the home) were related to higher hospital utilization. Health care need is the most important factor for describing hospital use in men and women. However, rates of hospital utilization for women are more sensitive to sociodemographic factors even in a setting with universal health insurance. This suggests that among women, societal factors may exist that relate to potential disparities in access to health services. Efforts to assess how these factors operate are necessary to aid the development of interventions to minimize disparities that may exist.
Adolescent↗
In vitro activities of ampicillin-sulbactam and amoxicillin-clavulanic acid against Acinetobacter baumannii.
In vitro susceptibility patterns of newer beta-lactamase-inhibiting antibiotics ampicillin-sulbactam (A/S) and amoxicillin-clavulanic acid (A/C) for 100 consecutive isolates of Acinetobacter baumannii obtained from various clinical samples were studied. The A/C MIC for 86% of the strains was more than 16/8 microgram/ml, whereas there was an A/S MIC of more than 16/8 microgram/ml for only 38% of the strains. This showed that A/S has significantly superior in vitro activity compared to A/C against A. baumannii, although, theoretically, both should have similar activities. The therapeutic superiority of A/S over A/C needs to be studied, or else the breakpoints for these agents in in vitro tests need to be redefined.
Acinetobacter↗
A novel function of the DNA repair gene rhp6 in mating-type silencing by chromatin remodeling in fission yeast.
Recent studies have indicated that the DNA replication machinery is coupled to silencing of mating-type loci in the budding yeast Saccharomyces cerevisiae, and a similar silencing mechanism may operate in the distantly related yeast Schizosaccharomyces pombe. Regarding gene regulation, an important function of DNA replication may be in coupling of faithful chromatin assembly to reestablishment of the parental states of gene expression in daughter cells. We have been interested in isolating mutants that are defective in this hypothesized coupling. An S. pombe mutant fortuitously isolated from a screen for temperature-sensitive growth and silencing phenotype exhibited a novel defect in silencing that was dependent on the switching competence of the mating-type loci, a property that differentiates this mutant from other silencing mutants of S. pombe as well as of S. cerevisiae. This unique mutant phenotype defined a locus which we named sng1 (for silencing not governed). Chromatin analysis revealed a switching-dependent unfolding of the donor loci mat2P and mat3M in the sng1(-) mutant, as indicated by increased accessibility to the in vivo-expressed Escherichia coli dam methylase. Unexpectedly, cloning and sequencing identified the gene as the previously isolated DNA repair gene rhp6. RAD6, an rhp6 homolog in S. cerevisiae, is required for postreplication DNA repair and ubiquitination of histones H2A and H2B. This study implicates the Rad6/rhp6 protein in gene regulation and, more importantly, suggests that a transient window of opportunity exists to ensure the remodeling of chromatin structure during chromosome replication and recombination. We propose that the effects of the sng1(-)/rhp6(-) mutation on silencing are indirect consequences of changes in chromatin structure.
Chromatin↗
Neuroanatomical correlates of human reasoning.
One of the important questions cognitive theories of reasoning must address is whether logical reasoning is inherently sentential or spatial. A sentential model would exploit nonspatial (linguistic) properties of representations whereas a spatial model would exploit spatial properties of representations. In general terms, the linguistic hypothesis predicts that the language processing regions underwrite human reasoning processes, and the spatial hypothesis suggests that the neural structures for perception and motor control contribute the basic representational building blocks used for high-level logical and linguistic reasoning. We carried out a [(15)O] H(2)O PET imaging study to address this issue. Twelve normal volunteers performed three types of deductive reasoning tasks (categorical syllogisms, three-term spatial relational items, and three-term nonspatial relational items) while their regional cerebral blood flow pattern was recorded using [(15)O] H(2)O PET imaging. In the control condition subjects semantically comprehended sets of three sentences. In the deductive reasoning conditions subjects determined whether the third sentence was entailed by the first two sentences. The areas of activation in each reasoning condition were confined to the left hemisphere and were similar to each other and to activation reported in previous studies. They included the left inferior frontal gyrus (Brodmann area 45, 47), a portion of the left middle frontal gyrus (Brodmann area 46), the left middle temporal gyrus (Brodmann areas 21, 22), a region of the left lateral inferior temporal gyrus and superior temporal gyrus (Brodmann areas 22, 37), and a portion of the left cingulate gyrus (Brodmann areas 32, 24). There was no significant right-hemisphere or parietal activation. These results are consistent with previous neuroimaging studies and raise questions about the level of involvement of classic spatial regions in reasoning about linguistically presented spatial relations.
Adult↗
Health services research in breast cancer: background paper for a Canadian Breast Cancer Research Initiative workshop.
OBJECTIVE: To describe a systematic review of breast cancer health services research that was conducted to guide a Canadian Breast Cancer Research Initiative workshop. DESIGN: A literature review of major citation databases was conducted. The National Cancer Institute of Canada Framework for Cancer Control was adopted to classify articles by theme area and by type of health services research. RESULTS: The majority of the studies focused on screening for breast cancer and were descriptive studies on accessibility. Relatively few studies examined quality and outcomes of breast cancer services or interventions to improve such services. Furthermore, few health services research studies examined the areas of supportive care or palliation. CONCLUSIONS: The results help to identify the gaps in the Canadian and international research in this area. The material from the review was used as background for a workshop to support the work of the Canadian Breast Cancer Research Initiative Task Force on Health Services Research.
Breast Neoplasms↗
Socioeconomic status and cancer incidence and survival.
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Breast Neoplasms↗
The derivation of life tables for local areas.
Life tables are seldom derived at the local level, despite a shift toward health service planning to that level. We calculated life tables by sex for the 42 public health units in Ontario, using 1988 1992 mortality files. Traditional methods of life table construction were compared and validated. Data quality, particularly geographical coding of death certificates, poses the greatest difficulty in deriving accurate life tables for comparison between areas. Migration will affect estimates, but it is best considered during the interpretation of results. Except for the final age interval, methods of modelling life tables have little impact on final life expectancy estimates. It is feasible to calculate local level life tables with data and tools that are readily available. The results highlight the importance of examining such life tables, as variations within a province in life expectancy at birth may be as important as the differences between provinces.
Adolescent↗
Visits by adults to family physicians for the common cold.
BACKGROUND: It is commonly believed that doctor's office visits for upper respiratory tract infections (URTI) occur too often given the self-limited nature of such illnesses. However, the frequency of visits for URTIs has not been well studied. We examined how often a large population of adults visited doctors when they had a cold, the degree to which they engaged in self care, and the characteristics of those seeking care. METHODS: We performed a secondary analysis of a population-based survey of 42,333 adults in the province of Ontario, Canada. Adults reporting an URTI in the previous 2 weeks were included. Multiple logistic regression was used to compare adults who made an office visit with those that did not, for differences in sociodemographic characteristics, health status, sick days, over-the-counter (OTC) medication use, and life satisfaction. RESULTS: Only 14% of the adults studied visited a doctor for an URTI. Most (76%) engaged in self care with OTC medications. Adults who visited a family physician were less likely to have taken an OTC medication (odds ratio [OR] = .11; 95% confidence interval [CI], .07-.19), and were more likely to have experienced three or more sick days (OR = 2.70; CI, 1.41-5.17), live in a larger household (OR = 1.88; CI, 1.37-2.57), not have completed high school, and be unhappy (OR = 2.47; CI, 1.35-4.52). CONCLUSIONS: The majority of adults do not visit a doctor when they have a cold, and most engage in self care. Illness severity, and its impact on patients and their families, seems to influence the decision to seek care.
Adult↗
The seats of reason? An imaging study of deductive and inductive reasoning.
We carried out a neuroimaging study to test the neurophysiological predictions made by different cognitive models of reasoning. Ten normal volunteers performed deductive and inductive reasoning tasks while their regional cerebral blood flow pattern was recorded using [15O]H2O PET imaging. In the control condition subjects semantically comprehended sets of three sentences. In the deductive reasoning condition subjects determined whether the third sentence was entailed by the first two sentences. In the inductive reasoning condition subjects reported whether the third sentence was plausible given the first two sentences. The deduction condition resulted in activation of the left inferior frontal gyrus (Brodmann areas 45, 47). The induction condition resulted in activation of a large area comprised of the left medial frontal gyrus, the left cingulate gyrus, and the left superior frontal gyrus (Brodmann areas 8, 9, 24, 32). Induction was distinguished from deduction by the involvement of the medial aspect of the left superior frontal gyrus (Brodmann areas 8, 9). These results are consistent with cognitive models of reasoning that postulate different mechanisms for inductive and deductive reasoning and view deduction as a formal rule-based process.
Adult↗
Patterns of initial management of node-negative breast cancer in two Canadian provinces. British Columbia/Ontario Working Group.
OBJECTIVE: To describe the patterns of initial management of node-negative breast cancer in Ontario and British Columbia and to compare the characteristics of the patients and tumours and of the physicians and hospitals involved in management. DESIGN: Retrospective, population-based, cohort study. PARTICIPANTS: All 942 newly diagnosed cases of node-negative breast cancer in 1991 in British Columbia and a random sample of 938 newly diagnosed cases in Ontario in the same year. OUTCOME MEASURES: Number and proportion of patients with newly diagnosed node-negative breast cancer who received breast-conserving surgery (BCS) or mastectomy and who received radiation therapy after BCS. RESULTS: BCS was used in 413 cases (43.8%) in British Columbia and in 634 cases (67.6%) in Ontario (p < 0.001). After BCS, radiation therapy was received by 378 patients (91.5% of those who had undergone BCS) in British Columbia and 479 patients (75.6% of those who had undergone BCS) in Ontario (p < 0.001). In both provinces, lower patient age, smaller tumour size, a noncentral unifocal tumour, absence of extensive ductal carcinoma in situ and initial surgery by a surgeon with an academic affiliation were associated with greater use of BCS. Lower patient age and larger tumour size were associated with greater use of radiation therapy after BCS in both provinces. CONCLUSION: Patient, tumour and physician factors are associated with the choice of initial management of breast cancer in these two Canadian provinces. However, the differences in management between the two provinces are only partly explained by these factors. Other possible explanations, such as the presence of provincial guidelines, differences in the organization of the health care system or differences in patient preference, require further research.
Age Distribution↗
Written patient information about triple-marker screening: a randomized, controlled trial.
OBJECTIVE: To investigate to what extent a newly revised educational pamphlet on triple-marker screening improves patient knowledge and to identify subgroups of women who may not benefit from these materials. METHODS: Women in six geographically and demographically diverse Ontario sites were allocated randomly to receive the pamphlet on triple-marker screening or a similar-appearing educational pamphlet on daily activities during pregnancy. The primary outcome measure was the Maternal Serum Screening Knowledge Questionnaire, a previously validated 14-item scale. RESULTS: Baseline demographic, obstetric, and medical factors were comparable in the intervention and control groups, as were measures of previous exposure to triple-marker screening. Knowledge scores were significantly higher among the 133 women receiving the intervention pamphlet than among 64 women who received the control pamphlet (0.89 versus 0.52 on a scale from -2 to +2, P < .001). Subgroups not benefiting from the pamphlet on triple-marker screening were women age 25 and younger and those not speaking English at home. Those who had completed university or postgraduate education had high levels of knowledge with and without the pamphlet. CONCLUSION: Written patient information can contribute in an important way to patient knowledge about triple-marker screening. Providers of antenatal care should be made aware of the value of written patient information as well as the limitations for some subgroups of women. These subgroups are likely to require additional educational materials and resources. It would be appropriate to make these materials available to the general public and pregnant women in their physicians' offices.
Adult↗
The rise of tamoxifen: temporal and geographical trends of tamoxifen use in Ontario.
PURPOSE: To describe the change in use of tamoxifen over time and across countries in Ontario. METHODS: Data from the Ontario Drug Benefit (ODB) plan, Census Canada, and the Ontario Cancer Registry (OCR) were combined and analysed to determine rates of tamoxifen use for females over 65 for each county and the province overall, by year. Rates were analyzed by repeated measures ANOVA to determine significance of changes over time. Consistency of tamoxifen use across counties was determined by the Spearman rank correlation coefficient, and overall variation between counties was described using three statistical techniques: Chi-square analysis, the extremal quotient (EQ), and the systematic component of variation (SCV). RESULTS: The number of one-month tamoxifen prescriptions per incident case of breast cancer rose significantly from 13.51 in 1985 to 20.54 in 1990 (p < 0.001) and to 34.06 in 1992 (p = 0.001). Viewed differently, the number of women over 65 receiving tamoxifen prescriptions per incident case of breast cancer changed from 1.91 in 1985 to 3.14 in 1990 to 4.54 in 1992. Statistically significant variation in the rate of tamoxifen prescribing was demonstrated between Ontario counties in all three years by Chi Squared analysis (p < 0.0001). Both the EQ and the SCV declined from 1985 to 1990, suggesting more uniform prescribing across the province. Little change in overall variation was seen between 1990 and 1992. All counties over time tended to prescribe generic preparations more often and shifted from 10 mg to 20 mg formulations. CONCLUSIONS: The significant increase in the rate of tamoxifen use and trend towards more uniform prescribing across Ontario between 1985 and 1990 coincided with the publication of two important documents outlining the benefits of tamoxifen in early breast cancer. Despite this trend, variation in tamoxifen use between counties remains. There has been little change in uniformity of prescribing since 1990.
Aged↗
The association between population-based treatment guidelines and adjuvant therapy for node-negative breast cancer. British Columbia/Ontario Working Group.
This study evaluated the impact of province-wide treatment guidelines on consistency of adjuvant therapy for node-negative breast cancer. A retrospective population-based cohort study was conducted in the Canadian provinces of British Columbia, which has province-wide guidelines, and Ontario, which does not. All eligible 1991 incident cases of node-negative breast cancer in British Columbia (n = 942) and a similar number of randomly selected 1991 incident cases in Ontario (n = 938) were reviewed. Consistency of adjuvant therapy received was evaluated by stratifying cases into discrete diagnostic groups using several grouping systems, and by then comparing the distribution of treatments received within each diagnostic group in the two provinces. Recursive partitioning was also performed. We observed that patterns of pathology reporting were consistent with awareness of the factors used in the British Columbia guidelines to define indications for adjuvant therapy. Consistency of care was greater in British Columbia than in Ontario by all diagnostic grouping systems and by recursive partitioning (P < 0.001), and the observed patterns in British Columbia corresponded to the British Columbia guidelines. We conclude that population-based treatment guidelines can play a role in promoting consistent patterns of adjuvant therapy for women with node-negative breast cancer.
Aged↗
A study of the performance of patients with frontal lobe lesions in a financial planning task.
It has long been argued that patients with lesions in the prefrontal cortex have difficulties in decision making and problem solving in real-world, ill-structured situations, particularly problem types involving planning and look-ahead components. Recently, several researchers have questioned our ability to capture and characterize these deficits adequately using just the standard neuropsychological test batteries, and have called for tests that reflect real-world task requirements more accurately. We present data from 10 patients with focal lesions to the prefrontal cortex and 10 normal control subjects engaged in a real-world financial planning task. We also introduce a theoretical framework and methodology developed in the cognitive science literature for quantifying and analysing the complex data generated by problem-solving tasks. Our findings indicate that patient performance is impoverished at a global level but not at the local level. Patients have difficulty in organizing and structuring their problem space. Once they begin problem solving, they have difficulty in allocating adequate effort to each problem-solving phase. Patients also have difficulty dealing with the fact that there are no right or wrong answers nor official termination points in real-world planning problems. They also find it problematic to generate their own feedback. They invariably terminate the session before the details are fleshed out and all the goals satisfied. Finally, patients do not take full advantage of the fact that constraints on real-world problems are negotiable. However, it is not necessary to postulate a 'planning' deficit. It is possible to understand the patients' difficulties in real world planning tasks in terms of the following four accepted deficits: inadequate access to 'structured event complexes', difficulty in generalizing from particulars, failure to shift between 'mental sets', and poor judgment regarding adequacy and completeness of a plan.
Brain Diseases↗
Sore throat management practices of Canadian family physicians.
OBJECTIVES AND METHODS: A survey was conducted of Canadian family physicians about their usual sore throat management practices. Physician knowledge, attitudes, beliefs and the effect of selected patient factors on variation in practices was assessed. RESULTS: The majority of physicians did not follow North American expert recommendations to usually take a throat culture and wait for culture results before prescribing an antibiotic. Similarly to the practices of family physicians in many countries, they favoured a clinical policy of selective use of throat cultures and decisions about the need for antibiotics based on clinical judgement. CONCLUSIONS: Physician practice site, demographics, knowledge, attitudes, beliefs and patient factors did not explain differences in approach. The implications for antibiotic utilization in the management of upper respiratory tract infections are discussed.
Adult↗