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Biomedical subjects

V Goel

Publications and source records attributed to V Goel.

At least 19 recordsLinked to original sources
PubMed2000

Quality of hospital discharge and physician data for type of breast cancer surgery.

OBJECTIVE: The quality of coding for breast surgical procedures was examined by comparing hospital discharge abstracts and physician claims with data abstracted from records of women diagnosed with node-negative breast cancer from April 1, 1991, to December 31, 1991. METHODS: The node-negative breast cancer cohort was linked with a population registry file. Hospital discharge abstracts and physician billing claims were retrieved for matched subjects. Overall agreement between two data sets was defined as the number of cases for which there was a match by specific type of procedure out of all eligible cases that were matched with the health care utilization file. Specific agreement was assessed by the kappa statistic, using only those records in the administrative data set that were coded for mastectomy or breast-conserving surgery. RESULTS: Of 735 eligible cases in the node-negative breast cancer cohort, 655 (89.1%) were linked to a health care utilization file. Overall agreement between surgeon billing claims and charts was 95.4% (CI = 93.5, 96.9) for most definitive procedure. Agreement for breast surgery type was 98.1% (kappa = 0.96; CI = 0.87,1.0) for cases coded as breast-conserving surgery or mastectomy. When hospital discharge and chart data were compared, overall agreement was 86.2% (CI = 83.4, 88.8), whereas agreement for breast surgery type was 93.2% (kappa = 0.86; CI = 0.77, 0.94). CONCLUSION: Overall, definitive surgical procedure in the two administrative databases accurately reflected information recorded in patients' charts. Physician claims appeared to provide more accurate information than did hospital discharge data.

Abstracting and Indexing↗
PubMed2000

Anatomical segregation of component processes in an inductive inference task.

Inductive inference underlies much of human cognition. The essential component of induction is hypothesis selection based on some criterion of relevance. The purpose of this study was to determine the neural substrate of inductive inference, particularly hypothesis selection, using fMRI. Ten volunteers were shown stimuli consisting of novel animals under two task conditions, and asked to judge whether all the animals in the set were the same type of animal. In one condition, subjects were given a rule that specified the criteria for "same type of animal". In the other condition, subjects had to infer the rule without instruction. The two conditions were further factored into easy and difficult components. Rule inference was specifically associated with bilateral hippocampal activation while the task by difficulty interaction was associated with activation in right lateral orbital prefrontal cortex. We interpret the former in terms of semantic encoding of novel stimuli and the latter in terms of hypothesis selection. Thus, we show an anatomical dissociation between task implementation and task difficulty that may correspond to a critical psychological distinction in the processes necessary for inductive inference.

Adult↗
PubMed2000

Spinal stability with anterior or posterior ray threaded fusion cages.

OBJECT: The authors conducted a study to determine if the rigidity supplied to the spine by posterior placement of the Ray threaded fusion cage (TFC) is further enhanced by the placement of pedicle screws and, additionally, if bilateral anteriorly placed TFCs render the spine more rigid than a single anteriorly placed TFC. METHODS: Ten human cadaveric spinal specimens (L2-S1) were affixed within a testing frame. Loads of 1.5, 3, 4.5, and 6 Nm were applied to the spine in six degrees of freedom: flexion-extension, right and left lateral bending, and right and left axial rotation. Motion in an x, y, and z cartesian axis system was tracked using dual video cameras following light-emitting diodes attached to the spine and base plate. Load testing of the spines was performed in the intact mode, following which the spinal segments were randomized to receive anterior or posterior instrumentation. In five spine specimens we performed posterior discectomy, posterior lumbar interbody fusion (PLIF) with placement of femoral rings and pedicle screws, PLIF with bilateral TFCs, and bilateral TFCs with pedicle screws. Five other spines underwent anterior-approach discectomy, followed by implantation of a unilateral cage and bilateral cages. Load testing was performed after each step. CONCLUSION: Spines in which PLIF with pedicle screws and TFCs with pedicle screws were placed were more rigid than after discectomy in all directions of motion except flexion. Anterior discectomy provided significantly (p < or = 0.05) less stability in left and right axial rotation than the intact spines and following posterior discectomy. Following anterior implantation of bilateral TFCs, spines were significantly more rigid than after discectomy in all directions except extension.

Bone Screws↗
PubMed2000

Comparing angiographic coronary revascularization strategies: a 'natural' experiment.

OBJECTIVE: To study the impact of intracoronary stents on clinical restenosis in the 'real world'. DESIGN: Retrospective comparison of the rates of clinical restenosis between two cohorts exposed to different strategies for percutaneous transcatheter intervention. The endpoint was the first of death, myocardial infarction, coronary artery bypass grafting, repeat percutaneous transluminal coronary angioplasty (PTCA) or repeat coronary angiography within nine months. SETTING: Tertiary care cardiac referral centre serving a large, metropolitan population. PATIENTS: Patients undergoing angiographic revascularization from January 1 to February 28, 1996 (the 'restricted' group [R], n=147) were compared with a before and after cohort (the 'usual' group [U], n=232, divided into those who underwent revascularization between November 1 and November 30, 1995, and those who underwent revascularization between April 1 and May 31, 1996). INTERVENTIONS: The R group was revascularized during a period of economic constraint, which imposed a shortage on stent availability. The U cohort underwent revascularization before and after the shortage (an 'unrestricted' environment for stent usage). MAIN RESULTS: There was no difference in clinical restenosis rates between the R (34.7%) and U (37.9%) groups (P=0.524, OR R/U=0.915, 95% CI 0.694 to 1.206). Also, the rate of clinical restenosis was the same among patients who underwent PTCA without stent insertion (34.8%) and those who received a stent (39.4%) (P=0.368, OR=1.13, 95% CI 0.87 to 1.44). CONCLUSIONS: At the authors' institution, a restricted stenting policy did not result in a higher clinical restenosis rate than that of usual practice.

Angioplasty, Balloon, Coronary↗
PubMed1999

Prostate-specific antigen testing in Ontario: reasons for testing patients without diagnosed prostate cancer.

BACKGROUND: The use of the prostate-specific antigen (PSA) test has been increasing rapidly in Canada since its introduction in 1988. The reasons for using the PSA test in patients without known prostate cancer are unclear. This paper reports on the first study in Canada to use physician records to assess the use of PSA testing. METHODS: A questionnaire was mailed to physicians attending 475 patients without diagnosed prostate cancer. The patients were randomly selected from 2 laboratory databases of PSA test records in the greater Toronto area during 1995. The physicians were asked to consult their patient records to avoid recall bias. Information obtained included physician's specialty, patient's age at time of PSA test and reason(s) for the test. RESULTS: There were 264 responses (56%), of which 240 (91%) were usable. Of these 240, 63% (95% confidence interval [Cl] 58%-70%) indicated that the test was conducted to screen for prostate cancer, 40% (95% Cl 34%-47%) said it was to investigate urinary symptoms, and 33% (95% Cl 27%-40%) responded that it was a follow-up to a medical procedure or drug therapy. More than one reason was permitted. Of 151 responses indicating screening as one reason for testing, 64% (95% Cl 56%-72%) stated that it was initiated by the patient, and 73% (95% Cl 65%-80%) stated that it was part of a routine examination. For 19%, both investigation of symptoms and screening asymptomatic patients were given as reasons for testing, and for another 19% both follow-up of a medical procedure and screening were given as reasons. Screening was recorded as a reason for testing far more commonly for patients seen by family physicians and general practitioners than for patients seen by urologists (67% v. 29%, p < 0.001). In contrast, the use of PSA testing to diagnose urinary symptoms was more common for patients seen by urologists than for those seen by family physicians and general practitioners (52% v. 37%, p = 0.044). No significant difference was found between physician groups in the use of PSA testing as a follow-up of a medical procedure (42% for urologists and 31% for family physicians and general practitioners). About 24% of the PSA test records were for patients younger than 50 and older than 70 years. PSA testing initiated by patients was more common in the practices of family physicians and general practitioners than in the practices of urologists (44% v. 13%, p < 0.001). INTERPRETATION: Screening for prostate cancer was the most common reason for PSA testing in our study group; it occurred most commonly in the family and general practice setting and was usually initiated by the patient. Differences in reasons for testing were identified by practice specialty. Although PSA screening for prostate cancer is sometimes recommended for men between 50 and 70 years of age, it is being conducted in men outside this age group.

Adult↗
PubMed1999

Time-series analysis of the relation between influenza virus and hospital admissions of the elderly in Ontario, Canada, for pneumonia, chronic lung disease, and congestive heart failure.

This study examined the relation between the presence of circulating influenza virus and all hospital admissions of people over age 65 years in Ontario, Canada, for pneumonia, congestive heart failure, and chronic lung disease in 1988-1993. Autoregressive integrated moving average (ARIMA) transfer function models were used to perform a time-series analysis. These models were compared with simple cross correlations by using Pearson's product moment correlation. The results showed statistically significant correlations between the presence of influenza virus and admissions of the elderly for pneumonia (in all 5 years under study) and chronic lung disease (in 4 of the 5 years under study). The relation between circulation of influenza virus and admissions for congestive heart failure was inconsistent. The simple cross correlation tended to overestimate the association between the presence of circulating influenza strains and hospital admissions. Measures of the impact of influenza should include chronic lung disease as an outcome. Further studies, with greater covariate control, are required to delineate more precisely the relation between influenza and hospital morbidity in the elderly. This study demonstrates the power and utility of using time-series methods in the epidemiologic study of communicable diseases.

Aged↗
PubMed1999

Development of a knowledge scale about breast cancer and heredity (BCHK).

An 11-item questionnaire, the Breast Cancer and Heredity Knowledge Scale (BCHK), was developed to test general knowledge about breast cancer and hereditary breast cancer (HBC) among women at low to moderate risk of HBC. The BCHK measures knowledge about breast cancer incidence and prognosis, risk factors, screening, disease presentation and treatment, and HBC. Scale items were generated from focus group interviews, previously published breast cancer knowledge scales, and consultation with a multidisciplinary research team, including health professionals and women with breast cancer or a family history of breast cancer. A 27-item draft scale was tested on 36 breast clinic patients and 17 women from the general public. Results were used to develop the final 11-item scale. Development of the scale and its potential uses are discussed.

Adult↗
PubMed1999

Dietary rhubarb (Rheum rhaponticum) stalk fibre stimulates cholesterol 7 alpha-hydroxylase gene expression and bile acid excretion in cholesterol-fed C57BL/6J mice.

Both experimental and clinical studies have indicated that a novel source of dietary fibre, produced from rhubarb (Rheum rhaponticum) stalks, is potentially hypolipidaemic. The present study, using C57BL/6J mice, was undertaken to examine if this fibre source affects cholesterol degradation. Mice were maintained on semi-purified diets containing 50 g rhubarb fibre or cellulose/kg with or without 5 g cholesterol/kg for 4 weeks. In cholesterol-supplemented mice, rhubarb fibre caused significant lowering of plasma cholesterol (-13%) and the hepatic concentrations of total cholesterol (-34%) and cholesteryl esters (-34%). In parallel to the reduction of hepatic cholesteryl ester content, animals fed on rhubarb fibre had significantly lower activity of acyl CoA: cholesterol acyltransferase (EC 2.3.1.26) than the mice maintained on a diet containing cellulose and cholesterol. Rhubarb-fibre feeding accelerated the faecal bile-acid loss and diminished the gall-bladder bile-acid pool in both the normal and the cholesterol-fed mice. The increase in the bile-acid excretion was positively correlated with an increased activity as well as mRNA abundance of cholesterol 7 alpha-hydroxylase (EC 1.14.13.17). The increased excretion of bile acids and induction of cholesterol 7 alpha-hydroxylase activity may account for the hypocholesterolaemic effect of rhubarb fibre.

Animals↗
PubMed1999

Biotyping of Acinetobacter species isolated from clinical samples.

We used the biotyping scheme using carbohydrate substrate utilization test with 14 carbon sources to speciate Acinetobacter isolates from blood and cerebrospinal fluid cultures of patients admitted to the postoperative neurosurgery ICU during January to November 1996. Sixty one patients culture positive for Acinetobacter sp. from blood or cerebrospinal fluid were followed up prospectively. Among these patients, 40 patients had clinically diagnosed infections like bacteriemia or meningitis while in 21 patients the isolation was regarded as contaminants. A. baumanniii was the most common isolate associated with clinical infections while A. lwoffii was more likely to be an environmental contaminant.

Acinetobacter↗
PubMed1998

Effect of population-based interventions on laboratory utilization: a time-series analysis.

CONTEXT: Previous studies have identified methods of decreasing laboratory utilization. However, most were hospital-based, relatively small, single-centered, or of limited duration. OBJECTIVE: To determine the effect of 3 population-based interventions (physician guidelines, laboratory requisition form modification, and changes to funding policy) on laboratory utilization in Ontario. DESIGN: Interventional time-series analysis in which data analysis was based on all claims made to the Ontario Health Insurance Program between July 1, 1991, and April 1997 for laboratory tests affected by the interventions. SETTING: All clinical laboratories (not based in hospitals) in Ontario. INTERVENTIONS: Physician guidelines, modification of laboratory requisition form, and changes in funding policy for the use of the erythrocyte sedimentation rate test (ESR), microscopic urinalysis, tests for renal function, iron stores, serum urea, and serum iron determinations, and tests for thyroid dysfunction (total thyroxine and thyroid-stimulating hormone [TSH]). MAIN OUTCOME MEASURES: Change from 1991 to 1997 in utilization rates of ESR, microscopic urinalysis, serum urea and iron determinations, and tests for total thyroxine and TSH. RESULTS: Age- and sex-standardized rates for laboratory tests unaffected by the interventions were stable during the study period. Utilization of ESR and urea determination decreased by 58% (P<.001) and 57% (P<.001), respectively, after they were removed from the requisition form and guidelines discouraging their use were disseminated. Rates for urinalyses without microscopy increased by 1700% (P<.001), while microscopic urinalysis decreased by 14% (P<.001), after a policy change eliminated microscopic urinalysis from routine urinalysis. Rates of iron determination declined by 80% (P<.001) and ferritin rates increased by 34% (P= .05) when policy changes eliminated iron testing when ordered with ferritin and guidelines advocating ferritin alone for investigating iron deficiency were disseminated. Utilization of total thyroxine testing declined by 96% (P = .02) when the provincial health plan stopped its funding. When TSH was removed from the laboratory requisition form, a 12% decline (P= .03) in its use was observed. Through April 1997, these interventions saved more than 625000 tests or $210400. CONCLUSIONS: The combination of guideline dissemination, laboratory requisition form modification, and changes to funding policy was associated with significant reductions in laboratory utilization.

Clinical Laboratory Techniques↗
PubMed1998

Psychological outcomes following maternal serum screening: a cohort study.

BACKGROUND: Maternal serum screening is used to assist in the prenatal detection of congenital anomalies. Its use is controversial, and one concern that has been expressed is its psychological effects on women. The authors examined whether this test leads to an increase in anxiety and depression among women who have a false-positive result as compared with those who have a true-negative result or do not undergo testing. METHODS: A prospective cohort study with baseline assessment at 15 to 18 weeks' gestation and follow-up at 24 weeks' gestation was conducted. Pregnant women at 8 geographically diverse sites across Ontario were recruited. The main outcome measures were the state portion of the State--Trait Anxiety Inventory and the Center for Epidemiologic Studies Depression Scale. RESULTS: Of the 2418 potential subjects 2020 (83.5%) were enrolled and eligible; 1741 (86.2%) completed the follow-up. A total of 1177 women (67.6%) underwent maternal serum screening. No overall adverse psychological effects as a result of testing were found at 24 weeks' gestation. Women with a false-positive result had a mean increase in anxiety score of 1.6 (95% confidence interval [CI] -1.7 to 4.9), whereas women with a true-negative result had a mean decrease of 1.1 (95% CI -1.8 to -0.3) and those not tested had a mean decrease of 0.4 (95% CI -1.3 to 0.5). The mean depression score increased by 0.5 (95% CI -0.9 to 2.0) in the false-positive group, was unchanged (95% CI -0.3 to 0.4) in the true-negative group and increased by 0.2 (95% CI -1.7 to 1.2) in the not tested group. Of the women who underwent testing, 87 (7.6%) were unsure of their result at the time of follow-up. INTERPRETATION: The results suggest that maternal screening in Ontario is not causing serious psychological harm to women. Communication regarding test results could be improved, since a substantial proportion of women were unsure of their test result.

Adult↗
PubMed1998

Outbreak of nosocomial Acinetobacter baumannii bacteremia in a high risk ward.

Acinetobacter baumannii is emerging as a major cause of nosocomial infections particularly in high risk patients. Being resistant to adverse environmental conditions, it can stay for prolonged periods in the hospital environment. We report an outbreak in the medical oncology ward where nine patients suspected of bacteraemia were blood culture positive for A. baumannii from the two samples each, one collected through the i.v. cannula and another through the peripheral veneous puncture. The bacteria was also isolated from the environmental sources from the various samples collected. The biotype, antibiogram, cellular protein profiles on SDS-PAGE and the restriction enzyme analysis patterns of the patient isolates and the environmental isolates were similar. This points to the environment as a source of infection. With reinforcement of proper barrier nursing and use of disposable heparine ampoules it was possible to control the outbreak.

Acinetobacter Infections↗
PubMed1998

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↗
PubMed1998

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↗
PubMed1998

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↗