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J J Spinelli

Publications and source records attributed to J J Spinelli.

At least 19 recordsLinked to original sources
PubMed2006

From expert-based to quantitative retrospective exposure assessment at a Soderberg aluminum smelter.

OBJECTIVES: Expert judgement of exposure levels is often only poorly or moderately correlated with directly measured levels. For a follow-up of a historical cohort study at a Söderberg aluminum smelter we updated an expert-based semiquantitative job exposure matrix of coal tar pitch volatiles (CTPV) to quantitative estimates of CTPV and benzo(a)pyrene (BaP). METHODS: Mixed effects models to predict exposure for potroom operation and maintenance jobs were constructed from personal CTPV and BaP measurements. Mean exposures of jobs in non-potroom locations were directly calculated when measurements were available. Exposure estimates for jobs/time periods with no measurements were based on proportion of time spent in exposed areas compared to jobs where exposure was modeled or measured. For pre-1977, the original expert exposure assignments were calibrated using the updated 1977 estimates. RESULTS: The rate of change in exposure levels varied by time period and was accounted for in mixed models with a linear spline time trend. Other variables significant in the models were job, potroom group and season as fixed effects, and worker as a random effect. The models for potroom operations explained 45 and 27% of the variability in the CTPV and BaP measurements, respectively. The models for maintenance jobs explained 40 and 19% of the variability in the CTPV and BaP measurements, respectively. For 1977-2000 model estimates, direct calculation of means and extrapolation from modeled/measured exposures accounted for 57, 6 and 37% of the exposed person-years, respectively. CONCLUSIONS: The above methodology maximized the use of exposure measurements and largely replaced the original expert-based estimates. Finer discrimination between exposure levels was possible with the updated exposure assessment. The new estimates are expected to reduce exposure misclassification and help better assess the exposure-response relationships.

Air Pollutants, Occupational↗
PubMed2003

Validation of a semi-quantitative job exposure matrix at a Söderberg aluminum smelter.

OBJECTIVES: We tested the validity of a job exposure matrix (JEM) for coal tar pitch volatiles (CTPV) at a Söderberg aluminum smelter. The JEM had been developed by a committee of company hygienists and union representatives for an earlier study of cancer incidence and mortality. Our aim was to test the validity and reliability of the expert-based assignments. METHODS: Personal CTPV exposure measurements (n = 1879) overlapped 11 yr of the JEM. The arithmetic mean was calculated for 35 job/time period combinations (35% of the exposed work history), categorized using the original exposure intervals, and compared with the expert-based assignments. RESULTS: The expert-based and the measurement-based exposure assignments were only moderately correlated (Spearman's rho = 0.42; weighted kappa = 0.39, CI 0.10-0.69). Only 40% of the expert-based medium category assignments were correctly assigned, with better agreement in the low (84%) and high (100%) categories. Pot operation jobs exhibited better agreement (rho = 0.60) than the maintenance and pot shell repair jobs (rho = 0.25). The mid-point value of the medium category was overestimated by 0.3 mg/m(3). CONCLUSIONS: The expert-based exposure assignments may be improved by better characterizing the transitions between exposure categories, by accounting for exposure differences between pot lines and by re-examining the category mid-point values used in calculating the cumulative exposure. Lack of historical exposure measurements often requires reliance on expert knowledge to assess exposure levels. Validating the experts' estimates against available exposure measurements may help to identify weaknesses in the exposure assessment where improvements may be possible, as was shown here.

Air Pollutants, Occupational↗
PubMed2002

Canadian male farm residents, pesticide safety handling practices, exposure to animals and non-Hodgkin's lymphoma (NHL).

BACKGROUND: A majority of published studies indicate that farmers have an elevated risk of developing non-Hodgkin's lymphoma (NHL) compared to other workers. METHODS: We evaluated accidental exposure to pesticides, the use of personal protective equipment, and exposure to animals among male farm residents in a Canadian population-based, multi-centre, NHL-control questionnaire study. RESULTS: In a multivariate model, the following variables had statistically significant adjusted odds ratios (OR) using 95% confidence intervals (95% CI) (a) higher risk: having more than 13 head of swine, raising bison, elk or ostriches, a personal history of cancer, > 4 and < or = 15 years of farm residence and occupational exposure to diesel fuel and exhaust; (b) lower risk: raising cattle and a personal history of measles. CONCLUSIONS: Future multidisciplinary studies of NHL should include a comprehensive review of exposure to animals in sufficient detail to assess etiological mechanisms to explain the putative associations between exposure to farm animals and NHL.

Adult↗
PubMed2001

Simultaneous modelling of operative mortality and long-term survival after coronary artery bypass surgery.

Typical analyses of lifetime data treat the time to death or failure as the response variable and use a variety of modelling strategies such as proportional hazards or fully parametric, to investigate the relationship between the response and covariates. In certain circumstances it may be more natural to view the distribution of the response variable as consisting of two or more parts since the survival curve appears segmented. This article addresses such a scenario and we propose a model for simultaneously investigating the effects of covariates over the two segments. The model is an analogue of that proposed by Lambert for zero-inflated Poisson regression. The application is central to the model development and is concerned with survival after coronary artery bypass surgery. Here operative mortality, defined as death within 30 days after surgery, and long-term mortality, are viewed as distinct outcomes. For the application considered, the survivor function displays much steeper descent during the first 30 days after surgery, that is, for operative mortality, than after this period. An investigation of the effects of covariates on operative and long-term mortality after coronary artery bypass surgery illustrates the usefulness of the proposed model.

Age Factors↗
PubMed2001

Double trouble: impact of inappropriate use of asthma medication on the use of health care resources.

BACKGROUND: There is considerable controversy about the regular use of short-acting beta-agonists for the treatment of asthma. Although case-control studies have suggested that excessive use of these drugs may worsen asthma control and increase the risk of fatal or near-fatal asthma, the controversy remains unresolved because of the confounding that exists among disease control, disease severity and the use of short-acting beta-agonists. Whatever the cause-and-effect relation between the use of short-acting beta-agonists and disease severity, we hypothesized that their excessive use, in conjunction with underuse of inhaled corticosteroids, would be a marker for poorly controlled asthma and excessive use of health care resources. METHODS: To characterize the pattern of health services utilization among asthmatic patients taking various doses of inhaled beta-agonists and corticosteroids in British Columbia, we linked the relevant health administrative databases. All patients between 5 and 50 years of age for whom a prescription for a short-acting beta-agonist was filled in 1995 and whose prescription data were captured through the provincial drug plan were included in a retrospective analysis of prescriptions for asthma drugs, physician prescribing patterns and health services utilization. Patients' use of asthma medication was classified as appropriate (low doses of short-acting beta-agonist and high doses of inhaled corticosteroid) or inappropriate (high doses of short-acting beta-agonist and low doses of inhaled corticosteroid), and the 2 resulting groups were compared, by means of logistic, Poisson and gamma regression, for differences in prescribing patterns, physician visits and use of hospital resources. RESULTS: A total of 23,986 patients were identified as having filled a prescription for a short-acting beta-agonist (for inhalation) in 1995. Of these, 3069 (12.8%) filled prescriptions for 9 or more canisters of beta-agonist, and of this group of high-dose beta-agonist users, 763 (24.9%) used no more than 100 micrograms/day of inhaled beclomethasone. On average, those with inappropriate use of beta-agonists visited significantly more physicians for their prescriptions (1.8 v. 1.4), and each of these physicians on average wrote significantly more prescriptions for asthma medications per patient than the physicians who prescribed to appropriate users (5.2 v. 2.5 prescriptions). Patients with inappropriate use were more likely to be admitted to hospital (adjusted relative risk [RR] 1.68, 95% confidence interval [CI] 1.25-2.26), were admitted to hospital more frequently (adjusted RR 1.81, 95% CI 1.41-2.32) and were more likely to require emergency admission (adjusted RR 1.93, 95% CI 1.35-2.77). INTERPRETATION: Despite the widespread distribution of guidelines for asthma pharmacotherapy, inappropriate use of asthma medications persists (specifically excessive use of inhaled short-acting beta-agonists combined with underuse of inhaled corticosteroids). Not only are patients who use medication inappropriately at higher risk for fatal or near-fatal asthma attacks, but, as shown in this study, they use significantly more health care resources than patients with appropriate medication use.

Administration, Inhalation↗
PubMed2001

HER-2/neu in breast cancer: interobserver variability and performance of immunohistochemistry with 4 antibodies compared with fluorescent in situ hybridization.

The immunohistochemistry (IHC) performance of 4 anti-HER-2/neu antibodies was compared with fluorescent in situ hybridization (FISH) analysis of HER-2/neu gene expression in breast cancer patients considered for Herceptin (Trastuzumab) therapy. Interobserver variability in IHC interpretation was measured. Formalin-fixed tissue was received from 24 provincial hospital laboratories. The following anti-Her-2 antibodies were used: DAKO A0485 (polyclonal), Novacastra CB11 (monoclonal), Zymed TAB250 (monoclonal), and DAKO HercepTest (polyclonal). Additional sections were analyzed by FISH (Vysis). Three pathologists blinded to FISH results independently interpreted invasive tumor cell membranous staining on a scale of 0 to +3. The HER-2/neu gene was considered amplified when the FISH signal ratio of HER-2/CEP-17 was > or =2.0. Blocks from all hospitals and of all ages were suitable for IHC and FISH analysis. No interlaboratory analysis variability was noted. The interobserver agreement (kappa) for stain intensity for each antibody was good for 0 and +3 but poor for +1 and +2. Reasonable concordance between IHC and FISH was found with three of the four antibodies. TAB250 was the most sensitive antibody. For the three pathologists, the IHC sensitivities and specificities compared with FISH using 0/+1 as negative and +2/+3 as positive were as follows: A0485, 63-84/95-98; CB11, 63-66/97-98; TAB-250, 82-100/94-95; HercepTest, 59-77/91-93. The positive and negative predictive values varied by stain intensity. Stain scores of 0 and +3 were highly predictive of gene status. Stain scores of +1 and +2 were not sufficiently predictive to classify cases as amplified versus nonamplified. IHC is a reasonable first test to assess HER-2/neu status in patients with breast cancer. For most cases, DAKO A0485, TAB250, and HercepTest adequately predicted gene status. In cases with stain intensity of +1 or +2, the interobserver agreement is poor, and the predictive value is unsatisfactory for clinical use. Additional testing, preferably with FISH, is recommended.

Antibodies, Monoclonal↗
PubMed2001

Underutilization of acute care settings in a tertiary care hospital.

OBJECTIVE: To estimate underutilization of acute care settings in a tertiary care hospital. DESIGN: A retrospective and concurrent cohort study using chart reviews and the Intensity of service, Severity of illness, Discharge screen for Acute Care (ISD-AC(R)) tool to measure appropriateness of acute care for patients who were receiving care in a less acute setting, as an indicator of underutilization. SETTING: A 450-bed tertiary care teaching hospital. STUDY PARTICIPANTS: Patients discharged from the emergency department, patients discharged from acute care inpatient units and patients in acute, non-critical care settings. INTERVENTIONS: None. MAIN OUTCOME MEASURES: The percentage of patients discharged from the emergency department who did not meet the criteria for acute care discharge screens; the percentage of patients discharged from an acute care inpatient unit who did not meet the criteria for discharge screens; and the percentage of patients who were in acute, non-critical care beds and who met the criteria for critical care. RESULTS: It was found that six out of 168 patients [3.57%; 95% confidence interval (CI), 1.32-7.61%] did not meet the discharge screens at the time of discharge from the emergency department. Four out of 156 patients (2.56%; 95% CI, 0.70-6.43%) did not meet the discharge screens at the time of discharge from an acute care inpatient service and two out of 156 acute care patients (1.33%; 95% CI, 0.02-4.73%) who were in non-critical care beds met the criteria for critical care. CONCLUSION: These findings of underutilization may help to quantitate an unmet need in health care.

Acute Disease↗
PubMed2001

Parity and carotid artery atherosclerosis in elderly women: The Rotterdam Study.

BACKGROUND AND PURPOSE: It has been postulated that physiological changes in the cardiovascular system, lipids, and glucose metabolism during pregnancy may increase subsequent risk of cardiovascular disease. Examination of the association between parity and risk factors for atherosclerosis may contribute information regarding possible mechanisms. METHODS: The relationship of parity with cardiovascular risk factors and the presence of carotid atherosclerosis was examined in the Rotterdam Study, a population-based study comprising 4878 women aged 55 years and older. Carotid atherosclerosis was assessed by ultrasonographic detection of plaques in the common carotid artery and bifurcation. Logistic regression models were used to compute odds ratios and 95% confidence intervals, adjusted for confounding factors. RESULTS: Parity was inversely associated with high-density lipoprotein cholesterol, and alcohol intake. Parity was positively associated with body mass index, total/HDL cholesterol ratio, insulin resistance, age at menopause, and socioeconomic status. Relative to nulliparous women, parous women had 36% (9% to 71%) greater risk of carotid atherosclerosis, rising to 64% in women with >/=4 children (19% to 127%). Adjustment for known cardiovascular risk factors, including insulin resistance and current lipid levels, did not diminish the magnitude of this association. CONCLUSIONS: Data demonstrated that there is a positive association between parity and risk of carotid artery plaques in elderly women and, further, that high parity is associated with lower HDL cholesterol levels and higher glucose/insulin ratios long after childbearing has ceased.

Aged↗
PubMed2001

Non-Hodgkin's lymphoma and specific pesticide exposures in men: cross-Canada study of pesticides and health.

Our objective in the study was to investigate the putative associations of specific pesticides with non-Hodgkin's Lymphoma [NHL; International Classification of Diseases, version 9 (ICD-9) 200, 202]. We conducted a Canadian multicenter population-based incident, case (n = 517)-control (n = 1506) study among men in a diversity of occupations using an initial postal questionnaire followed by a telephone interview for those reporting pesticide exposure of 10 h/year or more, and a 15% random sample of the remainder. Adjusted odds ratios (ORs) were computed using conditional logistic regression stratified by the matching variables of age and province of residence, and subsequently adjusted for statistically significant medical variables (history of measles, mumps, cancer, allergy desensitization treatment, and a positive history of cancer in first-degree relatives). We found that among major chemical classes of herbicides, the risk of NHL was statistically significantly increased by exposure to phenoxyherbicides [OR, 1.38; 95% confidence interval (CI), 1.06-1.81] and to dicamba (OR, 1.88; 95% CI, 1.32-2.68). Exposure to carbamate (OR, 1.92; 95% CI, 1.22-3.04) and to organophosphorus insecticides (OR, 1.73; 95% CI, 1.27-2.36), amide fungicides, and the fumigant carbon tetrachloride (OR, 2.42; 95% CI, 1.19-5.14) statistically significantly increased risk. Among individual compounds, in multivariate analyses, the risk of NHL was statistically significantly increased by exposure to the herbicides 2,4-dichlorophenoxyacetic acid (2,4-D; OR, 1.32; 95% CI, 1.01-1.73), mecoprop (OR, 2.33; 95% CI, 1.58-3.44), and dicamba (OR, 1.68; 95% CI, 1.00-2.81); to the insecticides malathion (OR, 1.83; 95% CI, 1.31-2.55), 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT), carbaryl (OR, 2.11; 95% CI, 1.21-3.69), aldrin, and lindane; and to the fungicides captan and sulfur compounds. In additional multivariate models, which included exposure to other major chemical classes or individual pesticides, personal antecedent cancer, a history of cancer among first-degree relatives, and exposure to mixtures containing dicamba (OR, 1.96; 95% CI, 1.40-2.75) or to mecoprop (OR, 2.22; 95% CI, 1.49-3.29) and to aldrin (OR, 3.42; 95% CI, 1.18-9.95) were significant independent predictors of an increased risk for NHL, whereas a personal history of measles and of allergy desensitization treatments lowered the risk. We concluded that NHL was associated with specific pesticides after adjustment for other independent predictors.

Adult↗
PubMed2000

Co-morbidity data in outcomes research: are clinical data derived from administrative databases a reliable alternative to chart review?

Evaluation of co-morbidity data is essential in health outcomes research. Co-morbidity data derived from administrative databases has been criticized for lacking the accuracy required for clinical research. We compared co-morbidity data derived from a Canadian provincial hospitalization database with chart review in 817 adults treated with a percutaneous coronary intervention at a single tertiary care hospital between 1994 and 1995. While the administrative database tended to under-estimate the prevalence of some co-morbid conditions, the agreement between chart review and administrative data was good to very good for most conditions. Asymptomatic conditions were noted to have lower levels of agreement. Multivariate risk models for all-cause mortality constructed from both data sources were almost identical, suggesting minimal misclassification. The results indicate that clinical data abstracted from most Canadian hospitalization databases can provide reliable information regarding baseline co-morbid conditions believed to influence survival in a population undergoing percutaneous coronary interventions.

Adult↗
PubMed2000

Polymorphisms in the IL4, IL4RA, and FCERIB genes and asthma severity.

BACKGROUND: Genetic polymorphisms have been associated with asthma and asthma severity. OBJECTIVE: We sought to determine whether 3 polymorphisms were associated with severe asthma indicated either by the occurrence of a fatal (or near-fatal) asthma attack or by severe airflow obstruction. METHODS: We obtained DNA and clinical data from asthmatic subjects who either died or nearly died during an asthma attack and from a group of subjects with mild-to-moderate asthma who had never experienced a fatal or near-fatal asthma episode. These groups were compared with a group of nonatopic nonasthmatic control subjects. The level of airflow obstruction (FEV(1) percent predicted) in the subjects with mild-to-moderate asthma was used as an additional measure of disease severity. The subjects were genotyped for the IL4*C-589T promoter polymorphism and the IL4RA*Q576R and the FCERIB*E237G amino acid substitutions. RESULTS: The results showed that the FCERIB*E237G and IL4RA*Q576R polymorphisms were not associated with fatal or near-fatal asthma. However, the IL4*-589T allele was significantly increased in the subjects with fatal or near-fatal asthma compared with nonasthmatic subjects (odds ratio [OR], 1.8; P =.02) and subjects with mild-to-moderate asthma (OR, 1.9; P =.02). There was no interaction between the IL4*-589T and IL4RA*576R alleles. Of the 3 polymorphisms, only the IL4RA*576R allele was associated with severe airflow obstruction (OR, 8.2; P =.01). CONCLUSION: These data suggest that the IL4*-589T allele is a risk factor for life-threatening asthma and that the IL4RA*576R allele is a risk factor for a low level of lung function in asthmatic subjects.

Airway Obstruction↗
PubMed2000

Volume expansion using pentastarch does not change gastric-arterial CO2 gradient or gastric intramucosal pH in patients who have sepsis syndrome.

OBJECTIVE: In hypovolemic patients with sepsis syndrome, to determine the effects of colloid volume infusion using 10% pentastarch on abnormal gastric tonometer measurements (gastric intramucosal CO2 tension, gastric intramucosal-arterial PCO2 gradient, and gastric intramucosal pH [pHi]) and on cardiac index, global oxygen delivery, and hemoglobin. DESIGN: Prospective prepost intervention study. SETTING: Tertiary care, university-affiliated 15-bed general systems intensive care unit. PATIENTS: Patients were studied who had sepsis syndrome, who had pulmonary arterial catheters in place, who were hypovolemic (pulmonary arterial occlusion pressure [PAOP] <15 mm Hg), and who had a gastric arterial PCO2 gradient >10 mm Hg. INTERVENTIONS: Baseline measurements of gastric intramucosal CO2 tension, gastric intramucosal-arterial PCO2 gradient, and pHi, as well as arterial lactate, pulmonary arterial occlusion, central venous and systemic arterial pressures, thermodilution cardiac output, and temperature. Boluses of 500 mL pentastarch were administered to a total of 1,000 mL or until PAOP was >18 mm Hg. Measurements were repeated at 30 mins and 120 mins postinfusion of pentastarch. MAIN RESULTS: Volume infusion using pentastarch did not change gastric PCO2, gastric-arterial PCO2 gradient, or pHi. Volume expansion with pentastarch significantly increased cardiac index, global oxygen delivery, and PAOP. Administration of pentastarch decreased hemoglobin and arterial lactate at 30 mins but not at 120 mins. CONCLUSIONS: Volume expansion using a colloidal solution of 10% pentastarch does not change abnormal intramucosal CO2 tension, gastric-arterial PCO2 gradient, or pHi in critically ill hypovolemic patients who have sepsis syndrome despite increasing cardiac index, oxygen delivery, and pulmonary artery occlusion pressure.

APACHE↗
PubMed2000

Early discharge of patients with presumed opioid overdose: development of a clinical prediction rule.

OBJECTIVE: To develop a clinical prediction rule to identify patients who can be safely discharged one hour after the administration of naloxone for presumed opioid overdose. METHODS: Patients who received naloxone for known or presumed opioid overdose were formally evaluated one hour later for multiple potential predictor variables. Patients were classified into two groups: those with adverse events within 24 hours and those without. Using classification and regression tree methodology, a decision rule was developed to predict safe discharge. RESULTS: Clinical findings from 573 patients allowed us to develop a clinical prediction rule with a sensitivity of 99% (95% CI = 96% to 100%) and a specificity of 40% (95% CI = 36% to 45%). Patients with presumed opioid overdose can be safely discharged one hour after naloxone administration if they: 1) can mobilize as usual; 2) have oxygen saturation on room air of >92%; 3) have a respiratory rate >10 breaths/min and <20 breaths/min; 4) have a temperature of >35.0 degrees C and <37.5 degrees C; 5) have a heart rate >50 beats/min and <100 beats/min; and 6) have a Glasgow Coma Scale score of 15. CONCLUSIONS: This prediction rule for safe early discharge of patients with presumed opioid overdose performs well in this derivation set but requires validation followed by confirmation of safe implementation.

Adult↗
PubMed1999

Improved clinical outcome after widespread use of coronary-artery stenting in Canada.

BACKGROUND: The introduction and refinement of coronary-artery stenting dramatically changed the practice of percutaneous coronary revascularization in the mid-1990s. We analyzed one-year follow-up data for all percutaneous coronary interventions performed in a large, unselected population in Canada to determine whether the use of coronary stenting has been associated with improved outcomes. METHODS: Prospectively collected data on all percutaneous coronary interventions performed on residents of British Columbia, Canada, between April 1994 and June 1997 were linked to province-wide health care data bases to provide the date of the following end points: subsequent target-vessel revascularization, myocardial infarction, and death. Baseline characteristics and procedural variables were identified and Kaplan-Meier survival curves were generated for 9594 procedures divided into seven groups, one for each sequential half-year period. RESULTS: The overall burden of coexisting illnesses remained stable throughout the study period. A large increase in the rate of coronary stenting (from 14.2 percent in the period from April to June 1994 to 58.7 percent in the period from January to June 1997) was associated with a significant reduction in the rate of adverse cardiac events at one year (from 28.8 percent to 22.8.percent; adjusted relative risk, 0.79; 95 percent confidence interval, 0.69 to 0.90; P<0.001). This reduction in adverse events was exclusively due to a large reduction in subsequent target-vessel revascularization (from 24.4 percent to 17.0 percent; adjusted relative risk, 0.72; 95 percent confidence interval, 0.62 to 0.83; P<0.001) without significant changes in the overall rates of myocardial infarction (5.4 percent, P=0.28) or death (3.9 percent, P=0.65). CONCLUSIONS: The need for target-vessel revascularization during one year of follow-up decreased after percutaneous coronary intervention during the mid-1990s. The reduction was coincident with the introduction and subsequent widespread use of coronary stenting.

Angioplasty, Balloon, Coronary↗
PubMed1999

Power-frequency electric and magnetic fields and risk of childhood leukemia in Canada.

In a case-control study of childhood leukemia in relation to exposure to power-frequency electric and magnetic fields (EMF), 399 children resident in five Canadian provinces who were diagnosed at ages 0-14 years between 1990 and 1994 (June 1995 in British Columbia and Quebec) were enrolled, along with 399 controls. Exposure assessment included 48-hour personal EMF measurement, wire coding and magnetic field measurements for subjects' residences from conception to diagnosis/reference date, and a 24-hour magnetic field bedroom measurement. Personal magnetic fields were not related to risk of leukemia (adjusted odds ratio (OR) = 0.95, p for trend = 0.73) or acute lymphatic leukemia (OR = 0.93, p for trend = 0.64). There were no clear associations with predicted magnetic field exposure 2 years before the diagnosis/reference date or over the subject's lifetime or with personal electric field exposure. A statistically nonsignificant elevated risk of acute lymphatic leukemia was observed with very high wiring configurations among residences of subjects 2 years before the diagnosis/reference date (OR = 1.72 compared with underground wiring, 95% confidence interval 0.54-5.45). These results provide little support for a relation between power-frequency EMF exposure and risk of childhood leukemia.

Adolescent↗