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Joel G Ray

Publications and source records attributed to Joel G Ray.

46 records · Page 3Linked to original sources
PubMed2002

Antipsychotic and antidepressant drug use in the elderly and the risk of venous thromboembolism.

BACKGROUND: Preliminary evidence suggests that use of antipsychotic drugs is associated with an increased risk of venous thromboembolism. OBJECTIVE: To evaluate the relationship between antipsychotic or antidepressant drug use and venous thromboembolism among adults aged 65 years and older. DESIGN: Retrospective cohort study using linked health care administrative databases over a nine year period. SETTING: The entire province of Ontario, Canada. PARTICIPANTS: Individuals aged 65 years and over exclusively prescribed either antipsychotic drugs (n = 22,514), antidepressant drugs (n = 75,649) or thyroid replacement hormones (33,033), the referent control group. We excluded those with an antecedent history of cardiovascular disease, venous thromboembolism or cancer, as well as those dispensed warfarin before study entry. MEASUREMENTS: Diagnosis of deep vein thrombosis or pulmonary embolism. RESULTS: Relative to those prescribed thyroid hormones, neither antidepressant (adjusted hazard ratio 1.02, 95% CI 0.91-1.14) nor antipsychotic (adjusted hazard ratio 1.13, 95% CI 0.96-1.32) drug use was associated with an increased risk for deep vein thrombosis. Similar risk estimates were found for deep vein thrombosis or pulmonary embolism. In a sub-group analysis, only butyrophenone use was found to be associated with a slightly increased risk of deep vein thrombosis (adjusted HR 1.51, 95% CI 1.23-1.86) as well as deep vein thrombosis or pulmonary embolism (adjusted HR 1.43, 95% CI 1.18-1.74). CONCLUSIONS: In a large cohort of adults aged 65 years and older, neither antipsychotic or antidepressant drug use was associated with an increased risk of venous thromboembolism, with the exception of a slightly increased risk among those prescribed butyrophenones. Further data are required before use of these psychoactive drugs can be considered a risk factor for venous thromboembolism.

Aged↗
PubMed2001

Use of a rapid arterial blood gas analyzer to estimate blood hemoglobin concentration among critically ill adults.

OBJECTIVE: To evaluate whether measurement of the hemoglobin (Hb) concentration with a blood gas analyzer approximates that determined by a conventional coulter counter in critically ill adults. DESIGN: Prospective patient series. SETTING: A 32-bed cardiovascular, neurosurgical, trauma and medical-surgical intensive care unit in a single Canadian center. PATIENTS: We consecutively recruited 202 critically ill adults, the majority of whom had recent cardiac or vascular surgery, neurosurgery or trauma. MEASUREMENTS: The nurse obtained a single arterial blood sample within a few hours of the patient's admission to the intensive care unit. The Hb concentration was determined from each blood sample in a masked fashion, using both a blood gas analyzer and a conventional laboratory coulter counter. MAIN RESULTS: A total of 202 consecutive paired analyses were conducted. There was a highly significant correlation between the coulter counter and blood gas analyzer methods of Hb measurement (r2 = 0.98, 95% confidence interval [CI] = 0.97-0.99; P < 0.0001). Using the method of Bland and Altman, the overall mean difference in Hb concentration between the coulter counter and the blood gas analyzer was -4.3 g/l (95% CI = -11.0 to 2.4). Of the 11 (5.4%) Hb measurements that extended beyond the upper and lower 95% CI, 10 (5.0%) were within +/- 3 g/l of these confidence limits. CONCLUSIONS: An arterial blood gas analyzer may provide a valid alternative method to the traditional coulter counter for the rapid assessment of Hb concentration among critically ill adults. Since issues related to its safety, quality control, data entry and cost savings have yet to be addressed, however, use of such point of care testing should be viewed as a supplement to conventional laboratory testing.

APACHE↗
PubMed2001

Use of antihypertensive medications in pregnancy and the risk of adverse perinatal outcomes: McMaster Outcome Study of Hypertension In Pregnancy 2 (MOS HIP 2).

BACKGROUND: Uncertainty remains about the potential harmful effects of antihypertensive therapy on the developing fetus, especially for beta-blockers (betab). METHODS: We prospectively enrolled all singleton women with a blood pressure >/= 140/90 mm Hg during pregnancy. The main analysis included 1948 women with all forms of hypertension and compared the use of betab drugs, non-betab drugs or a combination of both, to no treatment. The primary study outcome was a composite of the diseases of prematurity, need for assisted ventilation for greater than 1 day, or perinatal death. A sub-group analysis evaluated the four treatment options among 583 singleton women with chronic hypertension before 20 weeks gestation. RESULTS: In the main analysis, no association was observed between betab use and the primary composite outcome [adjusted odds ratio (OR) 1.4, 95% CI 0.9-2.2], while an association was seen with non-betab therapy (OR 5.0, 95% CI 2.6-9.6) and combination therapy (OR 2.9, 95% CI 1.8-4.7). In the sub-group of 583 women with hypertension before 20 weeks, use of a non-betab drug (OR 4.9, 95% CI 1.7-14.2) or combination therapy (OR 2.9. 95% CI 1.1-7.7) was significantly associated with the primary composite outcome, while betab monotherapy was not (OR 1.4, 95% CI 0.6-3.4). CONCLUSIONS: Maternal use of antihypertensive medications other than betabs was associated with both major perinatal morbidity and mortality, while betab monotherapy was not. The combined use of betab and non-betab medications demonstrated the strongest association. Before definitive conclusions can be drawn, a large multicentre randomized controlled trial is needed to address the issues of both maternal efficacy and fetal safety with the use of one or more antihypertensive agents in pregnancy.

Journal Article↗
PubMed2001

Genetics University of Toronto Thrombophilia Study in Women (GUTTSI): genetic and other risk factors for venous thromboembolism in women.

BACKGROUND: Women may be at increased risk for venous thromboembolism (VTE) as compared with men. We studied the effects of genetic and biochemical markers of thrombophilia in women, in conjunction with other established risk factors for VTE. METHOD: The present retrospective case-control study was conducted in a thrombosis treatment programme at a large Toronto hospital. The cases were 129 women aged 16-79 years with objectively confirmed VTE. Age-matched control individuals were women who were free of venous thrombosis. Neither cases nor control individuals had known cardiovascular disease. Participants were interviewed regarding personal risk factors for VTE, including smoking, history of malignancy, pregnancy, and oestrogen or oral contraceptive use. Blood specimens were analyzed for common single nucleotide polymorphisms of prothrombin, factor V and methylenetetrahydrofolate reductase (MTHFR; C677T, A1298C and T1317C), and the A66G polymorphism for methionine synthase reductase (MTRR).Fasting plasma homocysteine was also analyzed. RESULTS: Women with VTE were significantly more likely than female control individuals to carry the prothrombin polymorphism and the factor V polymorphism, or to have fasting hyperhomocysteinaemia. Homozygosity for the C677T MTHFR gene was not a significant risk factor for VTE, or were the A1298C or T1317C MTHFR homozygous variants. Also, the A66G MTRR homozygous state did not confer an increased risk for VTE. CONCLUSION: Prothrombin and factor V polymorphisms increased the risk for VTE in women, independent from other established risk factors. Although hyperhomocysteinaemia also heightens this risk, common polymorphisms in two genes that are responsible for homocysteine remethylation do not. These findings are consistent with previous studies that included both men and women.

Journal Article↗
PubMed2001

The role of dyslipidemia and statins in venous thromboembolism.

Recent studies have proposed an association between hyperlipidemia and venous thromboembolism (VTE). We review the epidemiological evidence linking dyslipidemia with VTE and examine several possible underlying mechanisms. We discuss the possible role of HMG CoA reductase inhibitors (statins) in the prevention and treatment of VTE and suggest future directions for research.

Journal Article↗
PubMedDate not supplied

Association of neural tube defects and folic acid food fortification in Canada.

Many women do not receive folic acid supplements before conception. In response, most of Canada's cereal grain products were being fortified with folic acid by January, 1998, thereby providing an additional 0.1-0.2 mg per day of dietary folate to the Canadian population. We assessed the effect of supplementation on prevalence of open neural tube defects in the province of Ontario. Among 336 963 women who underwent maternal serum screening over 77 months, the prevalence of open neural tube defects declined from 1.13 per 1000 pregnancies before fortification to 0.58 per 1000 pregnancies thereafter (prevalence ratio 0.52, 95% CI 0.40-0.67, p<0.0001). At a population level, folic acid food fortification is associated with a pronounced reduction in open neural tube defects.

Adult↗
PubMedDate not supplied

Long-term health sequelae following E. coli and campylobacter contamination of municipal water. Population sampling and assessing non-participation biases.

BACKGROUND: Following bacterial contamination of a municipal water system in the rural town of Walkerton, Ontario, over 2,300 cases of acute gastroenteritis were documented. The Walkerton Health Study is currently underway to assess for long-term health sequelae among consenting inhabitants of Walkerton, related to the original outbreak. We explored whether the association between the acute exposure and preliminary long-term health outcomes may have been biased through differences between early- and late-recruited study participants. METHODS: Using multiple data sources, including the 1996 and 2001 Canadian Census, and records from the Regional Health Unit, hospital and Walkerton Health Study, we determined both sample representativeness and the anticipated effects of intensifying study participant recruitment. Selection bias was assessed by examining for differences between initial and late participants, and their subsequent risk of having hypertension, proteinuria and reduced renal clearance. RESULTS: Of the 4,315 participants, 2,756 were permanent residents of Walkerton, representing 55% of the town's total population. The sample was demographically similar to the population of interest, although statistically women were more likely to participate than men (55% of sample were women compared to 52% of population, p<0.01), and the proportion of both young and very elderly adults was smaller than expected (13% of sample were > or = 65 years of age compared to 18% of population, p<0.01). Comparing the initial 3,959 participants to the 356 persons additionally recruited with substantial effort, the latter were more likely to be free of symptoms during the outbreak (21% vs. 7%, p<0.001), but were otherwise similar in terms of age, sex, the use of medical care resources and underlying health state predating the outbreak. The risk of long-term hypertension or renal sequelae did not significantly differ between initial and late study recruits. CONCLUSIONS: Participants in the Walkerton Health Study represent the population of interest, and comprise those who were acutely ill during the infected water outbreak. The available study sample should provide reasonably unbiased estimates of the associated risk between acute bacterial gastroenteritis and long-term health sequelae.

Acute Disease↗