Search PubMed⌕ Search

Biomedical subjects

J LeLorier

Publications and source records attributed to J LeLorier.

At least 37 records · Page 2Linked to original sources
PubMed1998

Persistence of use of lipid-lowering medications: a cross-national study.

CONTEXT: Although clinical trials have demonstrated the benefits of lipid-lowering therapy, little is known about how these drugs are prescribed or used in the general population. OBJECTIVE: To estimate predictors of persistence with therapy for lipid-lowering drug regimens in typical populations of patients in the United States and Canada. DESIGN: A cohort study defining all prescriptions filled for lipid-lowering drugs during 1 year, as well as patients' demographic and clinical characteristics. SETTING: New Jersey's Medicaid and Pharmacy Assistance for the Aged and Disabled programs and Quebec's provincial medical care program. PATIENTS: All continuously enrolled patients older than 65 years who filled 1 or more prescriptions for lipid-lowering drugs (N = 5611 in the US programs, and N = 1676 drawn from a 10% sample in Quebec). MAIN OUTCOME MEASURES: Proportion of days during the study year for which patients had filled prescriptions for lipid-lowering drugs; predictors of good vs poor persistence with therapy. RESULTS: In both populations, patients failed to fill prescriptions for lipid-lowering drugs for about 40% of the study year. Persistence rates with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors were significantly higher than those seen with cholestyramine (64.3% vs 36.6% of days with drug available, respectively). Patients with hypertension, diabetes, or coronary artery disease had significantly higher rates of persistence with lipid-lowering regimens. In New Jersey, multivariable analysis indicated that the poorest patients (those enrolled in Medicaid) had lower rates of drug use than less indigent patients (those enrolled in Pharmacy Assistance for the Aged and Disabled) after adjusting for possible confounders, despite virtually complete drug coverage in both programs. When rates of use were measured in the US population for the 5 years following the study year, only 52% of surviving patients who were initially prescribed lipid-lowering drugs were still filling prescriptions for this drug class. CONCLUSION: In all populations studied, patients who were prescribed lipid-lowering drug regimens remained without filled prescriptions for over a third of the study year on average. Rates of persistence varied substantially with choice of agent prescribed, comorbidity, and socioeconomic status, despite universal coverage of prescription drug costs. After 5 years, about half of the surviving original cohort in the United States had stopped using lipid-lowering therapy altogether.

Aged↗
PubMed1998

Exposure to allopurinol and the risk of cataract extraction in elderly patients.

OBJECTIVE: To determine whether exposure to allopurinol is associated with an increased risk of cataract extraction in elderly patients. METHODS: We conducted a case-control study using data from the Quebec universal health insurance program for all elderly patients. The 3677 cases were patients with a cataract extraction between 1992 and 1994. The 21,868 controls were randomly selected among patients not diagnosed with cataract and matched to cases on the date of the extraction. We determined the odds ratio of cataract extraction according to the cumulative dose and duration of allopurinol use relative to nonusers, using conditional logistic regression analysis. The analysis was adjusted for the effects of age, sex, diabetes mellitus, hypertension, glaucoma, and ophthalmic and oral corticosteroid exposure. RESULTS: A cumulative dose of allopurinol of more than 400 g or a duration of use of longer than 3 years were associated with an increased risk of cataract extraction, with odds ratios of 1.82 (95% confidence interval [CI], 1.18-2.80) and 1.53 (95% CI, 1.12-2.08), respectively. No increase in risk was observed for lower cumulative doses or shorter exposure periods. CONCLUSION: Long-term administration of allopurinol increases the risk of cataract extraction in elderly patients.

Aged↗
PubMed1998

Selection of controls in database case-control studies: glucocorticoids and the risk of glaucoma.

In case-control studies conducted using computerized databases, controls are often selected as a random sample from the base population. This representative choice of controls is intended to guard against selection bias. We show, using data from a database case-control study, that such a definition of controls may also lead to selection bias under two conditions: (1) if the target disease has a prolonged asymptomatic clinical course with its detection depending on a specific physical examination and (2) if exposed patients have a higher likelihood of having the disease detected than unexposed patients. The extent of the bias that could result from the use of randomly selected controls was investigated in the context of a case-control study of the risk of ocular hypertension or glaucoma associated with the use of glucocorticoids, conducted using the Quebec universal health insurance computerized databases. This article also illustrates that a computerized database can be useful to empirically explore opportunities for bias.

Aged↗
PubMed1998

The use of the bootstrap statistical method for the pharmacoeconomic cost analysis of skewed data.

In pharmacoeconomics, the comparison of the costs of 2 different drugs used for the same treatment is of great interest. The problem is especially challenging when the drugs are likely to produce costly adverse effects in a small number of patients, which is often the case. The data are then skewed and traditional statistical methods to analyse the difference in the mean costs produced by 2 treatments may be inappropriate. The bootstrap method is presented as an alternative approach. A pharmacoeconomic cost-analysis example is presented and used throughout this article.

Costs and Cost Analysis↗
PubMed1998

Comparison of efficacy and cost among lipid-lowering agents in patients with primary hypercholesterolemia.

OBJECTIVE: To compare efficacy and cost of lipid-lowering agents in patients with primary hypercholesterolemia. DESIGN: A meta-analysis was conducted to determine estimates of efficacy for lipid-lowering agents. Efficacy was defined as the change in the ratio of total cholesterol:high density lipoprotein (HDL) induced by treatment. This ratio was selected because of its good predictive value for the risk of coronary disease. Lipid-lowering agents were grouped into three categories according to the decrease in the total cholesterol:HDL ratio. Acquisition prices for drugs were obtained from the Quebec provincial drug formulary. An analysis determined which drugs in each category 'purchased' the greatest decrease in ratio for the lowest cost. SETTING: Clinical trial study centres. PATIENTS: The population analyzed had a mean baseline total cholesterol:HDL ratio of 7.3, an average age of 50.5 years and mean proportion of men of 62.5%. INTERVENTIONS: Twelve lipid-lowering therapies at various doses were investigated. RESULTS: Drugs that were more recently introduced had the greatest effect on the total cholesterol:HDL ratio. A direct dose-effect relationship was not evident, although there was a trend in this direction. In each of the three categories, there was wide range of cost, suggesting that the same effect is available at a broad range of prices. The drugs with the greatest effect on the ratio at the lowest cost were fluvastatin 60 mg/day, fenofibrate (micronized) 200 mg/day and simvastatin 20 mg/day. CONCLUSION: These results can be useful for clinicians in the selection of agents that achieve a specified goal of therapy at the lowest cost.

Anticholesteremic Agents↗
PubMed1997

Report of the Canadian Hypertension Society Consensus Conference: 3. Pharmacologic treatment of hypertensive disorders in pregnancy.

OBJECTIVE: To provide Canadian physicians with evidence-based guidelines for the pharmacologic treatment of hypertensive disorders in pregnancy. OPTIONS: No medication, or treatment with antihypertensive or anticonvulsant drugs. OUTCOMES: Prevention of maternal complications, and prevention of perinatal complications and death. EVIDENCE: Pertinent articles published from 1962 to September 1996 retrieved from the Pregnancy and Childbirth Module of the Cochrane Database of Systematic Reviews and from MEDLINE; additional articles retrieved through a manual search of bibliographies; and expert opinion. Recommendations were graded according to levels of evidence. VALUES: Maternal and fetal well-being were equally valued, with the belief that treatment side effects should be minimized. BENEFITS, HARMS AND COSTS: Reduction in the rate of adverse perinatal outcomes, including death. Potential side effects of antihypertensive drugs include placental hypoperfusion, intrauterine growth retardation and long-term effects on the infant. RECOMMENDATIONS: A systolic blood pressure greater than 169 mm Hg or a diastolic pressure greater than 109 mm Hg in a pregnant woman should be considered an emergency and pharmacologic treatment with hydralazine, labetalol or nifedipine started. Otherwise, the thresholds at which to start antihypertensive treatment are a systolic pressure of 140 mm Hg or a diastolic pressure of 90 mm Hg in women with gestational hypertension without proteinuria or pre-existing hypertension before 28 weeks' gestation, those with gestational hypertension and proteinuria or symptoms at any time during the pregnancy, those with pre-existing hypertension and underlying conditions or target-organ damage, and those with pre-existing hypertension and superimposed gestational hypertension. The thresholds in other circumstances are a systolic pressure of 150 mm Hg or a diastolic pressure of 95 mm Hg. For nonsevere hypertension, methyldopa is the first-line drug; labetalol, pindolol, oxprenolol and nifedipine are second-line drugs. Fetal distress attributed to placental hypoperfusion is rare, and long-term effects on the infant are unknown. Magnesium sulfate is recommended for the prevention and treatment of seizures. VALIDATION: The guidelines are more precise but compatible with those from the US and Australia.

Antihypertensive Agents↗
PubMed1997

Risk of ocular hypertension or open-angle glaucoma in elderly patients on oral glucocorticoids.

BACKGROUND: Ocular hypertension and open-angle glaucoma are well-known side-effects of treatment with topical ophthalmic glucocorticoids. There is uncertainty about the risk of these disorders with oral glucocorticoid therapy. METHODS: Data from the Quebec universal health insurance programme for the elderly were used to identify 9793 patients with a new diagnosis of ocular hypertension or open-angle glaucoma, or on newly prescribed treatment for these disorders (cases). 38,325 controls were randomly selected from ophthalmology patients seen in the same month and year as the case (index date). Current use of oral glucocorticoids was defined as that within 14 days of the index date. All glucocorticoid doses were converted to the equivalent amount of hydrocortisone. The case-control analysis was done by conditional logistic regression and adjusted for age, sex, systemic hypertension, diabetes mellitus, ophthalmic glucocorticoids, glucocorticoid injections, and variables related to general health. FINDINGS: The mean ages of cases and controls were similar (74.9 [SD 6.3] vs 74.7 [6.4]). The adjusted odds ratio of ocular hypertension or open-angle glaucoma for current users of oral glucocorticoids compared with non-users was 1.41 (95% CI 1.22-1.63). There was a dose-related increase in the adjusted odds ratios for current users: 1.26 (1.01-1.56) for less than 40 mg per day of hydrocortisone, 1.37 (1.06-1.76) for patients on 40-79 mg per day, and 1.88 (1.40-2.53) for patients on 80 mg or more per day. The odds ratios also increased with the duration of treatment over the first 11 months of exposure. INTERPRETATION: The use of oral glucocorticoids increases the risk of ocular hypertension or open-angle glaucoma in elderly patients. In patients in this age-group who need long-term treatment with high doses of oral glucocorticoids, monitoring of intraocular pressure may be justified.

Administration, Oral↗
PubMed1997

Discrepancies between meta-analyses and subsequent large randomized, controlled trials.

BACKGROUND: Meta-analyses are now widely used to provide evidence to support clinical strategies. However, large randomized, controlled trials are considered the gold standard in evaluating the efficacy of clinical interventions. METHODS: We compared the results of large randomized, controlled trials (involving 1000 patients or more) that were published in four journals (the New England Journal of Medicine, the Lancet, the Annals of Internal Medicine, and the Journal of the American Medical Association) with the results of meta-analyses published earlier on the same topics. Regarding the principal and secondary outcomes, we judged whether the findings of the randomized trials agreed with those of the corresponding meta-analyses, and we determined whether the study results were positive (indicating that treatment improved the outcome) or negative (indicating that the outcome with treatment was the same or worse than without it) at the conventional level of statistical significance (P<0.05). RESULTS: We identified 12 large randomized, controlled trials and 19 meta-analyses addressing the same questions. For a total of 40 primary and secondary outcomes, agreement between the meta-analyses and the large clinical trials was only fair (kappa= 0.35; 95 percent confidence interval, 0.06 to 0.64). The positive predictive value of the meta-analyses was 68 percent, and the negative predictive value 67 percent. However, the difference in point estimates between the randomized trials and the meta-analyses was statistically significant for only 5 of the 40 comparisons (12 percent). Furthermore, in each case of disagreement a statistically significant effect of treatment was found by one method, whereas no statistically significant effect was found by the other. CONCLUSIONS: The outcomes of the 12 large randomized, controlled trials that we studied were not predicted accurately 35 percent of the time by the meta-analyses published previously on the same topics.

Humans↗
PubMed1997

Inhaled and nasal glucocorticoids and the risks of ocular hypertension or open-angle glaucoma.

OBJECTIVE: To determine whether the use of inhaled and nasal glucocorticoids is associated with an increased risk of ocular hypertension or open-angle glaucoma. DESIGN: Case-control study. SETTING: Québec universal health insurance program for all elderly (registered in the Régie de l'assurance maladie du Québec [RAMQ] database). PATIENTS: Enrollees in the RAMQ database aged 66 years and older. The 9793 case patients were ophthalmology patients with a new diagnosis of borderline glaucoma or open-angle glaucoma or were newly started on treatment for ocular hypertension or glaucoma between 1988 and 1994. The 38,325 control patients were randomly selected among noncases with ophthalmologist visits in the same month and year as the case event (index date). MAIN OUTCOME MEASURES: The odds ratio (OR) of ocular hypertension or open-angle glaucoma was determined in patients using inhaled or nasal glucocorticoids relative to nonusers, using conditional logistic regression analysis. The OR was adjusted for age, sex, diabetes mellitus, systemic hypertension, use of ophthalmic and oral glucocorticoids, and characteristics of health care system use in the year before the index date. RESULTS: Overall, current use of inhaled and nasal glucocorticoids was not associated with an increased risk of ocular hypertension or open-angle glaucoma. Current users of high doses of inhaled steroids prescribed regularly for 3 or more months were at an increased risk with an OR of 1.44 (95% confidence interval, 1.01-2.06). CONCLUSION: Prolonged administration of high doses of inhaled glucocorticoids increases the risk of ocular hypertension or open-angle glaucoma. This finding suggests that in these patients intraocular pressure monitoring may be warranted.

Administration, Inhalation↗
PubMed1997

Long-term survival and functional status in the elderly after cardiac surgery.

BACKGROUND: Hospital mortality and morbidity of cardiac surgery have been well described in the elderly, but there is a paucity of data regarding long-term functional status. OBJECTIVE: To evaluate long-term survival and functional status of patients aged 70 years or older after cardiac surgery. DESIGN: Retrospective observational study. SETTING: University-affiliated tertiary care hospital. PATIENTS: Three hundred and twenty-nine consecutive patients aged 70 or older who had undergone cardiac surgery from January 1990 to December 1993. INTERVENTIONS: Besides postoperative mortality and morbidity, data regarding long-term survival and functional status and preoperative variables affecting these outcomes were analyzed. MAIN RESULTS: Mean age at surgery was 73.9 +/- 2.9 years, and 70.2% of the procedures were performed on an urgent basis. Postoperative mortality was 9.4%. Five-year Kaplan-Meier survival in postoperative survivors was 85.9% and is comparable with the survival of the general sex- and age-matched Quebec population. Preoperative variables affecting long-term survival were atrial fibrillation (RR 3.8; 95% CI 1.4 to 10.0), smoking status on admission (RR 3.6; CI 1.6 to 8.1), peripheral vascular disease (RR 2.9; CI 1.4 to 6.2) and low creatinine clearance (RR 1.4; CI 1.1 to 1.7). Functional status evaluated by the Karnofsky score showed a successful functional outcome in 84.6% of patients at follow-up (mean 2.6 +/- 1.1 years). Preoperative variables unfavourably influencing a successful functional outcome were hypertension (OR 0.34; CI 0.15 to 0.76), cerebrovascular disease (OR 0.35; CI 0.15 to 0.87) and low creatinine clearance (OR 0.73; CI 0.55 to 0.96). CONCLUSIONS: Despite severe cardiovascular and often urgent conditions, sustained functional improvement and good long term survival can be objectively documented in most elderly patients after cardiac surgery.

Activities of Daily Living↗
PubMed1996

Shanghai trial of nifedipine in the elderly (STONE).

OBJECTIVE: To assess the effectiveness of nifedipine treatment in elderly hypertensives. METHODS: A single-blind trial was conducted under the direction of the Shanghai Institute of Hypertension in 1632 subjects aged 60-79 years alternatively allocated to either nifedipine or placebo after a 4-week placebo run-in period between 1987 and 1990 with mean follow-up of 30 months. Clinical events and risk modification were analysed in collaboration with the University of Montreal. Seventy-four patients with severe hypertension were reallocated to active nifedipine treatment after placebo run-in. RESULTS: Cox's proportional hazards model accounting for covariates demonstrated a highly significant decrease in the probability of events: 'original treatment assignment' analysis indicated that 77 events occurred in the placebo and 32 in the nifedipine group. Similar significances were achieved with 'actual treatment' or 'changes excluded' (excluding reallocated subjects) analyses. A significant reduction in relative risk was observed for strokes and severe arrhythmia with an overall decrease from 1.0 to 0.41 (95% confidence interval 0.27-0.61). CONCLUSION: Nifedipine treatment diminished the number of severe clinical outcomes in elderly hypertensives significantly.

Aged↗
PubMed1995

Patterns of prescription of nonsteroidal antiinflammatory drugs and gastroprotective agents.

Peptic ulcer complications constitute the most important undesirable side effect of nonsteroidal antiinflammatory drugs (NSAID). The object of this study was to use the coprescription of a non-aspirin NSAID (NANSAID) and misoprostol or another antiulcer agent (AUA) as an endpoint to estimate the difference in the toxicity of ibuprofen compared to other available NANSAID. We also compared demographic characteristics of these 2 groups of patients. The study was done on the Quebec Health Insurance Board (RAMQ) database. The patients treated with ibuprofen are perceived by their physicians as having a lower need for AUA than those treated with other NANSAID. However, since patients treated with ibuprofen are younger, have fewer comedications, a lower frequency of medical visits, a lower frequency of arthritis, and a more occasional pattern of use, their lesser need for AUA might be due to a channelling of low risk patients toward this drug.

Aged↗
PubMed1984

Effect of nitroglycerin on regional myocardial blood flow following an experimental coronary spasm.

This study was designed to evaluate the effect of nitroglycerin (30 micrograms given as an i.v. bolus) on regional distribution of myocardial blood flow in conscious dogs, following an acute coronary occlusion similar to a coronary spasm. The left anterior descending (LAD) coronary artery was acutely occluded with a balloon cuff occluder. The distribution of blood flow between the endocardium and the epicardium of both the normal and ischemic area of the left ventricle was determined by means of the radioactive microsphere technique. Acute occlusion of the left anterior descending coronary artery produced a significant decrease of blood flow reaching the area irrigated by this artery; this decrease was of a lesser magnitude after administration of nitroglycerin. In addition, ischemia produced a disproportionate decrease in endocardial blood flow. This decrement was also of a lesser magnitude following administration of nitroglycerin. Blood perfusion to the non-ischemic myocardium was not altered. These results indicate that an intravenous bolus of nitroglycerin, given after a brief coronary occlusion simulating a coronary spasm, increases blood flow to the ischemic myocardium, induces a favorable redistribution of blood flow toward the ischemic endocardium and does not produce any decrement of blood perfusion to the non-ischemic myocardium.

Animals↗
PubMed1980

Usefulness of probucol in treating primary hypercholesterolemia.

Probucol (1 g per day) was administered in a double-blind crossover trial to 16 patients with familial hypercholesterolemia who had previously been tested for their response to clofibrate. Probucol led to a fall in the plasma cholesterol concentration of 15% or more (mean 20.2%) in 5 of the 12 clofibrate-resistant patients and between 8% and 15% in 3 others. The reduction was statistically significant in 7 of these 12 patients as well as in 3 of the 4 patients sensitive to clofibrate. Thus, probucol has a place in the treatment of patients with primary hypercholesterolemia who do not respond to clofibrate.

Adult↗