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Biomedical subjects

P A Rochon

Publications and source records attributed to P A Rochon.

At least 19 recordsLinked to original sources
PubMed2005

Survival in Parkinson disease: thirteen-year follow-up of the DATATOP cohort.

OBJECTIVE: To investigate predictors of survival in Parkinson disease (PD). METHODS: Vital status was determined in 800 subjects enrolled in a clinical trial of deprenyl (selegiline) and tocopherol 13 years earlier. RESULTS: Two hundred ninety-six deaths were recorded. There was no difference in the standardized mortality ratios across gender or age group. In univariate analyses, PD-specific variables associated with mortality were increased symmetry of parkinsonism, gait dysfunction as an initial symptom, severity of parkinsonism, and rate of worsening of parkinsonism prior to study enrollment. Cumulative exposure to deprenyl was not associated with mortality. In multivariable analysis, severity of parkinsonism and rate of worsening of parkinsonism remained associated with mortality. A poorer response to levodopa was associated with increased mortality independent of disease severity or dosage of levodopa. Results were unchanged when the analysis was restricted to 747 subjects maintaining a most likely diagnosis of PD throughout 6 years of active follow-up. CONCLUSIONS: Parkinson disease did not affect survival differently across gender or age groups in this selected group of otherwise healthy clinical trial participants. Severity and rate of worsening of parkinsonism and response to levodopa are strongly related to survival.

Cohort Studies↗
PubMed2001

Herbal-drug therapy interactions: a focus on dementia.

Older people with dementia are often prescribed numerous medications. Use of herbal therapies in addition to these conventional drug therapies may lead to interactions that result in an adverse drug event. We have conducted a systematic review to identify all studies that examined interactions between herbal and conventional drug therapies (i.e. prescription or over-the-counter). Using a MEDLINE search of English-language studies published between 1980 and 2000, we limited our search to those herbal therapies most likely to be used for the treatment of dementia (memory loss and decreased concentration) and related symptoms. We identified 28 articles that describe interactions between these herbal (i.e. St. John's wort, ginkgo biloba, kava, valerian, and ginseng) and conventional drug therapies. Of these articles, 11 examined St. John's wort, four examined ginkgo biloba, five examined kava, one examined valerian, and seven examined ginseng. We identified a series of potential interactions between herbal and conventional drug therapy that place older people at risk for an adverse drug event. Health care professionals need to be aware of these potential interactions.

Aged↗
PubMed2001

Increased risk of somnolence with the new dopamine agonists in patients with Parkinson's disease: a meta-analysis of randomised controlled trials.

BACKGROUND: Recent case reports and letters have alerted practitioners to the risk of sleep attacks, usually preceded by somnolence, in patients with Parkinson's disease treated with pramipexole and ropinirole. OBJECTIVE: To quantify the risk of somnolence with the new dopamine agonists pramipexole and ropinirole in patients with Parkinson's disease. METHODS: We searched MEDLINE, EMBASE, International Pharmaceutical Abstracts and Cochrane Library, contacted experts and pharmaceutical manufacturers, and manually reviewed all references retrieved to identify possible articles to include. Information on randomisation, blinding, type of treatment and reporting of somnolence were abstracted by 2 independent reviewers. Disagreements were resolved by a third author. ANALYSIS: We made 2 separate analyses. The first analysis compared the risk of somnolence in patients taking either pramipexole or ropinirole to that in patients taking placebo. The second analysis compared the risk of somnolence with these drugs (plus levodopa) versus that with levodopa alone. We calculated pooled relative risk estimates using the random effects model and when no heterogeneity was detected we used the fixed effects model. RESULTS: Four trials were included in the analysis of patients taking pramipexole or ropinirole compared with those taking placebo. The pooled relative risk of somnolence in this analysis was 4.98 [95% confidence interval (CI) 1.79 to 13.89]. Seven trials were included in the analysis of patients taking levodopa and pramipexole or ropinirole compared with those taking levodopa alone. The pooled relative risk was 2.06 (95% CI 1.47 to 2.88). CONCLUSION: Patients with Parkinson's disease using pramipexole or ropinirole are at higher risk of experiencing somnolence relative to patients taking placebo. Patients taking levodopa plus either one of these dopamine agonists are at higher risk than those taking levodopa alone. Clinicians should carefully weigh this risk against the benefit of these agents when prescribing these drugs.

Antiparkinson Agents↗
PubMed2000

Rate of heart failure and 1-year survival for older people receiving low-dose beta-blocker therapy after myocardial infarction.

BACKGROUND: Many older people do not receive beta-blocker therapy after myocardial infarction or receive doses lower than those tested in trials, perhaps because physicians fear that beta-blockers may precipitate heart failure. We examined the relation between use of beta-blockers, the dose used, and hospital admission for heart failure and 1-year survival in a cohort of all older patients surviving myocardial infarction in Ontario, Canada. METHODS: We collected data on a cohort of 13,623 patients aged 66 years or older who were discharged from hospital after a myocardial infarction and who did not receive beta-blocker therapy or received low, standard, or high doses. We used Cox's proportional-hazards models to study the association of dose with admission for heart failure and survival with adjustment for factors including age, sex, and comorbidity. FINDINGS: Among 8232 patients with no previous history of heart failure, dispensing of beta-blocker therapy was associated with a 43% reduction in subsequent admission for heart failure (adjusted risk ratio 0.57 [95% CI 0.48-0.69]) compared with patients not dispensed this therapy. Among the 4681 patients prescribed beta-blockers, the risk of admission was greater in the high-dose than in the low-dose group (1.53 [1.01-2.31]). Among all 13,623 patients in the cohort, 2326 (17.1%) died by 1 year. Compared with those not dispensed beta-blocker therapy, the adjusted risk ratio for mortality was lower for all three doses (low 0.40 [0.34-0.47], standard 0.36 [0.31-0.42], high 0.43 [0.33-0.56]). INTERPRETATION: Compared with high-dose beta-blocker therapy, low-dose treatment is associated with a lower rate of hospital admission for heart failure and has a similar 1-year survival benefit. Our findings support the need for a randomised controlled trial comparing doses of beta-blocker therapy in elderly patients.

Adrenergic beta-Antagonists↗
PubMed2000

Subcutaneous fluid infusion in a long-term care setting.

OBJECTIVE: To study the use of hypodermoclysis in a long-term care setting for chronic fluid supplementation and to compare it to intravenous (IV) fluid in the treatment of acute mild to moderate dehydration. DESIGN: A prospective observational study. PARTICIPANTS: Fifty-five residents of a long-term care facility treated with fluid therapy during a 5-week period. MAIN OUTCOME MEASURES: Efficacy of hydration and adverse effects were obtained from detailed chart review, interviews with healthcare providers, and investigators' observations. RESULTS: The study subjects were frail older people. Hypodermoclysis was used for maintenance fluid needs in 24 residents; none of these residents required any additional fluid therapy for dehydration. In addition, 37 residents received fluids for acute dehydration. In these residents, hypodermoclysis was associated with clinical improvement in 57% and no clinical change in 25%. Recipients of IV fluids improved 81% of the time and the remainder were unchanged. Hypodermoclysis was associated with fewer fluid therapy-related complications relative to IV therapy (P = .04). CONCLUSIONS: Hypodermoclysis is an effective procedure for providing fluids for both chronic maintenance needs and acute situations associated with mild to moderate dehydration in a long-term care setting. Hypodermoclysis appears safer and can avoid transfers to hospital for rehydration.

Aged↗
PubMed1999

Use of beta-blocker therapy in older patients after acute myocardial infarction in Ontario.

BACKGROUND: Despite its proven efficacy, beta-blocker therapy remains underused in elderly patients after myocardial infarction (MI). The objectives of this study were to identify undertreated groups of seniors and to determine whether older and frailer patients are being selectively dispensed low-dose beta-blocker therapy. METHODS: From a comprehensive hospital discharge database, all people aged 66 years or more in Ontario who survived an acute MI between April 1993 and March 1995 were identified and classified into those who did not receive beta-blocker therapy and those dispensed low, standard or high doses of this agent. Logistic regression models were used to study the effect of age, sex, comorbidity, potential contraindications to beta-blocker therapy and residence in a long-term-care facility on the odds of not being dispensed a beta-blocker. Among beta-blocker users, the odds of being dispensed low relative to standard or high doses of this agent were evaluated. RESULTS: Of the 15,542 patients, 7549 (48.6%) were not dispensed a beta-blocker. Patients 85 years of age or more were at greater risk of not receiving beta-blocker therapy (adjusted odds ratio [OR] 2.8, 95% confidence interval [CI] 2.5-3.2) than were those 66 to 74 years. Having a Charlson comorbidity index of 3 or greater was associated with an increased risk of not receiving beta-blocker therapy (adjusted OR 1.5, 95% CI 1.3-1.8) compared with having lower comorbidity scores. Patients who resided in a long-term-care facility were at increased risk of not being prescribed beta-blocker therapy (adjusted OR 2.6, 95% CI 2.0-3.4). Among the 5453 patients with no identifiable contraindication to beta-blocker therapy, women were significantly less likely than men to receive this agent (p = 0.005). Of the 6074 patients who received beta-blockers, 2248 (37.0%) were dispensed low-dose therapy. Patients aged 85 years or more had an increased risk of being dispensed low-dose therapy (adjusted OR 1.6, 95% CI 1.3-2.0) compared with those aged 66 to 74 years. Compared with those who had the lowest comorbidity scores, patients with the highest comorbidity scores were more likely to be dispensed low-dose beta-blocker therapy (adjusted OR 1.3, 95% CI 1.0-1.8). INTERPRETATION: Almost half of Ontario patients aged 66 or more who survived an MI, particularly those who were older or frailer, did not receive beta-blocker therapy. Among those dispensed beta-blocker therapy, older and frailer patients were more frequently dispensed low-dose therapy.

Adrenergic Antagonists↗
PubMed1999

The prevalence of low back pain in the elderly. A systematic review of the literature.

STUDY DESIGN: The prevalence of low back pain in the older population (> = or 65 years) was reviewed in an analysis of the literature from 1966 to the present. OBJECTIVE: To determine the prevalence of low back pain in the geriatric population. SUMMARY OF BACKGROUND DATA: Back pain is one of the most frequently reported conditions affecting the adult population. However, the prevalence of low back pain in the older age population is not accurately known. METHODS: A methodologic search of five computerized bibliographic databases was performed to identify citations on the prevalence of low back pain in the elderly. Data were summarized, and prevalence studies were critically appraised in detail for their quality. RESULTS: There is wide variability in the reported prevalence of back pain. Many factors have been proposed to explain these findings including sample source, study design, definitions of back pain, and use of patient-reported data. Comorbidity among older patients also contributes to the variability in the reporting of prevalence of back pain. CONCLUSION: There is an under-representation of the older population in the back pain literature. The data in the current study suggest that the prevalence of low back pain in this population is not known with certainty and is not comparable with that in the younger population. The authors stress the need for future studies to improve the reporting of age information to make prevalence studies more informative and applicable.

Aged↗
PubMed1999

Are randomized control trial outcomes influenced by the inclusion of a placebo group?: a systematic review of nonsteroidal antiinflammatory drug trials for arthritis treatment.

Placebo groups are often included in randomized control trials evaluating drug therapy, yet we know little about the placebo effect. The purpose of our study was to evaluate how the presence of a placebo group in a randomized control trial (RCT) influences the patients' ratings of the efficacy of an active drug therapy and their reporting of its adverse effects. We identified studies published between 1966 and 1994 using MEDLINE. Randomized control trials evaluating acetylsalicylic acid, diclofenac, or indomethacin for the treatment of osteo or rheumatoid arthritis were included in our sample. Two investigators independently extracted data. Fifty-eight treatment arms met our inclusion criteria and were available for analysis. Twenty-five treatment arms evaluated a nonsteroidal antiinflammatory drug (NSAID) in placebo control trials and 33 in comparative trials. Using a logistic regression model to adjust for the differences between the evaluated drugs and between the types of arthritis, we found that patients receiving an NSAID in a placebo control trial were more likely to withdraw due to inefficacy (OR=1.3; 95% CI, 1.0 to 1.6; P=0.04). Using a similar model, withdrawals due to adverse effects were found to be more common when the NSAID was given in trials that did not include a placebo group (OR=1.5; 95% CI, 1.1 to 1.9; P=0.002) as were reports of cutaneous (OR=4.2; 95% CI, 1.7 to 9.9), gastrointestinal (OR=1.6; 95% CI, 1.3 to 2.0), and other types (OR=5.3; 95% CI, 3.8 to 7.4) of adverse effects. Although reports of central nervous system adverse effects were more frequent in the comparative trials, this difference was not significant. Including a placebo group in a RCT changes how patients rate the efficacy and adverse effects of their therapy. Our results highlight the need to consider the placebo effect in the design and analyses of clinical trials.

Aged↗
PubMed1999

Age- and gender-related use of low-dose drug therapy: the need to manufacture low-dose therapy and evaluate the minimum effective dose.

OBJECTIVES: Low-dose drug therapy is promoted as a way to maximize benefit and minimize adverse drug effects when prescribing for older adults. This population-based study evaluates the age and sex-related use of two common therapies: thiazide diuretics, where evidence supports the use of low-dose therapy, and beta-blockers, where trials have not evaluated the minimum effective dose. DESIGN: Using linked administrative databases we identified all of the 120,613 persons dispensed a thiazide diuretic therapy and 12,908 myocardial infarction survivors dispensed beta-blocker therapy in Canada's largest province. We used logistic regression models to study the association of age and sex with dispensing of low-dose thiazide diuretic and beta-blocker therapy at doses lower than evaluated in trials. RESULTS: Of 120,613 older people dispensed a thiazide diuretic, 32,372 (26.8%) were dispensed a low dose. Patients 85 years of age or older, relative to the youngest group, were 30% more likely to be dispensed low-dose therapy (OR=1.31; 95% CI, 1.27 to 1.36; P < .001). Women were 8% more likely than men to be dispensed a low-dose thiazide diuretic (OR=1.08; 95% CI, 1.05 to 1.11; P < .001). Of 10,991 myocardial infarction survivors dispensed atenolol, metoprolol, propranolol, or timolol, 9458 (86.1%) were dispensed a lower-than-evaluated dose. Patients 85 years of age or older, relative to those in the youngest group, were more than twice as likely to be dispensed a lower-than-evaluated beta-blocker therapy dose (OR=2.28; 95% CI, 1.74 to 3.04; P < .001). No difference was noted in the use of beta-blocker therapy dose by sex (OR=1.0; 95% CI, .89 to 1.15; P = .95). CONCLUSIONS: Low-dose thiazide diuretic therapy prescribed widely to older people, particularly those of advanced age and women. The vast majority of myocardial infarction survivors were dispensed beta-blocker therapy at lower-than-evaluated doses. These findings highlight the need to manufacture low-dose thiazide diuretic therapy and to evaluate the minimum effective dose of beta-blocker therapy.

Adrenergic beta-Antagonists↗
PubMed1998

Reporting of gender-related information in clinical trials of drug therapy for myocardial infarction.

BACKGROUND: Concern has been expressed that women are not adequately represented in clinical trials evaluating treatments for medical conditions they commonly experience. This study was designed to assess the reporting of data on women in recently published trials of drug therapy for myocardial infarction, including those funded by an agency with a gender-related policy. METHODS: All randomized controlled trials and meta-analyses of drug therapies for myocardial infarction published in The New England Journal of Medicine, The Lancet, The Journal of the American Medical Association, the Annals of Internal Medicine and the British Medical Journal from January 1992 to December 1996 were evaluated. On preliminary review 102 articles met the inclusion criteria; these were reviewed in detail, and 59 were excluded. Two reviewers independently extracted gender-related information from the 43 articles; discrepancies were resolved by consensus. RESULTS: Women presented up to 48% of the trial participants (mean 24.1%). In the trials funded by an agency with a gender-related policy, only 16.8% of participants, on average, were women. Of the 43 articles in the sample, only 14 (32%) provided gender-related results. Funding from an agency with gender-related policy did not affect the reporting of gender-related information. Subgroup analyses were provided for 14 (32%) of the 43 trials, including 2 (29%) of 7 trials funded by an agency with a gender-related policy. Of the 12 trials that included interaction analyses (excluding the 2 trials in which secondary analyses were conducted specifically to identify differences between women and men), 7 (58%) conducted an interaction analysis to determine if women responded differently than men; for one of these the interaction analysis was for a secondary outcome measure (drug safety). Only 5 (12%) of the 43 articles mentioned the differences between men and women in the Discussion section; 2 of these were studies that used secondary analyses to examine sex differences. Of the 5, only 1 was funded by an agency with a gender-related policy. INTERPRETATION: Women were poorly represented in the randomized controlled trials in this sample, regardless of whether the trials were funded by an agency with a gender-related policy. Structured reporting of gender-related information for clinical trials may improve the quality of information available about women and therefore facilitate the application of research findings to the care of women.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

The controversy surrounding cholesterol treatment in older people.

The evidence of the benefit of lowering cholesterol levels in seniors from epidemiologic studies and RCTs is conflicting. Epidemiologic studies suggest that elevated cholesterol levels in elderly people may be a marker of good health. In some cases, lowering cholesterol in seniors may even prove harmful. Conversely, RCTs of lipid-lowering therapy have shown clear benefits in reducing coronary events in younger and middle-aged adults with or without pre-existing CAD. Both the epidemiologic studies and the RCTs we evaluated have methodologic concerns that make generalization to all seniors difficult. One epidemiologic study, in fact, found that there may be a physiologic decline in cholesterol levels as people age into their 70s and beyond [16]. We still do not appear to have a clear insight into the precise role cholesterol plays in seniors, especially those over the age of 75. In the future, as more data becomes available from RCTs and meta-analyses evaluating seniors in the older age group [15], we hope to have a better understanding of how to treat hypercholesterolaemia in this population. Until further studies are published, treatment plans need to be individualized, and the risks and benefits of treatment on various outcomes must be weighed according to the best evidence we have available.

Age Factors↗
PubMed1997

Atrial fibrillation and stroke prevention with warfarin in the long-term care setting.

BACKGROUND: While the benefits of warfarin sodium therapy for stroke prevention in patients with atrial fibrillation (AF) have been extensively documented, generalizing clinical trial results to the majority of elderly persons with AF, especially to those who reside in the long-term care setting, remains challenging. OBJECTIVES: To determine the prevalence of AF in the institutionalized elderly population and the proportion receiving anticoagulation therapy with warfarin: to identify the clinical and functional characteristics of institutionalized elderly persons with AF that are associated with the use of warfarin; and to assess the quality of prescribing and monitoring of warfarin therapy in institutionalized elderly persons with AF. METHODS: This study involved 30 long-term care facilities (total No. of beds, 6437) located in New England, Quebec, and Ontario. The proportion of patients with AF who were receiving treatment with warfarin was determined. The association between clinical and functional characteristics and the use of warfarin was examined with crude and multivariable-adjusted analyses. For study subjects with at least 2 weeks of warfarin therapy during the 12-month period preceding the date of medical record abstraction, we assessed the quality of warfarin prescribing based on all international normalized ratio or prothrombin time ratio values during this period. RESULTS: An electrocardiogram indicating AF was present in the records of 413 of 5500 long-term care residents (7.5%); 32% of such patients were being treated with warfarin. Only a history of stroke was found to be positively associated with the use of warfarin in this setting. Patients with a diagnosis of dementia and those in the oldest age group (> or = 85 years) were less likely to receive warfarin therapy. Warfarin was commonly prescribed to patients with a history of bleeding, substantial comorbidity and functional impairment, a history of falls, or concomitant potentiating drug therapy. Patients were maintained above or below the recommended therapeutic range 60% of the time. CONCLUSIONS: Atrial fibrillation is common in patients residing in long-term care facilities, but its management with warfarin is highly variable. A more systematic approach to decision making regarding the use of warfarin for stroke prevention in these patients is required. Among patients receiving warfarin, the quality of anticoagulation care warrants improvement.

Aged↗