Comparison of the impact of the Atrial Fibrillation Follow-Up Investigation of Rhythm Management trial on prescribing patterns: a time-series analysis.

Background: The AFFIRM (Atrial Fibrillation Follow-Up Investigation of Rhythm Management) trial demonstrated that rate control and rhythm control strategies result in similar survival and quality of life for patients with atrial fibrillation (AF). Because of superior safety and lower cost, rate control is now the recommended strategy for the management of most elderly, high-risk AF patients.

Objective: To determine the extent to which the AFFIRM trial results have been adopted into actual practice.

Pergolide associated cardiac valvulopathy based on Ontario administrative data.

Introduction: Pergolide is an ergot derived dopamine agonist that is widely used for the treatment of Parkinson's disease. Studies have found an association between pergolide and valvular heart abnormalities although there is still much to be learned about the clinical significance of the valvular changes, who is at risk, and whether there is duration of exposure effect.

Objective: To assess the long term risk of hospital admissions for valvular heart disease (VHD) or congestive heart failure (CHF, a clinically overt outcome of VHD) in new users of pergolide compared to new users of levodopa.

Antipsychotic therapy and short-term serious events in older adults with dementia.

Background: Antipsychotic therapy is widely used to treat behavioral problems in older adults with dementia. Cohort studies evaluating the safety of antipsychotic therapy generally focus on a single adverse event. We compared the rate of developing any serious event, a composite outcome defined as an event serious enough to lead to an acute care hospital admission or death within 30 days of initiating antipsychotic therapy, to better estimate the overall burden of short-term harm associated with these agents.

A population-based study of cholinesterase inhibitor use for dementia.

Objectives: To examine current utilization patterns of cholinesterase inhibitor (ChEI) therapy for dementia to determine treatment duration, use in long-term care, how often patients receive these drugs until death, and frequency of switching between the available ChEIs.

Design: A population-based healthcare administrative database study.

Setting: Patients aged 66 and older from the Canadian province of Ontario who received a new prescription for a ChEI between June 1, 2000, and December 31, 2002.

The effects of coxib formulary restrictions on analgesic use and cost: regional evidence from Canada.

Background: Public insurance plans for pharmaceuticals in Canada differ substantially across provinces in the conditions under which pharmaceuticals are reimbursed. Coxibs provide a good example. Québec had no restrictions on reimbursement for these drugs.

Antipsychotic drug use and mortality in older adults with dementia.

Background: Antipsychotic drugs are widely used to manage behavioral and psychological symptoms in dementia despite concerns about their safety.

Objective: To examine the association between treatment with antipsychotics (both conventional and atypical) and all-cause mortality.

Design: Population-based, retrospective cohort study.

Initiation of benzodiazepines in the elderly after hospitalization.

Objective: To estimate the rate of new chronic benzodiazepine use after hospitalization in older adults not previously prescribed with benzodiazepines.

Design: Retrospective cohort study using linked, population-based administrative data.

Setting: Ontario, Canada between April 1, 1992 and March 31, 2005.

Variation in nursing home antipsychotic prescribing rates.

Background: Excessive prescribing of antipsychotic therapy is a concern owing to their potential to cause serious adverse events. We explored variation in the use of antipsychotic therapy across nursing homes in Ontario, Canada, and determined if prescribing decisions were based on clinical indications.

Methods: A point-prevalence study of antipsychotic therapy use in 47 322 residents of 485 provincially regulated nursing homes in December 2003.

Antipsychotic use in older adults with Parkinson's disease.

The choice of agents to treat psychotic symptoms in Parkinson's disease is important given the potential for antipsychotics to worsen Parkinsonism. The purpose of this study was to estimate the incidence of psychotic symptoms requiring treatment in individuals with Parkinson's disease after starting dopaminergic medications, and to describe the agents being selected as initial antipsychotic therapy. Using the administrative health care databases of Ontario, Canada, individuals 66 years of age or older with Parkinson's disease who were newly treated with dopaminergic agents were identified.

Trends in deliveries, prenatal care, and obstetrical complications in women with pregestational diabetes: a population-based study in Ontario, Canada, 1996-2001.

Objective: To describe recent trends in the proportion of deliveries in women with pregestational diabetes (PGD), their use of services, and diabetes-related obstetrical complications.

Research Design And Methods: In this population-based retrospective cohort study, comprehensive administrative data were used to identify all women (with and without PGD) who gave birth in an Ontario, Canada, hospital from 1996 to 2001. Data on maternal complications and interventions were obtained from hospital discharge records; data on use of prenatal services were obtained from fee-for-service claims.

The evaluation of a formalized queue management system for coronary angiography waiting lists.

Background: Lengthy waiting lists for coronary angiography have been described in many health care systems worldwide. The extent to which formal queue management systems may improve the prioritization and survival of patients in the angiography queue is unknown.

Objective: To prospectively evaluate the performance of a formal queue management system for patients awaiting coronary angiography in Ontario.

Atypical antipsychotics and parkinsonism.

Background: Atypical antipsychotic agents are thought to be less likely than older typical agents to produce parkinsonism. This has not been well documented. We compared the risk of development of incident parkinsonism among older adults dispensed atypical relative to typical antipsychotics.

Antipsychotic medications and drug-induced movement disorders other than parkinsonism: a population-based cohort study in older adults.

Objectives: To study the relationship between initiating therapy with an antipsychotic medication and a subsequent new diagnosis of a drug-induced movement disorder other than parkinsonism in older adults with dementia.

Design: Retrospective, population-based cohort study.

Setting: Ontario, Canada.

Readers guide to critical appraisal of cohort studies: 3. Analytical strategies to reduce confounding.

Analytical strategies can help deal with potential confounding but readers need to know which strategy is appropriate

Reader's guide to critical appraisal of cohort studies: 2. Assessing potential for confounding.

Although confounding is an important problem of cohort studies, its effects can be minimised to enable valid comparison

New thyroxine treatment in older adults beginning lithium therapy: implications for clinical practice.

Objective: The authors sought to determine the incidence of lithium-induced hypothyroidism in a population-based cohort of older adults beginning lithium therapy and thereby to inform clinical guidelines on the frequency of monitoring necessary in this group.

Methods: The authors conducted a population-based observational cohort study using four administrative databases that contained information on over 1.3 million older adults in Ontario who receive universal healthcare coverage in terms of physician services, drugs, and hospitalizations.

Reader's guide to critical appraisal of cohort studies: 1. Role and design.

Cohort studies can provide valuable information unavailable from randomised trials, but readers need to be alert to possible flaws

Incidence of delirium in older adults newly prescribed lithium or valproate: a population-based cohort study.

Background: The use of lithium carbonate for the treatment of mood disorders in old age has decreased at a dramatic rate in favor of valproate. Because of lithium's narrow therapeutic range, neurotoxicity can be an important complication in lithium therapy and potentially influence prescription patterns. Therefore, we compared the incidence of delirium in older adults with mood disorders who were newly dispensed either lithium or valproate.

Atypical antipsychotic drugs and risk of ischaemic stroke: population based retrospective cohort study.

Objective: To compare the incidence of admissions to hospital for stroke among older adults with dementia receiving atypical or typical antipsychotics.

Design: Population based retrospective cohort study.

Setting: Ontario, Canada.

Statin use and survival outcomes in elderly patients with heart failure.

Background: Coronary artery disease is a leading cause of heart failure. Statins are efficacious drugs for the primary and secondary prevention of coronary heart disease, but their value in persons with heart failure remains unknown.

Methods: We performed a population-based retrospective cohort study involving the entire province of Ontario, Canada, restricting participants to those aged 66 to 85 years who were free of cancer and who survived at least 90 days following hospitalization for newly diagnosed heart failure.

Representation of patients with dementia in clinical trials of donepezil.

Objectives: To evaluate the representation of frail older adults in randomized controlled trials (RCTs), and to assess consequences of under representation by analyzing drug discontinuation rates.

Methods: A cohort of older adults newly dispensed donepezil in Ontario between September 2001 and March 2002 was constructed using administrative data. A systematic review of the literature identified RCTs of donepezil.

Potentially inappropriate prescribing in Canada relative to the US.

Objective: To explore the prescribing of potentially inappropriate drug therapy in Ontario, Canada where there is a restrictive drug formulary relative to the US where there is no single drug formulary.

Methods: A retrospective, cohort study using an administrative database (Ontario, Canada) compared with published survey results (US). All 1,088,680 community-dwelling adults >or=66 years of age in Ontario, Canada compared with published survey results from 2455 community-dwelling older adults in the US in 1996.

Use of angiotensin-converting enzyme inhibitor therapy and dose-related outcomes in older adults with new heart failure in the community.

Objective: To evaluate the dose-related benefit of angiotensin-converting enzyme (ACE) inhibitor therapy among older adults with heart failure and to evaluate whether low-dose ACE inhibitor therapy is better than none.

Design: Observational cohort study.

Setting: Community-dwelling older adults in Ontario, Canada.

Potentially inappropriate prescribing in Ontario community-dwelling older adults and nursing home residents.

Objectives: To compare patterns of potentially inappropriate drug therapy prescribing in community-dwelling older adults and nursing home residents in Ontario, Canada.

Design: A retrospective cohort study using administrative databases.

Setting: Ontario community and nursing home facilities.