Use of clarithromycin and adverse cardiovascular events among older patients receiving donepezil: a population-based, nested case-control study

BACKGROUND

Donepezil is a commonly used drug in older people that due to its procholinergic effects can provoke bradycardia and neurocardiogenic syncope. Donepezil is metabolized by the cytochrome P450 isozyme 3A4 (CYP3A4). Clarithromycin is a potent inhibitor of CYP3A4, and patients taking both of these drugs may be at increased risk of cardiac adverse events.

OBJECTIVE

The aim of this study was to evaluate the association between recent use of clarithromycin and adverse cardiovascular events in elderly patients receiving donepezil.

METHODS

A population-based, nested case-control study using provincial healthcare databases was conducted. The base cohort was made up of persons 66 years of age or older who were prescribed donepezil and also were prescribed clarithromycin, erythromycin, azithromycin, cefuroxime, moxifloxacin or levofloxacin. Cases were those members of the base cohort hospitalized for bradycardia, syncope or complete atrioventricular block. For each case patient, five controls were matched according to age, sex and residence (community or long-term care).

RESULTS

Between July 2002 and March 2010, 17,712 patients continuously receiving donepezil were prescribed one of the antibacterials. In 1400 person-years of follow-up, 59 cases were identified. As compared with azithromycin, there was no statistically significant association between use of clarithromycin in donepezil users and subsequent adverse cardiovascular events (odds ratio 0.67; 95% CI 0.28, 1.63). There was no significant risk associated with exposure to either cefuroxime or respiratory quinolones.

CONCLUSIONS

The use of clarithromycin in elderly donepezil users did not significantly increase the risk of adverse cardiovascular outcomes. However, our study cannot rule out a possible small increase in risk. Although antibacterials can be beneficial, care should be taken in selecting antibacterials for use in older people receiving donepezil.

Comparing the cohort design and the nested case-control design in the presence of both time-invariant and time-dependent treatment and competing risks: bias and precision

Purpose

Observational studies using electronic administrative healthcare databases are often used to estimate the effects of treatments and exposures. Traditionally, a cohort design has been used to estimate these effects, but increasingly, studies are using a nested case–control (NCC) design. The relative statistical efficiency of these two designs has not been examined in detail.

Methods

We used Monte Carlo simulations to compare these two designs in terms of the bias and precision of effect estimates. We examined three different settings: (A) treatment occurred at baseline, and there was a single outcome of interest; (B) treatment was time varying, and there was a single outcome; and C treatment occurred at baseline, and there was a secondary event that competed with the primary event of interest. Comparisons were made of percentage bias, length of 95% confidence interval, and mean squared error (MSE) as a combined measure of bias and precision.

Results

In Setting A, bias was similar between designs, but the cohort design was more precise and had a lower MSE in all scenarios. In Settings B and C, the cohort design was more precise and had a lower MSE in all scenarios. In both Settings B and C, the NCC design tended to result in estimates with greater bias compared with the cohort design.

Conclusions

We conclude that in a range of settings and scenarios, the cohort design is superior in terms of precision and MSE. Copyright © 2012 John Wiley & Sons, Ltd.

Altered response to neuroendocrine challenge linked to indices of the metabolic syndrome in healthy adults

Metabolic syndrome (MetS) is characterized by central obesity, hypertension, insulin resistance, and hypercholesterolemia. Hypothalamic-pituitary-adrenal (HPA) axis activity is frequently abnormal in MetS, and excessive cortisol exposure may be implicated in metabolic derangements. We investigated the hypothesis that cortisol and adrenocorticotropic hormone (ACTH) responses to a standardized neuroendocrine challenge test would be associated with indices of MetS in a community sample of healthy adults. Healthy adults, 125 men and 170 women, without significant medical problems or chronic medications were recruited from the community. Participants completed the dexamethasone/corticotropin-releasing hormone (Dex/CRH) test, and anthropometric measurements, blood pressure, glycosylated hemoglobin (HbA1c), and cholesterol were measured. Participants reported on their history of early life stress and recent stress, as well as mood and anxiety symptoms. Cortisol and ACTH responses to the Dex/CRH test were negatively associated with measures of central adiposity (p<0.001) and blood pressure (p<0.01), and positively associated with HDL cholesterol (p<0.01). These findings remained significant after controlling for body mass index (BMI). Measures of stress and anxiety and depressive symptoms were negatively correlated with cortisol and ACTH responses in the Dex/CRH test but were not related to MetS indices. That altered HPA axis function is linked to MetS components even in a healthy community sample suggests that these processes may be involved in the pathogenesis of MetS. Identification of premorbid risk processes might allow for detection and intervention prior to the development of disease.

Brain growth trajectories in mouse strains with central and peripheral serotonin differences: relevance to autism models

The genetic heterogeneity of autism spectrum disorders (ASDs) suggests that their underlying neurobiology involves dysfunction at the neural network level. Understanding these neural networks will require a major collaborative effort and will depend on validated and widely accepted animal models. Many mouse models have been proposed in autism research, but the assessment of their validity often has been limited to measuring social interactions. However, two other well-replicated findings have been reported in ASDs: transient brain overgrowth in early postnatal life and elevated 5-HT (serotonin) levels in blood platelets (platelet hyperserotonemia). We examined two inbred mouse strains (C57BL/6 and BALB/c) with respect to these phenomena. The BALB/c strain is less social and exhibits some other autistic-like behaviors. In addition, it has a lower 5-HT synthesis rate in the central nervous system due to a single-nucleotide polymorphism in the tryptophan hydroxylase 2 (Tph2) gene. The postnatal growth of brain mass was analyzed with mixed-effects models that included litter effects. The volume of the hippocampal complex and the thickness of the somatosensory cortex were measured in 3D-brain reconstructions from serial sections. The postnatal whole-blood 5-HT levels were assessed with high-performance liquid chromatography. With respect to the BALB/c strain, the C57BL/6 strain showed transient brain overgrowth and persistent blood hyperserotonemia. The hippocampal volume was permanently enlarged in the C57BL/6 strain, with no change in the adult brain mass. These results indicate that, in mice, autistic-like shifts in the brain and periphery may be associated with less autistic-like behaviors. Importantly, they suggest that consistency among behavioral, anatomical, and physiological measures may expedite the validation of new and previously proposed mouse models of autism, and that the construct validity of models should be demonstrated when these measures are inconsistent.

Prioritizing performance measurement for emergency department care: consensus on evidence-based quality of care indicators

BACKGROUND

The evaluation of emergency department (ED) quality of care is hampered by the absence of consensus on appropriate measures. We sought to develop a consensus on a prioritized and parsimonious set of evidence-based quality of care indicators for EDs.

METHODS

The process was led by a nationally representative steering committee and expert panel (representatives from hospital administration, emergency medicine, health information, government, and provincial quality councils). A comprehensive review of the scientific literature was conducted to identify candidate indicators. The expert panel reviewed candidate indicators in a modified Delphi panel process using electronic surveys; final decisions on inclusion of indicators were made by the steering committee in a guided nominal group process with facilitated discussion. Indicators in the final set were ranked based on their priority for measurement. A gap analysis identified areas where future indicator development is needed. A feasibility study of measuring the final set of indicators using current Canadian administrative databases was conducted.

RESULTS

A total of 170 candidate indicators were generated from the literature; these were assessed based on scientific soundness and their relevance or importance. Using predefined scoring criteria in two rounds of surveys, indicators were coded as "retained" (53), "discarded" (78), or "borderline" (39). A final set of 48 retained indicators was selected and grouped in nine categories (patient satisfaction, ED operations, patient safety, pain management, pediatrics, cardiac conditions, respiratory conditions, stroke, and sepsis or infection). Gap analysis suggested the need for new indicators in patient satisfaction, a healthy workplace, mental health and addiction, elder care, and community-hospital integration. Feasibility analysis found that 13 of 48 indicators (27%) can be measured using existing national administrative databases.

DISCUSSION

A broadly representative modified Delphi panel process resulted in a consensus on a set of 48 evidence-based quality of care indicators for EDs. Future work is required to generate technical definitions to enable the uptake of these indicators to support benchmarking, quality improvement, and accountability efforts.

The sensitivity of adverse event cost estimates to diagnostic coding error

OBJECTIVE

To examine the impact of diagnostic coding error on estimates of hospital costs attributable to adverse events.

DATA SOURCES

Original and reabstracted medical records of 9,670 complex medical and surgical admissions at 11 hospital corporations in Ontario from 2002 to 2004. Patient specific costs, not including physician payments, were retrieved from the Ontario Case Costing Initiative database.

STUDY DESIGN

Adverse events were identified among the original and reabstracted records using ICD10-CA (Canadian adaptation of ICD10) codes flagged as postadmission complications. Propensity score matching and multivariate regression analysis were used to estimate the cost of the adverse events and to determine the sensitivity of cost estimates to diagnostic coding error.

PRINCIPAL FINDINGS

Estimates of the cost of the adverse events ranged from $16,008 (metabolic derangement) to $30,176 (upper gastrointestinal bleeding). Coding errors caused the total cost attributable to the adverse events to be underestimated by 16 percent. The impact of coding error on adverse event cost estimates was highly variable at the organizational level.

CONCLUSIONS

Estimates of adverse event costs are highly sensitive to coding error. Adverse event costs may be significantly underestimated if the likelihood of error is ignored.

Exploring variation in rates of polypharmacy across long term care homes

OBJECTIVE

Use of multiple, concurrent drug therapies, often referred to as polypharmacy, is a concern in the long term care (LTC) setting, where frail older adults are particularly at risk for adverse events. We quantified the scope of this practice by exploring variation in the use of nine or more drug therapies across LTC homes.

DESIGN

Cross-sectional analysis of LTC home census data.

SETTING

All LTC homes in Ontario, Canada.

PARTICIPANTS

A total of 64,394 LTC residents aged 66 years and older residing in 589 LTC homes in the fall of 2005.

MEASUREMENTS

Facility-level rates of polypharmacy were compared with rates of use of Beers criteria and antipsychotic drug therapies. Multivariate logistic regression models were used to assess predictors of polypharmacy across residents and LTC homes.

RESULTS

Nine or more drug therapies were dispensed concurrently to 10,007 (15.5%) of LTC home residents. Compared with those dispensed fewer drugs, residents receiving 9 or more drug therapies were more likely to have multiple comorbidities. There was threefold variation in polypharmacy rates across homes (26.2% versus 7.9%) and facility-level rates of polypharmacy were modestly correlated with rates of use of Beers criteria drugs (r = 0.27, P < .001) and antipsychotic drug therapies (r = 0.16, P < .001). Controlling for resident factors, those living in LTC homes with high polypharmacy rates were more likely to receive 9 or more drug therapies (odds ratio 1.9, 95% confidence interval 1.7-2.0).

CONCLUSION

Residents in Ontario LTC homes commonly received nine or more concurrent drug therapies, particularly residents with multiple chronic conditions. The threefold variation in rate across homes suggests a role for this measure in guiding drug review at the facility level.

Inhaled anticholinergic drug therapy and the risk of acute urinary retention in chronic obstructive pulmonary disease: a population-based study

BACKGROUND

Inhaled anticholinergic medications (IACs) are widely used treatments for chronic obstructive pulmonary disease (COPD). The systemic anticholinergic effects of IAC therapy have not been extensively studied. This study sought to determine the risk of acute urinary retention (AUR) in seniors with COPD using IACs.

METHODS

A nested case-control study of individuals with COPD aged 66 years or older was conducted from April 1, 2003, to March 31, 2009, using population-based linked databases from Ontario, Canada. A hospitalization, same-day surgery, or emergency department visit for AUR identified cases, which were matched with up to 5 controls. Exposure to IACs was determined using a comprehensive drug benefits database. Conditional logistic regression analysis was conducted to determine the association between IAC use and AUR.

RESULTS

Of 565,073 individuals with COPD, 9432 men and 1806 women developed AUR. Men who just initiated a regimen of IACs were at increased risk for AUR compared with nonusers (adjusted odds ratio [OR], 1.42; 95% confidence interval [CI], 1.20-1.68). In men with evidence of benign prostatic hyperplasia, the risk was increased further (OR, 1.81; 95% CI, 1.46-2.24). Men using both short- and long-acting IACs had a significantly higher risk of AUR compared with monotherapy users (OR, 1.84; 95% CI, 1.25-2.71) or nonusers (2.69; 1.93-3.76).

CONCLUSIONS

Use of short- and long-acting IACs is associated with an increased risk of AUR in men with COPD. Men receiving concurrent treatment with both short- and long-acting IACs and those with evidence of benign prostatic hyperplasia are at highest risk.

Unplanned readmissions after hospital discharge among patients identified as being at high risk for readmission using a validated predictive algorithm

BACKGROUND

Unplanned hospital readmissions are common, expensive and often preventable. Strategies designed to reduce readmissions should target patients at high risk. The purpose of this study was to describe medical patients identified using a recently published and validated algorithm (the LACE index) as being at high risk for readmission and to examine their actual hospital readmission rates.

METHODS

We used population-based administrative data to identify adult medical patients discharged alive from 6 hospitals in Toronto, Canada, during 2007. A LACE index score of 10 or higher was used to identify patients at high risk for readmission. We described patient and hospitalization characteristics among both the high-risk and low-risk groups as well as the 30-day readmission rates.

RESULTS

Of 26 045 patients, 12.6% were readmitted to hospital within 30 days and 20.9% were readmitted within 90 days of discharge. High-risk patients (LACE ≥ 10) accounted for 34.0% of the sample but 51.7% of the patients who were readmitted within 30 days. High-risk patients were readmitted with twice the frequency as other patients, had longer lengths of stay and were more likely to die during the readmission.

INTERPRETATION

Using a LACE index score of 10, we identified patients with a high rate of readmission who may benefit from improved post-discharge care. Our findings suggest that the LACE index is a potentially useful tool for decision-makers interested in identifying appropriate patients for post-discharge interventions.

Transitions in long-term care and potential implications for quality reporting in Ontario, Canada

PURPOSE

To describe the proportion of long-term care (LTC) residents excluded from quality measurement because of standard length of stay inclusion criteria and the extent to which this varies across facilities.

DESIGN AND METHODS

A 2005 province-wide census of LTC residents' charts was linked to additional databases from Ontario, Canada. The proportion of residents who were newly admitted (≤90 days) and who exited the facility within 90 days were identified and interfacility variation in each was described.

RESULTS

Of the 68,930 residents in 574 facilities, 5363 (7.8%) were admitted in the prior 90 days and 7833 (11.4%) were discharged in the subsequent 90 days. Overall, 55,734 (80.4%) residents were neither admitted nor discharged within 90 days and were defined as "stable"; however, this ranged from 67.2% to 95.1% across facilities.

IMPLICATIONS

Stable residents are the focus of most quality measurement in LTC but transitioning residents are an important part of the caseload for these facilities. In Ontario, transitioning residents accounted for 20% of the population but there was substantial variation in this proportion across facilities. This raises concerns about the comprehensiveness and comparability of publicly reported quality indicators for a population with frequent transitions in Ontario and elsewhere.

Confounders and intermediaries in case-control study designs: a strategy for distinguishing between the two when measured using the same variable

PURPOSE

An intermediary falls within the exposure-outcome pathway and is distinct from a confounder. In case-control studies, it may be difficult to discern between the two when both are measured by the same variable. Using data from a study on the effects of antipsychotic initiation on risk of death among older adults, where hospital use is both a confounder and intermediary, we illustrate the bias introduced when this distinction is overlooked and propose a modified exposure classification strategy to mitigate this.

METHODS

We identified 5391 cases and 25,937 controls. Three analyses were completed: traditional analytic adjustment including hospital use (full), traditional analytic adjustment excluding hospital use (reduced) and exposure classification incorporating hospital use prior to antipsychotic initiation (extended).

RESULTS

The unadjusted odds ratio (OR) was 2.8 (95% confidence interval (CI) 2.1-3.8). Full and reduced analytic adjustment resulted in ORs of 0.8 (95% CI 0.6-1.2) and 1.4 (95% CI 1.0-1.9), respectively. The extended exposure classification strategy produced an OR of 1.4 (95% CI 0.9-2.1) among those without hospital use prior to antipsychotic initiation.

CONCLUSIONS

Full analytic adjustment resulted in a biased estimate of effect. The extended exposure analysis differentiated between hospital use that occurred prior (confounder) and subsequent (intermediary) to antipsychotic initiation. This strategy may overcome the limitations of analytic adjustment alone.

Both p110alpha and p110beta isoforms of phosphatidylinositol 3-OH-kinase are required for insulin signalling in the hypothalamus

Both insulin and leptin action in the brain are considered to involve activation of phosphoinositide 3-kinase (PI3K), although the roles of different PI3K isoforms in insulin signalling in the hypothalamus are unknown. In the present study, we characterised the roles of these isoforms in hypothalamic insulin and leptin signalling and investigated the cross-talk of both hormones. To evaluate PI3K levels in the hypothalamus, PI3K was immunoprecipitated using an antibody directed against the p85 subunit, and then total PI3K activity was measured in the presence of novel isoform-selective pharmacological inhibitors of each isoform of PI3K. Subsequently, these inhibitors were administered into the lateral ventricle of male Sprague-Dawley rats, followed by vehicle, insulin, leptin or both hormones 45 min later. PI3K activity was determined by immunohistochemical detection of phosphorylated AKT (S473). In a separate study, the effects of the inhibitors on the anorexigenic action of insulin and leptin were determined. Hypothalamic insulin signalling was specifically mediated by the combined actions of the class Ia isoforms p110alpha and p110beta. Total hypothalamic PI3K activity was inhibited 65% by a p110alpha inhibitor, and 35% by a p110beta inhibitor, with a combination of inhibitors being equally effective as the broad-spectrum PI3K inhibitor wortmannin. Individual i.c.v. administration of p110alpha and p110beta inhibitors partly prevented insulin-induced phosphorylated AKT (S473) in the arcuate nucleus, whereas simultaneous application completely blocked insulin action. Unlike insulin, leptin did not induce phosphorylated AKT in the hypothalamus, as detected by immunohistochemistry, and the anorectic effects of leptin were not affected by pre-treatment with a combination of p110alpha and p110beta inhibitors. The enhanced anorectic effect of a combined i.c.v. application of both insulin and leptin could be prevented by pre-treatment with the combination of p110alpha and p110beta inhibitors. The data suggest that p110alpha and p110beta isoforms of PI3K are necessary to mediate insulin action in the hypothalamus. The role of PI3K in leptin action is less clear, but it may be involved by means of an insulin-dependent sensitisation of leptin action.

Developmental and steroidogenic effects on the gene expression of RFamide related peptides and their receptor in the rat brain and pituitary gland

RFamide related peptides (RFRPs) have been extensively implicated in the neuroendocrine control of reproduction. While steroid hormones strongly regulate the closely-related kisspeptin gene and protein expression, the regulation of RFRPs or their receptor by steroid hormones is almost unknown. The present study aimed to quantify relative levels of RFRP and Kiss1 gene expression and their G protein-coupled receptors (GPR147 and GPR54, respectively) in various brain areas and the pituitary gland, and to determine the effects of differing levels of oestradiol and pubertal development on levels of these gene products. In Experiment 1, the treatment groups examined were: dioestrus, ovariectomised and ovariectomised with replacement oestradiol to induce a preovulatory-like luteinising hormone surge. Micropunched brain regions and whole pituitary glands were processed for measurement of RFRP, Kiss1, GPR147 and GPR54 mRNA by quantitative reverse transcriptase-polymerase chain reaction. As expected, Kiss1 gene expression was low in the rostral periventricular area of the third ventricle of ovariectomised animals, whereas levels were highest in the arcuate nucleus in this situation. No such oestrogenic effects were observed for RFRP gene expression. GPR147 gene expression was highest in the rostral periventricular region of the third ventricle. The levels of GPR147 and GPR54 mRNA were markedly lower in the pituitary gland than in the hypothalamic regions, and RFRP and Kiss1 mRNA were virtually undetectable in the pituitary gland. These data imply that the actions of RFamides are likely to be predominantly central in nature. In Experiment 2, hypothalamic RFRP and GPR147 mRNA levels were measured in male and female rats aged 2, 4, 6 and 8 weeks. In females, RFRP gene expression increased with developmental age, peaking around the time of puberty, whereas in males gene expression increased between 2 and 4 weeks of age. These results suggest a role in the regulation of adult reproduction rather that prepubertal infertility.

Current prescription patterns and safety profile of irreversible monoamine oxidase inhibitors: a population-based cohort study of older adults

OBJECTIVE

To determine the prescription pattern and safety profile for irreversible monoamine oxidase inhibitors (MAOIs) in older adults over the past decade.

METHOD

A population-based observational cohort study of older adults was conducted from January 1, 1997, to April 14, 2007, utilizing large administrative health care databases in Ontario, Canada. We examined the prevalence and incidence of irreversible MAOI use, as well as the frequency of coprescribing of MAOIs with contraindicated medications such as serotonergic and sympathomimetic drugs. We reviewed the most responsible diagnosis of emergency department (ED) visits and acute care admissions to assess for serious adverse events that may occur during MAOI treatment (ie, serotonin syndrome and hypertensive crisis).

RESULTS

Over a 10-year period, there were 348 new users of irreversible MAOIs. The majority of patients showed a previous treatment pattern consistent with recurrent major depressive disorder, including prior use of antidepressant treatment and electroconvulsive therapy. The yearly incidence of MAOI prescriptions remained low and decreased from a rate of 3.1/100,000 to 1.4/100,000. Concomitant exposure to at least 1 serotonergic drug occurred in 18.1% of patients treated with an MAOI. No ED visits or acute care admissions for serotonin syndrome or hypertensive crisis were identified.

CONCLUSIONS

The low prescription rate of MAOIs is not consistent with the continued recommendation of MAOIs by expert opinion leaders and consensus guidelines for use in atypical depression and treatment-refractory depression. While their use appeared safe, heightened awareness of the potential risk of concomitant use of serotonergic agents is necessary. Relative underuse of the MAOIs for a significant subgroup of depressed patients with atypical and treatment-refractory depression remains a concern.

Characterization of cerebrospinal fluid monoamine metabolites in peripubertal chimpanzees (Pan troglodytes)

BACKGROUND

Assessment of cerebrospinal (CSF) monoamine metabolites 5-hydroxyindoeacetic acid (5-HIAA) and homovanillic acid (HVA), and the serotonin precursor tryptophan (TRP), in chimpanzees may help in understanding the neurobiology underlying aggressive, impulsive behavior in humans and non-human primates.

METHODS

Two CSF samples were obtained from 11 peripubertal chimpanzees 8 months apart and were assayed for monoamine metabolite and TRP concentrations.

RESULTS

Substantial inter-individual stability was observed for 5-HIAA (n = 11; r = 0.83, P < 0.001) and HVA (r = 0.91, P < 0.001). Females had significantly higher concentrations of 5-HIAA compared to males (F(1,8) = 7.31; P < 0.05). Levels of 5-HIAA (r = -0.62, P < 0.05), HVA (r = -0.86, P < 0.001) and TRP levels (r = -0.67; P < 0.05) decreased with age.

CONCLUSION

Close parallels were observed between chimpanzees and humans with respect to absolute levels, sex effects, ontogeny, and 5-HIAA-HVA correlations, supporting the potential utility of the measures in understanding relationships between monoamine functioning and behavior in chimpanzees and humans.

Association between tamsulosin and serious ophthalmic adverse events in older men following cataract surgery

CONTEXT

Both benign prostatic hyperplasia (BPH) and cataract formation are common in older men. The alpha-adrenergic receptor blocker tamsulosin is frequently prescribed to treat BPH, and research suggests this drug may increase the intraoperative difficulty of cataract surgery. No studies have documented whether use of tamsulosin or other alpha-blocker drug therapies affect the risk of serious postoperative adverse events.

OBJECTIVE

To assess the risk of adverse events following cataract surgery in older men prescribed tamsulosin or other alpha-blocking drugs used to treat BPH.

DESIGN, SETTING, AND PATIENTS

Nested case-control analysis of a population-based retrospective cohort study using linked health care databases from Ontario, Canada. We included all men aged 66 years or older who had cataract surgery between 2002 and 2007 (N = 96 128).

MAIN OUTCOME MEASURES

A composite of procedures signifying retinal detachment, lost lens or lens fragment, or endophthalmitis occurring within 14 days after cataract surgery. The risk of these adverse events was compared between men treated with tamsulosin or other alpha-blockers and men with no exposure to these medications in the year prior to cataract surgery. We separately examined the association of drug exposure that was either recent (within the 14 days before surgery) or previous (15-365 days before surgery).

RESULTS

Overall, 3550 patients (3.7%) in the cohort had recent exposure to tamsulosin and 7426 patients (7.7%) had recent exposure to other alpha-blockers. Two hundred eighty-four patients (0.3%) had an adverse event. We randomly matched 280 of the cases to 1102 controls according to their age, surgeon, and year of surgery. Adverse events were significantly more common among patients with recent tamsulosin exposure (7.5% vs 2.7%; adjusted odds ratio [OR], 2.33; 95% confidence interval [CI], 1.22-4.43) but were not associated with recent exposure to other alpha-blockers (7.5% vs 8.0%; adjusted OR, 0.91; 95% CI, 0.54-1.54) or to previous exposure to either tamsulosin (< or = 1.8% vs 1%; adjusted OR, 0.94; 95% CI, 0.27-3.34) or other alpha-blockers (2.9% vs 2.1%; adjusted OR, 1.08; 95% CI, 0.47-2.48). This corresponds to an estimated number needed to harm (NNH) of 255 (95% CI, 99-1666).

CONCLUSIONS

Exposure to tamsulosin within 14 days of cataract surgery was significantly associated with serious postoperative ophthalmic adverse events. There were no significant associations with exposure to other alpha-blocker medications used to treat BPH.

Effect of regulatory warnings on antipsychotic prescription rates among elderly patients with dementia: a population-based time-series analysis

BACKGROUND

Three warnings of serious adverse events associated with the use of atypical antipsychotic drugs among elderly patients with dementia were sent to health care professionals in Canada. We assessed the impact of these warnings on prescription rates of antipsychotic drugs in this patient population.

METHODS

We used prescription drug claims data from Ontario to calculate prescription rates of atypical and conventional antipsychotic drugs among elderly patients with dementia from May 1, 2000, to Feb. 28, 2007. We performed a time-series analysis to estimate the effect of each warning on rates of antipsychotic drug use.

RESULTS

Before the first warning, growth in the use of atypical antipsychotics was responsible for an increasing rate of overall antipsychotic use. Each warning was associated with a small relative decrease in the predicted growth in the use of atypical antipsychotic drugs: a 5.0% decrease after the first warning, 4.9% after the second and 3.2% after the third (each p < 0.05). The overall prescription rate of antipsychotic drugs among patients with dementia increased by 20%, from 1512 per 100 000 elderly patients in September 2002, the month before the first warning, to 1813 per 100 000 in February 2007, 20 months after the last warning.

INTERPRETATION

Although the warnings slowed the growth in the use of atypical antipsychotic drugs among patients with dementia, they did not reduce the overall prescription rate of these potentially dangerous drugs. More effective interventions are necessary to improve postmarket drug safety in vulnerable populations.

Published randomized controlled trials of drug therapy for dementia often lack complete data on harm

OBJECTIVE

The objective of the study was to determine the extent to which published randomized controlled trials (RCTs) report data on harm.

STUDY DESIGN AND SETTING

A systematic search strategy was used to identify RCTs published between 1996 and 2005 on the use of cholinesterase inhibitors or atypical antipsychotics in patients with dementia. A structured abstraction form was used to determine if data on mortality or serious adverse events were reported and if the articles followed Consolidated Standards of Reporting Trials format for reporting harm.

RESULTS

Thirty-three RCTs were identified (27 on cholinesterase inhibitors and 6 on atypical antipsychotics). Nineteen trials (58%) had explicit data on mortality and only four (12%) reported regulatory-agency-defined serious adverse events. Most abstracts (31, 94%) stated that harm was studied but few studies (9, 27%) provided a clear definition of the measures of harm.

CONCLUSIONS

Although most published RCTs state that they examine harm, many failed to provide data on mortality and most lacked clear definitions or detailed analyses of harm. Better reporting of harm would provide timely and important information that could help physicians and the public to make more informed decisions.

Relationship Between Preventability of Death After Coronary Artery Bypass Graft Surgery and All-Cause Risk-Adjusted Mortality Rates

Background— The goal of this study was to determine the relationship between all-cause, risk-adjusted, in-hospital mortality after coronary artery bypass graft surgery and the proportion of preventable in-hospital deaths as a measure of quality of care at an institution level.

Methods and Results— We conducted a retrospective analysis of 347 randomly selected in-hospital deaths after isolated coronary artery bypass graft surgery at 9 institutions in Ontario over the period of 1998 to 2003. Nurse-abstracted chart summaries were reviewed by 2 experienced cardiac surgeons who were blinded to patient, surgeon, and hospital and used a standardized implicit tool to identify preventable death. A third reviewer reassessed all cases in which the first 2 reviewers disagreed. Rates of preventable deaths were estimated for each hospital and compared with all-cause mortality rates. A structured adverse event audit completed by each surgeon-reviewer was used to identify quality improvement opportunities for the preventable deaths. A total of 111 of 347 deaths (32%) were judged preventable despite a low risk-adjusted mortality range (1.3% to 3.1%) across hospitals. No significant correlation was found between all-cause, risk-adjusted in-hospital mortality rates and the proportion of preventable deaths at the hospital level (Spearman coefficient, −0.42; P =0.26). A large proportion of preventable deaths were related to problems in the operating room (86%) and intensive care unit (61%). Many deaths were associated with deviations in perioperative care (32% based on concurrence of 2 reviewers, and another 42% in cases in which 1 reviewer reached that opinion).

Conclusions— Approximately one third of in-hospital coronary artery bypass graft deaths were judged preventable by surgeon reviewers. All-cause risk-adjusted mortality rates are convenient measures of institutional quality of care but were not correlated with preventable mortality in our jurisdiction. Providers should conduct detailed adverse event audits to drive meaningful improvements in quality.

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.

METHODS

In this population-based, retrospective cohort study, we identified 20 682 matched older adults with dementia living in the community and 20 559 matched individuals living in a nursing home between April 1, 1997, and March 31, 2004. Propensity-based matching was used to balance differences between the drug exposure groups in each setting. To examine the effects of antipsychotic drug use on the composite outcome of any serious event we used a conditional logistic regression model. We also estimated adjusted odds ratios using models that included all covariates with a standard difference greater than 0.10.

RESULTS

Relative to those who received no antipsychotic therapy, community-dwelling older adults newly dispensed an atypical antipsychotic therapy were 3.2 times more likely (95% confidence interval, 2.77-3.68) and those who received conventional antipsychotic therapy were 3.8 times more likely (95% confidence interval, 3.31-4.39) to develop any serious event during the 30 days of follow-up. The pattern of serious events was similar but less pronounced among older adults living in a nursing home.

CONCLUSIONS

Serious events, as indicated by a hospital admission or death, are frequent following the short-term use of antipsychotic drugs in older adults with dementia. Antipsychotic drugs should be used with caution even when short-term therapy is being prescribed.