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Biomedical subjects

C David Naylor

Publications and source records attributed to C David Naylor.

At least 19 recordsLinked to original sources
PubMed2004

Age, risk-benefit trade-offs, and the projected effects of evidence-based therapies.

BACKGROUND: Physicians underutilize evidence-based therapies in the elderly, perhaps because of concerns about the generalizability of clinical trial results in elderly patients given that the relative efficacy of therapies may vary with age. We compared the estimated effects of age and efficacy of treatment on survival among patients with acute coronary syndromes. METHODS: Baseline risk, defined as mortality in the year after hospitalization for acute coronary syndromes, was determined for different age strata among 81,584 patients who had been discharged between April 1, 1997, and March 31, 2000, in Ontario, Canada. We calculated the relative efficacy (relative risk reduction) needed to achieve a clinically meaningful absolute survival benefit, using a number needed to treat of 50 patients for the different age strata. We also evaluated risk-benefit trade-offs in the elderly versus the young by modeling different levels of the relative efficacy and rates of fatal complication by age. RESULTS: Baseline risk (1-year all-cause mortality) was 12-fold lower in the youngest patients (age <50 years) than in oldest patients (age > or = 75 years). Given this gradient, a therapy would have to have a relative efficacy of 88% (i.e., a relative risk of 0.12) in the youngest age group, and 7% (a relative risk of 0.93) in the oldest age group, to generate a number needed to treat 50 patients. For a therapy whose relative efficacy was 25%, the fatal complication rate would have to be sevenfold greater in the oldest compared with the youngest age group to outweigh the survival benefits associated with treatment. CONCLUSION: For acute coronary syndromes, baseline mortality is so much higher for elderly patients that neither sharp reductions in the relative efficacy of therapies nor increases in the rates of serious complications are likely to negate the benefits of therapy. More attention should be paid to overall trial results and less to age-specific subgroup data, unless the latter provide very clear evidence for substantial reductions in absolute efficacy or net harm.

Aged↗
PubMed2004

Socioeconomic status, service patterns, and perceptions of care among survivors of acute myocardial infarction in Canada.

CONTEXT: Some have argued that Canada's uniquely restrictive approach to private health insurance keeps the socioeconomic elite inside the public system so that their demands and influence elevate the standard of service for all Canadian citizens. The extent to which this theory is a valid representation of Canadian health care is unknown. OBJECTIVES: To explore how patients with acute myocardial infarction from different socioeconomic backgrounds perceive their care in Canada's universal health care system and to correlate patients' backgrounds and perceptions with actual care received. DESIGN, SETTING, AND PATIENTS: Prospective observational cohort study with follow-up telephone interviews of 2256 patients 30 days following acute myocardial infarction discharged from 53 hospitals across Ontario, Canada, between December 1999 and June 2002. MAIN OUTCOME MEASURES: Postdischarge use of cardiac specialty services; satisfaction with care; willingness to pay directly for faster service or more choice; and mortality according to income and education, adjusted for age, sex, ethnicity, clinical factors, onsite angiography capacity at the admitting hospital, and rural-urban residence. RESULTS: Compared with patients in lower socioeconomic strata, more affluent or better educated patients were more likely to undergo coronary angiography (67.8% vs 52.8%; P<.001), receive cardiac rehabilitation (43.9% vs 25.6%; P<.001), or be followed up by a cardiologist (56.7% vs 47.8%; P<.001). Socioeconomic differences in cardiac care persisted after adjustment for confounders. Despite receiving more specialized services, patients with higher socioeconomic status were more likely to be dissatisfied with their access to specialty care (adjusted RR, 2.02; 95% confidence interval, 1.20-3.32) and to favor out-of-pocket payments for quicker access to a wider selection of treatment options (30% vs 15% for patients with household incomes of Can 60 000 dollars or higher vs less than Can 30 000 dollars, respectively; P<.001). After adjusting for baseline characteristics, socioeconomic status was not significantly associated with mortality at 1 year following hospitalization for myocardial infarction. CONCLUSIONS: Compared with those with lower incomes or less education, upper middle-class Canadians gain preferential access to services within the publicly funded health care system yet remain more likely to favor supplemental coverage or direct purchase of services.

Adult↗
PubMed2004

Parkinsonism in Ontario: comorbidity associated with hospitalization in a large cohort.

To study comorbidity in patients with Parkinsonism (PKM), relative hospitalization rates from 1994 to 1999 for 15,304 cases were compared with 30,608 controls. After correction for differential survival, the rates were higher for cases compared to controls for aspiration pneumonia (6.34; 95% confidence interval [CI], 5.23, 7.93), affective psychosis (2.71; 95% CI, 2.13, 3.32), hip fractures (2.56; 95% CI, 2.35, 2.76), other urinary tract disorders including infections (2.5; 95% CI, 2.17, 2.86), septicemia (2.39; 95% CI, 2.02, 2.85) and fluid and electrolyte disorders (2.27; 95% CI, 1.93,2.66). The rates for cardiac, cerebrovascular, and peripheral vascular disease were similar. Preventive measures and aggressive management of these conditions as outpatients may reduce the rates of hospitalization and improve the morbidity and mortality of PKM.

Adult↗
PubMed2003

Waiting times, revascularization modality, and outcomes after acute myocardial infarction at hospitals with and without on-site revascularization facilities in Canada.

OBJECTIVES: This study was designed to determine whether admission to a Canadian hospital with on-site revascularization (invasive hospital) affected revascularization choice, timing, and outcome compared with community (non-invasive) hospitals. BACKGROUND: Health care systems in Canada are characterized by relative restraint in diffusion of tertiary cardiovascular services, with capacity for revascularization procedures concentrated in large regional referral centers. METHODS: We used linked administrative data and a clinical registry to follow-up 15,166 Ontario patients who underwent revascularization within the year after their index acute myocardial infarction (MI). Outcomes included recurrent urgent cardiac hospitalization, hospital bed-days, and death within the same year after the index admission. We adjusted for age, gender, socioeconomic status, illness severity, attending physician specialty, and academic hospital affiliation. RESULTS: After adjusting for baseline factors, patients admitted to invasive hospitals were more likely to receive angioplasty than bypass surgery (adjusted odd ratio: 1.85; 95% confidence interval: 1.68 to 2.04, p < 0.001). The converse pattern was seen for patients admitted to community hospitals. Median revascularization waiting times were significantly shorter at invasive hospitals (12 vs. 48 days, p < 0.001). Patients admitted to invasive hospitals had fewer cardiac re-admissions (41.5 vs. 68.9 events per 100 patients, p < 0.001) before their first revascularization and consumed fewer hospital bed-days (379 vs. 517 per 100 patients, p < 0.001). There were no differences in outcomes beyond revascularization. CONCLUSIONS: Outcome advantages associated with timely post-MI revascularization highlight the importance of organizing revascularization referral networks and facilitating access to revascularization for patients with acute coronary syndromes admitted to community hospitals in Canada.

Canada↗
PubMed2003

Geography and service supply do not explain socioeconomic gradients in angiography use after acute myocardial infarction.

BACKGROUND: Socioeconomic status appears to be an important predictor of coronary angiography use after acute myocardial infarction. One potential explanation for this is that patients with lower socioeconomic status live in neighbourhoods near nonteaching hospitals that have no catheterization capacity, few specialists and lower volumes of patients with acute myocardial infarction. This study was conducted to determine whether the impact of socioeconomic status on angiography use would be lessened by considering variations in the supply of services. METHODS: We examined payment claims for physician services, hospital discharge abstracts and vital status data for 47 036 patients with acute myocardial infarction admitted to hospitals in Ontario between April 1994 and March 1997. Neighbourhood income of each patient was obtained from Canada's 1996 census. Using multivariate hierarchical logistic regression and adjusting for baseline patient and physician factors, we examined the interaction among hospital and regional characteristics, socioeconomic status and angiography use in the first 90 days after admission to hospital for acute myocardial infarction. RESULTS: Within each hospital and geographic subgroup, crude rates of angiography rose progressively with increases in neighbourhood income. After adjusting for sociodemographic, clinical and physician characteristics, hospitals with on-site angiography capacity (adjusted odds ratio [OR] 1.88, 95% confidence interval [CI] 1.52-2.33), those with university affiliations (adjusted OR 1.60, 95% CI 1.27-2.01) and those closest to tertiary institutions (adjusted OR 1.57, 95% CI 1.32-1.87) were all associated with higher 90-day angiography use after acute myocardial infarction. However, the relative impact of socioeconomic status on 90-day angiography use was similar whether or not hospitals had on-site procedural capacity (interaction term p = 0.68), had university affiliations (interaction term p = 0.99), were near tertiary facilities (interaction term p = 0.67) or were in rural or urban regions (interaction term p = 0.90). INTERPRETATION: Socioeconomic status was as important a predictor of angiography use in hospitals with ready access to cardiac catheterization facilities as it was in those without. The socioeconomic gradient in the use of angiography after acute myocardial infarction cannot be explained by the distribution of specialists or tertiary hospitals.

Cardiac Care Facilities↗
PubMed2003

Burden of parkinsonism: a population-based study.

Parkinson's disease (PD) is associated with a significant burden of illness and cost to society, which has been difficult to quantify. Our objective was to use linked administrative databases from the population of Ontario, Canada, to assess the prevalence of parkinsonism, physician- and drug-related costs, and hospital utilization for parkinsonian patients compared with age/sex matched controls. An inception cohort of parkinsonian cases from 1993/1994 was age and sex matched (1:2) to controls and followed for 6 years. Patients were identified by the diagnostic code for PD, the use of specific PD drugs, or a combination. The parkinsonian case cohort (15,304) was matched to (30,608) controls that did not have parkinsonism. The age-adjusted prevalence rates were 3.63 for men and for 3.24 women per 1,000 (increased by 5.4% for men and 9.8% for women). Physician costs were 1.4 times more, there were 1.44 times more hospital admissions, admissions were on average 1.19 times longer, and drug costs were 3.0 times more for parkinsonian cases. We conclude that the substantially higher physician and drug costs as well as hospitalization rates compared with controls clearly suggest that parkinsonism is associated with large direct costs to society.

Adult↗
PubMed2002

Accelerated publication versus usual publication in 2 leading medical journals.

BACKGROUND: A number of medical journals have developed policies for accelerated publication of articles judged by the authors, the editors or the peer reviewers to be of special importance. However, the validity of these judgements is unknown. We therefore compared the importance of articles published on a "fast track" with those published in the usual way. METHODS: We identified 12 "case" articles--6 articles from the New England Journal of Medicine that were prereleased on the journal's Web site before publication in print and 6 "fast-tracked" articles from The Lancet. We then identified 12 "control" articles matched to the case articles according to journal, disease or procedure of focus, theme area and year of publication. Forty-two general internists rated the articles, using 10-point scales, on dimensions addressing the articles' importance, ease of applicability and impact on health outcomes. RESULTS: For each dimension, the mean score for the case articles was significantly higher than the mean score for the control articles: importance to clinical practice 7.6 v. 7.1 respectively (p = 0.001), importance from a public health perspective 6.5 v. 6.0 (p < 0.001), contribution to advancement of medical knowledge 6.2 v. 5.8 (p < 0.001), ease of applicability in practice 7.0 v. 6.5 (p < 0.001), potential impact on health outcomes 6.5 v. 5.9 (p < 0.001). Despite these general findings, in 5 of the 12 matched pairs of articles the control article had a higher mean score than the case article across all the dimensions. INTERPRETATION: The accelerated publication practices of 2 leading medical journals targeted articles that, on average, had slightly higher importance scores than similar articles published in the usual way. However, our finding of higher importance scores for control articles in 5 of the 12 matched pairs shows that current journal practices for selecting articles for expedited publication are inconsistent.

Diffusion of Innovation↗
PubMed2002

Using disease risk estimates to guide risk factor interventions: field test of a patient workbook for self-assessing coronary risk.

OBJECTIVE: To assess the feasibility and acceptability of a patient workbook for self-assessing coronary risk. DESIGN: Pilot study, with post-study physician and patient interviews. SETTING AND SUBJECTS: Twenty southern Ontario family doctors and 40 patients for whom they would have used the workbook under normal practice conditions. INTERVENTIONS: The study involved convening two sequential groups of family physicians: the first (n=10) attended focus group meetings to help develop the workbook (using algorithms from the Framingham Heart Study); the second (n=20) used the workbook in practice with 40 patients. Follow-up interviews were by interviewer-administered questionnaire. MAIN OUTCOMES MEASURES: Physicians' and patients' opinions of the workbook's format, content, helpfulness, feasibility, and potential for broad application, as well as patients' perceived 10-year risk of a coronary event measured before and after using the workbook. RESULTS: It took an average of 18 minutes of physician time to use the workbook: roughly 7 minutes to introduce it to patients, and about 11 minutes to discuss the results. Assessments of the workbook were generally favourable. Most patients were able to complete it on their own (78%), felt they had learned something (80%) and were willing to recommend it to someone else (98%). Similarly, 19 of 20 physicians found it helpful and would use it in practice with an average of 18% of their patients (range: 1-80%). The workbook helped to correct misperceptions patients had about their personal risk of a coronary event over the next 10 years (pre-workbook (mean (SD) %): 35.2 (16.9) vs. post-workbook: 17.3 (13.5), P < 0.0001; estimate according to algorithm: 10.6 (7.6)). CONCLUSIONS: Given a simple tool, patients can and will assess their own risk of CHD. Such tools could help inform otherwise healthy individuals that their risk is increased, allowing them to make more informed decisions about their behaviours and treatment.

Adult↗
PubMed2002

Development and prognosis of non-Q-wave myocardial infarction in the thrombolytic era.

BACKGROUND: Data on non-Q myocardial infarctions (MI) are derived primarily from prethrombolytic era studies. Previous trials demonstrated different development rates and none reported on clinical outcomes. METHODS: Our goal was to determine the incidence and prognosis of non-Q-wave MI among patients with ST-segment elevation receiving thrombolysis. A retrospective analysis of 5 randomized controlled trials was made. The main outcome measures included rates of (1) transformation of ST-segment elevation to Q- and non-Q-wave MI and (2) inhospital and 1-year mortality and reinfarction among patients who subsequently develop a Q or non-Q MI postthrombolysis as compared to controls. RESULTS: Non-Q wave development was greater among patients receiving thrombolysis versus placebo/control (3.1% absolute difference, 95% CI 1.2%-5.0%). Among patients receiving thrombolysis, those who developed a non-Q MI experienced significantly lower inhospital and 1-year mortality (absolute differences -3.8% [95% CI -5.2% to -2.4%] and -6.4% [95% CI -9.9% to -3.0%], respectively) and reinfarction (absolute differences -2.9% [95% CI -4.3% to -1.6%] and -3.5% [95% CI -6.1% to -0.9%], respectively) rates, compared with those who evolved a Q MI. Inhospital and 1-year mortality was also significantly lower when compared to placebo/control patients who developed a non-Q MI (absolute differences 4.6% [95% CI -8.2% to -1.1%] and -7.5% [95% CI -12.5% to -2.5%], respectively). CONCLUSIONS: Patients receiving thrombolysis more often develop a non-Q-wave MI and have a better prognosis than either those who develop a Q MI postthrombolysis or a non-Q MI after standard medical therapy.

Electrocardiography↗