Appropriate measures of influenza immunization program effectiveness.

Groll and Thomson's evaluation of the effectiveness of Ontario's Universal Influenza Immunization Campaign used per capita cases of laboratory-confirmed influenza. We argue that these data are susceptible to various biases and should not be used as an outcome measure. Laboratory data are traditionally used to identify the presence of influenza activity rather than to identify levels of influenza activity.

Hospital volume and mortality for mechanical ventilation of medical and surgical patients: a population-based analysis using administrative data.

Objective: In an effort to improve efficiency and quality of care, regionalization of adult critical care services, similar to trauma and neonatal intensive care, has been suggested. However, there is little research to understand if hospitals with higher patient volumes have better outcomes. Our objective is to determine whether hospital volume is associated with improved survival for medical or surgical patients receiving mechanical ventilation.

A controlled trial of methods for managing pain in primary care patients with or without co-occurring psychosocial problems.

Purpose: Pain, a common reason for visits to primary care physicians, is often not well managed. The objective of this study was to determine the effectiveness of pain management interventions suitable for primary care physicians.

Methods: Patients from 14 rural primary care practices (47 physicians) who reported diverse pain problems with (n = 644) or without (n = 693) psychosocial problems were randomized to usual-care or intervention groups.

Surge capacity associated with restrictions on nonurgent hospital utilization and expected admissions during an influenza pandemic: lessons from the Toronto severe acute respiratory syndrome outbreak.

Background: Current influenza pandemic models predict a surge in influenza-related hospitalizations in affected jurisdictions. One proposed strategy to increase hospital surge capacity is to restrict elective hospitalizations, yet the degree to which this measure would meet the anticipated is unknown.

Objectives: To compare the reduction in hospitalizations resulting from widespread nonurgent hospital admission restrictions during the Toronto severe acute respiratory syndrome (SARS) outbreak with the expected increase in admissions resulting from an influenza pandemic in Toronto.

Study design to determine the effects of widespread restrictions on hospital utilization to control an outbreak of SARS in Toronto, Canada.

Context: Efforts to control an outbreak of severe acute respiratory syndrome (SARS) in Toronto, Canada, led to the imposition of major restrictions on nonurgent use of hospital-based services.

Objective: To describe a methodology to determine the impact of the restrictions on healthcare utilization. DESIGN, SETTING, POPULATION: Population-based study of the Greater Toronto area and unaffected comparator regions, before, during and after the SARS outbreak (April 2001 to March 2004).

The effect of universal influenza immunization on vaccination rates in Ontario.

Objectives: This article examines the association between introduction of Ontario's Universal Influenza Immunization Program and changes in vaccination rates over time in Ontario, compared with the other provinces combined.

Data Sources: The data are from the 1996/97 National Population Health Survey and the 2000/01 and 2003 Canadian Community Health Survey, both conducted by Statistics Canada.

Analytical Techniques: Cross-tabulations were used to estimate vaccination rates for the total population aged 12 or older, for groups especially vulnerable to the effects of influenza, and by selected socio-demographic variables.

Volume and process of care in high-risk cancer surgery.

Background: Although relations between procedure volume and operative mortality are well established for high-risk cancer operations, differences in clinical practice between high-volume and low-volume centers are not well understood. The current study was conducted to examine relations between hospital volume, process of care, and operative mortality in cancer surgery.

Methods: Using the Medicare claims database (2000-2002), we identified all patients undergoing major resections for lung, esophageal, gastric, liver, or pancreatic cancer (n=71,558).

Human papillomavirus infection and incidence of squamous cell and basal cell carcinomas of the skin.

Background: Although infection with human papillomaviruses (HPVs) is a major risk factor for several epithelial cancers, an etiologic relationship between HPV and keratinocyte cancers, such as squamous cell carcinomas (SCCs) and basal cell carcinomas (BCCs), remains unclear.

Methods: In a population-based case-control study of 252 SCC case patients, 525 BCC case patients, and 461 control subjects, we used multiplex serology to detect antibodies in plasma samples against 16 HPV types from phylogenetic genera alpha, beta, and mu. Multiplex serology is a new method that is based on fluorescent bead technology and allows simultaneous detection of antibodies against up to 100 different in situ affinity-purified recombinant HPV proteins.

End-of-life care at academic medical centers: implications for future workforce requirements.

The expansion of U.S. physician workforce training has been justified on the basis of population growth, technological innovation, and economic expansion.

Outpatient gatifloxacin therapy and dysglycemia in older adults.

Background: Gatifloxacin has been associated with both hypoglycemia and hyperglycemia. We examined dysglycemia-related health outcomes associated with various antibiotics in a population of approximately 1.4 million Ontario, Canada, residents 66 years of age or older.

Volume matters: physician practice characteristics and immunization coverage among young children insured through a universal health plan.

Objectives: We studied the association between immunization coverage for a cohort of 2-year-old children covered by a universal health insurance plan and pediatric provider and other health services characteristics.

Methods: We assembled a cohort of 101,570 infants born in urban areas in Ontario, Canada, between July 1, 1997, and June 31, 1998. Children were considered to have up-to-date (UTD) immunization coverage if they had > or =5 immunizations by 2 years of age, ie, the recommended 3 doses and 1 booster of diphtheria-polio-tetanus-pertussis/Haemophilus influenzae type b vaccine and 1 dose of measles-mumps-rubella vaccine.

Effect of NSAIDs on the recurrence of nonmelanoma skin cancer.

Experimental studies have consistently shown a protective effect of nonsteroidal antiinflammatory drugs (NSAIDs) against nonmelanoma skin cancers (NMSC). However, little human epidemiological research has been done in this regard. We used data from the Skin Cancer Chemoprevention Study to explore the association of NSAID use and with the risk of basal-cell carcinoma (BCC) and squamous-cell carcinoma (SCC).

Race and surgical mortality in the United States.

Objective: This study describes racial differences in postoperative mortality following 8 cardiovascular and cancer procedures and assesses possible explanations for these differences.

Summary Background Data: Although racial disparities in the use of surgical procedures are well established, relationships between race and operative mortality have not been assessed systematically.

Methods: We used national Medicare data to identify all patients undergoing one of 8 cardiovascular and cancer procedures between 1994 and 1999.

Proliferation of cardiac technology in Canada: a challenge to the sustainability of Medicare.

Background: Critics remain skeptical about the long-term sustainability of Medicare in Canada because of the proliferation of health technology and escalating expenditures. The objective of this study was to examine the temporal trends in the utilization and costs of cardiovascular technologies for the evaluation and/or management of patients with ischemic heart disease in Canada.

Methods And Results: This repeated cross-sectional population-based study of Ontario residents examined the temporal trends in the utilization and costs associated with echocardiography, stress (imaging and nonimaging) testing, coronary angiography, percutaneous coronary intervention (PCI), and bypass surgery between 1992 and 2001.

Pregnancy history and incidence of melanoma in women: a pooled analysis.

There is evidence that pregnancy history including age at first birth and parity may play a role in risk of cutaneous melanoma in women, although, epidemiological findings are inconsistent. We conducted a collaborative analysis of these factors using the original data from ten completed case-control studies (2391 cases and 3199 controls), and assessed the potential confounding effects of socioeconomic, pigmentary, and sun exposure-related factors. We found no overall association with ever having a live birth (pooled odds ratio (pOR) 0.

Regional variation in rates of low birth weight.

Objective: Low birth weight (LBW; < 2500 g) is the result of complex and poorly understood interactions between the biological determinants of the mother and the fetus, the parent's socioeconomic status, and medical care. After controlling for these established risk factors, the extent of regional variation in LBW rates remains unknown. This study measures regional variation in LBW rates and identifies regions of neonatal health services with significantly high or low adjusted rates.

Risk-treatment mismatch in the pharmacotherapy of heart failure.

Context: Patients with heart failure have a wide spectrum of mortality risks. To maximize the benefit of available pharmacotherapies, patients with high mortality risk should receive high rates of drug therapy.

Objective: To examine patterns of drug therapy and underlying mortality risk in patients with heart failure.

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.

How are volume-outcome associations related to models of health care funding and delivery? A comparison of the United States and Canada.

How models of health care financing and delivery affect patterns of procedure volumes, outcomes, and volume-outcome associations is not known. We compared volume-outcome studies done in Canada, which provides residents with universal, single-payer health care, with those done in the United States, to determine whether there was a difference in the likelihood of finding statistically significant volume-outcome associations. We analyzed 142 articles, most (90.

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.

Rate of elective cholecystectomy and the incidence of severe gallstone disease.

Background: The use of elective cholecystectomy has increased dramatically following the widespread adoption of laparoscopic cholecystectomy. We sought to determine whether this increase has resulted in a reduction in the incidence of severe complications of gallstone disease.

Methods: We examined longitudinal trends in the population-based rates of severe gallstone disease from 1988 to 2000, using a quasi-experimental longitudinal design to assess the effects of the large increase in elective cholecystectomy rates after 1991 among people aged 18 years and older residing in Ontario.

Long-term outcomes of regional variations in intensity of invasive vs medical management of Medicare Patients with acute myocardial infarction.

Context: The health and policy implications of the marked regional variations in intensity of invasive compared with medical management of patients with acute myocardial infarction (AMI) are unknown.

Objectives: To evaluate patient clinical characteristics associated with receiving more intensive treatment; and to assess whether AMI patients residing in regions with more intensive invasive treatment and management strategies have better long-term survival than those residing in regions with more intensive medical management strategies.

Design, Setting, And Patients: National cohort study of 158,831 elderly Medicare patients hospitalized with first episode of confirmed AMI in 1994-1995, followed up for 7 years (mean, 3.

The use of the propensity score for estimating treatment effects: administrative versus clinical data.

There is an increasing interest in using administrative data to estimate the treatment effects of interventions. While administrative data are relatively inexpensive to obtain and provide population coverage, they are frequently characterized by lack of clinical detail, often leading to problematic confounding when they are used to conduct observational research. Propensity score methods are increasingly being used to address confounding in estimating the effects of interventions in such studies.

Do cancer centers designated by the National Cancer Institute have better surgical outcomes?

Background: The National Cancer Institute (NCI) designates cancer centers as regional centers of excellence in research and patient care. Although these centers often advertise their superior outcomes, their relative performance has not been examined empirically. In the current study, the authors assessed whether patients at NCI cancer centers compared with patients at control hospitals had lower mortality rates after major cancer surgery.

Surgeon specialty and operative mortality with lung resection.

Objective: We sought to examine the effect of subspecialty training on operative mortality following lung resection.

Summary Background Data: While several different surgical subspecialists perform lung resection for cancer, many believe that this procedure is best performed by board-certified thoracic surgeons.

Methods: Using the national Medicare database 1998 to 1999, we identified patients undergoing lung resection (lobectomy or pneumonectomy) for lung cancer.