Increasing Access to Health Administrative Data with ICES Data & Analytic Services.

The Institute for Clinical Evaluative Sciences (ICES) is one of only a few organizations in Ontario permitted to access, link and analyze health administrative data for the purpose of generating evidence to inform decisions in policy and practice. Although ICES is a leading research institute, its access to the data has historically been restricted to scientists with an ICES affiliation. This requirement, designed to meet ICES' data privacy and security obligations, created barriers with respect to the widespread use of Ontario's data assets. In 2014, as part of the government's commitment to the Strategy for Patient-Oriented Research, ICES launched the Data & Analytic Services platform, which is aimed at increasing access to data and analytic services to investigators external to ICES. In making the data widely available to the broader research community, this initiative engages investigators involved in front-line care, stimulates new avenues of research and fosters collaboration that was previously challenging or unfeasible.

Access to rheumatologists among patients with newly diagnosed rheumatoid arthritis in a Canadian universal public healthcare system.

OBJECTIVES: Our objective was to estimate the percentage of patients with incident rheumatoid arthritis (RA) who were seen by a rheumatologist within 3, 6 and 12 months of suspected diagnosis by a family physician, and assess what factors may influence the time frame with which patients are seen. SETTING: Ontario, Canada. PARTICIPANTS: Over 2000-2009, we studied patients with incident RA who were initially diagnosed by a family physician. PRIMARY AND SECONDARY OUTCOME MEASURES: We assessed secular trends in rheumatology encounters and differences between patients who received versus did not receive rheumatology care. We performed hierarchical logistic regression analyses to determine whether receipt of rheumatology care was associated with patient, primary care physician and geographical factors. RESULTS: Among 19 760 patients with incident RA, 59%, 75% and 84% of patients were seen by a rheumatologist within 3, 6 and 12 months, respectively. The prevalence of initial consultations within 3 months did not increase over time; however, access within 6 and 12 months increased over time. Factors positively associated with timely consultations included higher regional rheumatology supply (adjusted OR (aOR) 1.35 (95% CI 1.13 to 1.60)) and higher patient socioeconomic status (aOR 1.18 (95% CI 1.07 to 1.30)). Conversely, factors inversely associated with timely consultations included remote patient residence (aOR 0.51 (95% CI 0.41 to 0.64)) and male family physicians (aOR 0.88 (95% CI 0.81 to 0.95)). CONCLUSIONS: Increasing access to rheumatologists within 6 and 12 months occurred over time; however, consultations within 3 months did not change over time. Measures of poor access (such as proximity to and density of rheumatologists) were negatively associated with timely consultations. Additional factors that contributed to disparities in access included patient socioeconomic status and physician sex.

Location, size, and distance: criteria for quality in esophagogastroduodenos copy reporting for pre-operative gastric cancer evaluation.

BACKGROUND: There is a lack of existing literature regarding the quality of esophagogastroduodenoscopy (EGD) reporting for gastric cancer evaluation. This study aims to determine criteria for quality endoscopic evaluation of gastric cancer in North America by identifying important features of the EGD report for pre-operative evaluation of gastric cancer and assessing inclusion of these features in existing reports. METHODS: Semi-structured interviews were conducted with experienced endoscopists from community and academic hospitals affiliated with the University of Toronto to identify essential elements for an EGD report. Then, 225 EGD reports from 2005 to 2008 were evaluated by two trained reviewers for inclusion of recommended EGD report elements and global assessment of report quality and adequacy for surgical planning. RESULTS: Essential elements recommended by interviewed endoscopists include tumor size, location, and distance from gastroesophageal junction (GEJ). Approximately 95 % of all reports documented the location of lesions, <5 % documented distance from the GEJ, and <15 % documented tumor size. Overall report quality was rated as excellent for 4-5 % of reports; 20-42 % of all reports were deemed to be adequate for surgical planning. All surgeons interviewed as part of the endoscopist panel indicated that they would repeat the EGD before consulting with patients regarding surgical planning. CONCLUSIONS: For pre-operative evaluation of gastric cancer, tumor size, location, and distance from key anatomical landmarks were proposed as essential elements of a quality EGD report. Most of the reviewed reports did not document these elements. Report quality is perceived to be poor and may lead to repeat endoscopy. Developing a standardized EGD reporting format based on inclusion of individual parameters can improve the quality of gastric cancer management.

Serious infections in a population-based cohort of 86,039 seniors with rheumatoid arthritis.

OBJECTIVE: To assess risk and risk factors for serious infections in seniors with rheumatoid arthritis (RA) using a case-control study nested within an RA cohort. METHODS: We assembled a retrospective RA cohort age ≥66 years from Ontario health administrative data across 1992-2010. Nested case-control analyses were done, comparing RA patients with a primary diagnosis of infection (based on hospital or emergency department records) to matched RA controls. We assessed independent effects of drugs, adjusting for demographics, comorbidity, and markers of RA severity. RESULTS: A total of 86,039 seniors with RA experienced 20,575 infections, for a rate of 46.4 events/1,000 person-years. The most frequently occurring events included respiratory infections, herpes zoster, and skin/soft tissue infections. Factors associated with infection included higher comorbidity, rural residence, markers of disease severity, and history of previous infection. In addition, anti-tumor necrosis factor agents and disease-modifying antirheumatic drugs were associated with a several-fold increase in infections, with an adjusted odds ratio (OR) ranging from 1.2-3.5. The drug category with the greatest effect estimate was glucocorticoids, which exhibited a clear dose response with an OR ranging from 4.0 at low doses to 7.6 at high doses. CONCLUSION: Seniors with RA have significant morbidity related to serious infections, which exceeds previous reports among younger RA populations. Rural residence, higher comorbidity, markers of disease severity, and previous infection were associated with serious infections in seniors with RA. Our results emphasize that many RA drugs may increase the risk of infection, but glucocorticoids appear to confer a particular risk.

Understanding the costs of cancer care before and after diagnosis for the 21 most common cancers in Ontario: a population-based descriptive study.

BACKGROUND: The first year after cancer diagnosis is a period of intensive treatment and high cost. We sought to estimate costs for the 21 most common cancers in Ontario in the 3-month period before and the first year after diagnosis. METHODS: We used the Ontario Cancer Registry to select patients who received diagnoses between 1997 and 2007 at 19 years of age or older, with valid International Classification of Diseases for Oncology (ICD-O) and histology codes, who survived 30 days or longer after diagnosis and had no second cancer within 90 days of the initial cancer (n = 402 399). We used linked administrative data to calculate mean costs for each cancer during the pre- and postdiagnosis periods for patients who died within 1 year after diagnosis and patients who survived beyond 1 year after diagnosis. RESULTS: Mean prediagnosis costs were $2060 (95% confidence interval [CI] $2023-$2098) for all patients with cancer. Costs ranged from $890 (95% CI $795-$985) for melanoma to $4128 (95% CI $3591-$4664) for liver cancer among patients who survived beyond 1 year after diagnosis, and ranged from $2188 (95% CI $2040-$2336) for esophageal cancer to $5142 (95% CI $4664-$5620) for multiple myeloma among patients who died within 1 year. The mean postdiagnosis cost for our cohort was $25 914 (95% CI $25 782-$26 046). Mean costs were lowest for melanoma ($8611 [95% CI $8221-$9001]) and highest for esophageal cancer ($50 620 [95% CI $47 677-$53 562] among patients who survived beyond 1 year after diagnosis, and ranged from $27 560 (95% CI $25 747-$29 373) for liver cancer to $81 655 (95% CI $58 361-$104 949) for testicular cancer among patients who died within 1 year. INTERPRETATION: Our research provides cancer-related cost estimates for the pre- and postdiagnosis phases and offers insight into the economic burden incurred by the Ontario health care system. These estimates can help inform policy-makers' decisions regarding resource allocation for cancer prevention and control, and can serve as important input for economic evaluations.

Comparison of orally administered bisphosphonate drugs in reducing the risk of hip fracture in older adults: a population-based cohort study.

BACKGROUND: Orally administered bisphosphonate drugs (i.e., alendronate, etidronate, risedronate) can reduce the risk of vertebral fracture. However, only alendronate and risedronate have proven efficacy in reducing the risk of hip fracture. We sought to examine the comparative effectiveness of orally administered bisphosphonate drugs in reducing hip fractures among older adults. METHODS: We identified new users of orally administered bisphosphonate drugs in British Columbia and Ontario between 2001 and 2008. We used province- and sex-specific propensity score-matching strategies to maximize comparability between exposure groups. We used Cox proportional hazards models to compare time-to-hip fracture within 1 year of treatment between exposures by sex in each province. Our secondary analyses considered hip fracture rates within 2 and 3 years' follow-up. We used alendronate as the reference for all comparisons and pooled provincial estimates using random effects variance-weighted meta-analysis. RESULTS: We identified 321 755 patients who were eligible for inclusion in the study. We found little difference in fracture rates between men (pooled hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.74-1.14) or women (pooled HR 1.15, 95% CI 0.73-1.56) taking risedronate and those taking alendronate. We similarly identified little difference in fracture rates between women taking etidronate and those taking alendronate (pooled HR 1.00, 95% CI 0.82-1.18). However, we identified lower rates of hip fracture among men taking etidronate relative to alendronate (pooled HR 0.77, 95% CI 0.60-0.94). Results extended to 2 and 3 years' follow-up were similar. However, with 3 years' follow-up, rates of hip fracture were lower among women in British Columbia who had taken alendronate. INTERPRETATION: We identified little overall difference between alendronate and risedronate in reducing the risk of hip fracture in men or women. Our finding that etidronate is associated with lower fracture risk among men is likely due to selection bias. The long-term comparative effects of orally administered bisphosphonate drugs warrant further study.

Trends in use and cost of initial cancer treatment in Ontario: a population-based descriptive study.

BACKGROUND: Cancer incidence and treatment-related costs are rising in Canada. We estimated health care use and costs in the first year after diagnosis for patients with 7 common types of cancer in Ontario to examine temporal trends in patterns of care and costs. METHODS: We selected patients aged 19-44 years who had received a diagnosis of melanoma, breast cancer (female only), testicular cancer or thyroid cancer, in addition to patients aged 45 years and older who had received a diagnosis of breast (female only), prostate, lung or colorectal cancer, between 1997 and 2007. Patients were identified from the Ontario Cancer Registry. Using linked administrative databases, we determined use and costs of chemotherapy, radiotherapy, cancer-related surgery, other admissions to hospital and home care. We adjusted all costs to 2009 Canadian dollars. RESULTS: We identified 20 821 patients aged 19-44 years and 178 797 patients aged 45 years and older. The greatest increases in costs during the study period were for melanoma, breast cancer, colorectal cancer, lung cancer and prostate cancer (p < 0.05). For prostate and lung cancers, mean costs increased 50% (from $11 490 and $22 037 to $15 170 and $34 473, respectively). Mean costs doubled for breast (from $15 460 and $12 909 to $35 977 and $29 362 for younger and older patients, respectively) and colorectal cancers (from $24 769 to $43 964), and nearly tripled for melanoma (from $3581 to $8934). Costs related to hospital admissions accounted for the largest portion of total costs. The use of chemotherapy, radiotherapy and home care generally increased for all cancers. INTERPRETATION: The significant increase in mean costs of initial cancer treatment among the patients included in this study was primarily due to more patients receiving adjuvant therapy and home care, and to the increasing expenditures for these services and cancer-related surgeries. Understanding trends in health care use and costs can help policy-makers to take the necessary measures to achieve a more accountable, high-performing health care system.

Cancer screening practices of cancer survivors: population-based, longitudinal study.

OBJECTIVE: To describe cancer screening rates for cancer survivors and compare them with those for matched controls. DESIGN: Population-based, retrospective study with individuals linked across administrative databases. SETTING: Ontario. PARTICIPANTS: Survivors of breast (n = 11 219), colorectal (n = 4348), or endometrial (n = 3473) cancer, or Hodgkin lymphoma (HL) (n = 2071) matched to general population controls. Survivors were those who had completed primary treatment and were on "well" follow-up. The study period was 4 years (1 to 5 years from the date of cancer diagnosis). MAIN OUTCOME MEASURES: Never versus ever screened (in the 4-year study period) for breast cancer, colorectal cancer (CRC), and cervical cancer and never versus ever received (during the study period) a periodic health examination; rates were compared between cancer survivors and controls. Random effects models were used to estimate odds ratios and 95% CIs. RESULTS: Sixty-five percent of breast cancer survivors were never screened for CRC and 40% were never screened for cervical cancer. Approximately 50% of CRC survivors were never screened for breast or cervical cancer. Thirty-two percent of endometrial cancer survivors were never screened for breast cancer and 66% were never screened for CRC. Forty-four percent of HL survivors were never screened for breast cancer, 77% were never screened for CRC, and 32% were never screened for cervical cancer. Comparison with matched controls showed a mixed picture, with breast and endometrial cancer survivors more likely, and CRC and HL survivors less likely, than controls to be screened. CONCLUSION: There is concern about the preventive care of cancer survivors despite frequent visits to both oncology specialists and family physicians during the "well" follow-up period.

Association of ICU or hospital admission with unintentional discontinuation of medications for chronic diseases.

CONTEXT: Patients discharged from acute care hospitals may be at risk for unintentional discontinuation of medications prescribed for chronic diseases. The intensive care unit (ICU) may pose an even greater risk because of the focus on acute events and the presence of multiple transitions in care. OBJECTIVE: To evaluate rates of potentially unintentional discontinuation of medications following hospital or ICU admission. DESIGN, SETTING, AND PATIENTS: A population-based cohort study using administrative records from 1997 to 2009 of all hospitalizations and outpatient prescriptions in Ontario, Canada; it included 396,380 patients aged 66 years or older with continuous use of at least 1 of 5 evidence-based medication groups prescribed for long-term use: (1) statins, (2) antiplatelet/anticoagulant agents, (3) levothyroxine, (4) respiratory inhalers, and (5) gastric acid-suppressing drugs. Rates of medication discontinuation were compared across 3 groups: patients admitted to the ICU, patients hospitalized without ICU admission, and nonhospitalized patients (controls). Odds ratios (ORs) were calculated and adjusted for patient demographics, clinical factors, and health services use. MAIN OUTCOME MEASURES: The primary outcome was failure to renew the prescription within 90 days after hospital discharge. RESULTS: Patients admitted to the hospital (n = 187,912) were more likely to experience potentially unintentional discontinuation of medications than controls (n = 208,468) across all medication groups examined. The adjusted ORs (AORs) ranged from 1.18 (95% CI, 1.14-1.23) for discontinuing levothyroxine in 12.3% of hospitalized patients (n = 6831) vs 11.0% of controls (n = 7114) to an AOR of 1.86 (95% CI, 1.77-1.97) for discontinuing antiplatelet/anticoagulant agents in 19.4% of hospitalized patients (n = 5564) vs 11.8% of controls (n = 2535). With ICU exposure, the AORs ranged from 1.48 (95% CI, 1.39-1.57) for discontinuing statins in 14.6% of ICU patients (n = 1484) to an AOR of 2.31 (95% CI, 2.07-2.57) for discontinuing antiplatelet/anticoagulant agents in 22.8% of ICU patients (n = 522) vs the control group. Admission to an ICU was associated with an additional risk of medication discontinuation in 4 of 5 medication groups vs hospitalizations without an ICU admission. One-year follow-up of patients who discontinued medications showed an elevated AOR for the secondary composite outcome of death, emergency department visit, or emergent hospitalization of 1.07 (95% CI, 1.03-1.11) in the statins group and of 1.10 (95% CI, 1.03-1.16) in the antiplatelet/anticoagulant agents group. CONCLUSIONS: Patients prescribed medications for chronic diseases were at risk for potentially unintentional discontinuation after hospital admission. Admission to the ICU was generally associated with an even higher risk of medication discontinuation.

Bisphosphonate use and the risk of subtrochanteric or femoral shaft fractures in older women.

CONTEXT: Osteoporosis is associated with significant morbidity and mortality. Oral bisphosphonates have become a mainstay of treatment, but concerns have emerged that long-term use of these drugs may suppress bone remodeling, leading to unusual fractures. OBJECTIVE: To determine whether prolonged bisphosphonate therapy is associated with an increased risk of subtrochanteric or femoral shaft fracture. DESIGN, SETTING, AND PATIENTS: A population-based, nested case-control study to explore the association between bisphosphonate use and fractures in a cohort of women aged 68 years or older from Ontario, Canada, who initiated therapy with an oral bisphosphonate between April 1, 2002, and March 31, 2008. Cases were those hospitalized with a subtrochanteric or femoral shaft fracture and were matched to up to 5 controls with no such fracture. Study participants were followed up until March 31, 2009. MAIN OUTCOME MEASURES: The primary analysis examined the association between hospitalization for a subtrochanteric or femoral shaft fracture and duration of bisphosphonate exposure. To test the specificity of the findings, the association between bisphosphonate use and fractures of the femoral neck or intertrochanteric region, which are characteristic of osteoporotic fractures, was also examined. RESULTS: We identified 716 women who sustained a subtrochanteric or femoral shaft fracture following initiation of bisphosphonate therapy and 9723 women who sustained a typical osteoporotic fracture of the intertrochanteric region or femoral neck. Compared with transient bisphosphonate use, treatment for 5 years or longer was associated with an increased risk of subtrochanteric or femoral shaft fracture (adjusted odds ratio, 2.74; 95% confidence interval, 1.25-6.02). A reduced risk of typical osteoporotic fractures occurred among women with more than 5 years of bisphosphonate therapy (adjusted odds ratio, 0.76; 95% confidence interval, 0.63-0.93). Among 52,595 women with at least 5 years of bisphosphonate therapy, a subtrochanteric or femoral shaft fracture occurred in 71 (0.13%) during the subsequent year and 117 (0.22%) within 2 years. CONCLUSION: Among older women, treatment with a bisphosphonate for more than 5 years was associated with an increased risk of subtrochanteric or femoral shaft fractures; however, the absolute risk of these fractures is low.

Overview of lung cancer surgery in Ontario.

BACKGROUND: Surgery is the primary curative treatment for lung cancer and thus appropriate surgical resource allocation is critical. This study describes the distribution of lung cancer incidence and surgical care in Ontario, a Canadian province with universal health care, for the fiscal year of 2004. METHODS: All new lung cancer cases in Ontario between April 1, 2003 and March 31, 2004 were identified in the Ontario Cancer Registry. Incidence rates and surgical procedures were compared by age, health region, neighborhood income, and community size. RESULTS: Lung cancer incidence was highest in lower income neighborhoods (90.2 cases of 100,000 vs 55.6 in the highest quintile, p < 0.001) and smaller communities (87.1 of 100,000 in communities less than 100,000 vs 56.3 of 100,000 in cities greater than 1.25 million, p < 0.001). Surgical interventions were most common in younger patients (47.4% aged 20 to 54 years versus 30.5% greater than 75 years, p < 0.001), and those in wealthier neighborhoods (43.4% in highest quintile versus 35.8% in the lowest, p < 0.001). Surgical procedures overall and specifically formal resections (20% in cities >1.25 million versus 18% in communities <100,000, p < 0.03) were more common in larger communities (43.4% versus 37.7%, p < 0.001). Pneumonectomy was more common in smaller communities (14.5% vs 9.9%, p = 0.048, whereas more lobar (53.8 vs 45.2%, p = 0.01) and sublobar resections (44.9% vs 31.7%, p < 0.0001) were more common in larger communities. Thoracic surgeons provided the majority of formal resections (51% to 57%) compared with general surgeons (17% to 21%). CONCLUSIONS: Lung cancer incidence and surgical care vary significantly by health region, income level, and community size. These disparities require further evaluation to meet the needs of patients with lung cancer.

Quality care in seniors with new-onset rheumatoid arthritis: a Canadian perspective.

OBJECTIVE: To estimate the percentage of seniors with rheumatoid arthritis (RA) receiving disease-modifying antirheumatic drugs (DMARDs) within the first year of diagnosis. METHODS: We assembled an incident RA cohort from Ontario physician billing data for 1997-2006. We used a standard algorithm to identify 24,942 seniors with RA based on ≥ 2 billing codes ≥ 60 days apart but within 5 years. Drug exposures were obtained from pharmacy claims data. We followed subjects for 1 year, assessing if they had been exposed (defined as ≥ 1 prescription) to 1 or more DMARDs within the first year of RA diagnosis. We assessed secular trends and differences for subjects who had received rheumatology care (defined as ≥ 1 rheumatology encounter) versus those who had not. RESULTS: In total, only 39% of the 24,942 seniors with new-onset RA identified over 1997-2006 were exposed to DMARD therapy within 1 year of diagnosis. This increased from 30% in 1997 to 53% in 2006. Patients whose care involved a rheumatologist were more likely to be exposed to DMARDs than those who had no rheumatology care. In 2006, 67% of subjects receiving rheumatology care were exposed to DMARDs versus 21% of those with no rheumatology care. CONCLUSION: Improvements in RA care have occurred, but more efforts are needed. Subjects receiving rheumatology care are much more likely to receive DMARDs as compared to those with no rheumatology care. This emphasizes the key role of rheumatologists.

Management of gastric cancer in Ontario.

OBJECTIVE: To describe the processes of care for gastric cancer in Ontario and identify areas in which care and possibly survival can be improved. SUMMARY BACKGROUND DATA: Survival in North America is poor for patients with gastric cancer, with stage-matched survival markedly worse than is seen in Asian and European series. Few Western studies have examined processes of care associated with gastric cancer. METHODS: We identified all cases of gastric cancer in Ontario, Canada from April 1, 2000 to March 31, 2005, and describe the demographics of patients, staging of the cancer, treatment, and survival. RESULTS: In this series of 3,666 patients, 81% of cases had a CT scan performed prior to resection and 90% of cases received an upper endoscopy. We found that 55% of patients were treated palliatively and only 1,645 patients underwent a curative-intent resection. Among patients who did not receive a resection over 50% of the cases appeared to have had a diagnostic laparoscopy rather than a laparotomy. Survival was related to the type of resection performed, likely reflecting the extent of disease. Higher institution volume and age were related to improved survival for curative-intent cases. CONCLUSION: In this population-based analysis, we found evidence of under-utilization of pre-operative radiology and endoscopy. Many patients were treated palliatively, reflecting presentation of the cancer at an advanced stage. For curative patients, survival was associated with age, surgical type, and resection in a higher volume institution.

A population-based study of follow-up care for Hodgkin lymphoma survivors: opportunities to improve surveillance for relapse and late effects.

BACKGROUND: The majority of Hodgkin lymphoma (HL) patients are cured, and post-treatment visits are a major component of their management. Little is known about the quality of follow-up care received by these survivors. METHODS: All patients who were diagnosed with HL in Ontario from 1992 through 2000 were identified from a population-based cancer registry. Individual-level linkage with physician claims was used to examine the follow-up care received by 2071 1-year survivors for up to 15 years after their HL diagnosis. Physician visits, imaging studies, and the use of routine and HL-specific cancer screening tests were evaluated. RESULTS: Most patients had visits with both a primary care provider and an oncologist in Years 2 through 5 after their HL diagnosis. In Year 5 after HL diagnosis, 31.8% of patients had at least 1 computed tomography (CT) scan, and 62.9% had a chest x-ray. There were 5352 CT scans performed in Years 2 through 5, and 125 patients subsequently received chemotherapy within 6 months of a CT. Among the survivors who met age criteria for routine screening, 62.5% had no evidence of colorectal cancer screening during Years 2 through 15, 32.3% had no evidence of breast cancer screening, and 19.9% had no evidence of cervical cancer screening. Among young women potentially at high risk of breast cancer because of radiation therapy, 87.1% had not received the recommended breast cancer screening. CONCLUSIONS: Radiologic surveillance of HL survivors rarely led to salvage therapy. Despite frequent physician contact, many survivors did not receive established cancer screening interventions, and the recommended early initiation of breast cancer screening among young women at high risk was not widely used.

Provider volumes and early outcomes of primary total joint replacement in Ontario.

BACKGROUND: A relation between provider volume and outcome of total joint replacement (TJR) has not been demonstrated in Canada. Given the recent increase in TJR, changing patient characteristics and small sizes of previous Ontario studies, we reassessed whether adverse outcomes of TJR are related to hospital and surgeon procedure volumes. METHODS: We included all Ontarians aged 20 years and older who underwent a unilateral elective primary total hip replacement (THR) or total knee replacement (TKR) between April 2000 and March 2004. The main data sources were hospital discharge abstracts and physician billings. We defined provider volume as the average annual number of primary and revision procedures performed by hospitals and surgeons during the study period. We assessed the association between procedure volumes and acute length of hospital stay (ALOS) and between volume and rate of surgical complications during the index admission; death within 90 days of operation; readmission for amputation, fusion or excision within 1 year; and revision arthroplasty within 1 year. We adjusted for age, sex, comorbidity, arthritis type, teaching hospital status and discharge disposition. The analyses of hospital volume were adjusted for surgeon volume and vice versa. RESULTS: We included 20,290 patients who received THR and 27,217 who received TKR. Patient age, sex and comorbidity were significant predictors of complications and mortality. There were no associations between provider volume and mortality. Findings for other outcomes were mixed. Surgeon procedure volume was related to rates of revision THR but not to rates of revision TKR. Shorter ALOS was associated with male sex, younger age, fewer comorbidities, discharge to a rehabilitation unit or facility and greater surgeon volume. CONCLUSION: Patient characteristics were significant predictors of complications, ALOS and mortality after primary TJR. Evidence for a relation between provider volume and outcome was limited and inconsistent.

Rates of new or missed colorectal cancer after barium enema and their risk factors: a population-based study.

OBJECTIVE: Double-contrast barium enema (DCBE) is widely used in clinical practice to detect colorectal cancer (CRC). Our objective was to evaluate the rate of new or missed CRC following DCBE and the associated risk factors in a population-based study. METHODS: All patients (> or =20 yr old) with a new diagnosis of CRC between April 1, 1997, and March 31, 2004, in Ontario were identified. Data were extracted from the Ontario Health Insurance Program, the Canadian Institute for Health Information, the Registered Persons Database and the Ontario Cancer Registry. Patients who had a DCBE examination 36 months prior to the diagnosis of CRC were divided into two groups: detected cancers (DCBE within 6 months prior to diagnosis) and new or missed cancers (DCBE 6-36 months prior to diagnosis). Multivariate analysis was used to evaluate factors associated with new or missed CRC. RESULTS: We identified 13,849 patients who had a DCBE 36 months prior to the diagnosis of CRC. The overall rate of new or missed cancers following DCBE was 22.4%. Independent risk factors for new or missed cancers were older age, female sex, previous abdominal or pelvic surgery, diverticular disease, right-sided CRC, and having the DCBE in an office setting. CONCLUSIONS: Physicians who use DCBE to evaluate the colon must inform their patients that if a cancer is present, there is an approximately one in five chance that it will be missed. Given the recent endorsement of CT colonography by the U.S. Multi-Society Task Force on Colorectal Cancer as an option for CRC screening, it may be time to reconsider the use of DCBE to detect CRC.

Is ramipril really better than other angiotensin-converting enzyme inhibitors after acute myocardial infarction?

Whether angiotensin-converting enzyme (ACE) inhibitors are interchangeable and equally efficacious after acute myocardial infarction (AMI) is controversial. We assessed whether ramipril was superior to other ACE inhibitors after AMI as suggested by a previously published study. We performed a retrospective cohort study using linked administrative databases on >1.4 million elderly residents in the province of Ontario who were admitted to the hospital for AMI, survived >or=30 days after discharge, and were initiated on an ACE inhibitor after AMI and remained on the same ACE inhibitor from April 1, 1997 to March 31, 2000. We followed patients for 2 years and measured readmission for AMI or mortality, together or alone. Our cohort included 5,408 elderly patients. Compared with patients on enalapril, there was no significant difference for the combined end points of readmission for AMI or mortality across users of ramipril (adjusted hazard ratio 0.95, 95% confidence interval 0.79 to 1.15), lisinopril (adjusted hazard ratio 1.02, 95% confidence interval 0.84 to 1.25), or other ACE inhibitors (adjusted hazard ratio 1.08, 95% confidence interval 0.88, 1.32). In conclusion, the findings of this study support a class effect among ACE inhibitors in treatment after AMI.

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. Patients 32,710 older adults (< or = 65 years) with dementia (17,845 dispensed an atypical antipsychotic and 14,865 dispensed a typical antipsychotic). MAIN OUTCOME MEASURES: Admission to hospital with the most responsible diagnosis (single most important condition responsible for the patient's admission) of ischaemic stroke. Observation of patients until they were either admitted to hospital with ischaemic stroke, stopped taking antipsychotics, died, or the study ended. RESULTS: After adjustment for potential confounders, participants receiving atypical antipsychotics showed no significant increase in risk of ischaemic stroke compared with those receiving typical antipsychotics (adjusted hazard ratio 1.01, 95% confidence interval 0.81 to 1.26). This finding was consistent in a series of subgroup analyses, including ones of individual atypical antipsychotic drugs (risperidone, olanzapine, and quetiapine) and selected subpopulations of the main cohorts. CONCLUSION: Older adults with dementia who take atypical antipsychotics have a similar risk of ischaemic stroke to those taking typical antipsychotics.

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.