Universal drug coverage and income-related disparities in glycaemic control.

AIMS: To examine whether income-related disparities in glycaemic control decline after the age of 65 years, when publicly funded universal drug insurance is acquired in Ontario, Canada. METHODS: We conducted a population-based cross-sectional study using linked administrative healthcare databases. Adults with diabetes, aged 40-89 years, with available HbA1c data were included (N = 716 297). Income was based on median neighbourhood household income. Multiple linear regression was used to test for effect modification of age ≥65 years on the relationship between income and HbA1c . RESULTS: There was a significant inverse association between income and HbA1c level. After adjusting for baseline factors, the effect of income on HbA1c level was significantly greater for individuals aged <65 years (mean difference HbA1c for lowest vs highest income group +2.5 mmol/mol, 95% CI +2.3 to +2.7 [+0.23%, 95% CI 0.21 to 0.24]) than for those aged ≥65 years (+1.2 mmol/mol, 95% CI +1.0 to +1.3 [+0.11%, 95% CI 0.10 to 0.12]; P < 0.0001 for interaction). CONCLUSIONS: Despite universal access to healthcare, people with diabetes with lower incomes had significantly worse glycaemic control compared with their counterparts on higher incomes. However, income gradients in glycaemic control were markedly reduced after the age of 65 years, possibly as a result of access to prescription drug coverage.

Emergency department visits and unplanned hospitalizations in the treatment period for head and neck cancer patients treated with curative intent: A population-based analysis.

BACKGROUND: Mucosal head and neck squamous cell cancers are often managed with multimodality treatment which can be associated with significant toxicity. The objective of this study was to assess emergency department visits and unplanned hospitalizations for these patients during and immediately after their treatment. METHODS: A cohort of patients treated for head and neck squamous cell carcinoma was developed using administrative data. Emergency department visits and hospitalizations in the 90-day post-treatment period was determined. If a second treatment was initiated prior to the completion of 90 days, the attributable risk period was changed to the second treatment. RESULTS: Cohort of 3898 patients (1312 larynx/hypopharynx; 2586 oral cavity/oropharynx) from 2008 to 2012. The number of unplanned hospitalizations or ED visits (per 100 patient days) were 0.69 for surgery, 0.78 for surgery followed by concurrent chemoradiotherapy (CCRT), 0.55 for surgery followed by radiotherapy, 0.86 for CCRT, and 0.50 for radiation. Patients receiving CCRT had a statistically higher likelihood of treatment period events. The larynx/hypopharynx cancer subsite, higher comorbidity and more advanced stage of disease were all independent predictors of events. CONCLUSIONS: Patients undergoing treatment for head and neck cancer have significant unplanned hospitalizations and visits to the emergency department in the treatment period. Rates are higher in patients receiving CCRT. Quality improvement interventions should be used to improve these rates.

A systematic review of propensity score methods in the acute care surgery literature: avoiding the pitfalls and proposing a set of reporting guidelines.

BACKGROUND: Propensity score methods are techniques commonly employed in observational research to account for confounding when estimating the effects of treatments and exposures. These methods have been increasingly employed in the acute care surgery literature in an attempt to infer causality; however, the adequacy of reporting and the appropriateness of statistical analyses when using propensity score matching remain unclear. OBJECTIVES: The goal of this systematic review is to assess the adequacy of reporting of propensity score methods, with an emphasis on propensity score matching (to assess balance and the use of appropriate statistical tests), in acute care surgery (ACS) studies and to provide suggestions for improvement for junior investigators. METHODS: We searched three databases, and other relevant literature (from January 2005 to June 2015) to identify observational studies within the ACS literature using propensity score methods (PROSPERO No: CRD42016036432). Two reviewers extracted data and assessed the quality of the studies retrieved by reviewing the adequacy of both overall reporting and of the propensity score matching methods used. RESULTS: A total of 49/71 (69%) of studies adequately reported propensity score methods overall. Matching was the most common propensity score method used in 46/71 (65%) studies, with 36/46 (78%) studies reporting matching methods adequately. Only 19/46 (41%) of matching studies reported the balance of baseline characteristics between treated and untreated subjects while 6/46 (13%) used correct statistical methods to assess balance. There were 35/46 (76%) of matching studies that explicitly used statistical methods appropriate for the analysis of matched data when estimating the treatment effect and its statistical significance. CONCLUSION: We have proposed reporting guidelines for the use of propensity score methods in the acute care surgery literature. This is to help investigators improve the adequacy of reporting and statistical analyses when using observational data to estimate effects of treatments and exposures.

Metformin and breast cancer stage at diagnosis: a population-based study.

PURPOSE: The objective of the present study was to use a large, population-based cohort to examine the association between metformin and breast cancer stage at diagnosis while accounting for mammography differences. METHODS: We used data from Ontario administrative health databases to identify women 68 years of age or older with diabetes and invasive breast cancer diagnosed from 1 January 2007 to 31 December 2012. Adjusted logistic regression models were used to compare breast cancer stage at diagnosis (stages i and ii vs. iii and iv) between the women exposed and not exposed to metformin. We also examined the association between metformin use and estrogen receptor status, tumour size, and lymph node status in the subset of women for whom those data were available. RESULTS: We identified 3125 women with diabetes and breast cancer; 1519 (48.6%) had been exposed to metformin before their cancer diagnosis. Median age at breast cancer diagnosis was 76 years (interquartile range: 72-82 years), and mean duration of diabetes was 8.8 ± 5.9 years. In multivariable analyses, metformin exposure was not associated with an earlier stage of breast cancer (odds ratio: 0.98; 95% confidence interval: 0.81 to 1.19). In secondary analyses, metformin exposure was not associated with estrogen receptor-positive breast cancer, tumours larger than 2 cm, or positive lymph nodes. CONCLUSIONS: This population-based study did not show an association between metformin use and breast cancer stage or tumour characteristics at diagnosis. Our study considered older women with long-standing diabetes, and therefore further studies in younger patients could be warranted.

Early specialist care for diabetes: who benefits most? A propensity score-matched cohort study.

AIMS: To examine whether early endocrinologist care reduces the risk of cardiovascular complications among newly diagnosed patients with diabetes of differing complexity. METHODS: We conducted a population-based propensity score-matched cohort study using provincial health data from Ontario, Canada. Adults (≥ 30 years) diagnosed with diabetes between 1 April 1998 and 31 March 2006 who received endocrinologist care in the first year of diagnosis were matched to a comparison group receiving primary care alone (N = 79 020) based on propensity scores and medical complexity (assigned using information on chronic conditions). Individuals were followed for 3- and 5-year outcomes, including non-fatal acute myocardial infarction or coronary heart disease death (primary endpoint), major cardiovascular events (acute myocardial infarction, stroke) or all-cause death, amputation and end-stage renal disease. RESULTS: Among medically complex patients, early endocrinologist care was associated with a lower 3-year incidence of the primary endpoint (hazard ratio 0.89, 95% CI 0.78-1.01) and major cardiovascular events or all-cause death (hazard ratio 0.91, 95% CI 0.85-0.97). These effects persisted after accounting for a higher incidence of end-stage renal disease on follow-up and were greatest in those with ≥ 3 visits to an endocrinologist (primary endpoint: hazard ratio 0.69, 95% CI 0.56-0.86 and 0.61, 95% CI 0.45-0.82, for unadjusted and end-stage renal disease adjusted analyses, respectively). In contrast, no benefit was observed in the non-medically complex subgroup. Overall effects were similar at 5 years. CONCLUSIONS: Early endocrinologist care is associated with a lower incidence of cardiovascular events and death among newly diagnosed patients with diabetes who have comorbid medical conditions.

Impact of socio-economic status on breast cancer screening in women with diabetes: a population-based study.

AIMS: There is evidence to suggest that mammography rates are decreased in women with diabetes and in women of lower socio-economic status. Given the strong association between low socio-economic status and diabetes, we explored the extent to which differences in socio-economic status explain lower mammography rates in women with diabetes. METHODS: A population-based retrospective cohort study in Ontario, Canada, of women aged 50 to 69 years with diabetes between 1999 and 2010 age matched 1:2 to women without diabetes. Main outcome measure is the likelihood of at least one screening mammogram in women with diabetes within a 36-month period, starting as of either 1 January 1999, their 50th birthday, or 2 years after diabetes diagnosis--whichever came last. Outcomes were compared with those in women without diabetes during the same period as their matched counterparts, adjusting for socio-economic status based on neighbourhood income and other demographic and clinical variables. RESULTS: Of 504,288 women studied (188,759 with diabetes, 315,529 with no diabetes), 63.8% had a screening mammogram. Women with diabetes were significantly less likely to have a mammogram after adjustment for socio-economic status and other factors (odds ratio 0.79, 95% CI 0.78-0.80). Diabetes was associated with lower mammogram use even in women from the highest socio-economic status quintile (odds ratio 0.79, 95% CI 0.75-0.83). CONCLUSIONS: The presence of diabetes was an independent barrier to breast cancer screening, which was not explained by differences in socio-economic status. Interventions that target patient, provider, and health system factors are needed to improve cancer screening in this population.

The risk of falls on initiation of antihypertensive drugs in the elderly.

SUMMARY: Antihypertensive drugs are associated with an immediate increased falls risk in elderly patients which was significant during the first 14 days after receiving a thiazide diuretic, angiotensin-converting enzyme inhibitor, angiotensin II receptor blocker, calcium channel blocker, or beta-adrenergic blocker. Fall prevention strategies during this period may prevent fall-related injuries. INTRODUCTION: The purpose of this study is to evaluate if initiation of the common antihypertensive drugs is associated with the occurrence of falls. METHODS: This population-based self-controlled case series study used healthcare administrative databases to identify new users of antihypertensive drugs in the elderly aged 66 and older living in Ontario, Canada who suffered a fall from April 1, 2000 to March 31, 2009. The risk period was the first 45 days following antihypertensive therapy initiation, further subdivided into 0-14 and 15-44 days with control periods before and after treatment in a 450-day observation period. We calculated the relative incidence (incidence rate ratio, IRR), defined as the rate of falls in the risk period compared to falls rate in the control periods. RESULTS: Of the 543,572 new users of antihypertensive drugs among community-dwelling elderly, 8,893 experienced an injurious fall that required hospital care during the observation period. New users had a 69 % increased risk of having an injurious fall during the first 45 days following antihypertensive treatment (IRR = 1.69; 95 % CI, 1.57-1.81). This finding was consistent for thiazide diuretics, angiotensin-converting enzyme inhibitors, calcium channel blockers, and beta-adrenergic blockers but not angiotensin II receptor antagonists. There was also an increased falls risk during the first 14 days of antihypertensive drug initiation (IRR = 1.94; 95 % CI, 1.75-2.16), which was consistent for all antihypertensive drug classes. CONCLUSIONS: This study suggests that initiation of antihypertensive drugs is a risk factor for falls in the elderly. Fall prevention strategies during this period may reduce injuries.

Incidence of diabetes among postmenopausal breast cancer survivors.

AIMS/HYPOTHESIS: Evidence is emerging of an association between breast cancer and diabetes; however, it is uncertain whether diabetes incidence is increased in postmenopausal breast cancer survivors compared with women without breast cancer. The objective of this study was to determine whether postmenopausal women who develop breast cancer have a higher incidence of diabetes than those who do not develop breast cancer. METHODS: We used population-based data from Ontario, Canada to compare the incidence of diabetes among women with breast cancer, aged 55 years or older, from 1996 to 2008, with that of age-matched women without breast cancer. We used Cox proportional hazard models to estimate the effect of breast cancer on the cause-specific hazard of developing diabetes overall and in the subgroup of women who received adjuvant chemotherapy. RESULTS: Of 24,976 breast cancer survivors and 124,880 controls, 9.7% developed diabetes over a mean follow-up of 5.8 years. The risk of diabetes among breast cancer survivors compared with women without breast cancer began to increase 2 years after diagnosis (HR 1.07 [95% CI, 1.02, 1.12]), and rose to an HR of 1.21 (95% CI, 1.09, 1.35) after 10 years. Among those who received adjuvant chemotherapy (n = 4,404), risk was highest in the first 2 years after diagnosis (HR 1.24 [95% CI 1.12, 1.38]) and then declined. CONCLUSIONS/INTERPRETATION: We found a modest increase in the incidence of diabetes among postmenopausal breast cancer survivors that varied over time. In most women the risk began to increase 2 years after cancer diagnosis but the highest risk was in the first 2 years in those who received adjuvant therapy. Our study suggests that greater diabetes screening and prevention strategies among breast cancer survivors may be warranted.

Impact of Clostridium difficile colitis on 5-year health outcomes in patients with ulcerative colitis.

BACKGROUND: Clostridium difficile colitis (CDC) is associated with an increased short-term mortality risk in hospitalised ulcerative colitis (UC) patients. We sought to determine whether CDC also impacts long-term risks of adverse health events in this population. AIM: To determine whether CDC also impacts long-term risks of adverse health events in this population. METHODS: A population-based retrospective cohort study was conducted of UC patients hospitalised in Ontario, Canada between 2002 and 2008. Patients with and without CDC were compared on the rates of adverse health events. The primary outcomes were the 5-year adjusted risks of colectomy and death. RESULTS: Among 181 patients with CDC and 1835 patients without CDC, the 5-year cumulative colectomy rates were 44% and 33% (P = 0.0052) and the 5-year cumulative mortality rates were 27% and 14% (P < 0.0001) respectively. CDC was associated with a higher adjusted 5-year risk of mortality [adjusted hazard ratio (aHR) 2.40, 95% CI 1.37-4.20], but not of colectomy (aHR 1.18, 95% CI 0.90-1.54). CDC impacted mortality risk both during index hospitalisation (adjusted odds ratio 8.90, 95% CI 2.80-28.3) as well as over 5 years following hospital discharge among patients who recovered from their acute illness (aHR 2.41, 95% CI 1.37-4.22). Colectomy risk was not influenced by CDC in this cohort. CONCLUSION: Clostridium difficile colitis is associated with increased short-term and long-term mortality risks among hospitalised ulcerative colitis patients. As colectomy risk is not similarly impacted by Clostridium difficile colitis, factors predictive of death among C. difficile-infected ulcerative colitis patients require elucidation.

Using the Johns Hopkins' Aggregated Diagnosis Groups (ADGs) to predict 1-year mortality in population-based cohorts of patients with diabetes in Ontario, Canada.

AIMS: There are limited validated methods to ascertain comorbidities for risk adjustment in ambulatory populations of patients with diabetes using administrative health-care databases. The objective was to examine the ability of the Johns Hopkins' Aggregated Diagnosis Groups to predict mortality in population-based ambulatory samples of both incident and prevalent subjects with diabetes. METHODS: Retrospective cohorts constructed using population-based administrative data. The incident cohort consisted of all 346,297 subjects diagnosed with diabetes between 1 April 2004 and 31 March 2008. The prevalent cohort consisted of all 879,849 subjects with pre-existing diabetes on 1 January, 2007. The outcome was death within 1 year of the subject's index date. RESULTS: A logistic regression model consisting of age, sex and indicator variables for 22 of the 32 Johns Hopkins' Aggregated Diagnosis Group categories had excellent discrimination for predicting mortality in incident diabetes patients: the c-statistic was 0.87 in an independent validation sample. A similar model had excellent discrimination for predicting mortality in prevalent diabetes patients: the c-statistic was 0.84 in an independent validation sample. Both models demonstrated very good calibration, denoting good agreement between observed and predicted mortality across the range of predicted mortality in which the large majority of subjects lay. For comparative purposes, regression models incorporating the Charlson comorbidity index, age and sex, age and sex, and age alone had poorer discrimination than the model that incorporated the Johns Hopkins' Aggregated Diagnosis Groups. CONCLUSIONS: Logistical regression models using age, sex and the John Hopkins' Aggregated Diagnosis Groups were able to accurately predict 1-year mortality in population-based samples of patients with diabetes.

Effect of subsequent pregnancies on the risk of developing diabetes following a first pregnancy complicated by gestational diabetes: a population-based study.

AIMS: Women with gestational diabetes mellitus have a high risk of developing Type 2 diabetes, secondary to post-partum progression of the chronic pancreatic ß-cell defect that underlies their presenting with dysglycaemia in pregnancy. Insulin-sensitizing therapy can decrease this risk of Type 2 diabetes, partly by offloading the secretory demand placed on the ß-cells. Conversely, however, it is not known whether the considerable secretory demands posed by the physiologic insulin resistance of a subsequent pregnancy could accelerate the progression to Type 2 diabetes. Thus, we sought to determine whether subsequent pregnancies are associated with the risk of developing diabetes following gestational diabetes. METHODS: Using a population-based administrative database, we identified all women in Ontario, Canada, whose first pregnancy was between April 2000 and March 2007 and was complicated by gestational diabetes (n = 16,817). This cohort was followed for a median 4.5 years for subsequent pregnancies and the development of diabetes. RESULTS: During follow-up, 2731 women (16.2%) developed diabetes. Gestational diabetes recurred in 41.5% of subsequent pregnancies. Interestingly, after covariate adjustment, a subsequent pregnancy was associated with a reduced risk of diabetes (adjusted hazard ratio (HR) = 0.68, 95%CI 0.60-0.76; P < 0.0001). Specifically, whereas each subsequent gestational diabetes pregnancy was associated with a modestly increased risk of diabetes (adjusted HR = 1.16, 95%CI 1.01-1.34; P = 0.03), each non-gestational diabetes pregnancy was associated with a significantly reduced risk of diabetes (adjusted HR=0.34, 95%CI 0.27-0.41; P < 0.0001). CONCLUSIONS: A subsequent pregnancy is not necessarily associated with an increased risk of Type 2 diabetes following gestational diabetes. Instead, the absence of recurrent gestational diabetes in a subsequent pregnancy may identify a lessened risk of developing Type 2 diabetes in this high-risk patient population.

Continental variations in IgA nephropathy among Asians.

BACKGROUND/AIMS: Local variations in patient demographics and medical practice can contribute to differences in renal outcomes in patients with IgA nephropathy. We report the experiences of two groups of Asians with IgA nephropathy across continents. MATERIALS AND METHODS: We retrospectively examined two cohorts of Asian patients with IgA nephropathy from The King Chulalongkorn Memorial Hospital registry, Thailand (1994 - 2005), and The Metropolitan Toronto Glomerulonephritis registry, Canada (1975 - 2006), and compared their baseline characteristics. Slope of estimated glomerular filtration rate (eGFR) in each group was approximated using separate repeated measures regression models for each country. RESULTS: There were 152 Canadian and 76 Thai patients. At the time of first presentation, Thai patients were more likely to be female (63.2 vs. 44.1%, p = 0.01), have less baseline proteinuria (1.2 vs. 1.7 g/d, p = 0.08) and more likely to receive angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin receptor blockers (ARB) (64.0 vs. 15.2%, p < 0.01), or prednisone (41.3 vs. 4.6%, p < 0.01). The annual change in estimated glomerular filtration rate (eGFR) for the Thai and Canadian groups were -0.82 ml/min/1.73 m2/year and -3.35 ml/min/1.73 m2/year, respectively, after adjustment for age, sex, mean arterial pressure (MAP), proteinuria, body mass index, Haas histological grade, chronicity scores and baseline medications. CONCLUSIONS: Although disease severity was similar among IgA nephropathy patients in Canada and Thailand, more Thai patients were on ACE-I/ARB or prednisone therapy at baseline. Further prospective research is needed to explore international differences in demographic and environmental factors, health resources, and disease management to determine how they may impact long-term outcomes in Asians with IgA nephropathy.

New use of rosiglitazone decreased following publication of a meta-analysis suggesting harm.

AIMS: It is uncertain whether meta-analyses lead to changes in prescribing practices. We studied trends in the prescribing of glucose-lowering therapy before and after the publication of a meta-analysis suggesting harm from rosiglitazone. METHODS: We examined the prescription records of all residents of Ontario, Canada, aged > or = 66 years. For each week between January and December 2007, we identified new users of five categories of glucose-lowering medications: rosiglitazone, pioglitazone, metformin, glibenclamide (glyburide) and insulin. The effect of the meta-analysis was assessed using interventional autoregressive integrated moving-average models. RESULTS: Following the release of the meta-analysis, there was a sudden decline in new users of rosiglitazone (P = 0.01), mirrored by a nearly identical but transient increase in new users of pioglitazone (P < 0.001). There was also a net decline in new users of thiazolidinediones as a class (P < 0.001). The number of new users of other glucose-lowering medications did not change. CONCLUSIONS: A highly-publicized meta-analysis regarding rosiglitazone's potential harms led to an abrupt decline in new users of the drug, as well as a transient surge in new use of pioglitazone.

Age-social stratification designs had a negligible impact on income-mortality associations.

OBJECTIVES: Age-social stratification has been used to offset socioeconomic status (SES) misclassification due to cohort effects. This study was to evaluate whether age-income stratification designs generate comparable income-mortality associations as those whose income rankings are based on absolute thresholds. STUDY DESIGN AND SETTING: Using self-reported income as our SES variable, and mortality as our outcome measure, the impact of age-social stratification was examined in two distinct cohorts: one with acute myocardial infarction (AMI) (n=3,138), and the second free of cardiovascular disease (n=15,115). Age-adjusted income-mortality associations were compared between age-social stratification techniques, which used "age-relative" income thresholds and "absolute" income thresholds whose ranks were independent of patient age. RESULTS: In both cohorts, crude mortality inversely correlated with age and income. Techniques using "age-relative" income thresholds yielded similar adjusted odds ratio for mortality as did those that used "absolute" income threshold methods (differences in adjusted odds ratios [+/-95% confidence interval (CI)] between "absolute" and "age-relative" classifications for highest vs. lowest income tertiles: -0.05 [-0.24, 0.12] among patients with AMI and 0.05 [-0.03, 0.13] among patients without cardiovascular disease). CONCLUSION: More complex designs incorporating age-social stratification techniques generate similar income-mortality associations as more simplified approaches, which classified SES using absolute income thresholds.

Accuracy of administrative health data for the diagnosis of upper gastrointestinal diseases.

BACKGROUND: The use of administrative health data is increasingly common for the study of various medical and surgical diseases. The validity of diagnosis codes for the study of benign upper gastrointestinal disorders has not been well studied. METHODS: The authors abstracted the charts for 590 adult patients who underwent upper gastrointestinal endoscopy between January 1, 2000 and June 30, 2001 in Toronto, Ontario, Canada. Clinical diagnoses from medical records were compared with International Classification of Diseases Version 9 (ICD-9) codes in electronic hospital discharge abstracts. The primary analysis aimed to determine the sensitivity, specificity, and positive predictive value (PPV) of a most responsible "esophagitis" diagnosis code for the prediction of esophagitis. Secondary analyses determined the performance characteristics of the diagnostic codes for esophageal ulcer, esophageal stricture, gastroesophageal reflux disease (GERD), gastritis, gastric ulcer, and duodenal ulcer. RESULTS: The authors linked 500 patient records to electronic discharge abstracts. When listed as the most responsible diagnosis for admission, the ICD-9 codes for esophagitis showed a sensitivity of 46.79%, a specificity of 98.83%, and a PPV of 94.81%. When listed as a secondary diagnosis, the ICD-9 codes showed a sensitivity of 70.51%, a specificity of 97.67%, and a PPV of 93.22%. The diagnostic properties of ICD-9 codes for GERD (most responsible, secondary) were as follows: sensitivity (56.10%, 78.66%), specificity (98.51%, 96.73%), and PPV (94.84%, 92.14%). CONCLUSIONS: The ICD-9 diagnosis codes for benign upper gastrointestinal diseases are highly specific and associated with strong PPVs, but have poor sensitivity.

Utilisation of coronary angiography after acute myocardial infarction in Ontario over time: have referral patterns changed?

OBJECTIVE: To examine how physicians in Ontario, Canada, have altered their referral patterns for coronary angiography after acute myocardial infarction (AMI) over time. DESIGN: Retrospective analysis of multilinked administrative data. SETTING: Province of Ontario, Canada. PATIENTS: 146 365 Ontario AMI patients hospitalised between 1 April 1992 and 31 March 1999. MAIN OUTCOME MEASURES: Utilisation trends of coronary angiography among all patients, as well as within six subgroups: elderly (versus young), women (versus men), high (versus low) risk of 30 day mortality, high (versus low) socioeconomic status, cardiology (versus non-cardiology) attending physician specialty, and hospitals with (versus without) onsite revascularisation capacity. Cox proportional hazard models were adjusted for variations in patient, physician, and hospital characteristics over time. RESULTS: Angiography rates in Ontario increased from 23.2% in 1992 to 35.5% in 1999 (p < 0.0001). Increases in utilisation of coronary angiography were most pronounced among the elderly (12.4-24.3% v 39.3-54.4% for non-elderly patients, p < 0.0001), the affluent (24.6-38.7% v 22.0-32.3% for less affluent patients, p = 0.01), and those tended to by cardiologists (32.0-47.1% v 20.3-30.1% for non-cardiology attending specialties, p < 0.0001) after adjusting for changes in baseline patient, physician, and hospital characteristics over time. CONCLUSIONS: Despite universal health care availability, not all patients benefited equally from increases in service capacity for coronary angiography after AMI in Ontario. Wider implementation of data monitoring and explicit management systems may be required to ensure that appropriate utilisation of cardiac services is allocated to patients who are most in need.

Biology or bias: practice patterns and long-term outcomes for men and women with acute myocardial infarction.

OBJECTIVES: The goal of our study was to examine how age and gender affect the use of coronary angiography and the intensity of cardiac follow-up care within the first year after acute myocardial infarction (AMI). Another objective was to evaluate the association of age, gender and treatment intensity with five-year survival after AMI. BACKGROUND: Utilization rates of specialized cardiac services inversely correlate with age. Gender-specific practice patterns may also vary with age in a manner similar to known age-gender survival differences after AMI. METHODS: Using linked population-based administrative data, we examined the association of age and gender with treatment intensity and long-term survival among 25,697 patients hospitalized with AMI in Ontario between April 1, 1992, and December 31, 1993. A Cox proportional hazards model was used to adjust for socioeconomic status, illness severity, attending physician specialty and admitting hospital characteristics. RESULTS: After adjusting for baseline differences, the relative rates of angiography and follow-up specialist care for women relative to men, respectively, fell 17.5% (95% confidence interval [CI], 13.6 to 21.3, p < 0.001) and 10.2% (95% CI, 7.1 to 13.2, p < 0.001) for every 10-year increase in age. Conversely, long-term AMI survival rates in women relative to men improved with increasing age, such that the relative survival in women rose 14.2% (95% CI, 10.1 to 17.5, p < 0.001) for every 10-year age increase. CONCLUSIONS: Gender differences in the intensity of invasive testing and follow-up care are strongly age-specific. While care becomes progressively less aggressive among older women relative to men, survival advantages track in the opposite direction, with older women clearly favored. These findings suggest that biology is likely to remain the main determinant of long-term survival after AMI for women.

Investigating the determinants of decreasing postmyocardial infarction mortality: an analysis of in-hospital data from 1992 and 1997.

BACKGROUND: Although acute myocardial infarction (AMI) is the leading cause of mortality in the industrialized world, postmyocardial infarction mortality rates have been declining in recent decades. Two possible contributing factors toward this encouraging trend include changing patient characteristics and improved patient management. OBJECTIVES: To compare temporal changes in the characteristics and management of patients with AMI at a tertiary care hospital (Sunnybrook and Women's College Health Sciences Centre) in Toronto, Ontario. METHODS: Two hundred hospital charts of patients with AMI as the most responsible diagnosis were reviewed (100 from 1992 and 100 from 1997). One hundred thirty prespecified variables were extracted from each chart, with emphasis placed on baseline clinical characteristics, AMI management and survival. RESULTS: Between 1992 and 1997, AMI in-hospital mortality declined from 20% to 15%. Most baseline clinical characteristics (age, sex, comorbidity, cardiac history, and presenting symptoms and signs) were similar across the 1992 and 1997 patient populations. The only significant risk factor change involved an increase in the prevalence of hypercholesterolemia. In contrast, between 1992 and 1997 there was an increased in-hospital use of anticoagulants, antiplatelets, thrombolytics, beta-blockers, angiotensin-converting enzyme inhibitors and statins. Similarly, there was an increased use of coronary angioplasty and coronary bypass surgery. There was no significant change in the use of AMI therapies that are potentially harmful, including antiarrythmic agents and calcium channel blockers. CONCLUSIONS: AMI patient characteristics were similar between 1992 and 1997 but there were striking changes in AMI treatment patterns. The increased use of evidence-based pharmacotherapy may be the most significant contributing factor to declining postmyocardial infarction mortality.