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Background Variations in inpatient medical care are typically attributed to system, hospital or patient factors. Little is known about variations at the physician level within hospitals. We described the physician-level variation in clinical outcomes and resource use in general internal medicine (GIM). Methods This was an observational study of all emergency admissions to GIM at seven hospitals in Ontario, Canada, over a 5-year period between 2010 and 2015. Physician-level variations in inpatient mortality, hospital length of stay, 30-day readmission and use of 'advanced imaging' (CT, MRI or ultrasound scans) were measured. Physicians were categorised into quartiles within each hospital for each outcome and then quartiles were pooled across all hospitals (eg, physicians in the highest quartile at each hospital were grouped together). We report absolute differences between physicians in the highest and lowest quartiles after matching admissions based on propensity scores to account for patient-level variation. Results The sample included 103 085 admissions to 135 attending physicians. After propensity score matching, the difference between physicians in the highest and lowest quartiles for in-hospital mortality was 2.4% (95% CI 0.6% to 4.3%, p<0.01); for readmission was 3.3% (95% CI 0.7% to 5.9%, p<0.01); for advanced imaging was 0.32 tests per admission (95% CI 0.12 to 0.52, p<0.01); and for hospital length of stay was 1.2 additional days per admission (95% CI 0.5 to 1.9, p<0.01). Physician-level differences in length of stay and imaging use were consistent across numerous sensitivity analyses and stable over time. Differences in mortality and readmission were consistent across most sensitivity analyses but were not stable over time and estimates were limited by sample size. Conclusions Patient outcomes and resource use in inpatient medical care varied substantially across physicians in this study. Physician-level variations in length of stay and imaging use were unlikely to be explained by patient factors whereas differences in mortality and readmission should be interpreted with caution and could be explained by unmeasured confounders. Physician-level variations may represent practice differences that highlight quality improvement opportunities. [ABSTRACT FROM AUTHOR]

Background: A randomized controlled trial of adults with empyema recently demonstrated decreased length of stay in hospital in patients treated with intrapleurally administered dornase alfa and fibrinolytics compared to fibrinolytics alone. Whether this treatment strategy is safe and effective in children remains unknown.Methods/design: This study protocol is for a superiority, placebo-controlled, parallel-design, multicenter randomized controlled trial. The participants are previously well children admitted to a children's hospital with a diagnosis of empyema requiring chest tube insertion and fibrinolytics administered intrapleurally. Children will be randomized after the treating physician has decided that pleural drainage is required but prior to chest tube insertion. After chest tube insertion, participants in the treatment group will receive intrapleurally administered tissue plasminogen activator (tPA) 4 mg followed by dornase alfa 5 mg. Participants in the placebo group will receive tPA 4 mg followed by normal saline. Study treatments will be administered once daily for 3 days. All participants, parents or caregivers, clinicians, and research personnel will remain blinded. The primary outcome is length of stay from chest tube insertion to discharge from hospital. Secondary outcomes include time to meeting discharge criteria, chest tube duration, fever duration, need for additional procedures, adverse events, hospital readmission, cost of hospitalization, and mortality.Discussion: This multicenter randomized controlled trial will assess the safety, effectiveness, and cost-effectiveness of combined treatment with dornase alfa and fibrinolytics compared to fibrinolytics alone for the treatment of empyema in children.Trial Registration: ClinicalTrials.gov: NCT01717742 . Registered on 8 October 2012. [ABSTRACT FROM AUTHOR]

Background: Income-based deductibles are present in several provincial public drug plans in Canada and have been the subject of extensive debate. We studied the impact of such deductibles in British Columbia's Fair PharmaCare plan on drug and health care utilization among older adults.Methods: We used a quasi-experimental regression discontinuity design to compare the impact of deductibles in BC's PharmaCare plan between older community-dwelling adults registered for the plan who were born in 1928 through 1939 (no deductible) and those born in 1940 through 1951 (deductible equivalent to 2% of household income). We used 1.2 million person-years of data between 2003 and 2015 to study public drug plan expenditures, overall drug use, and physician and hospital resource utilization in these 2 groups.Results: The income-based deductible led to a 28.6% decrease in person-years in which public drug plan benefits were received (95% confidence interval [CI] -29.7% to -27.5%) and to a reduction in the per capita extent of annual benefits by $205.59 (95% CI -$247.81 to -$163.37). Despite this difference in public subsidy, we found no difference in the number of drugs received or in total drug spending once privately paid amounts were accounted for (p = 0.4 and 0.8, respectively). Further, we found only small or nonexistent changes in health care resource utilization at the 1939 threshold.Interpretation: A modest income-based deductible had a considerable impact on the extent of public subsidy for prescription drugs. However, it had only a trivial impact on overall access to medicines and use of other health services. Unlike copayments, modest income-based deductibles may safely reduce public spending on drugs for some population groups. [ABSTRACT FROM AUTHOR]

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Background: Vascular injuries add substantial complexity to trauma care, yet Canadian epidemiologic data on such injuries are not readily available. We conducted a retrospective cross-sectional study to examine temporal trends in the rate of hospital admissions for vascular injuries from 1991 to 2009 in Ontario. Methods: Individuals of any age admitted to hospital because of vascular trauma in Ontario were included. Details of vascular injury and patient demographic characteristics were recorded, hospital admission rates estimated and analyses stratified by sex, age, mechanism of injury, economic status and geographic location. Time-series analysis was used to examine trends in hospital admission rates. Results: Of the 8252 hospital admissions for vascular trauma, 4287 (52.0%) involved injuries to the upper limb and 1819 (22.0%) were due to transport-related causes. Overall, the annual rate declined significantly over time, from 3.3 per 100 000 in 1991 to 2.7 per 100 000 in 2009 (p < 0.01). The subgroups with the highest rates were young men, patients with a low economic status and those living in a rural location. Declines occurred in both sexes and in all age groups except those 65 years and older. The rates of vascular injury to the neck, thorax, upper limbs and lower limbs declined over time, but not the rate of abdominal vascular injury. Although the rate of non-transport-related vascular injuries declined, the rate of transport-related vascular injuries did not change significantly over time. Decreases in annual rates occurred in both low- and high-economic status groups and in urban populations but not in rural populations. Interpretation: Overall, the annual rate of hospital admissions for vascular trauma declined significantly in Ontario over the study period. Our findings have important implications for public health and the development of injury-prevention strategies, particularly for population subgroups at high risk of vascular injury. [ABSTRACT FROM AUTHOR]

Health care organizations continue to implement organization-wide educational approaches to enhance patient safety with less attention on evaluating the impact of these approaches. In this context, a study was conducted to measure the impact of an organization-wide patient safety network approach on patient safety event reporting. A time-series analysis with reported rates of adverse events (major and moderate), near misses, sentinel events, and incidents from 2 years prior through 13 months following implementation was conducted. Study findings include a significant increase in reporting of patient safety events (an approximately 50% increase in overall reporting of safety events was observed; p < .001), especially near misses (an approximately 100% increase following implementation; p = .002). Study findings suggest that a multifaceted networked approach does contribute to improving patient safety event reporting. [ABSTRACT FROM AUTHOR]

Background: Current evidence suggests that statin use plays an important role in improving adverse cardiovascular outcomes in patients with atherosclerosis. However, limited population-based data are available on use of statin therapy in these patients in Canada. We sought to study trends in statin use to treat these patients in Ontario during a 10-year period. Methods: We conducted a population-based cross-sectional time series analysis between April 1, 1995, and March 31, 2004, using health care data from Ontario, Canada. Results: During the study period, 343,154 elderly patients with atherosclerosis were identified. Of these, 235,615 (68.7%) had coronary artery diseases (CAD), 115,012 (33.5%) had cerebrovascular disease (CVD), and 23,886 (7.0%) had peripheral arterial disease (PAD). About 46% were women, and mean patient age was 77.1 (SD, 7.5) years. During the study period, the percentage of patients treated with a statin in each group increased considerably, from 9.8% to 55.3% in all atherosclerotic patients (P < .01), from 11.8% to 61.2% in CAD patients (P < .01), from 5.3% to 41.2% in CVD patients (P < .01), and from 6.8% to 43.3% in PAD patients (P < .01). During the entire study period, the percentage of statin users was lowest among PAD and CVD patients, followed by patients with both a history of PAD and CVD. Conclusion: The use of statin therapy in elderly patients with symptomatic atherosclerosis has increased substantially during the past decade, but many patients remain untreated. The suboptimal use is greatest among patients with PAD or CVD, or both, and lowest in patients with CAD. Given the heightened risk of cardiovascular adverse outcomes in patients with atherosclerosis, these data have important and immediate implications. [Copyright &y& Elsevier]

Abstract: Background: In light of growing concerns of bacterial resistance to fluoroquinolones, the province of Ontario instituted a fluoroquinolone restriction policy in March of 2001. The objective of this study was to examine the immediate impact of this policy on the rates of antibiotic prescription use and infectious disease-related hospitalizations among elderly individuals who are dispensed antibiotics. Methods: An interrupted time series analysis was conducted from January 1, 1994, to March 31, 2002, using administrative health care databases covering more than 1.4 million residents of Ontario, Canada, aged 65 years and older. Population rates of antibiotic use and infectious disease-related hospitalizations within 4 weeks after an antibiotic prescription were examined using interventional autoregressive integrated moving average models. Results: Immediately after the introduction of the fluoroquinolone policy, fluoroquinolone prescription rates decreased to approximately 70% of expected rates (P <.01). Approximately 30% higher than expected use of sulfonamide (P =.01) and urinary anti-infectives (primarily nitrofurantoin and trimethoprim; P <.01) were observed within 1 year after policy implementation. No significant changes in the use of any other groups of antibiotics were observed. Although no significant changes in the rates of overall infection-related hospital admissions among antibiotic users were observed, the rate of hospital admission for gastrointestinal infections was 32% lower than expected in the 1 year after the policy change (P <.01). The hospital admission rate for urinary tract infections was approximately 8% higher than expected (P <.01). Conclusions: These findings suggest that formulary restrictions to fluoroquinolones can be implemented effectively to decrease use among an elderly population without adverse impact on hospital admission rates. [Copyright &y& Elsevier]

Rationale Observational cohort studies are frequently used to measure the impact of therapies on the time to a particular outcome. Treatment often has a time-variant nature since it is frequently initiated at varying times during a patient’s follow-up. Studies in the medical literature frequently ignore the time-dependent nature of treatment exposure. Survivor treatment bias can arise when the time dependent nature of treatment exposure is ignored since patients who survived to receive treatment may be healthier than patients who died prior to receipt of treatment. Aims and objectives The objective of the current study was to explicitly quantify the magnitude of survivor-treatment bias. Methods Monte Carlo simulations using parameters obtained from an analysis of patients admitted to hospital with a diagnosis of acute myocardial infarction in Ontario, Canada. Results and conclusions When the true treatment was null (hazard ratio of 1), estimated treatment effects varied from a 4% reduction in mortality to a reduction in mortality of 27% when the time varying nature of the treatment was ignored. Furthermore, survivor-treatment bias increased as the time required foe exposed patients to receive treatment increased. Similarly, survivor treatment bias was amplified as exposure was defined to be exposure at any time prior to mortality compared to exposure within a fixed time interval starting at the time origin. Ignoring the time-dependent nature of treatment results in overly optimistic estimates of treatment effects. Depending on the period required for patients to initiate therapy, treatments with no effect on survival can appear to be strongly associated with improved survival. The current study is the first to explicitly quantify the magnitude of bias that results from ignoring the time-varying nature of treatment exposure in survival studies. [ABSTRACT FROM AUTHOR]

Objectives: To examine temporal trends in electroconvulsive therapy (ECT) use among all 12 million Ontario residents between January 1992 and December 2004 and to examine the differential trends in older adults, compared with younger ones.Methods: We undertook a time-series analysis to examine annual trends in the use and prevalence of ECT, using linked provincial datasets. Descriptive data were presented for the population as a whole, and then trends were described separately by age groups (younger and older). As a comparator, we similarly examined antidepressant prevalence for older adults over the same time period.Results: Overall rates of ECT prevalence were stable. Annual population rates of individuals receiving ECT increased by about 27%, from 12.3 per 100 000 population in 1992 to 15.6 per 100 000 in 1997, and then decreased to 12.5 per 100 000 by 2004. The population rates of ECT were about threefold higher among older adults, relative to the younger population. Antidepressant prevalence increased by 90.1% among older adults over the same time period. The female-to-male ratio was relatively stable over time.Conclusions: The rate of ECT has been relatively stable since the early 1990s. Older adults were much more likely to be prescribed a course of ECT than younger adults. ECT remains a commonly prescribed treatment, particularly in old age. [ABSTRACT FROM AUTHOR]

Background: Canada''s universal health care system is designed to ensure equitable access to medical care based on need rather than socioeconomic status, although a number of studies indicate a preferential access and greater use of specialist services for those patients in higher socioeconomic groups. Objectives: The primary objective of this study was to determine whether socioeconomic status influences access to specialist care by a dermatologist for the management of acne in Ontario, Canada. A secondary objective was to determine whether the urban-rural dwelling status of patients affects access to specialty care. Methods: We conducted a population-based cohort study using administrative health care databases covering more than 12 million residents of Ontario. Individuals age 12 to 27 years with a new diagnosis of acne by a general practitioner were identified as belonging to 1 of 5 socioeconomic groups based on median annual neighborhood household income. Patients were then observed for 2 years after the index visit to identify visits to a dermatologist. The main outcome measure was visitation to a dermatologist within 2 years of an initial diagnosis of acne. Results: The study cohort consisted of 295,469 patients given a diagnosis of acne by their primary care physician of which 59,799 (20%) were subsequently referred to a dermatologist. Of those in the lowest income group of less than Can $20,000, 17% were referred to a dermatologist, as compared with 24% in the highest income group of greater than Can $80,000 (P value for trend < .001). Furthermore, patients living in an urban area had a 43% greater likelihood of being referred to a dermatologist (odds ratio 1.43, 95% confidence interval 1.39-1.48) as compared with patients in a rural location. Limitations: Limitations of our study include imputing socioeconomic status of patients on the basis of median income at the neighborhood level rather than on the basis of data on individual patients. Furthermore, our use of administrative databases did not allow us to characterize the severity of acne in our population cohort and whether that would affect referral patterns. Conclusion: Within Canada''s universal health care system, those likely to be in lower socioeconomic groups are significantly less likely to visit a dermatologist for specialist consultation. [Copyright &y& Elsevier]

Background: The question of how best to reduce waiting times for health care, particularly surgical procedures such as hip and knee replacements is among the most pressing concern of the Canadian health care system. The objective of this study was to test the hypothesis that significant seasonal variation exists in the performance of hip and knee replacement surgery in the province of Ontario. Methods: We performed a retrospective, cross-sectional time series analysis examining all hip and knee replacement surgeries in people over the age of 65 in the province of Ontario, Canada between 1992 and 2002. The main outcome measure was monthly hospitalization rates per 100 000 population for all hip and knee replacements. Results: There was a marked increase in the rate of hip and knee replacement surgery over the 10-year period as well as an increasing seasonal variation in surgeries. Highly significant (Fisher Kappa = 16.05, p < 0.01; Bartlett-Kolmogorov-Smirnov Test = 0.31, p < 0.01) and strong (R2 Autoreg = 0.85) seasonality was identified in the data. Conclusion: Holidays and utilization caps appear to exert a significant influence on the rate of service provision. It is expected that waiting times for hip and knee replacement could be reduced by reducing seasonal fluctuations in service provision and benchmarking services to peak delivery. The results highlight the importance of system behaviour in seasonal fluctuation of service delivery. [ABSTRACT FROM AUTHOR]

Context The benefits of cardiovascular therapies such as statins for secondary prevention have been well documented, although they may not be optimally used in patients most likely to benefit. Ideally, aggressiveness in the use of these beneficial therapies should correlate with baseline cardiovascular risk. Objective To examine the association between physicians' treatment aggressiveness and baseline cardiovascular risk. Design, Setting, and Patients Retrospective cohort study incorporating the use of multiple linked health care administrative databases covering more than 1.4 million elderly residents of Ontario. We included 396 077 patients aged 66 years or older who had a history of cardiovascular disease or diabetes while undergoing medical treatment and who were alive on April 1, 1998. Baseline cardiovascular risk was derived using a risk-adjustment index in which we modeled probability of death after 3 years of follow-up. Main Outcome Measure Likelihood of statin use, stratified by baseline cardiovascular risk, after adjusting for age, sex, socioeconomic status, and rural or urban residence. Results Only 75 617 patients (19.1%) in this secondary prevention cohort were prescribed statins. In patients 66 to 74 years old, the adjusted probabilities of statin prescription were 37.7%, 26.7%, and 23.4% in the categories of low, intermediate, and high baseline risk, respectively. The likelihood of statin prescription was 6.4% lower (adjusted odds ratio, 0.94; 95% confidence interval, 0.93-0.95) for each year of increase in age and each 1% increase in predicted 3-year mortality risk. The influence of age also interacted synergistically with baseline risk on the prescription of statins (P<.001). Conclusions We found that prescription of statins diminished progressively as baseline cardiovascular risk and future probability of death increased. Since the benefits of a therapy are dependent on the baseline risk, the maximum benefits of statins may not be fully realized... [ABSTRACT FROM AUTHOR]

Background: The study of the seasonal variation of disease is receiving increasing attention from health researchers. Available statistical tests for seasonality typically indicate the presence or absence of statistically significant seasonality but do not provide a meaningful measure of its strength. Methods: We propose the coefficient of determination of the autoregressive regression model fitted to the data RAutoreg² as a measure for quantifying the strength of the seasonality. The performance of the proposed statistic is assessed through a simulation study and using two data sets known to demonstrate statistically significant seasonality: atrial fibrillation and asthma hospitalizations in Ontario, Canada. Results: The simulation results showed the power of the RAutoreg² in adequately quantifying the strength of the seasonality of the simulated observations for all models. In the atrial fibrillation and asthma datasets, while the statistical tests such as Bartlett's Kolmogorov-Smirnov (BKS) and Fisher's Kappa support statistical evidence of seasonality for both, the RAutoreg² quantifies the strength of that seasonality. Corroborating the visual evidence that asthma is more conspicuously seasonal than atrial fibrillation, the calculated RAutoreg² for atrial fibrillation indicates a weak to moderate seasonality RAutoreg² = 0.44, 0.28 and 0.45 for both genders, males and females respectively), whereas for asthma, it indicates a strong seasonality RAutoreg² 0.82, 0.78 and 0.82 for both genders, male and female respectively). Conclusions: For the purposes of health services research, evidence of the statistical presence of seasonality is insufficient to determine the etiologic, clinical and policy relevance of findings. Measurement of the strength of the seasonal effect, as can be determined using the RAutoreg² technique, is also important in order to provide a robust sense of seasonality. [ABSTRACT FROM AUTHOR]

An introduction to the journal is presented wherein the editors discuss the launch of an initiative on health services, published within the issue, the recognition of Canada as an international leader in health services research, and the goal of the "CMAJ: Canadian Medical Association Journal."

Background: The Randomized Aldactone Evaluation Study (RALES) demonstrated that spironolactone significantly improves outcomes in patients with severe heart failure. Use of angiotensin-converting–enzyme (ACE) inhibitors is also indicated in these patients. However, life-threatening hyperkalemia can occur when these drugs are used together. Methods: We conducted a population-based time-series analysis to examine trends in the rate of spironolactone prescriptions and the rate of hospitalization for hyperkalemia in ambulatory patients before and after the publication of RALES. We linked prescription-claims data and hospital-admission records for more than 1.3 million adults 66 years of age or older in Ontario, Canada, for the period from 1994 through 2001. Results: Among patients treated with ACE inhibitors who had recently been hospitalized for heart failure, the spironolactone-prescription rate was 34 per 1000 patients in 1994, and it increased immediately after the publication of RALES, to 149 per 1000 patients by late 2001 (P<0.001). The rate of hospitalization for hyperkalemia rose from 2.4 per 1000 patients in 1994 to 11.0 per 1000 patients in 2001 (P<0.001), and the associated mortality rose from 0.3 per 1000 to 2.0 per 1000 patients (P<0.001). As compared with expected numbers of events, there were 560 (95 percent confidence interval, 285 to 754) additional hyperkalemia-related hospitalizations and 73 (95 percent confidence interval, 27 to 120) additional hospital deaths during 2001 among older patients with heart failure who were treated with ACE inhibitors in Ontario. Publication of RALES was not associated with significant decreases in the rates of readmission for heart failure or death from all causes. Conclusions: The publication of RALES was associated with abrupt increases in the rate of prescriptions for spironolactone and in hyperkalemia-associated morbidity and mortality. Closer laboratory monitoring and more judicious use of spironolactone may reduce the occurrence of this complication. N Engl J Med 2004;351:543-51. [ABSTRACT FROM AUTHOR]

Purpose: Previous studies have shown hematologists and medical oncologists may not accept the financial limits set by governing agencies on patient access to oral chemotherapy. The purpose of this study was to capture the methods physicians used to overcome barriers to accessing chemotherapeutic regimens for their patients. Methods: A total of 640 medical oncologists and hematologists across Canada were surveyed using a 13-item Web-based survey tool. The survey was delivered by e-mail with three follow-up reminders. After a response period of 3 months, results were collated and analyzed with descriptive statistics. Results: Of the 640 invitations, 568 were successfully delivered, and 183 responses were received (response rate, 32.0%). Among respondents, 101 treated solid malignancies (55.2%), 49 treated nonsolid malignancies (26.8%), and 33 treated both (18.0%). To overcome funding barriers, participating oncologists enrolled patients onto clinical trials (90.5%), used compassionate access programs (96.1%), and made special requests to government (91.8%). Other methods included writing false claims on forms to fit funding criteria for drugs (31.1%) and using leftover drug supplies (31.0%). Physicians felt their inability to obtain unfunded medications had a negative impact on their patients' clinical outcomes (56.0%) and psychosocial quality of life (73.0%). Only 28.5% of physicians contacted their governing body with concerns about oral chemotherapy funding. Conclusion: Canadian physicians use numerous methods to obtain unfunded oral chemotherapies, including falsifying claims on access forms and submitting special requests to government agencies. Further study is warranted to explore the disconnection between policymakers and physicians with regard to funding of oral chemotherapies. [ABSTRACT FROM AUTHOR]

Background. Inuit infants who reside in the Nunavut (NU) regions of Arctic Canada have extremely high rates of lower respiratory tract infections (LRTIs) associated with significant health expenditures, but the costs in other regions of Arctic Canada have not been documented. Objective. This prospective surveillance compares, across most of Arctic Canada, the rates and costs associated with LRTI admissions in infants less than 1 year of age, and the days of hospitalization and costs adjusted per live birth. Design. This was a hospital-based surveillance of LRTI admissions of infants less than 1 year of age, residing in Northwest Territories (NT), the 3 regions of Nunavut (NU); [Kitikmeot (KT), Kivalliq (KQ) and Qikiqtani (QI)] and Nunavik (NK) from 1 January 2009 to 30 June 2010. Costs were obtained from the territorial or regional governments and hospitals, and included transportation, hospital stay, physician fees and accommodation costs. The rates of LRTI hospitalizations, days of hospitalization and associated costs were calculated per live birth in each of the 5 regions. Results. There were 513 LRTI admissions during the study period. For NT, KT, KQ, QI and NK, the rates of LRTI hospitalization per 100 live births were 38, 389, 230, 202 and 445, respectively. The total days of LRTI admission per live birth were 0.25, 3.3, 2.6, 1.7 and 3 for the above regions. The average cost per live birth for LRTI admission for these regions was $1,412, $22,375, $14,608, $8,254 and $10,333. The total cost for LRTI was $1,498,232 in NT, $15,662,968 in NU and $3,874,881 in NK. Medical transportation contributed to a significant proportion of the costs. Conclusion. LRTI admission rates in NU and Nunavik are much higher than that in NT and remain among the highest rates globally. The costs of these admissions are exceptionally high due to the combination of very high rates of admission, very expensive medical evacuations and prolonged hospitalizations. Decreasing the rates of LRTI in this population could result in substantial health savings. [ABSTRACT FROM AUTHOR]

Abstract: Background: For patients taking oral anticoagulants (OAC), the proportion of time spent in the therapeutic range is strongly associated with bleeding and thromboembolic risk. Previous studies examining OAC control may not generalize because the patient population was select or INR capture was incomplete. Objectives: Measure OAC control for an entire population of elderly people and determine patient factors associated with OAC control. Patients: People in Eastern Ontario without valve replacement aged 65 years or greater who were treated with warfarin between 1 September 1999 and 1 September 2000. Design: Retrospective cohort study using population-based administrative databases. OAC control was measured as the proportion of days in therapeutic range (PDTR), defined as the number days with the INR between 2 and 3 divided by total number of days observation. Linear interpolation was used to determine INR levels between measures. Negative binomial regression was used to identify patient factors independently associated with PDTR. We also determined which factors were associated with proportion of days with a critically low (<1.5) or critically high (≥5) INR. Results: 7179 people were followed for a total of 3238 years. 15% of people were hospitalized during the study. Overall, PDTR was 59.2% (95% CI 59.1%–59.2%). Independent of all other significant factors, hospitalization was associated with a 15% decrease in the PDTR 15% (rate ratio 0.85, 95% CI 0.83–0.87). Hospitalization was also independently associated with greater proportion of time with a critically low INR (rate ratio 1.68, 95% CI 1.51–1.88) and a critically high INR (1.70, 95% CI 1.38–2.08). Conclusions: Elderly people in eastern Ontario taking warfarin were therapeutic 59.2% of the time. Independent of other patient factors, patients who are hospitalized have the greatest risk of poor anticoagulation control. Control for anticoagulated patients who get hospitalized should be reviewed to determine if and how it could be improved. [Copyright &y& Elsevier]

Objective. Croup is the most common form of airway obstruction in children. Known to be primarily viral, the seasonality of croup has been examined largely through its association with the human para-influenza viruses. This study examined the seasonal pattern of croup hospitalizations in relation to age and gender for the province of Ontario during a 14-year period. Methods. A retrospective, population-based study design was used to examine seasonal and temporal patterns of croup hospitalizations from April 1, 1988, to March 31, 2002. All residents of Ontario who were aged 0 to 4 years and eligible for universal health coverage during the study period were included for analysis. Time-series analyses then were conducted on monthly aggregations of hospitalizations. Results. This study found strong evidence of croup hospitalization seasonality, with a biennial midautumn peak and annual summer trough, evident throughout the 14-year study period (Fisher's κ = 51.11; Bartlett Kolmogorov Smirnov = 0.552). The pattern was observed in all children aged 0 to 4, although boys were hospitalized 2 times more often than girls of the same age. Rates of croup hospitalization were lower for children aged 1 to 4 years than for children aged 0 to <1. A marked decrease in croup hospitalizations was observed after the winter of 1993/1994 and continued to decrease in a step-wise manner for the remainder of the study period. Conclusions. This study delineates a clear biennial pattern of seasonal croup hospitalizations, varying by age and gender, with a large decrease in hospitalizations after the winter of 1993/1994. It is expected that these findings will have important implications for the treatment and management of childhood croup. [ABSTRACT FROM AUTHOR]