P C Austin

Summary

Affiliation: Institute for Clinical Evaluative Sciences
Country: Canada

Publications

  1. ncbi Comparing hierarchical modeling with traditional logistic regression analysis among patients hospitalized with acute myocardial infarction: should we be analyzing cardiovascular outcomes data differently?
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Am Heart J 145:27-35. 2003
  2. ncbi Generating survival times to simulate Cox proportional hazards models with time-varying covariates
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Stat Med 31:3946-58. 2012
  3. ncbi Interpreting the concordance statistic of a logistic regression model: relation to the variance and odds ratio of a continuous explanatory variable
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    BMC Med Res Methodol 12:82. 2012
  4. ncbi Comparative ability of comorbidity classification methods for administrative data to predict outcomes in patients with chronic obstructive pulmonary disease
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Ann Epidemiol 22:881-7. 2012
  5. ncbi Regression trees for predicting mortality in patients with cardiovascular disease: what improvement is achieved by using ensemble-based methods?
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Biom J 54:657-73. 2012
  6. ncbi Using the Johns Hopkins' Aggregated Diagnosis Groups (ADGs) to predict 1-year mortality in population-based cohorts of patients with diabetes in Ontario, Canada
    P C Austin
    Institute for Clinical Evaluative Sciences, University of Toronto, Ontario, Canada
    Diabet Med 29:1134-41. 2012
  7. ncbi Using the Johns Hopkins Aggregated Diagnosis Groups (ADGs) to predict mortality in a population-based cohort of adults with schizophrenia in Ontario, Canada
    Peter C Austin
    Institute for Clinical Evaluative Sciences, University of Toronto, Toronto, Ontario, Canada
    Psychiatry Res 196:32-7. 2012
  8. ncbi Type I error rates, coverage of confidence intervals, and variance estimation in propensity-score matched analyses
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Canada
    Int J Biostat 5:Article 13. 2009
  9. ncbi Optimal caliper widths for propensity-score matching when estimating differences in means and differences in proportions in observational studies
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ont, Canada
    Pharm Stat 10:150-61. 2011
  10. ncbi The performance of different propensity-score methods for estimating relative risks
    Peter C Austin
    Institute for Clinical Evaluative Sciences, G1 06, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada
    J Clin Epidemiol 61:537-45. 2008

Detail Information

Publications116 found, 100 shown here

  1. ncbi Comparing hierarchical modeling with traditional logistic regression analysis among patients hospitalized with acute myocardial infarction: should we be analyzing cardiovascular outcomes data differently?
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Am Heart J 145:27-35. 2003
    ..Furthermore, imputing characteristics measured at higher levels of the hierarchy to the patient-level artificially inflates the amount of available information on the effect of higher-level characteristics on outcomes...
  2. ncbi Generating survival times to simulate Cox proportional hazards models with time-varying covariates
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Stat Med 31:3946-58. 2012
    ..This is compared with the statistical power to detect as statistically significant a binary time-invariant covariate...
  3. ncbi Interpreting the concordance statistic of a logistic regression model: relation to the variance and odds ratio of a continuous explanatory variable
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    BMC Med Res Methodol 12:82. 2012
    ..When outcomes are binary, the c-statistic (equivalent to the area under the Receiver Operating Characteristic curve) is a standard measure of the predictive accuracy of a logistic regression model...
  4. ncbi Comparative ability of comorbidity classification methods for administrative data to predict outcomes in patients with chronic obstructive pulmonary disease
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Ann Epidemiol 22:881-7. 2012
    ..Our objective was to compare the ability of the Charlson index, the Elixhauser method, and the Johns Hopkins' Aggregated Diagnosis Groups (ADGs) to predict outcomes in patients with COPD...
  5. ncbi Regression trees for predicting mortality in patients with cardiovascular disease: what improvement is achieved by using ensemble-based methods?
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Biom J 54:657-73. 2012
    ....
  6. ncbi Using the Johns Hopkins' Aggregated Diagnosis Groups (ADGs) to predict 1-year mortality in population-based cohorts of patients with diabetes in Ontario, Canada
    P C Austin
    Institute for Clinical Evaluative Sciences, University of Toronto, Ontario, Canada
    Diabet Med 29:1134-41. 2012
    ..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...
  7. ncbi Using the Johns Hopkins Aggregated Diagnosis Groups (ADGs) to predict mortality in a population-based cohort of adults with schizophrenia in Ontario, Canada
    Peter C Austin
    Institute for Clinical Evaluative Sciences, University of Toronto, Toronto, Ontario, Canada
    Psychiatry Res 196:32-7. 2012
    ..845 and 0.836 in the derivation and validation samples, respectively. Furthermore, the model demonstrated very good calibration...
  8. ncbi Type I error rates, coverage of confidence intervals, and variance estimation in propensity-score matched analyses
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Canada
    Int J Biostat 5:Article 13. 2009
    ..Finally, accounting for the matched nature of the sample resulted in estimates of standard error that more closely reflected the sampling variability of the treatment effect compared to when matching was not taken into account...
  9. ncbi Optimal caliper widths for propensity-score matching when estimating differences in means and differences in proportions in observational studies
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ont, Canada
    Pharm Stat 10:150-61. 2011
    ..When all of the covariates were binary, then the choice of caliper width had a much smaller impact on the performance of estimation of risk differences and differences in means...
  10. ncbi The performance of different propensity-score methods for estimating relative risks
    Peter C Austin
    Institute for Clinical Evaluative Sciences, G1 06, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada
    J Clin Epidemiol 61:537-45. 2008
    ..Conditioning on the propensity-score results in unbiased estimation of the expected difference in observed responses to two treatments. The performance of propensity-score methods for estimating relative risks has not been studied...
  11. ncbi Bayes rules for optimally using Bayesian hierarchical regression models in provider profiling to identify high-mortality hospitals
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario
    BMC Med Res Methodol 8:30. 2008
    ..Several researchers have shown that some degree of misclassification will result when hospital report cards are produced. The impact of misclassifying hospital performance can be quantified using different loss functions...
  12. ncbi Pisces did not have increased heart failure: data-driven comparisons of binary proportions between levels of a categorical variable can result in incorrect statistical significance levels
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    J Clin Epidemiol 61:295-300. 2008
    ....
  13. ncbi A critical appraisal of propensity-score matching in the medical literature between 1996 and 2003
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ont, Canada
    Stat Med 27:2037-49. 2008
    ..We provide guidelines for the analysis and reporting of studies that employ propensity-score matching...
  14. ncbi Propensity-score matching in the cardiovascular surgery literature from 2004 to 2006: a systematic review and suggestions for improvement
    Peter C Austin
    Institute for Clinical Evaluative Sciences, the Department of Public Health Sciences, University of Toronto, Ontario, Canada
    J Thorac Cardiovasc Surg 134:1128-35. 2007
    ..I conducted a systematic review of the use of propensity score matching in the cardiovascular surgery literature. I examined the adequacy of reporting and whether appropriate statistical methods were used...
  15. ncbi Bootstrap model selection had similar performance for selecting authentic and noise variables compared to backward variable elimination: a simulation study
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    J Clin Epidemiol 61:1009-17.e1. 2008
    ..The performance of this method for identifying predictor variables has not been examined...
  16. ncbi Using the bootstrap to improve estimation and confidence intervals for regression coefficients selected using backwards variable elimination
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ont, Canada
    Stat Med 27:3286-300. 2008
    ..We illustrate the utility of our method by applying it to a large sample of subjects hospitalized with a heart attack...
  17. ncbi A comparison of the statistical power of different methods for the analysis of cluster randomization trials with binary outcomes
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ont, Canada
    Stat Med 26:3550-65. 2007
    ..02. The largest observed difference in power between two different statistical methods across the 240 scenarios and 15 pair-wise comparisons of methods was 0.14...
  18. ncbi The performance of different propensity score methods for estimating marginal odds ratios
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Stat Med 26:3078-94. 2007
    ..8 to 59.2 per cent. For both methods, relative bias was proportional to the true odds ratio. Finally, matching on the propensity score tended to result in estimators with the lowest MSE...
  19. ncbi A comparison of regression trees, logistic regression, generalized additive models, and multivariate adaptive regression splines for predicting AMI mortality
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ont, Canada
    Stat Med 26:2937-57. 2007
    ..However, the logistic regression model had performance comparable to that of more flexible, data-driven models such as GAMs and MARS...
  20. ncbi A comparison of propensity score methods: a case-study estimating the effectiveness of post-AMI statin use
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Stat Med 25:2084-106. 2006
    ..5 per cent, while estimates of the relative risk reduction ranged from 13.3 to 17.0 per cent. Adjusted estimates of the reduction in the odds of 3-year death varied from 15 to 24 per cent across the different propensity score methods...
  21. ncbi Missed opportunities in the secondary prevention of myocardial infarction: an assessment of the effects of statin underprescribing on mortality
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Am Heart J 151:969-75. 2006
    ..We explored the potential reduction in mortality at the population level that could result from improving statin prescribing among patients least likely to be prescribed a statin after acute myocardial infarction (AMI)...
  22. ncbi How many "Me-Too" drugs are enough? The case of physician preferences for specific statins
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Canada
    Ann Pharmacother 40:1047-51. 2006
    ..The increasing availability of "Me-Too" drugs has provided considerable treatment options for clinicians. However, the number of such drugs within a class that are actually used by clinicians has not been well studied...
  23. ncbi A comparison of the ability of different propensity score models to balance measured variables between treated and untreated subjects: a Monte Carlo study
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ont, Canada
    Stat Med 26:734-53. 2007
    ..Finally, the mean squared error for estimating a null treatment effect was lower when either of the first two propensity scores was used compared to when either of the last two propensity score models was used...
  24. ncbi Conditioning on the propensity score can result in biased estimation of common measures of treatment effect: a Monte Carlo study
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ont, Canada
    Stat Med 26:754-68. 2007
    ..In several settings with non-linear treatment effects, marginal and conditional treatment effects do not coincide...
  25. ncbi Testing multiple statistical hypotheses resulted in spurious associations: a study of astrological signs and health
    Peter C Austin
    Institute for Clinical Evaluative Sciences, G1 06, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5 Canada
    J Clin Epidemiol 59:964-9. 2006
    ..To illustrate how multiple hypotheses testing can produce associations with no clinical plausibility...
  26. ncbi The impact of unmeasured clinical variables on the accuracy of hospital report cards: a Monte Carlo study
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Med Decis Making 26:447-66. 2006
    ..Hospital report cards are commonly produced using administrative data. The objective of this study was to determine the impact of unmeasured clinical data on the accuracy of hospitals' report cards...
  27. ncbi Quantifying the impact of survivor treatment bias in observational studies
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    J Eval Clin Pract 12:601-12. 2006
    ..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...
  28. ncbi R and S-PLUS produced different classification trees for predicting patient mortality
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    J Clin Epidemiol 61:1222-6. 2008
    ..Both R and S-PLUS allow users to fit classification and regression trees. The objective was to compare classification trees grown using R with those grown using S-PLUS...
  29. ncbi Comparing clinical and administrative data for profiling hospitals on postdischarge medication use by patients with acute myocardial infarction
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Am Heart J 156:595-605. 2008
    ..We determined the concordance between hospital-specific prescribing rates of evidence-based medical therapies obtained from clinical and administrative data in Ontario, Canada...
  30. ncbi Use of evidence-based therapies after discharge among elderly patients with acute myocardial infarction
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ont
    CMAJ 179:895-900. 2008
    ..We examined trends in the use of evidence-based drug therapies after discharge among elderly patients with myocardial infarction...
  31. ncbi Using the Johns Hopkins Aggregated Diagnosis Groups (ADGs) to predict mortality in a general adult population cohort in Ontario, Canada
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Department of Health Management, Policy and Evaluation, University of Ottawa, Ottawa, Ontario, Canada
    Med Care 49:932-9. 2011
    ..There are limited validated methods for risk adjustment in ambulatory populations using administrative healthcare databases...
  32. ncbi Comparing paired vs non-paired statistical methods of analyses when making inferences about absolute risk reductions in propensity-score matched samples
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ont, Canada
    Stat Med 30:1292-301. 2011
    ..We recommend using statistical methods for paired samples when using propensity-score matched samples for making inferences on the effect of treatment on the reduction in the probability of an event occurring...
  33. ncbi Statistical criteria for selecting the optimal number of untreated subjects matched to each treated subject when using many-to-one matching on the propensity score
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Am J Epidemiol 172:1092-7. 2010
    ..The authors recommend that, in most settings, researchers match either 1 or 2 untreated subjects to each treated subject when using propensity-score matching...
  34. ncbi Logistic regression had superior performance compared with regression trees for predicting in-hospital mortality in patients hospitalized with heart failure
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    J Clin Epidemiol 63:1145-55. 2010
    ..To compare the predictive accuracy of regression trees with that of logistic regression models for predicting in-hospital mortality in patients hospitalized with heart failure...
  35. ncbi The performance of different propensity-score methods for estimating differences in proportions (risk differences or absolute risk reductions) in observational studies
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, ON, Canada
    Stat Med 29:2137-48. 2010
    ..Differences between IPTW and propensity-score matching may reflect that these two methods estimate the average treatment effect and the average treatment effect for the treated, respectively...
  36. ncbi Primer on statistical interpretation or methods report card on propensity-score matching in the cardiology literature from 2004 to 2006: a systematic review
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario M4N 3M5, Canada
    Circ Cardiovasc Qual Outcomes 1:62-7. 2008
    ..The study objective was to examine the quality of the implementation of propensity-score matching in the general cardiology literature...
  37. ncbi Balance diagnostics for comparing the distribution of baseline covariates between treatment groups in propensity-score matched samples
    Peter C Austin
    Institute for Clinical Evaluative Sciences, G1 06, 2075 Bayview Avenue, Toronto, Ontario, Canada M4N 3M5
    Stat Med 28:3083-107. 2009
    ..In particular, methods based on comparing the distribution of the estimated propensity score between treated and untreated subjects are uninformative...
  38. ncbi A substantial and confusing variation exists in handling of baseline covariates in randomized controlled trials: a review of trials published in leading medical journals
    Peter C Austin
    Institute for Clinical Evaluative Sciences, G1 06, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada
    J Clin Epidemiol 63:142-53. 2010
    ..Furthermore, some have advocated for the use of regression adjustment to estimate the effect of treatment after adjusting for potential imbalances in prognostically important baseline covariates between treatment groups...
  39. ncbi The relative ability of different propensity score methods to balance measured covariates between treated and untreated subjects in observational studies
    Peter C Austin
    Institute for Clinical Evaluative Sciences, G1 06, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5 Canada
    Med Decis Making 29:661-77. 2009
    ..In the Monte Carlo simulations, propensity score matching tended to have either comparable or marginally superior performance compared with propensity-score weighting...
  40. ncbi Absolute risk reductions and numbers needed to treat can be obtained from adjusted survival models for time-to-event outcomes
    Peter C Austin
    Institute for Clinical Evaluative Sciences, G1 06, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada
    J Clin Epidemiol 63:46-55. 2010
    ..The resultant hazard ratio is a relative measure of effect that provides limited clinical information...
  41. ncbi Are (the log-odds of) hospital mortality rates normally distributed? Implications for studying variations in outcomes of medical care
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Department of Public Health Sciences, University of Toronto, Toronto, ON, Canada
    J Eval Clin Pract 15:514-23. 2009
    ..These models frequently assume a normal distribution for the provider-specific random effects. The appropriateness of this assumption for examining variations in health care outcomes has never been explicitly tested...
  42. ncbi The concept of the marginally matched subject in propensity-score matched analyses
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Ontario, Canada
    Pharmacoepidemiol Drug Saf 18:469-82. 2009
    ..The concept of the marginally matched subject can be used as a sensitivity analysis to examine the impact of the matching method on the estimates of treatment effectiveness...
  43. ncbi Absolute risk reductions, relative risks, relative risk reductions, and numbers needed to treat can be obtained from a logistic regression model
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario M4N 3M5, Canada
    J Clin Epidemiol 63:2-6. 2010
    ..Several authors have suggested that for dichotomous outcomes, RRs, RR reductions, absolute risk reductions, and the number needed to treat (NNT) are more clinically meaningful measures of treatment effect...
  44. ncbi Some methods of propensity-score matching had superior performance to others: results of an empirical investigation and Monte Carlo simulations
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, ON, Canada
    Biom J 51:171-84. 2009
    ..2 of the standard deviation of the logit of the propensity score and the use of calipers of width 0.02 and 0.03 tended to have superior performance for estimating treatment effects...
  45. ncbi Assessing balance in measured baseline covariates when using many-to-one matching on the propensity-score
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Pharmacoepidemiol Drug Saf 17:1218-25. 2008
    ..We illustrate our methods using a large sample of patients discharged from hospital with a diagnosis of a heart attack (acute myocardial infarction). The exposure was receipt of a prescription for a statin at hospital discharge...
  46. ncbi Goodness-of-fit diagnostics for the propensity score model when estimating treatment effects using covariate adjustment with the propensity score
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Pharmacoepidemiol Drug Saf 17:1202-17. 2008
    ..We illustrate our methods using a large dataset of patients discharged from hospital with a diagnosis of a heart attack (acute myocardial infarction). The exposure was receipt of a prescription for a beta-blocker at hospital discharge...
  47. ncbi Factors associated with the use of evidence-based therapies after discharge among elderly patients with myocardial infarction
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ont
    CMAJ 179:901-8. 2008
    ..Our objective was to identify the characteristics of patients, physicians, hospitals and communities associated with differences in the use of these medications after discharge...
  48. ncbi The mortality risk score and the ADG score: two points-based scoring systems for the Johns Hopkins aggregated diagnosis groups to predict mortality in a general adult population cohort in Ontario, Canada
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Med Care 49:940-7. 2011
    ..Logistic regression models that incorporated age, sex, and indicator variables for the Johns Hopkins' Aggregated Diagnosis Groups (ADGs) categories have been shown to accurately predict all-cause mortality in adults...
  49. ncbi The use of the propensity score for estimating treatment effects: administrative versus clinical data
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario M4N 3M5, Canada
    Stat Med 24:1563-78. 2005
    ..Furthermore, measures of treatment effectiveness were attenuated when obtained using clinical data compared to when administrative data were used...
  50. ncbi Bayeswatch: an overview of Bayesian statistics
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Canada
    J Eval Clin Pract 8:277-86. 2002
    ..It is noted that in this example, there are clinically relevant questions that are more easily addressed from a Bayesian perspective. Finally, areas in clinical research where Bayesian ideas are increasingly common are highlighted...
  51. ncbi The use of quantile regression in health care research: a case study examining gender differences in the timeliness of thrombolytic therapy
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Canada
    Stat Med 24:791-816. 2005
    ..Investigators who want to determine how a distribution of delays in treatment or of waiting times changes with patient or system characteristics should consider complementing their analyses with the use of quantile regression...
  52. ncbi The impact of the Women's Health Initiative study on incident clonidine use in Ontario, Canada
    Peter C Austin
    Institute of Clinical Evaluative Sciences, Department of Public Health Sciences, University of Toronto
    Can J Clin Pharmacol 11:e191-4. 2004
    ..There is some evidence that the antihypertensive agent clonidine can reduce the frequency of hot flashes associated with menopause...
  53. ncbi A brief note on overlapping confidence intervals
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    J Vasc Surg 36:194-5. 2002
    ..The purpose of this brief communication is to illustrate that the 95% confidence intervals for two means can overlap and yet the two means can be statistically significantly different from one another at the alpha = 0.05 level...
  54. ncbi A comparison of methods for analyzing health-related quality-of-life measures
    Peter C Austin
    Institute for Clinical Evaluative Sciences, North York, Ontario M4N 3M5, Canada
    Value Health 5:329-37. 2002
    ..The authors examine the performance of three different models for assessing the relationship between demographic characteristics and health status...
  55. ncbi Adverse effects of observational studies when examining adverse outcomes of drugs: case-control studies with low prevalence of exposure
    Peter C Austin
    Institute for Clinical Evaluative Sciences, North York, Ontario, Canada
    Drug Saf 25:677-87. 2002
    ..The objective of the current study was to examine the bias inherent in the odds ratio assessing the association between exposure and an adverse outcome when prevalence of exposure in the source population is extremely low...
  56. ncbi Inflation of the type I error rate when a continuous confounding variable is categorized in logistic regression analyses
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Canada
    Stat Med 23:1159-78. 2004
    ..Even when the confounder is divided in a five-level categorical variable, the inflation of the type I error rate remained high when both the sample size and the correlation between the risk factor and the confounder were high...
  57. ncbi Quantile regression: a statistical tool for out-of-hospital research
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Acad Emerg Med 10:789-97. 2003
    ..The flexibility of quantile regression models makes them particularly well suited to out-of-hospital research, and they may allow for more relevant evaluation of out-of-hospital system performance...
  58. ncbi A multicenter study of the coding accuracy of hospital discharge administrative data for patients admitted to cardiac care units in Ontario
    Peter C Austin
    Institute for Clinical Evaluative Sciences, University of Toronto, Toronto, Ontario, Canada
    Am Heart J 144:290-6. 2002
    ..The goal of this study was to examine the accuracy of the coding of acute myocardial infarction and other cardiac diagnoses in the Canadian Institute of Health Information hospital discharge abstracts...
  59. ncbi The use of fixed- and random-effects models for classifying hospitals as mortality outliers: a Monte Carlo assessment
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Med Decis Making 23:526-39. 2003
    ..There is an increasing movement towards the release of hospital "report-cards. "However, there is a paucity of research into the abilities of the different methods to correctly classify hospitals as performance outliers...
  60. ncbi A comparison of several regression models for analysing cost of CABG surgery
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, ON, Canada
    Stat Med 22:2799-815. 2003
    ..The final choice of regression model should be made after a careful assessment of how best to assess predictive ability and should be tailored to the particular data in question...
  61. ncbi Anxiety-related visits to Ontario physicians following September 11, 2001
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Department of Public Health Sciences, University of Toronto, Toronto, Ontario
    Can J Psychiatry 48:416-9. 2003
    ..To determine whether the climate of increased anxiety following the terrorist attacks of September 11, 2001, and the subsequent anthrax cases led to increased anxiety-related physician visits...
  62. ncbi An introduction to multilevel regression models
    P C Austin
    Institute for Clinical Evaluative Sciences, G 160, 2075 Bayview Avenue, North York, ON, M4N 3M5
    Can J Public Health 92:150-4. 2001
    ..In comparing the resultant models, we see that false inferences can be drawn by ignoring the structure of the data...
  63. ncbi A comparison of Bayesian methods for profiling hospital performance
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Med Decis Making 22:163-72. 2002
    ....
  64. ncbi Automated variable selection methods for logistic regression produced unstable models for predicting acute myocardial infarction mortality
    Peter C Austin
    Institute for Clinical Evaluative Sciences, G1 06, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada
    J Clin Epidemiol 57:1138-46. 2004
    ..The objective of this study was to determine the reproducibility of logistic regression models developed using automated variable selection methods...
  65. ncbi Estimating linear regression models in the presence of a censored independent variable
    Peter C Austin
    Institute for Clinical Evaluative Sciences, G1 06, 2075 Bayview Avenue, Toronto, Ontario, Canada M4N 3M5
    Stat Med 23:411-29. 2004
    ....
  66. ncbi Impact of the choice of benchmark on the conclusions of hospital report cards
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Am Heart J 148:1041-6. 2004
    ..The objective of the current study was to determine whether the number of hospitals identified as mortality outliers depended upon the benchmark against which hospitals are compared...
  67. ncbi Impact of the pravastatin or atorvastatin evaluation and infection therapy-thrombolysis in myocardial infarction 22/Reversal of Atherosclerosis with Aggressive Lipid Lowering trials on trends in intensive versus moderate statin therapy in Ontario, Canada
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Department of Public Health Sciences, University of Toronto, Toronto, Ontario, Canada
    Circulation 112:1296-300. 2005
    ..We sought to determine the impact of these 2 trials on trends in intensive versus moderate statin therapy in Ontario, Canada...
  68. ncbi Bayesian extensions of the Tobit model for analyzing measures of health status
    Peter C Austin
    Institute for Clinical Evaluative Sciences, North York, Ontario, Canada
    Med Decis Making 22:152-62. 2002
    ....
  69. ncbi Optimal statistical decisions for hospital report cards
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Med Decis Making 25:11-9. 2005
    ..Second, to determine optimal significance levels for specific cost functions describing the relative costs associated with different types of misclassifications...
  70. ncbi The impact of under coding of cardiac severity and comorbid diseases on the accuracy of hospital report cards
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Med Care 43:801-9. 2005
    ..Hospital report cards usually are based on administrative discharge abstracts. However, cardiac severity and comorbidities generally are under-reported in administrative data...
  71. ncbi The use of the Tobit model for analyzing measures of health status
    P C Austin
    Institute for Clinical Evaluative Sciences, North York, Ontario, Canada
    Qual Life Res 9:901-10. 2000
    ..However, if the conditional distribution had non-uniform variance, then the Tobit model performed at least as poorly as the OLS model...
  72. ncbi Care and outcomes of patients newly hospitalized for heart failure in the community treated by cardiologists compared with other specialists
    Philip Jong
    Heart and Stroke/Richard Lewar Centre of Excellence, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada
    Circulation 108:184-91. 2003
    ..These data raise the need to identify specialty-driven differences in processes of care for heart failure patients, which may explain the observed disparity in clinical outcomes that presently favor cardiologist care...
  73. ncbi Predictors of postacute mortality following traumatic brain injury in a seriously injured population
    Angela Colantonio
    Toronto Rehabilitation Institute, University of Toronto, Toronto, Ontario, Canada
    J Trauma 64:876-82. 2008
    ..This study investigates the rate and predictors of postacute mortality (1-9 years after the initial injury) of severely injured persons with TBI in the Province of Ontario from April 1, 1993 to March 31, 1995...
  74. ncbi Quality of care of international and Canadian medical graduates in acute myocardial infarction
    Dennis T Ko
    Division of Cardiology and Schulich Heart Centre, Sunnybrook and Women's College Health Sciences Centre, Ontario, Canada
    Arch Intern Med 165:458-63. 2005
    ..This information places the care provided by IMGs into perspective and supports the ability of well-selected IMGs in caring for AMI patients...
  75. ncbi Sex differences in carotid endarterectomy outcomes: results from the Ontario Carotid Endarterectomy Registry
    Moira K Kapral
    Institute for Clinical Evaluative Sciences, Division of General Internal Medicine and Clinical Epidemiology and Women s Health Program, University Health Network, Toronto, Ontario, Canada
    Stroke 34:1120-5. 2003
    ..We used data from a large population-based carotid surgery registry to determine whether sex differences exist in the risk of perioperative complications from carotid endarterectomy...
  76. ncbi Comparison of cardiovascular risk profiles among ethnic groups using population health surveys between 1996 and 2007
    Maria Chiu
    Institute for Clinical Evaluative Sciences, Toronto, Ont
    CMAJ 182:E301-10. 2010
    ..We conducted a large, population-based comparison of cardiovascular risk among people of white, South Asian, Chinese and black ethnicity living in Ontario, Canada...
  77. ncbi Evaluating sex differences in population-based utilization of implantable cardioverter-defibrillators: role of cardiac conditions and noncardiac comorbidities
    Derek R MacFadden
    Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
    Heart Rhythm 6:1289-96. 2009
    ..The influence of age and comorbidities on sex-specific implantable cardioverter-defibrillator (ICD) use for primary or secondary prevention is undefined...
  78. ncbi Gender differences in outcomes after hospital discharge from coronary artery bypass grafting
    Veena Guru
    Institute for Clinical Evaluative Sciences, Sunnybrook and Women s College Health Sciences Centre, University of Toronto, Toronto, Canada
    Circulation 113:507-16. 2006
    ..This study compares gender differences in cardiac events in a population of hospital survivors up to 11 years after isolated CABG surgery in Ontario, Canada...
  79. ncbi Effect of discharge summary availability during post-discharge visits on hospital readmission
    Carl van Walraven
    Department of Medicine, University of Ottawa, Clinical Epidemiology Unit, Ottawa Health Research Institute, Ottawa, ON, Canada
    J Gen Intern Med 17:186-92. 2002
    ..To determine if the delivery of hospital discharge summaries to follow-up physicians decreases the risk of hospital readmission...
  80. ncbi Predictors of peritonitis in patients on peritoneal dialysis: results of a large, prospective Canadian database
    Sharon J Nessim
    Department of Medicine, Division of Nephrology, St Michael s Hospital, Toronto, Ontario, Canada
    Clin J Am Soc Nephrol 4:1195-200. 2009
    ..Determining factors that are associated with PD peritonitis may facilitate the identification of patients who are at risk...
  81. ncbi Income-related differences in mortality among people with diabetes mellitus
    Lorraine L Lipscombe
    Institute for Clinical Evaluative Sciences, Toronto, Ont
    CMAJ 182:E1-E17. 2010
    ..Whether all income groups have benefited equally, however, is unclear. We examined the impact of income on mortality trends among people with diabetes...
  82. ncbi Outcomes and processes of care related to preoperative medical consultation
    Duminda N Wijeysundera
    Institute for Clinical Evaluative Sciences, Keenan Research Centre, Li Ka Shing Knowledge Institute of St Michael s Hospital, Department of Anesthesia, Toronto General Hospital and University of Toronto, EN 3 450, 200 Elizabeth St, Toronto, ON M5G 2C4, Canada
    Arch Intern Med 170:1365-74. 2010
    ..Nonetheless, the impact of these consultations, which may be performed by general internists or specialists, on outcomes is unclear...
  83. ncbi A modification of the Elixhauser comorbidity measures into a point system for hospital death using administrative data
    Carl van Walraven
    Ottawa Health Research Institute, Ottawa, Ontario, Canada
    Med Care 47:626-33. 2009
    ..However, the Elixhauser classification system requires 30 binary variables, making its use for reporting and analysis of comorbidity cumbersome...
  84. ncbi Paclitaxel versus sirolimus stents in diabetic and nondiabetic patients
    Maria Chiu
    Institute for Clinical Evaluative Sciences, Toronto, Canada
    Circ Cardiovasc Qual Outcomes 2:96-107. 2009
    ..We therefore studied the long-term effectiveness and safety of sirolimus versus paclitaxel stents overall and stratified by the absence or presence of diabetes...
  85. ncbi Continuity of care and patient outcomes after hospital discharge
    Carl van Walraven
    Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
    J Gen Intern Med 19:624-31. 2004
    ..Transfer of information between physicians can be poor. We determined whether early postdischarge outcomes changed when patients were seen after discharge by physicians who treated them in the hospital...
  86. ncbi Risk-treatment mismatch in the pharmacotherapy of heart failure
    Douglas S Lee
    Institute for Clinical Evaluative Sciences, Department of Health Policy, Management, and Evaluation, University of Toronto, Toronto, Ontario, Canada
    JAMA 294:1240-7. 2005
    ..Understanding the reasons underlying this mismatch may facilitate improvements in care and outcomes for patients with heart failure...
  87. ncbi Outcome of heart failure with preserved ejection fraction in a population-based study
    R Sacha Bhatia
    Heart and Stroke/Richard Lewar Centre of Excellence, University of Toronto, and the Division of Cardiology, Toronto General Hospital, University Health Network, Toronto, ON, Canada
    N Engl J Med 355:260-9. 2006
    ..The survival of patients with heart failure with preserved ejection fraction was similar to that of patients with reduced ejection fraction...
  88. ncbi Comparison of coding of heart failure and comorbidities in administrative and clinical data for use in outcomes research
    Douglas S Lee
    Institute for Clinical Evaluative Sciences, Toronto, Canada
    Med Care 43:182-8. 2005
    ..Examination of hospitalization data up to 1 year prior to the index admission improves comorbidity detection and may provide enhancements to future studies of heart failure mortality...
  89. ncbi Statin therapy and clinical outcomes in heart failure: a propensity-matched analysis
    Maral Ouzounian
    Heart and Stroke Richard Lewar Centre for Excellence, University of Toronto, Toronto, Ontario, Canada
    J Card Fail 15:241-8. 2009
    ..The influence of statin therapy in heart failure (HF) has been of considerable interest. The objective of this study was to determine if statins are associated with improved outcomes in patients discharged after hospitalization for HF...
  90. ncbi The real-world outcomes of off-pump coronary artery bypass surgery in a public health care system
    Veena Guru
    Institute for Clinical Evaluative Sciences, Division of Cardiovascular Surgery, University of Toronto, Ontario
    Can J Cardiol 23:281-6. 2007
    ..The population-based results of off-pump coronary artery bypass surgery (OPCAB) in a public health care system have not been reported...
  91. ncbi Trends in heart failure outcomes and pharmacotherapy: 1992 to 2000
    Douglas S Lee
    Faculty of Pharmacy, Toronto, Canada
    Am J Med 116:581-9. 2004
    ..CONCLUSION: During 1992 to 2000, mortality and morbidity improved among elderly patients with heart failure, with increased utilization of beta-blockers contributing most to the beneficial trends in outcomes...
  92. ncbi Bayesian statistical inference enhances the interpretation of contemporary randomized controlled trials
    Duminda N Wijeysundera
    Department of Health Policy Management and Evaluation, University of Toronto, Toronto, Ontario, Canada
    J Clin Epidemiol 62:13-21.e5. 2009
    ..Frequentist methods have limitations that might be overcome, in part, by Bayesian inference. To illustrate these advantages, we re-analyzed randomized trials published in four general medical journals during 2004...
  93. ncbi Measuring the effect of a large reduction in welfare payments on mental health service use in welfare-dependent neighborhoods
    Leah S Steele
    Department of Family and Community Medicine, University of Toronto, and Inner City Health Research Unit, St Michael s Hospital, Toronto, Ontario, M4X 1K2, Canada
    Med Care 43:885-91. 2005
    ..Major social policy changes were implemented in Canada in the last decade with few efforts to examine their potential health effects...
  94. ncbi Relationship between preventability of death after coronary artery bypass graft surgery and all-cause risk-adjusted mortality rates
    Veena Guru
    Institute for Clinical Evaluative Sciences, G 106, 2075 Bayview Ave, Toronto, Ontario M4N 3M5 Canada
    Circulation 117:2969-76. 2008
    ....
  95. ncbi Development and validation of the Ontario acute myocardial infarction mortality prediction rules
    J V Tu
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    J Am Coll Cardiol 37:992-7. 2001
    ..To develop and validate simple statistical models that can be used with hospital discharge administrative databases to predict 30-day and one-year mortality after an acute myocardial infarction (AMI)...
  96. ncbi Long-term MI outcomes at hospitals with or without on-site revascularization
    D A Alter
    Institute for Clinical Evaluative Sciences, G106 2075 Bayview Ave, Toronto, Ontario, Canada M4N 3M5
    JAMA 285:2101-8. 2001
    ..Whether such differences are due to invasive procedure rates alone or to other patient, physician, and hospital characteristics is unknown...
  97. ncbi Relationship between annual volume of patients treated by admitting physician and mortality after acute myocardial infarction
    J V Tu
    Institute for Clinical Evaluative Sciences, G 106, 2075 Bayview Ave, Toronto, Ontario, Canada M4N 3M5
    JAMA 285:3116-22. 2001
    ..Acute myocardial infarction (AMI) is a common condition that is treated by physicians with varying levels of clinical experience, but whether the level of experience affects outcome remains uncertain...
  98. ncbi Use of antidepressants among elderly subjects: trends and contributing factors
    M M Mamdani
    Institute for Clinical Evaluative Sciences, the Center for Addiction and Mental Health, Toronto, Canada
    Am J Psychiatry 157:360-7. 2000
    ..The authors assessed changes over time in antidepressant utilization among elderly subjects regarding the prevalence of antidepressant users, shifts in prescription patterns, and related financial implications...
  99. ncbi Utilisation of coronary angiography after acute myocardial infarction in Ontario over time: have referral patterns changed?
    Y Khaykin
    Division of Cardiology, Schulich Heart Centre, Sunnybrook and Women s College Health Sciences Centre and the University of Toronto, Toronto, Ontario, Canada
    Heart 88:460-6. 2002
    ..To examine how physicians in Ontario, Canada, have altered their referral patterns for coronary angiography after acute myocardial infarction (AMI) over time...
  100. ncbi Biology or bias: practice patterns and long-term outcomes for men and women with acute myocardial infarction
    D A Alter
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    J Am Coll Cardiol 39:1909-16. 2002
    ..Another objective was to evaluate the association of age, gender and treatment intensity with five-year survival after AMI...
  101. ncbi Safety and effectiveness of drug-eluting stents among diabetic patients: a propensity analysis
    Dennis T Ko
    Division of Cardiology, Schulich Heart Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
    Am Heart J 156:125-34. 2008
    ..Accordingly, we sought to evaluate the long-term safety and effectiveness of DES in diabetic patients...