P C Austin

Summary

Affiliation: Institute for Clinical Evaluative Sciences
Country: Canada

Publications

  1. ncbi request reprint 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. doi request reprint Using methods from the data-mining and machine-learning literature for disease classification and prediction: a case study examining classification of heart failure subtypes
    Peter C Austin
    Institute for Clinical Evaluative Sciences, G105, 2075 Bayview Ave, Toronto, Ontario, Canada
    J Clin Epidemiol 66:398-407. 2013
  3. doi request reprint The relationship between the C-statistic of a risk-adjustment model and the accuracy of hospital report cards: a Monte Carlo Study
    Peter C Austin
    Institute for Clinical Evaluative Sciences Institute of Health Management, Policy and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
    Med Care 51:275-84. 2013
  4. doi request reprint Using G-computation to estimate the effect of regionalization of surgical services on the absolute reduction in the occurrence of adverse patient outcomes
    Peter C Austin
    Institute for Clinical Evaluative Sciences, University of Toronto, Toronto, ON, Canada
    Med Care 51:797-805. 2013
  5. pmc Obesity, lifestyle risk-factors, and health service outcomes among healthy middle-aged adults in Canada
    David A Alter
    Institute for Clinical Evaluative Sciences, 2075 Bayview Avenue, Toronto, ON, Canada
    BMC Health Serv Res 12:238. 2012
  6. pmc The performance of different propensity score methods for estimating marginal hazard ratios
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Stat Med 32:2837-49. 2013
  7. pmc Predictive accuracy of risk factors and markers: a simulation study of the effect of novel markers on different performance measures for logistic regression models
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, ON, Canada
    Stat Med 32:661-72. 2013
  8. pmc 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
  9. pmc 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
  10. doi request reprint 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

Detail Information

Publications126 found, 100 shown here

  1. ncbi request reprint 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. doi request reprint Using methods from the data-mining and machine-learning literature for disease classification and prediction: a case study examining classification of heart failure subtypes
    Peter C Austin
    Institute for Clinical Evaluative Sciences, G105, 2075 Bayview Ave, Toronto, Ontario, Canada
    J Clin Epidemiol 66:398-407. 2013
    ..In the data-mining and machine-learning literature, alternate classification schemes have been developed. These include bootstrap aggregation (bagging), boosting, random forests, and support vector machines...
  3. doi request reprint The relationship between the C-statistic of a risk-adjustment model and the accuracy of hospital report cards: a Monte Carlo Study
    Peter C Austin
    Institute for Clinical Evaluative Sciences Institute of Health Management, Policy and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
    Med Care 51:275-84. 2013
    ..Many applied researchers use the c-statistic (equivalent to the area under the receiver operating characteristic curve) of the logistic regression model as a measure of the credibility and accuracy of hospital report cards...
  4. doi request reprint Using G-computation to estimate the effect of regionalization of surgical services on the absolute reduction in the occurrence of adverse patient outcomes
    Peter C Austin
    Institute for Clinical Evaluative Sciences, University of Toronto, Toronto, ON, Canada
    Med Care 51:797-805. 2013
    ..However, the odds ratio is a relative measure of effect and does not allow policy makers to estimate the absolute benefit of regionalization...
  5. pmc Obesity, lifestyle risk-factors, and health service outcomes among healthy middle-aged adults in Canada
    David A Alter
    Institute for Clinical Evaluative Sciences, 2075 Bayview Avenue, Toronto, ON, Canada
    BMC Health Serv Res 12:238. 2012
    ..The extent to which uncomplicated obesity among an otherwise healthy middle-aged population is associated with higher longitudinal health-care expenditures remains unclear...
  6. pmc The performance of different propensity score methods for estimating marginal hazard ratios
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
    Stat Med 32:2837-49. 2013
    ..Applied researchers are encouraged to use propensity score matching and IPTW using the propensity score when estimating the relative effect of treatment on time-to-event outcomes...
  7. pmc Predictive accuracy of risk factors and markers: a simulation study of the effect of novel markers on different performance measures for logistic regression models
    Peter C Austin
    Institute for Clinical Evaluative Sciences, Toronto, ON, Canada
    Stat Med 32:661-72. 2013
    ..In conclusion, the increase in predictive accuracy by adding a marker should be considered in the context of the accuracy of the initial model...
  8. pmc 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...
  9. pmc 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...
  10. doi request reprint 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...
  11. pmc 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
    ....
  12. doi request reprint 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...
  13. doi request reprint 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...
  14. pmc 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...
  15. pmc 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...
  16. doi request reprint 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...
  17. ncbi request reprint 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...
  18. pmc 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...
  19. doi request reprint 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...
  20. pmc 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...
  21. ncbi request reprint 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...
  22. ncbi request reprint 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...
  23. ncbi request reprint 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...
  24. ncbi request reprint 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...
  25. ncbi request reprint 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...
  26. pmc 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...
  27. ncbi request reprint 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...
  28. ncbi request reprint 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...
  29. ncbi request reprint 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...
  30. ncbi request reprint 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...
  31. ncbi request reprint 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...
  32. ncbi request reprint 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...
  33. ncbi request reprint 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
    ....
  34. ncbi request reprint 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...
  35. doi request reprint 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...
  36. ncbi request reprint 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...
  37. ncbi request reprint 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...
  38. doi request reprint 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...
  39. pmc 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...
  40. ncbi request reprint 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...
  41. ncbi request reprint 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...
  42. doi request reprint 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...
  43. doi request reprint 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...
  44. ncbi request reprint 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...
  45. pmc 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...
  46. doi request reprint 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...
  47. doi request reprint 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...
  48. ncbi request reprint 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...
  49. ncbi request reprint 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...
  50. ncbi request reprint 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...
  51. ncbi request reprint 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
    ....
  52. ncbi request reprint 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...
  53. doi request reprint 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...
  54. ncbi request reprint 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...
  55. ncbi request reprint 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...
  56. ncbi request reprint 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
    ....
  57. ncbi request reprint 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...
  58. ncbi request reprint 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...
  59. ncbi request reprint 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...
  60. ncbi request reprint 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...
  61. ncbi request reprint 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...
  62. ncbi request reprint 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...
  63. ncbi request reprint 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...
  64. ncbi request reprint 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...
  65. ncbi request reprint 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...
  66. ncbi request reprint 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)...
  67. pmc 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...
  68. ncbi request reprint 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...
  69. ncbi request reprint 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...
  70. pmc 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...
  71. ncbi request reprint 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...
  72. ncbi request reprint 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...
  73. doi request reprint 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...
  74. ncbi request reprint 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...
  75. ncbi request reprint 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
    ....
  76. ncbi request reprint 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...
  77. ncbi request reprint 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...
  78. ncbi request reprint 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
    ..It is not known whether subspecialty care by cardiologists improves outcomes in heart failure patients from the community over care by other physicians...
  79. doi request reprint 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...
  80. ncbi request reprint 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...
  81. pmc 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...
  82. ncbi request reprint 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
    ..There are concerns that IMGs may provide inferior medical care compared with locally trained medical graduates, but that has not been established...
  83. ncbi request reprint 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...
  84. pmc 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...
  85. ncbi request reprint 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...
  86. doi request reprint 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...
  87. pmc 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...
  88. doi request reprint 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...
  89. pmc 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...
  90. pmc 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...
  91. ncbi request reprint 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...
  92. ncbi request reprint 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
    ....
  93. ncbi request reprint 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
    ..Patients with heart failure have a wide spectrum of mortality risks. To maximize the benefit of available pharmacotherapies, patients with high mortality risk should receive high rates of drug therapy...
  94. ncbi request reprint 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
    ..Despite the potential usefulness of administrative databases for evaluating outcomes, coding of heart failure and associated comorbidities have not been definitively compared with clinical data...
  95. ncbi request reprint 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
    ..To review trends in drug therapy and concomitant outcomes of elderly heart failure patients in Ontario, Canada...
  96. doi request reprint 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...
  97. doi request reprint 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...