Addressing unmeasured confounding in comparative observational research

Observational pharmacoepidemiological studies can provide valuable information on the effectiveness or safety of interventions in the real world, but one major challenge is the existence of unmeasured confounder(s). While many analytical methods have been developed for dealing with this challenge, they appear under‐utilized, perhaps due to the complexity and varied requirements for implementation. Thus, there is an unmet need to improve understanding the appropriate course of action to address unmeasured confounding under a variety of research scenarios.

[1]  D. Rubin ASSIGNMENT TO TREATMENT GROUP ON THE BASIS OF A COVARIATE , 1976 .

[2]  J. Angrist,et al.  Identification and Estimation of Local Average Treatment Effects , 1994 .

[3]  C. Manski Nonparametric Bounds on Treatment Effects , 1989 .

[4]  D. Gold,et al.  Rationale, objectives and design of the Direct Analysis of Nonvertebral Fracture in the Community Experience (DANCE) Study , 2005, Osteoporosis International.

[5]  Thomas D. Cook,et al.  "Waiting for Life to Arrive": A history of the regression-discontinuity design in Psychology, Statistics and Economics , 2008 .

[6]  Scott R. Smith,et al.  Developing a Protocol for Observational Comparative Effectiveness Research: A User's Guide , 2013 .

[7]  M. Lipsitch,et al.  Negative Controls: A Tool for Detecting Confounding and Bias in Observational Studies , 2010, Epidemiology.

[8]  S. Schneeweiss Sensitivity analysis and external adjustment for unmeasured confounders in epidemiologic database studies of therapeutics , 2006, Pharmacoepidemiology and drug safety.

[9]  Dylan S. Small,et al.  The Trend-in-trend Research Design for Causal Inference , 2017, Epidemiology.

[10]  H. Wahner,et al.  Updated Data on Proximal Femur Bone Mineral Levels of US Adults , 1998, Osteoporosis International.

[11]  R. Kronmal,et al.  Assessing the sensitivity of regression results to unmeasured confounders in observational studies. , 1998, Biometrics.

[12]  M. Baiocchi,et al.  Instrumental variable methods for causal inference , 2014, Statistics in medicine.

[13]  Til Stürmer,et al.  Performance of propensity score calibration--a simulation study. , 2007, American journal of epidemiology.

[14]  J. Angrist,et al.  Empirical Strategies in Labor Economics , 1998 .

[15]  Olaf H. Klungel,et al.  Instrumental Variable Analysis in Epidemiologic Studies: An Overview of the Estimation Methods , 2015 .

[16]  P. Rosenbaum The Role of a Second Control Group in an Observational Study , 1987 .

[17]  Dylan S Small,et al.  Using an instrumental variable to test for unmeasured confounding , 2014, Statistics in medicine.

[18]  K. Anstrom,et al.  Comparing Inverse Probability of Treatment Weighting and Instrumental Variable Methods for the Evaluation of Adenosine Diphosphate Receptor Inhibitors After Percutaneous Coronary Intervention. , 2016, JAMA cardiology.

[19]  Kit C.B. Roes,et al.  Methods to control for unmeasured confounding in pharmacoepidemiology: an overview , 2016, International Journal of Clinical Pharmacy.

[20]  I. Bross Spurious effects from an extraneous variable. , 1966, Journal of chronic diseases.

[21]  G. W. Imbens Sensitivity to Exogeneity Assumptions in Program Evaluation , 2003 .

[22]  R. Bourne,et al.  Pharmacist independent prescribing in secondary care: opportunities and challenges , 2016, International Journal of Clinical Pharmacy.

[23]  P. Holland Statistics and Causal Inference: Rejoinder , 1986 .

[24]  P. Rothwell,et al.  Factors That Can Affect the External Validity of Randomised Controlled Trials , 2006, PLoS clinical trials.

[25]  David Madigan,et al.  Empirical Performance of the Calibrated Self-Controlled Cohort Analysis Within Temporal Pattern Discovery: Lessons for Developing a Risk Identification and Analysis System , 2013, Drug Safety.

[26]  A. Silman,et al.  Predictive Value of BMD for Hip and Other Fractures , 2005, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[27]  Donald B. Rubin,et al.  AN OVERVIEW OF MULTIPLE IMPUTATION , 2002 .

[28]  D. Melzer,et al.  Adjusting for unmeasured confounding in nonrandomized longitudinal studies: a methodological review , 2017, Journal of clinical epidemiology.

[29]  Karen Price,et al.  Evaluating the impact of unmeasured confounding with internal validation data: an example cost evaluation in type 2 diabetes. , 2013, Value in health : the journal of the International Society for Pharmacoeconomics and Outcomes Research.

[30]  Donald B. Rubin,et al.  Bayesian Inference for Causal Effects: The Role of Randomization , 1978 .

[31]  O Johnell,et al.  Meta-analysis of how well measures of bone mineral density predict occurrence of osteoporotic fractures. , 1996, BMJ.

[32]  D. Rubin The design versus the analysis of observational studies for causal effects: parallels with the design of randomized trials , 2007, Statistics in medicine.

[33]  D B Rubin,et al.  Multiple imputation in health-care databases: an overview and some applications. , 1991, Statistics in medicine.

[34]  P. Souverein,et al.  Unmeasured confounding in pharmacoepidemiology. , 2016, Annals of epidemiology.

[35]  D. Campbell,et al.  Regression-Discontinuity Analysis: An Alternative to the Ex-Post Facto Experiment , 1960 .

[36]  Z. Shahn Trends in Control of Unobserved Confounding. , 2017, Epidemiology.

[37]  K. Krohn,et al.  Gender differences for initiating teriparatide therapy: Baseline Data from the Direct Assessment of Nonvertebral Fracture in the Community Experience (DANCE) study , 2012, Osteoporosis International.

[38]  J. Angrist,et al.  Identification and Estimation of Local Average Treatment Effects , 1995 .

[39]  E. C. Hammond,et al.  Smoking and lung cancer: recent evidence and a discussion of some questions. , 1959, Journal of the National Cancer Institute.

[40]  Menggang Yu,et al.  Prior event rate ratio adjustment: numerical studies of a statistical method to address unrecognized confounding in observational studies , 2012, Pharmacoepidemiology and drug safety.

[41]  A. Qaseem,et al.  Treatment of Low Bone Density or Osteoporosis to Prevent Fractures in Men and Women: A Clinical Practice Guideline Update From the American College of Physicians. , 2017, Annals of internal medicine.

[42]  P. Holland Statistics and Causal Inference , 1985 .

[43]  D. Rubin Estimating causal effects of treatments in randomized and nonrandomized studies. , 1974 .

[44]  Til Stürmer,et al.  Adjusting effect estimates for unmeasured confounding with validation data using propensity score calibration. , 2005, American journal of epidemiology.

[45]  B J McNeil,et al.  Does more intensive treatment of acute myocardial infarction in the elderly reduce mortality? Analysis using instrumental variables. , 1994, JAMA.

[46]  D. Rubin Using Propensity Scores to Help Design Observational Studies: Application to the Tobacco Litigation , 2001, Health Services and Outcomes Research Methodology.

[47]  Till Bärnighausen,et al.  Regression discontinuity designs are underutilized in medicine, epidemiology, and public health: a review of current and best practice. , 2015, Journal of clinical epidemiology.

[48]  Timothy L Lash,et al.  Methods to apply probabilistic bias analysis to summary estimates of association , 2010, Pharmacoepidemiology and drug safety.

[49]  M. Abrahamowicz,et al.  Advantages and limitations of using national administrative data on obstetric blood transfusions to estimate the frequency of obstetric hemorrhages. , 2013, Journal of public health.

[50]  V. Prasad,et al.  Prespecified falsification end points: can they validate true observational associations? , 2013, JAMA.

[51]  J. Avorn,et al.  Adjustments for Unmeasured Confounders in Pharmacoepidemiologic Database Studies Using External Information , 2007, Medical care.

[52]  Alberto Abadie Semiparametric Difference-in-Differences Estimators , 2005 .

[53]  Joshua D. Angrist,et al.  Identification of Causal Effects Using Instrumental Variables , 1993 .

[54]  Douglas Faries,et al.  Bayesian modeling of cost‐effectiveness studies with unmeasured confounding: a simulation study , 2014, Pharmaceutical statistics.

[55]  T. Shakespeare,et al.  Observational Studies , 2003 .

[56]  D. Rubin,et al.  The central role of the propensity score in observational studies for causal effects , 1983 .

[57]  William DuMouchel,et al.  Interpreting observational studies: why empirical calibration is needed to correct p-values , 2013, Statistics in medicine.

[58]  C. Manski Partial Identification of Probability Distributions , 2003 .

[59]  J. Seaman,et al.  “A Bayesian sensitivity analysis to evaluate the impact of unmeasured confounding with external data: a real world comparative effectiveness study in osteoporosis” , 2016, Pharmacoepidemiology and drug safety.

[60]  Wen-Chung Lee Detecting and correcting the bias of unmeasured factors using perturbation analysis: a data-mining approach , 2014, BMC Medical Research Methodology.

[61]  S Richardson,et al.  Simplified Bayesian Sensitivity Analysis for Mismeasured and Unobserved Confounders , 2010, Biometrics.

[62]  Dylan S. Small,et al.  Building a Stronger Instrument in an Observational Study of Perinatal Care for Premature Infants , 2010 .

[63]  P. Rothwell,et al.  External validity of randomised controlled trials: “To whom do the results of this trial apply?” , 2005, The Lancet.

[64]  Timothy L. Lash,et al.  Applying Quantitative Bias Analysis to Epidemiologic Data , 2009, Statistics for Biology and Health.

[65]  Yang C. Yuan,et al.  Multiple Imputation for Missing Data: Concepts and New Development , 2000 .

[66]  D. V. Lindley,et al.  Randomization Analysis of Experimental Data: The Fisher Randomization Test Comment , 1980 .

[67]  D. Rubin,et al.  Assessing Sensitivity to an Unobserved Binary Covariate in an Observational Study with Binary Outcome , 1983 .

[68]  R. Groenwold Falsification end points for observational studies. , 2013, JAMA.

[69]  Richard Grieve,et al.  Statistical methods for cost-effectiveness analyses that use observational data: a critical appraisal tool and review of current practice. , 2013, Health economics.

[70]  M. Abrahamowicz,et al.  The missing cause approach to unmeasured confounding in pharmacoepidemiology , 2016, Statistics in medicine.