Harvard Catalyst Profiles

Contact, publication, and social network information about Harvard faculty and fellows.

Miguel Hernan, D.P.H., M.D.

Profile Picture
Other Positions

My research is focused on methodology for causal inference, including comparative effectiveness of policy and clinical interventions.

In an ideal world, all policy and clinical decisions would be based on the findings of randomized experiments. For example, public health recommendations to avoid saturated fat or medical prescription of a particular painkiller would be based on the findings of long-term studies that compared the effectiveness of several randomly assigned interventions in large groups of people from the target population that adhered to the study interventions. Unfortunately, such randomized experiments are often unethical, impractical, or simply too lengthy for timely decisions.

My collaborators and I combine observational data, mostly untestable assumptions, and statistical methods to emulate hypothetical randomized experiments. We emphasize the need to formulate well defined causal questions, and use analytic approaches whose validity does not require assumptions that conflict with current subject-matter knowledge. For example, in settings in which experts suspect the presence of time-dependent confounders affected by prior treatment, we do not use adjustment methods (e.g., conventional regression analysis) that require the absence of such confounders.

While causal inferences from observational data are always risky, an appropriate analysis of observational studies often results in the best available evidence for policy or clinical decision-making. At the very least, the findings from well designed and properly analyzed observational studies may guide the design of future randomized experiments.

Our applied work is focused on optimal use of antiretroviral therapy in persons infected with HIV, lifestyle and pharmacological interventions to reduce the incidence of cardiovascular disease, and the effects of erythropoiesis-stimulating agents among dialysis patients.

The research activities and funding listed below are automatically derived from NIH ExPORTER and other sources, which might result in incorrect or missing items. Faculty can login to make corrections and additions.
  1. P50MH115846 (ONGUR, DOST) May 15, 2019 - Mar 31, 2023
    Laboratory for Early Psychosis Research (LEAP)
    Role: Co-Principal Investigator
  2. R01HD088393 (HSU, JOHN) Sep 2, 2017 - Nov 30, 2022
    Long-term Impact of Fertility Treatment Study
    Role: Co-Principal Investigator
  3. R01AI102634 (HERNAN, MIGUEL) Jan 1, 2013 - Jun 7, 2018
    Dynamic strategies for the clinical management of HIV disease
    Role: Principal Investigator
  4. R37AI102634 (HERNAN, MIGUEL) Aug 9, 2012 - May 31, 2023
    Dynamic Strategies for the clinical management of HIV disease
    Role: Principal Investigator
  5. R56AI102634 (HERNAN, MIGUEL) Aug 9, 2012 - Dec 31, 2012
    Dynamic Strategies for the clinical management of HIV disease
    Role: Principal Investigator

Featured Content

Publications listed below are automatically derived from MEDLINE/PubMed and other sources, which might result in incorrect or missing publications. Faculty can login to make corrections and additions.
Newest   |   Oldest   |   Most Cited   |   Most Discussed   |   Timeline   |   Field Summary   |   Plain Text
PMC Citations indicate the number of times the publication was cited by articles in PubMed Central, and the Altmetric score represents citations in news articles and social media. (Note that publications are often cited in additional ways that are not shown here.) Fields are based on how the National Library of Medicine (NLM) classifies the publication's journal and might not represent the specific topic of the publication. Translation tags are based on the publication type and the MeSH terms NLM assigns to the publication. Some publications (especially newer ones and publications not in PubMed) might not yet be assigned Field or Translation tags.) Click a Field or Translation tag to filter the publications.
  1. Hernán MA. Causal analysis of existing databases: no power calculations required. Responses to Campbell, Morris and Mansournia, et al. J Clin Epidemiol. 2022 04; 144:193. PMID: 34875379; PMCID: PMC8977232.
    Citations:    Fields:    Translation:Humans
  2. Hernán MA. Causal analyses of existing databases: no power calculations required. J Clin Epidemiol. 2022 04; 144:203-205. PMID: 34461211; PMCID: PMC8882204.
    Citations: 16     Fields:    Translation:Humans
  3. D GB, D P, Jm G, B P, C FE, M L, A L, E G, Ma H. Lockdown measures and relative changes in the age-specific incidence of SARS-CoV-2 in Spain. medRxiv. 2020 Jul 02. PMID: 32637975.
  4. Emilsson L, García-Albéniz X, Hernan MA. Association of Statin Use With Overall and Cancer Survival-Reply. JAMA Oncol. 2018 07 01; 4(7):1016-1017. PMID: 29800046.
    Citations:    Fields:    Translation:Humans
  5. Huitfeldt A, Hernan MA, Kalager M, Robins JM. Comparative Effectiveness Research Using Observational Data: Active Comparators to Emulate Target Trials with Inactive Comparators. EGEMS (Wash DC). 2016; 4(1):1234. PMID: 27891526; PMCID: PMC5108633.
    Citations: 14     
  6. Hernán MA. Does water kill? A call for less casual causal inferences. Ann Epidemiol. 2016 10; 26(10):674-680. PMID: 27641316; PMCID: PMC5207342.
    Citations: 46     Fields:    Translation:Humans
  7. Hernán MA, Sauer BC, Hernández-Díaz S, Platt R, Shrier I. Specifying a target trial prevents immortal time bias and other self-inflicted injuries in observational analyses. J Clin Epidemiol. 2016 11; 79:70-75. PMID: 27237061.
    Citations: 118     Fields:    Translation:Humans
  8. Beardsley J, Le T. Antiretroviral penetration into the CNS and incidence of AIDS-defining neurologic conditions. Neurology. 2015 Feb 10; 84(6):632. PMID: 25666633.
    Citations: 1     Fields:    Translation:Humans
  9. Caniglia EC, Hernan MA. Author response. Neurology. 2015 Feb 10; 84(6):632-3. PMID: 25811065.
    Citations:    Fields:    Translation:Humans
  10. Young JG, Hernan MA, Robins JM. Identification, estimation and approximation of risk under interventions that depend on the natural value of treatment using observational data. Epidemiol Methods. 2014 Dec; 3(1):1-19. PMID: 25866704; PMCID: PMC4387917.
    Citations: 24     
  11. Hernán MA, Savitz DA. From "big epidemiology" to "colossal epidemiology": when all eggs are in one basket. Epidemiology. 2013 May; 24(3):344-5. PMID: 23549177.
    Citations: 7     Fields:    
  12. Hernán MA. Comments on Lauer's 'How the debate about comparative effectiveness research should impact the future of clinical trials'. Stat Med. 2012 Nov 10; 31(25):3060-1; discussion 3066-7. PMID: 23055183.
    Citations:    Fields:    
  13. Danaei G, Tavakkoli M, Hernán MA. Bias in observational studies of prevalent users: lessons for comparative effectiveness research from a meta-analysis of statins. Am J Epidemiol. 2012 Feb 15; 175(4):250-62. PMID: 22223710.
    Citations: 79     Fields:    Translation:HumansPHPublic Health
  14. Danaei G, Rodríguez LA, Cantero OF, Logan R, Hernán MA. Observational data for comparative effectiveness research: an emulation of randomised trials of statins and primary prevention of coronary heart disease. Stat Methods Med Res. 2013 Feb; 22(1):70-96. PMID: 22016461.
    Citations: 77     Fields:    Translation:Humans
  15. Hernán MA, Hernández-Díaz S. Beyond the intention-to-treat in comparative effectiveness research. Clin Trials. 2012 Feb; 9(1):48-55. PMID: 21948059.
    Citations: 139     Fields:    
  16. Hernán MA, Lipsitch M. Oseltamivir and risk of lower respiratory tract complications in patients with flu symptoms: a meta-analysis of eleven randomized clinical trials. Clin Infect Dis. 2011 Aug 01; 53(3):277-9. PMID: 21677258.
    Citations: 35     Fields:    Translation:Humans
  17. Hernán MA, VanderWeele TJ. Compound treatments and transportability of causal inference. Epidemiology. 2011 May; 22(3):368-77. PMID: 21399502.
    Citations: 96     Fields:    Translation:Humans
  18. Cain LE, Logan R, Robins JM, Sterne JA, Sabin C, Bansi L, Justice A, Goulet J, van Sighem A, de Wolf F, Bucher HC, von Wyl V, Esteve A, Casabona J, del Amo J, Moreno S, Seng R, Meyer L, Perez-Hoyos S, Muga R, Lodi S, Lanoy E, Costagliola D, Hernan MA. When to initiate combined antiretroviral therapy to reduce mortality and AIDS-defining illness in HIV-infected persons in developed countries: an observational study. Ann Intern Med. 2011 Apr 19; 154(8):509-15. PMID: 21502648; PMCID: PMC3610527.
    Citations: 101     Fields:    Translation:Humans
  19. Hernán MA, Clayton D, Keiding N. The Simpson's paradox unraveled. Int J Epidemiol. 2011 Jun; 40(3):780-5. PMID: 21454324.
    Citations: 53     Fields:    Translation:Humans
  20. Ray M, Logan R, Sterne JA, Hernández-Díaz S, Robins JM, Sabin C, Bansi L, van Sighem A, de Wolf F, Costagliola D, Lanoy E, Bucher HC, von Wyl V, Esteve A, Casbona J, del Amo J, Moreno S, Justice A, Goulet J, Lodi S, Phillips A, Seng R, Meyer L, Pérez-Hoyos S, García de Olalla P, Hernán MA. The effect of combined antiretroviral therapy on the overall mortality of HIV-infected individuals. AIDS. 2010 Jan 02; 24(1):123-37. PMID: 19770621; PMCID: PMC2920287.
    Citations: 184     Fields:    Translation:HumansCells
  21. Hernán MA. The hazards of hazard ratios. Epidemiology. 2010 Jan; 21(1):13-5. PMID: 20010207.
    Citations: 275     Fields:    
  22. Hernán MA, Cole SR. Invited Commentary: Causal diagrams and measurement bias. Am J Epidemiol. 2009 Oct 15; 170(8):959-62; discussion 963-4. PMID: 19755635.
    Citations: 65     Fields:    Translation:Humans
  23. Hernán MA, McAdams M, McGrath N, Lanoy E, Costagliola D. Observation plans in longitudinal studies with time-varying treatments. Stat Methods Med Res. 2009 Feb; 18(1):27-52. PMID: 19036915.
    Citations: 43     Fields:    Translation:Humans
  24. Hernán MA, Alonso A, Logan R, Grodstein F, Michels KB, Willett WC, Manson JE, Robins JM. Observational studies analyzed like randomized experiments: an application to postmenopausal hormone therapy and coronary heart disease. Epidemiology. 2008 Nov; 19(6):766-79. PMID: 18854702.
    Citations: 261     Fields:    Translation:Humans
  25. Hernán MA, Taubman SL. Does obesity shorten life? The importance of well-defined interventions to answer causal questions. Int J Obes (Lond). 2008 Aug; 32 Suppl 3:S8-14. PMID: 18695657.
    Citations: 120     Fields:    Translation:Humans
  26. Hernán MA, Alonso A, Logroscino G. Cigarette smoking and dementia: potential selection bias in the elderly. Epidemiology. 2008 May; 19(3):448-50. PMID: 18414087.
    Citations: 66     Fields:    Translation:Humans
  27. Hernán MA, Jick SS. Hepatitis B vaccination and multiple sclerosis: the jury is still out. Pharmacoepidemiol Drug Saf. 2006 Sep; 15(9):653-5. PMID: 16245367.
    Citations: 3     Fields:    Translation:Humans
  28. Hernán MA, Alonso A, Hernández-Díaz S. Tetanus vaccination and risk of multiple sclerosis: a systematic review. Neurology. 2006 Jul 25; 67(2):212-5. PMID: 16864810.
    Citations: 13     Fields:    Translation:HumansPHPublic Health
  29. Hernán MA, Robins JM. Estimating causal effects from epidemiological data. J Epidemiol Community Health. 2006 Jul; 60(7):578-86. PMID: 16790829.
    Citations: 311     Fields:    Translation:Humans
  30. Hernán MA, Logroscino G, García Rodríguez LA. Nonsteroidal anti-inflammatory drugs and the incidence of Parkinson disease. Neurology. 2006 Apr 11; 66(7):1097-9. PMID: 16606925.
    Citations: 49     Fields:    Translation:Humans
  31. Hernán MA. Invited commentary: hypothetical interventions to define causal effects--afterthought or prerequisite? Am J Epidemiol. 2005 Oct 01; 162(7):618-20; discussion 621-2. PMID: 16120710.
    Citations: 47     Fields:    Translation:Humans
  32. Hernán MA, Cole SR, Margolick J, Cohen M, Robins JM. Structural accelerated failure time models for survival analysis in studies with time-varying treatments. Pharmacoepidemiol Drug Saf. 2005 Jul; 14(7):477-91. PMID: 15660442.
    Citations: 46     Fields:    Translation:Humans
  33. Hernán MA, Jick SS, Logroscino G, Olek MJ, Ascherio A, Jick H. Cigarette smoking and the progression of multiple sclerosis. Brain. 2005 Jun; 128(Pt 6):1461-5. PMID: 15758034.
    Citations: 73     Fields:    Translation:Humans
  34. Hernán MA, Logroscino G, Rodríguez LA. A prospective study of alcoholism and the risk of Parkinson's disease. J Neurol. 2004 Oct; 251 Suppl 7:vII14-7. PMID: 15505749.
    Citations: 23     Fields:    Translation:Humans
  35. Hernán MA, Jick SS, Olek MJ, Jick H. Recombinant hepatitis B vaccine and the risk of multiple sclerosis: a prospective study. Neurology. 2004 Sep 14; 63(5):838-42. PMID: 15365133.
    Citations: 36     Fields:    Translation:HumansPHPublic Health
  36. Hernán MA, Hernández-Díaz S, Robins JM. A structural approach to selection bias. Epidemiology. 2004 Sep; 15(5):615-25. PMID: 15308962.
    Citations: 875     Fields:    Translation:HumansPHPublic Health
  37. Hernán MA. A definition of causal effect for epidemiological research. J Epidemiol Community Health. 2004 Apr; 58(4):265-71. PMID: 15026432.
    Citations: 123     Fields:    Translation:Humans
  38. Hernán MA, Chen H, Schwarzschild MA, Ascherio A. Alcohol consumption and the incidence of Parkinson's disease. Ann Neurol. 2003 Aug; 54(2):170-5. PMID: 12891669.
    Citations: 32     Fields:    Translation:Humans
  39. Hernán MA, Takkouche B, Caamaño-Isorna F, Gestal-Otero JJ. A meta-analysis of coffee drinking, cigarette smoking, and the risk of Parkinson's disease. Ann Neurol. 2002 Sep; 52(3):276-84. PMID: 12205639.
    Citations: 251     Fields:    Translation:Humans
  40. Hernán MA, Brumback BA, Robins JM. Estimating the causal effect of zidovudine on CD4 count with a marginal structural model for repeated measures. Stat Med. 2002 Jun 30; 21(12):1689-709. PMID: 12111906.
    Citations: 114     Fields:    Translation:HumansCells
  41. Hernán MA, Checkoway H, O'Brien R, Costa-Mallen P, De Vivo I, Colditz GA, Hunter DJ, Kelsey KT, Ascherio A. MAOB intron 13 and COMT codon 158 polymorphisms, cigarette smoking, and the risk of PD. Neurology. 2002 May 14; 58(9):1381-7. PMID: 12011284.
    Citations: 13     Fields:    Translation:Humans
  42. Hernán MA, Hernández-Díaz S, Werler MM, Mitchell AA. Causal knowledge as a prerequisite for confounding evaluation: an application to birth defects epidemiology. Am J Epidemiol. 2002 Jan 15; 155(2):176-84. PMID: 11790682.
    Citations: 432     Fields:    Translation:Humans
  43. Hernán MA, Zhang SM, Rueda-deCastro AM, Colditz GA, Speizer FE, Ascherio A. Cigarette smoking and the incidence of Parkinson's disease in two prospective studies. Ann Neurol. 2001 Dec; 50(6):780-6. PMID: 11761476.
    Citations: 55     Fields:    Translation:Humans
  44. Hernán MA, Olek MJ, Ascherio A. Cigarette smoking and incidence of multiple sclerosis. Am J Epidemiol. 2001 Jul 01; 154(1):69-74. PMID: 11427406.
    Citations: 75     Fields:    Translation:Humans
  45. Hernán MA, Hohol MJ, Olek MJ, Spiegelman D, Ascherio A. Oral contraceptives and the incidence of multiple sclerosis. Neurology. 2000 Sep 26; 55(6):848-54. PMID: 10994007.
    Citations: 33     Fields:    Translation:Humans
Local representatives can answer questions about the Profiles website or help with editing a profile or issues with profile data. For assistance with this profile: SPH faculty should contact Faculty Affairs at facultyaffairshsph.harvard.edu). HMS/HSDM faculty should contact contactcatalyst.harvard.edu. For faculty or fellow appointment updates and changes, please ask your appointing department to contact HMS. For fellow personal and demographic information, contact HMS Human Resources at human_resourceshms.harvard.edu. For faculty personal and demographic information, contact HMS Office for Faculty Affairs at facappthms.harvard.edu.
Hernan's Networks
Click the
buttons for more information and interactive visualizations!
Concepts (150)
Co-Authors (15)
Similar People (60)
Same Department 
Physical Neighbors
Funded by the NIH National Center for Advancing Translational Sciences through its Clinical and Translational Science Awards Program, grant number UL1TR002541.