Review Article| Volume 30, ISSUE 1, P147-154, 2012

Observational Data

Pitfalls and Pearls
  • Brian D. Sites
    Department of Anesthesiology, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH.
    Department of Anesthesiology, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH, USA

    Department of Pain Management, Dartmouth-Hitchcock Medical Center, One Medical Center Drive, Lebanon, NH, USA
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Published:September 10, 2012DOI:
      Key Points
      • Observational research entails examining the relationship between exposures and outcomes. Cohort and case-control research methodologies are important in the context of rare outcomes and dangerous interventions, and for the external validation of randomized controlled trials.
      • Observational research has the risk of drawing incorrect conclusions based on the presence of confounders.
      • Regression analysis is the major technique for addressing potential confounders by providing adjusted estimates.
      In medicine and anesthesiology, observational research is common and supports quality improvement, performance assessment, and clinical research. This article discusses the benefits and challenges of observational research.


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        • Stampfer M.
        • Colditz G.
        Estrogen replacement therapy and coronary heart disease: a quantitative assessment of the epidemiologic evidence.
        Prev Med. 1991; 20: 47-63
        • Bush T.L.
        • Barrett-Connor E.
        • Cowan L.D.
        • et al.
        Cardiovascular mortality and noncontraceptive use of estrogen in women: results from the Lipid Research Clinics Program follow-up study.
        Circulation. 1987; 75: 1102-1109
        • Grady D.
        • Rueben S.B.
        • Petitti D.B.
        • et al.
        Hormone therapy to prevent disease and prolong life in postmenopausal women.
        Ann Intern Med. 1992; 117: 1016-1037
        • Col N.F.
        • Eckmen M.H.
        • Keris R.
        • et al.
        Patient-specific decisions about hormone replacement therapy in premenopausal women.
        JAMA. 1997; 277: 1146-1147
        • Zandi P.P.
        • Carlson M.C.
        • Plassman B.L.
        • et al.
        Hormone replacement therapy and incidence of Alzheimer disease in older women the cache county study.
        JAMA. 2002; 288: 2123-2129
        • Petitti D.B.
        • Perlman J.A.
        • Sidney S.
        Postmenopausal estrogen use and heart disease.
        N Engl J Med. 1986; 15: 131-136
      1. Available at: Accessed February 14, 2012.

        • Rossouw J.E.
        • Anderson G.L.
        • Prentice R.L.
        • et al.
        Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the Women's Health Initiative randomized controlled trial. writing group for the women's health initiative investigators.
        JAMA. 2002; 288: 321-333
        • Shumaker S.A.
        • Legault C.
        • Rapp S.R.
        • et al.
        Estrogen plus progestin and the incidence of dementia and mild cognitive impairment in postmenopausal women: the Women's Health Initiative Memory Study: a randomized controlled trial.
        JAMA. 2003; 289: 2651-2662
      2. FDA information. Available at: Accessed February 14, 2012.

        • Surgenor S.D.
        • Kramer R.S.
        • Olmstead E.M.
        • et al.
        The association of perioperative red blood cell transfusions and decreased long-term survival after cardiac surgery.
        Anesth Analg. 2009; 108: 1741-1746
        • Goodney P.P.
        • Jorgensen J.E.
        • Nolan B.W.
        • et al.
        A regional quality improvement effort to increase beta-blocker administration before vascular surgery.
        J Vasc Surg. 2011; 53: 1328