Perioperative Medicine  |   April 2016
Preoperative Laboratory Investigations: Rates and Variability Prior to Low-risk Surgical Procedures
Author Notes
  • From the Department of Anesthesia and Pain Management, Toronto Western Hospital, Toronto, Ontario, Canada (K.R.K.); Department of Anesthesia, Women’s College Hospital, Toronto, Ontario, Canada (K.R.K.); Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada (D.N.W.); Department of Anesthesia and Pain Management, Toronto General Hospital, Toronto, Ontario, Canada (D.N.W.); Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada (D.N.W., J.V.T., J.T., M.J.S., R.S.B.); Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada (D.N.W., R.N., J.V.T., M.J.S., R.S.B.); Institute for Health System Solutions, Women’s College Hospital, Toronto, Ontario, Canada (C.P., R.S.B.); Department of Medicine, University of Toronto, Toronto, Ontario, Canada (J.V.T., M.J.S., W.L., R.S.B.); Division of Cardiology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada (J.V.T.); Department of Health Policy and Management, Harvard School of Public Health, Boston, Massachusetts (A.S.B.); Health Quality Ontario, Toronto, Ontario, Canada (J.T.); Department of Family and Community Medicine, University of Toronto, Toronto, Ontario, Canada (J.T.); Department of Emergency Medicine, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada (M.J.S.); and Department of Cardiology, Women’s College Hospital, Toronto, Ontario, Canada (R.S.B.).
  • Corresponding article on page 755.
    Corresponding article on page 755.×
  • Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).
    Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org).×
  • R.S.B. had full access to all of the data in the study and takes responsibility for the integrity of the data and accuracy of the data analysis. R.S.B., K.R.K., and D.N.W. helped in study concept and design. R.S.B. and R.N. helped in acquisition of data. All authors helped in analysis and interpretation of data. R.S.B., K.R.K., and C.P. helped in drafting of the manuscript. All authors helped in critical revision of the manuscript for important intellectual content. R.N. helped in statistical analysis. R.S.B. obtained funding. R.S.B., K.R.K., and D.N.W. helped in study supervision.
    R.S.B. had full access to all of the data in the study and takes responsibility for the integrity of the data and accuracy of the data analysis. R.S.B., K.R.K., and D.N.W. helped in study concept and design. R.S.B. and R.N. helped in acquisition of data. All authors helped in analysis and interpretation of data. R.S.B., K.R.K., and C.P. helped in drafting of the manuscript. All authors helped in critical revision of the manuscript for important intellectual content. R.N. helped in statistical analysis. R.S.B. obtained funding. R.S.B., K.R.K., and D.N.W. helped in study supervision.×
  • Submitted for publication June 19, 2015. Accepted for publication November 4, 2015.
    Submitted for publication June 19, 2015. Accepted for publication November 4, 2015.×
  • Address correspondence to Dr. Bhatia: Division of Cardiology, University Health Network and Women’s College Hospital, University of Toronto, 76 Grenville Street, 6th Floor, Toronto, Ontario, Canada M5S 1B2. sacha.r.bhatia@wchospital.ca. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. Anesthesiology’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue.
Article Information
Perioperative Medicine / Clinical Science / Cardiovascular Anesthesia / Coagulation and Transfusion / Endocrine and Metabolic Systems
Perioperative Medicine   |   April 2016
Preoperative Laboratory Investigations: Rates and Variability Prior to Low-risk Surgical Procedures
Anesthesiology 4 2016, Vol.124, 804-814. doi:10.1097/ALN.0000000000001013
Anesthesiology 4 2016, Vol.124, 804-814. doi:10.1097/ALN.0000000000001013
Abstract

Background: Increasing attention has been focused on low-value healthcare services. Through Choosing Wisely campaigns, routine laboratory testing before low-risk surgery has been discouraged in the absence of clinical indications. The authors investigated rates, determinants, and institutional variation in laboratory testing before low-risk procedures.

Methods: Patients who underwent ophthalmologic surgeries or predefined low-risk surgeries in Ontario, Canada, between April 1, 2008, and March 31, 2013, were identified from population-based administrative databases. Preoperative blood work was defined as a complete blood count, prothrombin time, partial thromboplastin, or basic metabolic panel within 60 days before an index procedure. Adjusted associations between patient and institutional factors and preoperative testing were assessed with hierarchical multivariable logistic regression. Institutional variation was characterized using the median odds ratio.

Results: The cohort included 906,902 patients who underwent 1,330,466 procedures (57.1% ophthalmologic and 42.9% low-risk surgery) at 119 institutions. Preoperative blood work preceded 400,058 (30.1%) procedures. The unadjusted institutional rate of preoperative blood work varied widely (0.0 to 98.1%). In regression modeling, significant predictors of preoperative testing included atrial fibrillation (adjusted odds ratio [AOR], 2.58; 95% CI, 2.51 to 2.66), preoperative medical consultation (AOR, 1.68; 95% CI, 1.65 to 1.71), previous mitral valve replacement (AOR, 2.33; 95% CI, 2.10 to 2.58), and liver disease (AOR, 1.69; 95% CI, 1.55 to 1.84). The median odds ratio for interinstitutional variation was 2.43.

Conclusions: Results of this study suggest that testing is associated with a range of clinical covariates. However, an association was similarly identified with preoperative consultation, and significant variation between institutions exists across the jurisdiction.

Abstract

The cohort included more than 900,000 patients in 119 hospitals who had ophthalmologic and other low-risk procedures. Various risk factors and medical consultation increased use of preoperative testing. The amount of testing varied widely among institutions.

Supplemental Digital Content is available in the text.