Statistics column Research methods: Clinical studies based on routine laboratory tests Shengping Yang PhD, Menfil Orellana-Barrios MD, Kenneth Nugent MD ABSTRACT Clinical research using routine laboratory tests can provide important opportunities to investigators, especially those with limited resources, and can improve patient care, especially if the result improves clinical decision making without the use of more sophisticated or expensive tests. Laboratory analysis of biological parameters can be used for screening, diagnostic testing, predicting prognosis, and measuring treatment responses. Often the same parameter can be used for several purposes, depending on the clinical scenario and the patient population. For example, several studies have suggested the mean platelet volume (MPV) is different in patients with acute coronary syndrome compared to patients with coronary disease but no acute syndrome. Given this information it might seem relatively easy to start studies using this laboratory test. However, multiple questions need to be considered before starting any research using MPV measurements. We will discuss some of these considerations in this review article. This approach applies to most research projects based on laboratory tests. Keywords: laboratory data, mean platelet volume, study design, literature searches, data management Article citation: Yang S, Orellana-Barrios M, Nugent K. Research methods: clinical studies based on routine laboratory tests. The Southwest Respiratory and Critical Care Chronicles 2018; 6(23):33–39 From: The Departments of Internal Medicine (MOB, KN) and Pathology (SY) at Texas Tech University Health Sciences Center in Lubbock, TX Submitted: 2/16/2018 Accepted: 3/15/2018 Reviewers: Jeff Dennis PhD, Gilbert Berdine MD Conflicts of interest: None This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.