Sternal surgical site infection (SSI) after coronary artery bypass graft surgery is a complication that increases patient morbidity and costs for patients, payers, and the health care system. Segal and Anderson (A-5) performed a study that examined two types of preoperative skin preparation before performing open heart surgery. These two preparations used aqueous iodine and insoluble iodine with the following results.

Comparison of Aqueous and Insoluble Preps Prep Group Infected Not Infected Aqueous iodine 14 94 Insoluble iodine 4 97 Source: Cynthia G. Segal and Jacqueline J. Anderson, “Preoperative Skin Preparation of Cardiac Patients,” AORN Journal, 76 (2002), 821–827.

Do these data provide sufficient evidence at the a ¼ .05 level to justify the conclusion that the type of skin preparation and infection are related?