Table 2.

Description of the independent variables

Independent variables	Definition
Surgeon	Professional that performs the surgery.
Sociodemographic variable	This includes the age and the gender.
American Society of Anesthesiologists (ASA)	The surgical risk that a patient can experiment according to the measuring scale of the American Society of Anesthesiologists. The ordinal scale from ASA I to ASA V.
Type of surgery	Osteoarticular surgeries with or without implants and nails or skin surgery.
Fulfillment of the Informed Consent	It measures the correct fulfillment of the informed consent, codified in complete, incomplete or nonexistent.
Identification of the surgical site	It measures the correct identification of the anatomical site where the surgical procedure is going to be performed in the medical history. When the identification is correct, it is codified with a YES, or NO when it is incorrect. The reasons of a NO codification can be an inconsistency of the identification of the surgical site between the documents, or the anatomical site of the operation is not identified, or a surgery has been performed in the wrong site.
Fulfillment of the DVT Prophylaxis Protocol (DVTPP)	This is applied to patients undergoing surgery and assesses the risk of a thromboembolism. On the other hand, it measures the level of compliance of the protocol. A “Secure” codification is given to the patient when the assessment page of DVTPP risk is completed, when a DVT prophylaxis is required or when the assessment is completed and the patient does not require it or prophylaxis is not established as a treatment. The rest of the variations are considered insecure practices.
Correct use of the antibiotic prophylaxis	Antibiotic prophylaxis is require when the patient presents 3 or more risk factors (≥65 years, Diabetes Mellitus, malnutrition, obesity, ASA ≥ 3, smoking habits, coexistence of the infection in other locations, immunosuppression and radiotherapy treatment) in the cases of surgery with osteosynthesis materials. It is considered a secure practice when the subjects require antibiotic prophylaxis and it is established as a treatment; or when, on the contrary, the antibiotic prophylaxis is not required or established.
Infection of the surgical site	This happens when clear signs of infection are described in the medical history (such as pain, swelling, suppuration, erythema, redness) or when a local or oral antibiotic is prescribed during the postsurgical process.
Postoperative days	From the days of the operation till the date of discharge.