2.3 Data collection
Electronic medical records were identified and the following data elements were derived: age, postpartum time, parity, history of mastitis, time from onset, laterality, pain, swelling, heat and redness in the breast, breast mass, body temperature and SLCs. Antibiotic use and clinical outcomes were also collected from medical records.
Patients were asked to return to the hospital for follow-up on the seventh day and to report the current situation by telephone if they could not return to the hospital for any reason. For patients who returned to the hospital, a clinical physician could make an efficacy evaluation by comparing the signs and symptoms between their first presentation and the last follow up; for patients who did not return to the hospital, an efficacy evaluation was made by the patients themselves and was reported to the physicians by telephone.