Hematopoietic stem cell transplantation (HSCT) involves the administration of anticancer treatment at high doses that exceed the patient’s maximum required dose for total body irradiation, to eliminate malignancy and achieve myeloablation. Hematopoietic stem cells are then transfused to re-establish the lost hematopoietic function. The use of radiation, anticancer drugs, and immunosuppressive drugs can cause adverse events in the oral cavity such as mucositis, bleeding, opportunistic infections, and graft versus host disease. This collaborative report by the departments of hematology and oncology as well as dentistry and oral surgery at our institution discusses the perioperative oral functional management of patients undergoing HSCT. Subjects enrolled were 191 transplantation patients (52 autologous, 139 allogeneic) between 2008 and 2015. The subjects underwent professional tooth cleaning before commencing a transplant conditioning regimen. When the professional oral health care (POHC) treatment was completed, professional tooth cleaning (PTC), professional mechanical tooth cleaning (PMTC), and treatment with a dental drug delivery (3DS) system were provided. This perioperative oral functional management resulted in a decrease in the frequency of oropharyngeal candidiasis from 19.3% to 4.3%. We devised a standardized supportive oral care program from the preoperative period onward to minimize adverse oral events associated with HSCT. The program could effectively improve the quality of life of patients undergoing HSCT.

Although the recent revision of the ministerial ordinance on Good Post-marketing Study Practice (GPSP) included the utilization of medical information databases for post-marketing surveillance, there has been limited research on the validity of diagnosis codes and other outcome definitions in Japanese databases such as administrative claims (“receipt”) database. This task force proposed how to conduct good validations studies, based on the narrative review on around 100 published papers around the world. The established check list consists of ： (ⅰ) understanding the type of the database (e.g. administrative claims data, electronic health records, disease registry) ； (ii) understanding the setting of the validation study (e.g. “population-based” or not) ； (iii) defining the study outcome ； (iv) determining the way of linkage between databases ； (v) defining the gold standard ； (vi) selecting the sampling method (e.g. using the information of all patients in the database or a hospital, random sampling from all patients, random sampling from patients satisfying the outcome definition, random sampling from patients satisfying and not satisfying the outcome definition, “all possible cases” method) and sample size ； (vii) calculating the measures of validity (e.g. sensitivity, specificity, positive predictive value, negative predictive value) ； and (viii) discussing how to use the result for future studies. In current Japan, where the linkage between databases is logistically and legally difficult, most validation studies would to be conducted on a hospital basis. In such a situation, detailed description of hospital and patient characteristics is important to discuss the generalizability of the validation study result to the entire database. This report is expected to encourage and help to conduct appropriate validation studies.