Purpose: To clarify intervention methods used by medical professionals in clinical situations and their effects on the health literacy of patients.Method: Reports on randomized controlled trials for the health literacy of patients were collected from the electronic database. The reports were then evaluated using qualitative systematic reviews conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement.Result: On examination of the effects by intervention methods, we found that many reports concluded an improvement in health literacy by patients by "only the distribution of handouts". Moreover, many reports also noted improved "adherence for health behavior" by patients following the "distribution of handouts and explanation by medical professionals". Furthermore, improved "health literacy" by "one-way intervention from medical professionals to patients" and "two-way intervention by both medical professionals and patients" was reported.Conclusion: Based on this study, it may be possible to provide information considering individuality when the medical professional provides an explanation to the patient in addition to giving handouts. Improved disorder comprehension and self-management skills are expected when the medical professional appropriately confirms the patient's comprehension level.