1. The document discusses a study assessing the effectiveness of laughter therapy in reducing blood pressure among patients with primary hypertension. 2. The study involved 60 subjects divided into experimental and control groups, with the experimental group receiving laughter therapy sessions over 5 days while the control did not. 3. The study aimed to evaluate the difference in blood pressure levels before and after the laughter therapy for the experimental group, and examine the association between demographic variables and changes in blood pressure.