Health Belief Model-Based Education to Improve Water Intake and Hydration in Older Adults: A Randomized Controlled Trial

PURPOSE: The current randomized controlled trial examined the effects of Health Belief Model (HBM)-based education on daily water intake, hydration biomarkers, thirst discomfort, and dry eye complaints in older adults. METHOD: Eighty community-dwelling older adults aged >= 65 years with insufficient daily water intake (<1 L/day) were screened and randomly assigned to intervention (n = 40) and control (n = 40) groups. Eligibility was determined using predefined inclusion criteria and baseline assessments. The intervention included individualized HBM-based education supported by a booklet and intake log. Data were collected using a descriptive form, Thirst Discomfort Scale, Ocular Surface Disease Index, and refractometer-based measurements of urine specific gravity and refractive index. RESULTS: Postintervention mean daily water intake significantly increased in the intervention group (mean = 749.8 [SD = 176] mL vs. 572.9 [SD = 159.3] mL; p < .001). Thirst discomfort scores decreased, and between-group differences were found in urine specific gravity and refractive index (p < .001). Although Ocular Surface Disease Index scores improved (p = .002), the clinical impact was limited. CONCLUSION: HBM-based education increased water intake and reduced thirst discomfort, supporting community-based geriatric nursing practice. Future studies should examine long-term effects and support integration of theory-based hydration education into nursing training and clinical practice.