An appropriate diagnosis and effective treatment of sleep apnea can improve the associated quality of care and reduce morbidities. The study aims to develop and evaluate an educational intervention tailored to patients' needs in order to increase the rate of patients' adherence to physician's prescription for a sleep test. A multi-center, stratified, 2 parallel-arm, randomized controlled trial was conducted. The patients in the intervention group received the educational booklets on sleep apnea and sleep test which was designed based on the extracted factors through an in-depth interview with patients. All participants were contacted after two months to ask whether they completed an assessment for OSA. A total number of 1,650 individuals were screened. Finally, 104 participants were randomized to the control group (n = 50) or intervention group (n = 45) that did not differ significantly in baseline characteristics. The results of the intention to treat analysis indicate that patients in the intervention group were significantly more adherent to attend a sleep assessment for their OSA risk (30%; n = 15/50) than the patients in the control group (11.1%; n = 5/45, P <0.05). Age, history of diabetes, and the educational intervention were effective in performing the sleep test. Time limitations, Condition improvement, and high cost of diagnostic test were the most barriers, respectively. The intervention was successful in improving the adherence rate of patients to prescribed sleep test. However, the adherence rate to sleep study testing is still far from desirable and requires more complex interventions.