“…Andersen's behavioral model of health service utilization was used as a theoretical framework to classify the Results of this study into three categories: Predisposing factors (Age, gender, marital status, ethnicity), Enabling factors (Education level, employment status, income level, insurance coverage, social network, social support, place of residence) and Need factors (Having a chronic disease, self-assessed health status, need for health care services, severity of the disease, number of diseases, comorbid diseases, type and duration of disease, having disability or functional limitation, unhealthy lifestyle). Findings of the reviewed articles showed that with the increase of age, the need to use health services increases [3,15,25,33,37,39,40,43,50,53,54,56,59], but in some studies, with increasing age and exceeding 85 years, the use of health services decreased [55,58,61]. Gender was associated with access to health services such that women were significantly more likely to seek health services [5,9,15,17,25,30,39,43,45,49,50,52,53,54,58,59,61,64].…”