Comparing outpatient and inpatient utilization rate in physicians, informed healthcare service consumers, and non-physicians, uninformed healthcare service consumers

Abstract

Background Supplier-induced demand(SID)cause a considerable but preventable economic burden on health systems.SID exists when the supplier changes a patient’s demand for his greater interest because of their asymmetric medical information.The informed patient is expected to resist demand induction;thus,his amount of utilization would be free of induction.In this study,we aimed to examine the impact of the opportunity of SID,information asymmetry,on healthcare utilization.As the nature of the association of interest could be considered to be the same in variety of contexts,we believe our results are generalizable to other countries as well. Methods We compared the individual outpatient and inpatient utilization rates in randomly chosen physicians(medically-informed)and non-physicians(medically-uninformed)with university degree and same living area in the Tehran province,the capital of Iran.Subjects were chosen by simple random selection with replacement from the relevant phone number list.Phone number lists were extracted from the Tehran province phone number list categorized by occupation.We excluded non-physicians with at least one physician in their close family and medical interns and subjects who did not answer the phone call and were unwilling to cooperate.Negative-binomial was used for comparing incidence rates of utilization(Hurdle in inpatient utilization),adjusted for demographic characteristics,insurance coverage,access to healthcare,and health status as healthcare-utilization-altering factors.The data collection tool consisted of 22 questions and was designed based on the list of the services that are prone to be induced by a supplier.The questionnaire was face-validated and content-validated in face to face interviews. Results In 349 physicians and 295 non-physicians,the adjusted outpatient and inpatient-utilization incidence was higher in non-physicians(incidence-rate-ratio: 1.38 and 3.19,respectively),p-value < 0.05.The only variable that correlated significantly with utilization rates was the presence of chronic diseases as the incidence rate of inpatient utilization was in patients with chronic conditions was 2.01 times of the individuals without. Conclusions The higher incidence rate of utilization in non-physicians comparing to physicians suggest SID existence and might be caused by information asymmetry and non-physicians’ vulnerability for SID,especially that utilization-altering factors were considered in the study design and analysis.The findings validate policies to regulate service provision,plan an appropriate payment system,which is mainly fee for service payment in Iran,and increase general population-health information via trusted routes.