What Factors Determine Doctors' Preferences for Originator Drugs and Their Willingness to Prescribe Generic Drugs in Korea ?

Abstract

This study explored factors that influence the preference for originator drugs and the willingness of physicians to prescribe generic drugs in South Korea.

We used data from 500 physicians surveyed between September 2005 and October 2005 (response rate 23.6%). Logistic regression was used to analyze the determinants of doctors' opinions about medications: strong preference for originator drugs; and strong willingness to prescribe generic drugs. Among the 500 respondents, 46.6% of participants were primary care doctors, 23.6% were surgeons, 15.8% were pediatricians, and 14.0% were ENT doctors. Most physicians (86.7%) practiced alone and 73.2% reported treating mostly middle or upper socioeconomic class patients.

Younger, under age 50, physicians differed significantly from older physicians in several key characteristics, including a lower proportion of metropolitan area practices, and higher probability of training in private medical schools and having residencies in private hospitals. 59.5% of participants expressed strong preference for originator drugs, and more doctors in older group (78.9%) were more willing to prescribe generic drugs than younger doctors (58.4%). From the result of logistic regression model, physicians who cited the patients' clinical condition to be the most important factors in their prescribing decisions had more than twice the odds of preference for originator medicines, and physicians who trusted equivalency data had four times the odds of willingness to prescribe generic medications. Younger doctors appear to be more susceptible to commercial sources of information, because younger doctors who trust advertisement had higher odds of preference for originator drugs and lower odds of willingness to prescribe generics. Even though younger doctors were more exposed to formulary, guidelines, and educational training, exposure to guidelines made them less willing to prescribe generics. Economic stability is proved as the most important value in job for younger doctors and social respect for older doctors.

Keywords: originator drug, generic drug, preference