Associations between generic substitution and patients' attitudes, beliefs and experiences

Background: Generic substitution has been implemented in many countries, but knowledge about patients' attitudes, beliefs and experiences is still sparse. Aim: To assess associations between generic switching and patients' attitudes, beliefs and experiences with previous generic switching. Design and setting: A cross-sectional study comprising questionnaire responses from 2,476 randomly selected patients aged 20 years or older and living in the Region of Southern Denmark, who had redeemed substitutable drugs. Methods: The questionnaire included items on beliefs about medicine, views on generic medicine and confidence in the healthcare system. Only prescriptions issued by the general practitioners were included. For each patient, we focused on one purchase of a generically substitutable drug (index drug). Patients were identified by means of a dispensing database. Results: Earlier generic switches within the index ATC code were statistically significantly associated with experience of a generic switch (adjusted OR 5.93; 95 % CI 4.70-7.49). Having had more than five earlier switches within other ATC codes and having negative views on generic medicines reduced the odds of experiencing a generic switch. No associations were found between generic substitution and gender, drug group, number of different drugs used by the patient, confidence in the health care system and beliefs about medicine in general. Conclusion: Patients who had once experienced a generic switch were more likely to accept a future generic switch within the same ATC code. Negative views on generic medicines were negatively associated with switching, while beliefs about medicine and confidence in the healthcare system had no influence.