Increasing efforts to influence both the prescriber and patient factors involved in determining the type of initial prescription may benefit everyone involved in paying for medications to get the most cost-effective treatment for their condition.
Current opinion in the scientific literature is that the overall expenditure on drugs could be reduced by over 10% if generics were prescribed whenever they were available [1]. Studies also suggest a strong correlation between therapy initiation with generic medications and an improved patient compliance and adherence to the chronic therapy prescribed [2]. It is therefore beneficial to study the factors that influence the use of generics over brand-name treatments.
Factors associated with the prescription of generic medications
There are many factors that influence whether patients are prescribed with generic medications. The most prominent factor is the physician who writes the initial prescriptions and therefore has the largest influence on which medication is chosen. The patients themselves may also request generic versions of the prescribed medication when they are either with the doctor or when they visit the pharmacy to collect their prescription.
Health insurance companies use the pharmacy benefit designs and tiered co-payment requirements to guide patients towards the less expensive, generic medications. Characteristics of the pharmacy may also influence medication choice by influencing the rates that patients can communicate concerning the cost of their medication or by using protocols or standard operating procedures to increase generic medication use.
If we have a better understanding of these factors associated with generic drug use, it may be possible to intervene at certain points to reduce unnecessary drug costs. A recent study by Shrank et al. has highlighted just these factors [3].
Results of the study by Shrank et al
Population statistics
From the 5,399 new prescriptions that were filled between 2001–2002, 1,262 (23.4%) were found to be generics and of the patients who were initially prescribed brand-name drugs, 606 (14.9%) switched to a generic drug in the same class in the following year.
Factors influencing whether patients initially filled prescriptions for a generic medication
Patients living in high-income areas were found to be more likely to begin treatment with generics than patients living in low-income areas (RR = 1.29; 95%CI 1.04–1.60) and elderly patients were more likely to switch to generic drugs from brand-name drugs than younger patients. In fact, males > 55 years old were 7.5 times more likely to switch to generic drugs than males < 25 years old (P = 0.04). Older females were 2–3 times more likely to switch than females less than 25 years old (P<0.001).
Medication choices by type of doctor
Consistent with previous reports [4], it was found that patients of obstetricians/gynaecologists were 27% less likely to switch than those seen by generalist physicians (P = 0.01).
Factors influencing switching to a generic medication
Pharmacy benefit design and the type of pharmacy, however, was not found to be linked with generic medication initiation, although it did have a substantial influence on switching rates. If patients were enrolled in a three-tier pharmacy plan, they were over 2.5 times more likely to switch from brand-name to generic medications than patients in a one- or two-tiered plan (P = 0.03) and patients in plans with three or four tiers of co-payments and higher co-payment requirements were almost four times more likely to switch to the generic counterpart (P = 0.001). Similarly, if patients used mail-order pharmacies to buy their prescription medication, they were 65% more likely to switch to a generic version after beginning treatment with the brand-name drug (P = 0.003). However, no differences were seen when patients refilled their medications in independent versus chain pharmacies.
Conclusion
This study by the team of Professor Shrank has shown that both physician and patient factors have an important influence on whether patients are initiated on generics or brand-name drugs. Although few studies have investigated the proportion of switch from brand-name to generic drug use when prescriptions are refilled, the study of Shrank et al. has shown that only one in seven patients initiated on brand-name drugs switch to the generic version in the subsequent year, which highlights the importance of influencing the medication choice at the time of the initial prescription choice [3].
Editor’s comment
This article has highlighted the factors involved which can influence whether brand-name or generic medications are used. Opportunities may currently exist therefore to influence patients and prescribers in their initial decision of whether to use a generic or brand-name drug.
Please feel free to share your thoughts and ideas on influencing the use of generic medications via email to editorial@gabionline.net or in the comments section below.
Raising awareness of the benefit design incentives for generic drug use can be one way, but what would this awareness campaign look like? What shape could other methods of influencing cost-effective medication use take? Have you ever been (knowingly) influenced in your choice of medication?
Related article
Influence these two factors and the use of generics will increase
References
1. Haas JS, Phillips KA, Gerstenberger EP, Seger AC. Potential savings from substituting generic drugs for brand-name drugs: medical expenditure panel survey, 1997–2000. Ann Intern Med. 2005;142(11):891–7.
2. Kaiser Family Foundation and Health Research and Educational Trust. Employer health benefits: 2004 summary of findings. Available from: www.kff.org/insurance/7148/loader.cfm?url=/commonspot/security/getfile.cfm&PageID=46206 [Accessed March 08, 2011].
3. Shrank WH, Stedman M, Ettner SL, DeLapp D, Dirstine J, Brookhart MA, et al. Patient, physician, pharmacy, and pharmacy benefit design factors related to generic medication use. J Gen Intern Med. 2007;22(9):1298-304.
4. Federman AD, Halm EA, Siu AL. Use of generic cardiovascular medications by elderly Medicare beneficiaries receiving generalist or cardiologist care. Med Care. 2007;45(2):109-15.
0
Post your comment