Impact of Dispensing Restriction Policy on Antibiotic Prescribing in Korea

1. Abstract Decreased Inappropriate Antibiotic Use Following a Korean National Policy to Prohibit Medication Dispensing by Physicians Problem Statement: Korean government introduced a new policy in July 2000 that prohibited physicians from dispensing and pharmacists from prescribing medication. Objectives: To evaluate the impact of the new policy on antibiotic prescribing for cases of viral disease, in which antibiotic prescribing was likely inappropriate, compared to bacterial disease, where antibiotic prescribing could be appropriate; to determine provider factors associated with reductions in inappropriate antibiotic prescribing for viral illness following the policy change. Design: Retrospective, before/after study. Setting and Population: National health insurance claims data on monthly episodes of care for patients with viral or bacterial illness, collected for January 2000 and January 2001. Nationally representative sample consisted of 50,999 cases from 1,372 primary care clinics. Intervention: As of July 2000, physicians were prohibited from dispensing and pharmacists were prohibited from prescribing. Outcome Measures: Rate of antibiotic prescribing; average number of different antibiotics per case. Results: After the dispensing restriction, antibiotic prescribing declined for both patients with viral illness (from 80.8% to 72.8%, adjusted relative risk (RR)= 0.89, [95% confidence interval: 0.86, 0.91], p<0.0001) and patients with bacterial illness (from 91.6% to 89.7%, adjusted RR= 0.98, [0.97, 0.99], p=0.0171). Reductions in antibiotic prescribing were significantly larger (adjusted RR=0.90, [0.87, 0.93], p<0.0001) for patients with viral illness. The number of different antibiotics prescribed per episode also decreased significantly after the policy, but there were no significant differences in these reductions between viral and bacterial illness. The dispensing restriction also reduced prescribing of non-antibiotic drugs, with no difference by diagnosis. Provider factors found to be associated with reduced inappropriate antibiotic prescribing were young age and practice location in an urban area. Conclusions: Prohibiting doctors from dispensing drugs reduced prescribing overall and selectively reduced inappropriate antibiotic prescribing for patients with viral diagnoses. Since our findings were based on single observations before and after the policy intervention, further study using longitudinal data is needed to evaluate the long-term effects of such policies. Sylvia Park, PhD; Stephen B. Soumerai, ScD; Alyce S. Adams, PhD; Jonathan A. Finkelstein, MD,MPH; Sunmee Jang, PhD*; Dennis Ross-Degnan, ScD Department of Ambulatory Care and Prevention, Harvard Medical School, USA;Health Insurance Review Agency, Korea*

2. Introduction Research on Dispensing Doctors • Dispensing Doctors were found to - prescribe greater numbers of drugs - prescribe more antibiotics and injections - have higher prescribing costs. • Little is known about whether incentives related to dispensing affect the quality of prescribing. • Most of previous research has been cross-sectional. New Policy in Korea (July, 2000) • Prohibiting doctors from dispensing drugs and pharmacists from prescribing drugs Antibiotics in Korea • Antibiotics accounted for 20% of ambulatory drug expenditures in 2000. • Korea has very high resistance rates, with 86% of Streptococcus pneumoniae resistant to penicillin in 2001.

3. Objectives • To evaluate the impact of the dispensing restriction policy in Korea on the quantity and quality of physician prescribing - selectivity in the decrease of antibiotic prescribing in cases with viral illness, in which antibiotic prescribing was likely inappropriate, compared to bacterial illness, where antibiotic prescribing could be appropriate • To investigate provider characteristics related to the decrease of inappropriate antibiotic prescribing in viral illness

4. Methods Data Collection • NHI monthly claims data(patient level) • monthly episodes • diagnosis, prescription, patient information Jan. 2000 (6 months before policy) Jan. 2001 (6 months after policy) Viral Illness Common Cold / Upper respiratory tract infection / Bronchiolitis Bacterial Illness Penumonia/ Otitis media/ Tonsilitis/ Strep. Sore throat/ Sinusitis/ Urinary tract infection/ Skin and soft tissue infection Sampling: 10% of all clinics (1476 clinics)  20% of claims with above diagnoses in sampled clinics Including cases with no commorbidity From 1372 clinics, Viral: 18,656(pre), 16,736(post) cases Bacterial: 7758(pre), 7849(post) cases

5. Analysis : Impact of the Policy on Prescribing • Prescription Variables (patient level) • Antibiotics - antibiotic prescribing - number of different antibiotics • Non-antibiotics - gastrointestinal drug prescribing - number of different non-antibiotic drugs • Generalized Estimating Equations Y = ß0 + ß1×Policy+ ß2×Illness + ß3×Policy × Illness (+ ß4 Patient or provider char. + ß5 … ) +  - Y: Prescription Variables (patient level) - X : Policy: after policy=1 / before policy=0 : Illness: viral=1 / bacterial=0 : Policy × illness: Interaction (different policy effect between illnesses) : Patient or provider characteristics : gender, age, location, size, type - Cluster effect : clinic

6. Analysis : Provider Characteristics Related to Decrease of Inappropriate Antibiotic Prescribing in Viral Illness • Data Rearrangement • Only clinics having >= 10 cases in each period in viral illness • Aggregating data to clinic level • Adjusting to patient gender, age distribution and diagnosis mix of total sample in Jan. 2001 • Multiple Regression Y= ß0 + ß1 Location + ß2 Type+ ß3 Size (+ ß4 Age + ß5 Gender) +  Y: Antibiotic prescribing rate : Average # of different antibiotics per case (baseline & pre/post change) (clinic level) X: Location : Urban / Rural Type : Group / Solo Size : <= 150 pt / 151 - 250 pt / >= 251 pt Age : <= 39 / 40 - 49 / >= 50 Gender: Male / Female

7. Results Characteristics of Cases

8. Impact of the Policy on Antibiotic Prescribing • Antibiotic prescribing decreased after the policy in both illness groups. • Reduction of antibiotic prescribing was significantly larger in viral illness than in bacterial illness.

9. Impact of the Policy on the Number of Different Antibiotics • Number of different antibiotics decreased after the policy, with no difference between illness groups.

10. Impact of the Policy on Gastrointestinal Drug Prescribing • Gastrointestinal drug prescribing decreased after the policy, with no difference between illness groups. Impact of the Policy on the Number of Different Non-antibiotic Drugs • Number of different non-antibiotic drugs decreased after the policy, with no difference between illness groups.

11. Provider Characteristics Related to Decrease of Inappropriate Antibiotic Prescribing in Viral Illness • At baseline, physicians in group practice were less likely to prescribing antibiotics for viral illness than those in solo practice by 14.3 percentage points. • After the policy, younger physicians were more likely to decrease antibiotic polypharmacy than those age 50 and older. • Physicians in urban area were more likely to reduced prescribing per patient by 0.14 antibiotics than those in rural area.

12. Conclusion • Prohibiting doctors from dispensing drugs reduced prescribing overall, both antibiotics and other drugs, and selectively reduced inappropriate antibiotic prescribing for patients with viral diagnosis. • There was no evidence of diagnosis shift or change in the proportion with bacterial or possibly bacterial diagnoses as either primary or secondary diagnosis. • Data on pre-intervention trends supports the validity of our findings: antibiotic prescribing had not decreased before intervention in 1994-2000. • Still high rate of antibiotic prescribing for viral illness after policy indicates the need for further targeted interventions. • Further study using longitudinal data is needed to evaluate whether these reductions in prescribing and improvements in quality are maintained. • Removing the financial motivation to prescribe can contribute significantly to quality use of medicines.