Evaluating the impact of a novel restricted reimbursement policy for quinolone antibiotics: A time series analysis

Braden Manns,Kevin Laupland,Brenda Hemmelgarn,Song Gao,Marcello Tonelli

doi:10.1186/1472-6963-12-290

Abstract

BackgroundPublicly-funded drug plans often use prior authorization policies to limit drug prescribing. To guide physician prescribing of a class of antibiotics with broad antimicrobial activity (quinolone antibiotics) in accordance with new prescribing guidelines, Alberta’s provincial health ministry implemented a new mechanism for formulary restriction entitled the optional special authorization (OSA) program. We conducted an observational study to determine the impact of this new formulary restriction policy on antimicrobial prescription rates as well as any clinical consequences.MethodsQuinolone antibiotic use, and adherence with quinolone prescribing guidelines, was assessed before and after implementation of the OSA program in patients with common outpatient infections using an administrative data cohort and a chart review cohort, respectively. At the same time this policy was implemented to limit quinolone prescribing, two new quinolone antibiotics were added to the formulary. Using administrative data, we analysed a total of 397,534 unique index visits with regard to overall antibiotic utilization, and through chart review, we analysed 1681 charts of patients with infections of interest to determine the indications for quinolone usage.ResultsUsing segmented regression models adjusting for age, sex and physician enrollment in the OSA program, there was no statistically significant change in the monthly rate of all quinolone use (−3.5 (95% CI −5.5, 1.4) prescriptions per 1000 index visits) following implementation of the OSA program (p = 0.74). There was a significant level change in the rate of quinolone antibiotic use for urinary tract infection (−33.6 (95% CI: -23.8, -43.4) prescriptions and upper respiratory tract infection (−16.1 (95%CI: -11.6, -20.6) prescriptions per 1000 index visits. Among quinolone prescriptions identified on chart review, 42.5% and 58.5% were consistent with formulary guidelines before and after the implementation of the OSA program, respectively (p = 0.002). There was no change in hospitalization, mortality or use of physician services after implementation of the OSA program.ConclusionsDespite the addition of two new quinolone antibiotics to the formulary, we found that there was no change in the use of quinolones after implementation of a new formulary restriction policy for outpatients with common outpatient infections.

Highlights

Publicly-funded drug plans often use prior authorization policies to limit drug prescribing
The majority of unique index visits were for acute exacerbation of chronic bronchitis or for upper respiratory tract infection (76.8%) (Table 1)
Of the 196,740 unique index visits followed by an antibiotic prescription, additional antibiotics were prescribed on a subsequent day within the 30 day period for 20% of the unique index visits

Summary

Introduction

Publicly-funded drug plans often use prior authorization policies to limit drug prescribing. In an attempt to guide appropriate prescribing, maximize health benefits, and limit costs, most publicly funded health care systems have developed formularies or implemented policies to optimize prescription drug use. Traditional prior authorization programs have been shown to reduce prescription rates of several classes of medications including COX II inhibitors [2,3], respiratory drugs [4,5] and antidepressant agents [6]. They have been criticized as being intrusive [7], time-consuming, expensive to administer, and their effects may be temporary [8]. Interventions to limit outpatient prescribing of antibiotics, where the majority of use occurs, have received less attention

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Conclusion