Changes in Outpatient Use of Antibiotics by Adults in the United States, 2006-2015

Outpatient Antibiotic Use and Costs in Adults: A Nationwide Register-Based Study in Finland 2008-2019

The objective of this study was to describe the prevalence of outpatient use and costs for systemic antibacterials by age and sex among adults in Finland from 2008-2019. Data from the Finnish statistical database Kelasto, containing information concerning all reimbursed medicines for 18+-year-olds during 2008-2019, were analyzed. In addition to the decreased (26%) use of systemic antibiotics, decreased use was observed in all antibiotic categories, notably including several wide-spectrum antibiotics. The use of quinolones decreased by 49% and of tetracyclines by 39%. The 10 most frequently used antibiotics covered 89% of all adult antibiotic prescriptions. Antibiotic use also decreased in every age group during the study period. Although the overall yearly costs of outpatient antibiotics during the 10-year study period decreased from EUR 36.4 million to EUR 30.7 million, the cost per prescription increased slightly. In conclusion, according to the findings of this study, concerning adults and the results of our previous study concerning children and adolescents (2008-2016), there has been a decreasing trend of outpatient antibacterial use among the whole Finnish outpatient population over the duration of nearly one decade. However, during the same time period, there has been a specific increasing trend for the Gram-negative AMR threat regarding E. coli resistance. Therefore, based on our important findings in Finland, methods other than the restriction of antibiotic use, such as new anti-infective innovations, including antibacterials, are needed as soon as possible to tackle this major global health threat-a silent pandemic.

Epidemiology of Antibiotic Use and Drivers of Cross-Border Procurement in a Mexican American Border Community

Background

The U.S.-Mexico Border is an area of opportunity for improved health care access; however, gaps remain as to how and where U.S. border residents, particularly those who are underinsured, obtain care. Antibiotics are one of the most common reported drivers of cross-border healthcare access and a medication of particular concern since indiscriminate or inappropriate use is associated with antimicrobial resistance. In addition, many studies assessing preferences for Mexican pharmaceuticals and healthcare in U.S. border residents were done prior to 2010 when many prescription medications, including antibiotics, were available over the counter in Mexico.

Methods

Data used in this study were collected during the baseline examination of an ongoing longitudinal cohort study in Starr Country, Texas, one of 14 counties on the Texas-Mexico border. Participants self-reported the name, date of use, and the source country of each antibiotic used in the past 12 months. Logistic regression was used to determine social, cultural, and clinical features associated with cross-border procurement of antibiotics.

Results

Over 10% of the study cohort reported using antibiotics in the past 30 days with over 60% of all rounds used in the past 12 months sourced from Mexico. A lack of health insurance and generation score, a measure of acculturation, were the strongest predictors of cross-border procurement of antibiotics.

Conclusions

Factors previously associated with cross-border acquisition of antibiotics are still present despite changes in 2010 to prescription drug regulations in Mexico. These results may be used to inform future public health initiatives to provide culturally sensitive education about responsible antibiotic stewardship and to address barriers to U.S. healthcare and pharmaceutical access in medically underserved, impoverished U.S.-Mexico border communities.

Non-Visit-Based and Non-Infection-Related Antibiotic Use in the US: A Cohort Study of Privately Insured Patients During 2016-2018

BACKGROUND

Ambulatory antibiotic prescriptions without a clinic visit or without documentation of infection could represent overuse and contribute to adverse outcomes. We aim to describe US ambulatory antibiotic prescribing, including those without an associated visit or infection diagnosis.

METHODS

We conducted an observational cohort study using data of all patients receiving antibacterial, antibiotic prescriptions from 04/01/2016 to 06/30/2018 in a large US private health insurance plan. We identified outpatient antibiotic prescriptions as (1) associated with a clinician visit and an infection-related diagnosis; (2) associated with a clinician visit but no infection-related diagnosis; or (3) not associated with an in-person clinician visit in the 7 days before the prescription (non-visit-based). We then assessed whether non-visit-based antibiotic prescriptions (NVBAPs) differed from visit-based antibiotics by patient, clinician, or antibiotic characteristics using multivariable models.

RESULTS

The cohort included 8.6M enrollees who filled 22.3M antibiotic prescriptions. NVBAP accounted for 31% (6.9M) of fills, and non-infection-related prescribing accounted for 22% (4.9M). NVBAP rates were lower for children than for adults (0-17 years old, 16%; 18-64 years old, 33%; >65 years old, 34%). Among most commonly prescribed antibiotic classes, NVBAP was highest for penicillins (36%) and lowest for cephalosporins (25%) and macrolides (25%). Specialist physicians had the highest rate of NVBAP (38%), followed by internists (28%), family medicine (20%), and pediatricians (10%). In multivariable models, NVBAP was associated with increasing age, and NVBAP was less likely for patients in the South, those with more baseline clinical visits, or those with chronic lung disease.

CONCLUSIONS

Over half of ambulatory antibiotic use was either non-visit-based or non-infection-related. Particularly given health care changes due to the coronavirus disease 2019 pandemic, efforts to improve antibiotic prescribing must account for non-visit-based and non-infection-related prescribing.

Childhood Respiratory Outpatient Visits Correlate With Socioeconomic Status and Drive Geographic Patterns in Antibiotic Prescribing

BACKGROUND

Reducing geographic disparities in antibiotic prescribing is a central public health priority to combat antibiotic resistance, but drivers of this variation have been unclear.

METHODS

We measured how variation in outpatient visit rates (observed disease) and antibiotic prescribing rates per visit (prescribing practices) contributed to geographic variation in per capita antibiotic prescribing in Massachusetts residents younger than 65 years between 2011 and 2015.

RESULTS

Of the difference in per capita antibiotic prescribing between high- and low-prescribing census tracts in Massachusetts, 45.2% was attributable to variation in outpatient visit rates, while 25.8% was explained by prescribing practices. Outpatient visits for sinusitis, pharyngitis, and suppurative otitis media accounted for 30.3% of the gap in prescribing, with most of the variation in visit rates concentrated in children younger than 10 years. Outpatient visits for these conditions were less frequent in census tracts with high social deprivation index.

CONCLUSIONS

Interventions aimed at reducing geographic disparities in antibiotic prescribing should target the drivers of outpatient visits for respiratory illness and should account for possible underutilization of health services in areas with the lowest antibiotic consumption. Our findings challenge the conventional wisdom that prescribing practices are the main driver of geographic disparities in antibiotic use.

Changes in US Outpatient Antibiotic Prescriptions From 2011-2016

BACKGROUND

While antibiotics are life-saving drugs, their use is not without risk, including adverse events and antibiotic resistance. The majority of US antibiotic prescriptions are prescribed in outpatient settings, making outpatient antibiotic prescribing an important antibiotic stewardship target. The primary objective of this study was to describe trends in US outpatient oral antibiotic prescriptions from 2011-2016.

METHODS

We estimated annual oral antibiotic prescription rates using national prescription dispensing count data from IQVIA Xponent, divided by census estimates for 2011-2016. We calculated the ratio of broad- to narrow-spectrum prescriptions by dividing broad-spectrum prescription rates by narrow-spectrum prescription rates. We used Poisson models to estimate prevalence rate ratios, comparing 2011 and 2016 antibiotic prescription rates, and linear models to evaluate temporal trends throughout the study period.

RESULTS

Oral antibiotic prescription rates decreased 5%, from 877 prescriptions per 1000 persons in 2011 to 836 per 1000 persons in 2016. During this period, rates of prescriptions dispensed to children decreased 13%, while adult rates increased 2%. The ratio of broad- to narrow-spectrum antibiotics decreased from 1.62 in 2011 to 1.49 in 2016, driven by decreases in macrolides and fluoroquinolones. The proportion of prescriptions written by nurse practitioners and physician assistants increased during the study period; in 2016, these providers prescribed over one-quarter of all antibiotic prescriptions.

CONCLUSIONS

Outpatient antibiotic prescription rates, especially of broad-spectrum agents, have decreased in recent years. Clinicians who prescribe to adults, including nurse practitioners and physician assistants, are important targets for antibiotic stewardship.

Outpatient Fluoroquinolone Use in Children, 2000-2018

BACKGROUND

While fluoroquinolones are commonly used in adults, the use in children has been low. Since 2000, there were 3 US Food and Drug Administration (FDA) Boxed warnings regarding fluoroquinolones (2008, 2013, and 2016). Our objective was to describe the use of fluoroquinolones in children and assess the impact of 3 recent FDA warnings on fluoroquinolone use.

METHODS

From 2000 to 2018, we assessed claims for all outpatient prescription fills to measure the use of systemic fluoroquinolones and other broad-spectrum antibiotics in children  less than 18 years old in the MarketScan Commercial Claims and Encounters database. We describe demographics, indication for antibiotic, and clinical characteristics. To assess the impact of FDA warnings on fill rates, we conducted an interrupted time-series analysis.

RESULTS

The cohort included 34.6 million unique beneficiaries less than 18 years old with 441 062 fluoroquinolone fills (5.5 fills per 1000 person-years). The fluoroquinolone fill rate was highest among children > 11 years old. Urinary tract infection was the most common associated diagnosis (21.8%). Since 2008, the fluoroquinolone fill rate has declined. By the end of the study period in December 2018, in the (counterfactual) absence of the FDA warnings, fluoroquinolone fill rate would have been 7.5 (95% confidence interval [CI]: 5.2-9.7); however, the corresponding rate in observed data was 2.8 (95% CI: 1.7-3.9).

CONCLUSIONS

Fluoroquinolone use was low compared with other common broad-spectrum antibiotics and declining trends over time were associated with FDA warnings, even though these warnings were not pediatric specific. Future work should assess the adverse events at issue in these warnings in children.

Prevalence and Determinants of Antibiotic Consumption in the Elderly during 2006-2017

Elderly people are a particularly important population with regard to antibiotic overuse, using around 50% more antibiotics per capita than younger adults. The aim of this study was to analyze the prevalence, associated factors and evolution over time of antibiotic consumption among the Spanish population aged ≥ 65 years from 2006 to 2017. A descriptive cross-sectional study was conducted using data from the Spanish National Health Survey in 2006, 2011/2012 and 2017, and from the European Health Survey in Spain in 2009 and 2014. The sample consisted of 26,891 non-institutionalized individuals ≥ 65 years. Antibiotic consumption was the dependent variable, and sociodemographic variables, lifestyle habits and health status were analyzed using a logistic regression model. The prevalence of antibiotic consumption was 4.94%, with a marked increase from 2006 (4.64%) to 2017 (5.81%) (p < 0.0001). Higher antibiotic consumption was associated with poor or very poor self-perceived health status, no polypharmacy and not having been in hospital during the previous twelve months, while a lower consumption was linked to being limited but not severely due to a health problem and not being at all limited.

Outpatient Antibiotic Prescribing in Massachusetts, 2011-2015

BACKGROUND

The objectives of this study were to develop methods to measure population-based outpatient antibiotic prescribing in Massachusetts and to describe the findings as a first step toward institution of ongoing surveillance.

METHODS

We analyzed outpatient prescription claims from the Massachusetts All-Payers Claims Database from 2011 to 2015. We grouped claims for antibiotics according to the World Health Organization's Anatomical Therapeutic Chemical Classification System using the National Library of Medicine's RXNorm database. We grouped prescribers into 17 specialties. Antibiotic use rates were calculated, and simple frequencies were used to describe patterns.

RESULTS

The overall annual rate of outpatient antibiotic use for individuals aged 0-64 years was 696 prescriptions per 1000 people. During 2015, 68% of people in Massachusetts had no antibiotic prescription, and 17% had only 1 prescription. There was dramatic variability in antibiotic use rates by census tract within the state (rates of penicillin use ranged from 31 to 265 prescriptions per 1000 people, macrolides from 28 to 333, cephalosporins from 8 to 89, quinolones from 13 to 118). Antibiotic use rates were generally lower in urban census tracts. From 2011 to 2015, there was a 17% decline in antibiotic prescribing, with the greatest decline for macrolides (28%).

CONCLUSIONS

There was variability in antibiotic prescribing within Massachusetts by age, sex, and antibiotic class. Variation in antibiotic use across census tracts within the state was similar to the variation in use across US states. Continued measurement and detailed local population rates of antibiotic use in Massachusetts will provide feedback for local prescribers.