Risks and Benefits Associated With Antibiotic Use for Acute Respiratory Infections: A Cohort Study

To the Editor,

Meropol et al (1) provide clinicians with valuable information about outcomes of patients treated with antibiotics for acute respiratory infections (ARI). As they note, there is continued difficulty in balancing the potential benefits of treatment to an individual patient (e.g. providing possible symptom relief and preventing the development of pneumonia) and the societal benefits provided by improved antibiotic stewardship practices (e.g. eliminating costs related to unnecessary treatments while limiting development of antimicrobial resistance).

Patients in the cohort who had received antibiotics for their ARI (65% of subjects) were not at a significantly increased risk of a substantial adverse event requiring hospitalization compared to those who did not receive antibiotics. There were significantly increased risks, however, for "minor adverse events" that brought the patient back to the primary care office. Certainly, we could assume, antibiotic related side effects (nausea, diarrhea, etc) were encountered that did not necessitate a return to providers that went undocumented.

It is illustrative that those who did receive antibiotics for ARI were older and had more historical markers for potential co-morbidities. These patients may have had risks recognized by their providers for a complicated course and the increased possibility of pneumonia development. These findings are in similar to our prior work demonstrating increased rates of antibiotic prescribing for patients who were older and had medical complexity. (2,3)

The specific ARI diagnosis of the individual patient makes a difference in the potential development of pneumonia. The benefit for the entire cohort, who had over a million patient visits for ARI treated with antibiotics, was minimal. The numbers need to treat to prevent one case of pneumonia requiring hospitalization for an undifferentiated ARI patient was over 12,000 (based on an adjusted risk difference of 8.16 fewer hospital admissions per 100,000 visits for those with antibiotic treatment, compared to those who were untreated.) When the authors analyzed data from those who had an acute bronchitis diagnosis, the risk difference for pneumonia hospitalization was 37.26 fewer per 100,000 visits. That would equate to about 2700 acute bronchitis patients needing to be treated with antibiotics to prevent one pneumonia hospitalization. This is a new fact for me to share with patients in our clinical discussions about whether to consider an antibiotic prescription.

Interestingly, subjects in this cohort did not include ARI patients who had a sinusitis diagnosis. We have reported persistently high rates of antibiotic prescribing in our practices for sinusitis patients, as opposed to those with other ARI diagnosis subtypes, even after multifaceted quality improvement interventions. (2,3) Fairley, et al recently reported analyses from the National Ambulatory Medical Care Survey data from the last decade confirming a persistently high rate of antibiotic treatment for sinusitis patients of about 80% (ranging from between 74% to 87%).(4) Half of these patients were treated with macrolides and quinolones rather than the guideline recommended penicillin derivatives. Limiting unnecessary antibiotic use for sinusitis is one of the "Choosing Wisely" goals for Family Medicine because of "the potential positive impact on quality and cost, and the ease with which the recommendations could be implemented."(5,6) Unfortunately, change has not proven to be easy.

As the authors noted "antibiotic prescribing decisions are based, at least partially, on nonclinical factors, such as patient expectation or physician practice patterns". Mark Ebell and colleagues recently elucidated the false expectations about the duration of symptoms for patients with acute cough illness. (7) As with other diagnoses where controversy about treatment benefit exist, shared decision making between providers and patients may be facilitated by utilizing patient decision aids. These tools educate as to the best available evidence and formalize explicit discussion of patients' values and preferences. Legare et al recently described successful development and implementation of these tools for multiple ARI clinical diagnoses.(8) As discussed in Cals et al, in the same Annals of Family Medicine edition, "enhanced communication skills" trump additional diagnostic testing modalities (in this case, point of care C-reactive protein testing) in helping to lower overall antibiotic prescribing rates.(9) We are hopeful that we can demonstrate successful utilization of patient decision aids through translational research in our clinical practice and then disseminate this to our health system practice based research network sites.

In summary, Dr Meropol and her colleagues provide many important new caveats which illuminate this difficult topic for the practicing clinician. While very few individual patients will suffer extreme harm from antibiotics being used for ARI's, few prescriptions are truly preventing serious illness as well.

Congratulations on an interesting and significant work!

Michael Grover, DO, Assistant Professor, Vice Chair-Research
Department of Family Medicine, Mayo Clinic, Scottsdale, AZ
Grover.michael@mayo.edu

1. Meropol SB, Localio AR, Metlay JP. Risks and benefits associated with antibiotic use for acute respiratory infections: a cohort study. Ann Fam Med. 2013;11(2):165-172.
2. Grover M, Mookadam M, Rutkowski R, Cullan A, Hill D, Patchett D, Simon E, Mulheron M, Noble B. Acute Respiratory Tract Infection: A practice examines its antibiotic prescribing habits. JFP 2012; 61 (6): 330 -5.
3. Grover M, Nordrum J, Mookadam M, Engle R, Moats C, Noble B. Decreasing antibiotic use rates for acute respiratory tract infections in an academic family medicine practice. Published online 11 February 2013 American Journal of Medical Quality. DOI: 10.1177/1062860613476133
4. Fairlie T, Shapiro DJ, Hersh AL, Hicks LA. National trends in visit rates and antibiotic prescribing for adults with acute sinusitis. Arch Intern Med. 2012;172:1513-1514
5. The "Top 5" Lists in Primary Care: Meeting the Responsibility of Professionalism. Arch Intern Med. 2011;171(15):1385-1390. doi:10.1001/archinternmed.2011.231.
6. Choosing Wisely. An Initiative of the ABIM Foundation. Accessed March 26, 2013. http://www.choosingwisely.org/
7. Ebell MH, Lundgren J, Youngpairoj S. How long does a cough last? Comparing patients' expectations with data from a systematic review of the literature. Ann.Fam.Med. 2013;11:5-13.
8. Legare F, Labrecque M, Cauchon M, Castel J, Turcotte S, Grimshaw J. Training family physicians in shared decision- making to reduce the overuse of antibiotics in acute respiratory infections: a cluster randomized trial. CMAJ. 2012;184:E726-E734.
9. Cals JWL, de Bock L, Beckers PHW, et al. Enhanced communication skills and C-reactive protein point-of-care testing for respiratory tract infection: 3.5-year follow-up of a cluster randomized trial. Ann Fam Med. 2013;11(2):157-164

Competing interests:   None declared