Acute bronchitis is one of the most common diagnoses for adults in the United States. Approximately 5 percent of adults self-report an episode each year and up to 90 percent of these people seek medical attention.¹ According to the American College of Chest Physicians (ACCP), acute bronchitis is defined as an acute cough illness, with or without phlegm production, lasting for up to three weeks.² ACCP limits treatment assessment and guideline to patients who are considered to have “uncomplicated” acute bronchitis. Patients with underlying issues such as AIDS, chemotherapeutic treatments, and congestive heart failures, along with the co-morbid conditions listed in Chart 1, are excluded from the discussion. Acute bronchitis is a self-limiting respiratory disorder that is diagnosed only in the absence of pneumonia, the common cold, acute asthma, or an exacerbation of chronic obstructive pulmonary disorder.³

The etiology of acute bronchitis can be either bacterial or viral in nature. Several randomized trials and meta-analysis studies (on the effects of antibiotics on the duration and severity of cough) have led to the conclusion that viral infections are the primary cause of acute bronchitis.⁴ Respiratory viruses such as influenza A and B, respiratory syncytial virus, coronavirus, rhinovirus and a few others are responsible for more than 90 percent of the cases of acute bronchitis.⁵ Yet, viruses are rarely identified because viral cultures and serologic assays are seldom performed. Although rapid diagnostic tests exist for several bacteria that are linked to acute bronchitis, their routine use is not cost-effective because bacteria are the causative agent in less than 10 percent of the cases.^6,7

Despite the low rate of infection by bacterial agents, the diagnosis of acute bronchitis has become synonymous with antibiotic treatment.⁸ Studies have shown that 70 – 90 percent of office visits for acute bronchitis receive antibiotic treatment even though this illness is (without the presence of pneumonia) often self-limited.⁹ Routine treatment with antibiotics does not have consistent impact on duration or severity of illness or on potential complications such as pneumonia.¹⁰ However, despite multiple evidences that antibiotics are ineffective, an average of 80 percent of patients received an antibiotic. ¹¹

The primary diagnostic objective needs to be the exclusion of pneumonia. According to ACCP guidelines, the absence of abnormalities in vital signs and chest exams sufficiently reduces the likelihood of pneumonia. Normal vital signs criteria are: a) heart rate less than 100 beats per minute; b) resting respiratory rate less than 24 breaths per minute; c) oral temperature less than 38 degrees Celsius. For chest exams, the absence of asymmetrical lung sounds, rales, and egophony will minimize the likelihood of pneumonia. If any of the variables are positive, then the recommendation is to perform a chest X-ray for diagnosis of pneumonia. (See Diagram for Treatment Algorithm for Adult Acute Cough Illness.)¹²

An exception to non-antibiotic treatment of acute bronchitis is in cases with an etiology of Bordetella pertussis. Pertussis bronchitis occurs in 10 – 20 percent of the cases where the cough lasts longer than 2 – 3 weeks.¹³ There are no clinical features to distinguish pertussis from acute bronchitis. Pertussis in adults with previous immunity does not lead to the classic features of whooping cough that is normally present in children. Suspicion for diagnosis and treatment of pertussis in primary acute bronchitis is limited to patients with the high probability of exposure, such as during a time of documented outbreaks.¹⁴ Antibiotic treatment, in this case, is definitely necessary to limit the spread of the disease. In addition if a patient has a post-infectious cough lasting for ≥ 2 weeks without another apparent cause and it is accompanied by paroxysms of coughing, post-tussive vomiting, and/or an inspiratory whooping sound, the diagnosis of a B. pertussis infection should be made unless another diagnosis is proven. The Centers for Disease Control (CDC) and ACCP guidelines recommend macrolides, such as erythromycin or azithromycin, as first-line therapy for pertussis. If erythromycin cannot be given, alternative choices are doxycycline or trimethoprim/sulfamethoxazole. In all cases, diagnostic tests for pertussis must always be performed along with antibiotic treatment.

A 12-month retrospective study – July 2006 to June 2007 – of Medi-Cal Fee-for-Service (FFS) recipients was conducted to determine whether adults between 18 – 64 years of age with acute bronchitis filled a prescription for an antibiotic within three days of being diagnosed. The study included only those patients who are normally healthy and were considered to have “uncomplicated” acute bronchitis. Patients with the co-morbid conditions listed in Chart 1 were excluded from the study. The study followed specific diagnosis codes, procedural codes and criteria from “Avoidance of Antibiotic Treatment in Adults with Acute Bronchitis” by the National Committee for Quality Assurance (NCQA) for HEDIS 2008.¹⁵ It yielded the following data:

• 11,773 Medi-Cal FFS recipients met the criteria for inclusion in the study

          – Over 69 percent of recipients filled a prescription for an antibiotic medication.

          – Of the recipients who received an antibiotic, 50 percent received a broad-spectrum antibiotic.

The data suggest that patients are being over-treated with antibiotics for acute bronchitis. Half of the patients that received an antibiotic were prescribed a broad-spectrum antibiotic, which is a contributing factor to the emergence and spread of antibiotic-resistant bacteria.¹⁶ Rather than prescribing an antibiotic as an empiric treatment, ACCP recommends symptomatic treatments for patients.

Bacterial bronchitis, viral bronchitis and the common cold share many of the same symptoms, thus, making the clinical distinctions between these diagnoses difficult if not impossible.¹⁷ Nonetheless, studies have shown that antibiotic treatment shows no benefit on duration of illness, limitation of activity or loss of work.^18,19 Patient satisfaction with care is not dependent on an antibiotic prescription, but rather on physician-patient communications.²⁰ Studies have shown that physician-educational intervention to reduce the use of antibiotics for acute bronchitis did not lead to greater patient dissatisfaction, longer duration of illness or greater utilization of services such as non-antibiotic prescriptions or return visits.²¹ Based on such findings and the treatment guidelines of ACCP, Medi-Cal encourages clinicians to refrain from routine prescribing of antibiotics for uncomplicated acute bronchitis.

Chart 1 COMORBID CONDITIONS EXCLUSIONS Cystic Fibrosis Disorders of the Immune System Malignancy Neoplasms Chronic Bronchitis Emphysema Bronchiectasis Extrinsic Allergic Alveolitis Chronic Airway Obstruction Chronic Obstructive Asthma Pneumoconiosis and other Lung Disease Due to External Agents Other Diseases of the Respiratory System Congestive Heart Failure

References

1. Gonzales R, et al. Principles of Appropriate Antibiotic Use for Treatment of Uncomplicated Acute Bronchitis: Background. Ann Intern Med 2001; 134: 521-529.
2. Braman S. Chronic Cough Due to Acute Bronchitis: ACCP Evidence-Based Clinical Practice Guidelines. Chest 2006; 129:95-103.
3. Braman S.
4. Braman S.
5. Gonzales R, et al.
6. Braman S.
7. Wenzel R, Fowler A. Acute Bronchitis. NEJM 2006; 355: 2125-2130
8. Gonzales R and Sande M. Uncomplicated Acute Bronchitis. Ann Intern Med 2000; 133: 981-991.
9. Gonzales R and Sande M.
10. Ressel G. Principles of Appropriate Antibiotic Use: Part V. Acute Bronchitis. www.aafp.org/afp/20010915/practice.html.
11. Braman S.
12. Gonzales R and Sande M.
13. Gonzales R, et al.
14. Gonzales R, et al.
15. National Committee for Quality Assurance (NCQA). Hedis 2008; 2: 96-100.
16. Gonzales R, et al. Excessive Antibiotic Use for Acute Respiratory Infections in the United States. Clinical Infectious Diseases 2001; 33: 757-762.
17. Braman S.
18. Ressel G.
19. Wenzel R, Fowler A.
20. Gonzales R, et al.
21. Gonzales R, et al.

Please refer to pages 36-45 and 36-47 in the Medi-Cal Drug Use Review Manual.