Antibiotics show little benefit for uncomplicated lower respiratory tract infections

Jun 21 2005

Patients with uncomplicated lower respiratory tract infections, such as bronchitis, who were given antibiotics had little difference in symptom relief compared to patients who did not receive antibiotics, according to a study in the June 22/29 issue of JAMA: The Journal of the American Medical Association.

Acute lower respiratory tract illness is the most common condition treated in primary care, according to background information in the article. In the United States, excess antibiotic prescribing is mainly for pharyngitis and acute bronchitis, amounting to 55 percent of prescriptions and costing $726 million per year. A consensus has been made for limiting antibiotic use in acute lower respiratory tract infection. However, recent reviews have come to diverse conclusions about the likely effectiveness of antibiotics and a recent review confirms a moderate effect of antibiotics on illness course; the debate continues unabated about the role of antibiotics because these reviews are relatively small. There are also concerns about complications if antibiotics are not prescribed and debate about which clinical characteristics identify those patients at higher risk.

The relative importance of prescribing strategies and information about natural history is also unclear. Preliminary evidence suggests that provision of an information leaflet can affect return rate and antibiotic use in lower respiratory tract infection, although the effect on symptomatic management of such a simple leaflet and whether a leaflet provides additional benefit to simple verbal information remains unclear.

Paul Little, M.D., of the University of Southampton, Highfield, England, and colleagues conducted a study to assess the effectiveness of three different antibiotic prescribing strategies on symptoms, beliefs, and behavior and to assess the effectiveness of an information leaflet compared with brief verbal information alone. The randomized controlled trial, conducted from August 1998 to July 2003, included 807 patients who presented to a primary care setting and had acute uncomplicated lower respiratory tract infection. Patients were assigned to 1 of 6 groups: information leaflet or no leaflet and 1 of 3 antibiotic groups (no offer of antibiotics [n=273], a delayed antibiotic prescription [n=272], and immediate antibiotics prescribed [n=262]). Approximately half of each group received an information leaflet (129 for immediate antibiotics, 136 for delayed antibiotic prescription, and 140 for no antibiotics).

A total of 562 patients (70 percent) returned complete diaries and 78 (10 percent) provided information about both symptom duration and severity. The researchers found that cough rated at least "a slight problem" lasted an average 11.7 days (25 percent of patients had a cough lasting 17 days or more). An information leaflet had no effect on the main outcomes. Compared with no offer of antibiotics, other strategies did not alter cough duration (delayed 0.75 days; immediate 0.11 days) or other primary outcomes. Compared with the immediate antibiotic group, slightly fewer patients in the delayed and control groups used antibiotics (96 percent, 20 percent, and 16 percent, respectively), fewer patients were "very satisfied" (86 percent, 77 percent, and 72 percent, respectively), and fewer patients believed in the effectiveness of antibiotics (75 percent, 40 percent, and 47 percent, respectively).

"In conclusion, in our patients from primary care who presented with acute uncomplicated lower respiratory tract infection, the use of delayed antibiotics or no antibiotics was acceptable, resulted in little difference in duration or severity of symptoms compared with immediate treatment with antibiotics, and considerably reduced both antibiotic use and belief in antibiotics. These findings suggest that adopting these strategies would help limit the vicious circle of the medicalization of self-limiting illness when antibiotics are prescribed. Immediate antibiotic prescribing is likely to limit the number of patients who return for cough within the next month but only by a little more than delayed antibiotic prescription. The challenge now is for clinicians and researchers to determine which groups are at risk of adverse outcomes and identify those patients who might selectively benefit from immediate antibiotic prescription," the researchers write.