A study on the management of acute respiratory tract infection in adults.

Antimicrobials are commonly used to treat acute respiratory tract infection in adults. Furthermore, their overuse has raised concern. We conducted a field survey study that included 170 medical institutions from January 2008 to June 2010. The purpose of this study was to clarify the relationship between the rate of antimicrobial use and patient outcomes with each indication. The study included 1753 patients diagnosed with acute respiratory tract infection. Antimicrobials were used for treatment of 1420 of these patients, whereas 333 cases were not treated with antimicrobials. After 3 days of treatment, patients administered antimicrobials experienced a higher improvement rate than those who did not receive antimicrobial treatment (92.2% vs. 83.3%, p < 0.0001). However, after 7 days of treatment, the rates of improvement for patients in both groups were similar (95.0% and 93.4%, respectively, p = 0.2391). In addition, according to the criteria for the usage of antimicrobials described in the Japanese Respiratory Society guidelines for the management of respiratory tract infection in adults, the patients were classified into the 3 categories (6 indication factors for antimicrobial use): Grade 1, ≤ 2 factors; Grade 2, 3-4 factors; Grade 3, 5-6 factors). The indication factors considered were the following: 1) temperature; 2) purulent sputum or nasal discharge; 3) tonsillar enlargement and tonsillolith/white puss; 4) middle otitis/sinusitis; 5) inflammatory reaction; and 6) high-risk patients. The results indicate that the improvement observed after 3 days of treatment in Grade 2 and Grade 3 patients was significantly higher with antimicrobial treatment than without antimicrobial treatment. In conclusion, the administration of antimicrobials is not recommended in younger patients with no underlying disease. However, the use of antimicrobials is required in patients with a higher relative risk that corresponds to the presence of ≥ 3 of the 6 indication factors for antimicrobial use.