A study of clinical features and treatment of acute bronchitis by Japanese primary care physicians

Objective. This study aimed to examine the factors affecting prescription of antibiotics for acute bronchitis in ambulatory care settings in Japan. Method. A prospective study was conducted on 92 physicians engaged in primary care regarding their prescription behaviour for a series of 20 new patients with acute respiratory diseases seen during November 1996 and the background factors affecting the behaviour. Results. A total of 1755 patients were registered during the study period, 302 (17.2 %) of whom were diagnosed with acute bronchitis and 1165 (66.4%) with upper respiratory tract infection. Independent background factors related to diagnosis of acute bronchitis included self-care prior to visit (odds ratio 1.93, 95% CI 1.33-2.80), complaints such as cough (8.80, 4.77-16.2), sputum (2.24, 1.59-3.14) and purulent sputum (6.47, 3.02-13.9). The odds ratio was high in patients with more severe findings of the chest (5.00, 3.64-6.85), given chest X-ray (2.68, 1.33-5.38) while it was low in those feeling cold (0.68, 0.48-0.96), and those with a sore throat (0.63, 0.45-0.90), nasal symptoms (0.75, 0.54-1.04) and more severe findings of the pharynx (0.74, 0.58-0.92). In those with an upper respiratory tract infection, the odds ratio was high for complaints such as feeling cold (1.51, 1.11-2.05) and nasal symptoms (1.39, 1.04-1.86), while it was low for complaints such as cough (0.67, 0.48-0.95), sputum (0.43, 0.30-0.62), purulent sputum (0.19, 0.08-0.44), wheeze (0.34, 0.13-0.92), in those with more severe findings of the tonsil (0.36, 0.29-0.44) and the chest (0.30, 0.19-0.47) and given chest X-rays (0.29, 0.12-0.66). For acute bronchitis, antibiotics were administered to 67.5% and symptomatic therapy concurrently given to 64.9%. As for independent background factors related to prescription of antibiotics for acute bronchitis, the odds ratio was higher in physicians denying the efficacy of antibiotics for treating a cold (4.58, 1.94-10.8), and the patients with complaints such as purulent sputum (22.9, 2.66-197.2), more severe findings of the pharynx (2.26, 1.34-3.79) and of the chest (2.73, 1.53-4.88), and those who had a body temperature measurement taken (4.42, 1.71-11.4) and a chest X-ray (6.11, 1.07-34.9), but was lower in those complaining of chills (0.16, 0.04-0.66) and diarrhoea (0.11, 0.01-1.11). Conclusions. A majority of patients receiving medical care for acute bronchitis are given an unnecessary antibiotic prescription. The result of this study may be useful for the finding of appropriate forms of intervention for changing physicians' prescription behaviour.