Underdiagnosis of nocturnal symptoms in asthma in general practice.

Objective: To evaluate the prevalence of nocturnal symptoms in a large sample of asthmatic patients, and to assess the agreement between patients' complaints and general practitioners' (GPs') reports in primary care.

Design: Cross-sectional survey involved 3,526 GPs and 751 specialists (pulmonologists and allergists) and included 13,493 patients with persistent asthma. Symptoms, treatment, and social and medical data were collected in real time by the patients and their GPs.

Setting: France.

Results: Prevalence of nocturnal symptoms was 60%. A total of 7,989 patients with nocturnal symptoms had complete data for both patients and GPs; 3,849 (48.1%) had perfect agreement between GP and their complaints for nocturnal symptoms (agreement group; [kappa = 1]); 3,376(42.2%) declared having no symptoms during the night, but these were detected by the GP during the visit (underestimated by patients and detected by GPs); 773(9.6%) declared having nocturnal symptoms, but these were not detected by GPs. Patients with a good agreement with their GP's opinion were significantly more frequently followed-up by a specialist than other patients (p = 0.002).

Conclusions: Nocturnal symptoms appear to be underdeclared by patients. GPs should therefore systematically ask their patients about nocturnal symptoms to increase control of asthma and to adequately manage its treatment.