RESUMEN
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is markedly under-diagnosed, which may be related to the under-reporting of symptoms and poor awareness of the disease. We hypothesized that written information on COPD may help increase awareness of the disease in people at risk of developing it. OBJECTIVES: To evaluate the impact of an information leaflet sent by postal mail on the level of knowledge of COPD in subjects with or at risk of COPD. METHODS: A total of 860 subjects with or at risk of COPD were selected by using a phone questionnaire. All subjects who reported a known diagnosis of COPD, a chronic cough and sputum production, or a smoking history of at least 15 pack-years were eligible for selection. Their knowledge of COPD was assessed during a telephone interview (baseline). They were randomized into 2 groups, with only 1 group receiving the information leaflet, and were then contacted 3 months later for a second interview. The changes in the knowledge of COPD from baseline were compared between subjects who reported receiving and reading the leaflet (true sensitized group) and subjects to whom the leaflet was not sent (control group). RESULTS: At the follow-up interview, the proportion of patients who spontaneously mentioned 'respiratory difficulties', when asked about the meaning of COPD, significantly increased in the true sensitized group (+11.9%) compared with the control group (+2.6%, p < 0.05). In addition, the frequency of patients who cited lung function test as the primary diagnostic tool for COPD increased by +14.4% in the true sensitized group versus+2.0% in the control group (p < 0.05). However, there was no short-term leaflet-dependent improvement in smoking behaviour or utilization of health-care resources. CONCLUSIONS: This study shows that an information leaflet sent by postal mail to subjects with or at risk of COPD can significantly improve their knowledge of COPD; however, it has no significant impact on their behaviour.