Asthma in an Urban Population in Portugal: A prevalence study

BMC Public Health

Table 4 Comparison of asthma prevalence rates for all age groups and methods in Portuguese surveys

Year	Study	Prevalence %	Method
1992	Nunes et al [26]	5.5	Questionnaire
2005	Branco et al [31]	8.6	Self-report/Interview
2006	Portuguese National Health Survey [40]	5.5	Self-report/Interview
2009	Correia-de-Sousa et al	10.2	Questionnaire, self-report of symptoms

ISSN: 1471-2458