Prevalence of nasal polyposis in France: a cross-sectional, case-control study

The prevalence of nasal polyposis (NP) has never been established in France due to the lack of diagnostic tools for population-based studies.Using a recently validated questionnaire/algorithm (90% specificity and sensitivity) in a population-based random sample, the present cross-sectional, case-control study allowed to determine NP prevalence and describe the principal aspects of NP epidemiology. A total of 10 033 subjects (>/=18 years) were screened. After identification of subjects with NP and those without, another questionnaire was submitted to NP patients only for further data collection. Controls were individuals without NP, matched by gender and age to NP patients.Nasal polyposis prevalence was 2.11% (95% CI 1.83-2.39). NP patients (n = 212, 45% males) were aged 49.4 +/- 17.6 years. No gender preponderance was observed, but NP tended to increase with age. Mean duration of nasal symptoms was 22.4 +/- 15.7 years. Among the 145 patients having already seen a doctor for their symptoms, 77.2% have been referred to a specialist, and 18.6% had a diagnosis of NP. Rhinorrhoea was reported by 39.9% of NP patients, blocked nose by 30.8%, and anosmia by 28.9%. Only 6.9% reported facial discomfort while 24.6% complained about general discomfort. Most NP patients (61.3%) had a pharmacological treatment, a nasal spray for the major part (76.9%).The present study provides valuable and reliable information on NP epidemiology in France; the collected information are in accordance with most published international data.