Incidence of all-cause adult community-acquired pneumonia in primary care settings in France.

OBJECTIVES: To estimate the incidence of all-cause outpatient community-acquired pneumonia (CAP) in adults in France from a national prospective observational study of CAP management in general practice (CAPA).

METHODS: Patients aged over 18 years presenting with signs or symptoms indicative of CAP associated with recent onset of unilateral crackles on auscultation and/or a new opacity on chest X-ray were included in the CAPA study. An ancillary survey (AIMSIS) aiming at identifying family physicians' difficulties in including patients and at collecting their opinion on the use of an electronic case report form, determined the number of non-included eligible patients. A three-step analysis was then performed, including computation of the total number of eligible patients, adjustment for seasonality, and extrapolation to the French FP population using indirect standardization to adjust for differences in characteristics between CAPA FPs and French FPs.

RESULTS: Between September 2011 and July 2012, 267 (63%) CAPA investigators included 886 CAP patients. Most patients presented with mild CAP. The rates of hospitalization and one-month case fatality were 7% and 0.3%, respectively. Data from 336 (79%) AIMSIS investigators identified 641 additional patients and estimated at 234,023 the number of CAP patients per year (incidence of 4.7 per 1000 persons per year).

CONCLUSIONS: Using a pragmatic case definition of CAP patients, this study estimated an incidence of 4.7 per 1000 persons per year that is in the lower half of the range of estimated incidences reported in primary care settings in industrialized countries.