Vaccination coverage against 2009 seasonal influenza in chronically ill children and adults: analysis of population registries in primary care in Madrid (Spain).

Using electronic clinical records in primary care (ECRPC) of the entire population living in the Autonomous Community of Madrid, Spain (5,102,568 persons) as a data source, this study aimed to ascertain seasonal anti-influenza vaccination coverage in the chronically ill at-risk children (aged 6 months to 14 years) and adults (15-59 years). Of the total population aged 6 months to 59 years with a medical card in the Autonomous Community of Madrid, 10.3% (n=528,095 patients) had a chronic condition for which anti-influenza vaccination was indicated. In children with chronic conditions, coverage was 27.1% and it was particularly high among diabetics (41.1%) and particularly low in children with "other pulmonary conditions" (15.2%). In adults with chronic conditions, coverage was 22.1% and in patients with diagnosed heart failure coverage reached 39.1%; with the lowest coverage was observed in patients suffering neuromuscular diseases (12.8%). The factors associated with vaccination among children and adults suffering a chronic condition included: having been vaccinated during the previous campaign, national origin (lower among immigrants), and having more than one chronic condition. In conclusion, our study shows that vaccination coverage for 2009 seasonal influenza in children and adults with chronic conditions living in Madrid (Spain) was less than acceptable.