The 2009 influenza pandemic in primary care. Clinical manifestations, attitudes and utilisation of services

Background: Primary care plays a major role in the response to a pandemic. The objectives of this thesis were to investigate the outbreak of the 2009 influenza pandemic from a primary care perspective with focus on clinical manifestations, behavioural measures and utilisation of services. Methods: Cross-sectional questionnaire and clinical observational data from patients in general practice diagnosed with influenza-like illness, and nationwide registrybased studies based on claims data from general practice and out-of-hours services in Norway. Results: Pandemic influenza in general practice was characterised by symptoms of fever, fatigue, cough and headache of 1 week duration. Hospitalisation was reported in 0.6% of cases and oseltamivir treatment in 39% of cases, but antiviral treatment did not affect the duration of illness. Women reported better adherence to personal protective measures and were more concerned about the side effects of the pandemic vaccine then men. The majority of influenza-like illness consultations took place in general practice as compared to out-of-hours services, however there was a 5.5-fold increase of influenza-like illness consultations in the out-of-hours services during the 2009 pandemic season in comparison to the 2008-9 season. General practice increased its capacity in response to the increased patient surge. Young age was associated with attending out-of-hours services for influenza-like illness as compared to attending the general practitioner. Pregnancy, diabetes and chronic lung disease were significant risk conditions for attending out-of-hours services among patients with influenza-likeillness during the pandemic. Contrary to this, having consultations with the general practitioner before the pandemic was associated with relatively lower use of out-ofhours services in the pandemic period