Predictors of yearly influenza vaccination in hospitalized and community based patients.

Background: Understanding positive and negative influences on adult immunization status can help healthcare providers to better identify and target patients who are likely to need immunization. Our aim was to assess and compare influenza and pneumococcal (IV/PV) immunisation rates to identify vaccination predictors in Malta.

Method: One group consisted of all medical patients discharged from Mater Dei Hospital (MDH) over a one week period in February 2013. Patients were administered a phone questionnaire. A second group of patients receiving community-based care at local health centres over a one week period in March 2013 were interviewed, identifying vaccination eligibility as per 2010 WHO recommendations.

Results: A total of 150 community (Mean age 61.5 SD 15.8, Male 60%) and 149 hospitalised (Mean age 66.8, SD 13.6%, Male 48.3%) patients in whom influenza vaccine was indicated were recruited. In the current year, 44 and 48.3% received the seasonal influenza vaccine, while 32.0, and 49% vaccinated yearly respectively. Pneumococcal vaccination advice was less than 5% in both groups. On stepwise binary regression, vaccination predictors for the current year were regular yearly influenza vaccination (OR 93.62, CI: 31.8-275.5, p  < 0.001) and vaccination reminders (OR 27.5, CI: 9.63-78.31, p < 0.001). Nursing home residence (OR 5.78, CI: 1.22-27.4, p  = 0.011), congestive cardiac failure (OR 2.11, CI: 1.1-4.08, p  = 0.02) and diabetes mellitus (OR 1.68, CI: 1.04-2.72, p  = 0.034) were all predictors for vaccination on exclusion of the strongest two predictors. For successive yearly vaccination, influenza vaccine recommendation by healthcare professionals (OR 12.35, CI: 4.5-33.91, p  < 0.001) and vaccination reminders (OR 5.99, CI: 3.13-11.45, p  < 0.01) were main predictors. Congestive cardiac failure (OR 2.37, CI: 1.20-4.7, p  = 0.13) and nursing home residence (OR 7.07, CI: 1.45-34.5, p = 0,005) were also positive predictors. Male gender was a negative predictor (OR 0.51, CI: 0.31-0.83, p  = 0.006). Some of those who did not vaccinate were unaware of such need (40.5% of community and 15.6% of hospitalised patients).

Conclusions: Just under half of the patient population received the IV during 2012-2013 period. Hospitalized patients are more likely to vaccinate regularly while a large proportion of community patients are unaware of the indication to vaccinate.