Predictors of influenza vaccination uptake among elderly in Croatia

Abstract

Background Influenza vaccination (IV) is recommended for elderly but vaccination coverage in this group remains unsatisfactory in Croatia. The aim of this study was to explore IV uptake among elderly from Eastern Croatia and predictors that influence this uptake. Methods This cross-sectional questionnaire study was conducted during 2018/2019 influenza season in convenient sample of older adults aged 65 years or more from Eastern Croatia at the primary health care setting. Results The study sample consisted of 816 subjects (48.0% males and 52.0% females). The median age of all subjects was 73.0 years (interquartile range (IQR) 69.5 - 79.0 years). The overall prevalence of IV uptake was 33.3%. The IV uptake was statistically more frequent among females (P < 0.001) and old-old subgroup (85 years and older) (P < 0.001). There was no statistically significant difference in IV uptake considering marital status of subjects (P > 0.999). The median number of positive attitudes towards IV was 4.0 (IQR 2.0 - 4.0) and the median number of correct answers was 6.0 (IQR 4.0 - 8.0). The study revealed fair positive correlation between attitudes and IV uptake (rho=0.477; P < 0.001) and poor positive correlation between knowledge and IV uptake (rho=0.242; P < 0.001). The study further showed poor positive correlation between presence of comorbidities and IV uptake (rho=0.187; P < 0.001) and moderate positive correlation between previous year vaccination history and IV uptake (rho=0.669; P < 0.001). Conclusions The study showed that observed IV uptake is far below EU target influenza vaccination coverage among elderly of 75%. The study revealed that fairly good predictors of IV uptake in study population were gender, older age group, and previous year vaccination history while attitudes, knowledge and presence of comorbidities were fairly poor predictors. The good predictors of IV uptake among elderly should be taken into account during influenza vaccination popularization strategies development. Key messages Understanding the factors that could improve the acceptance of vaccination is crucial to design effective public health interventions. The structured communication campaigns on influenza and influenza vaccines should be developed and directed specifically to elderly as one of target groups for vaccination.