Children hospitalised with four common viral diseases showed epidemiological differences but few socio-economic variations.

Aim This study explored the differences in demographic and socioeconomic factors between children hospitalised due to four common viral infections. Methods Demographic data were obtained from Statistics Sweden on >3,000 children admitted to Astrid Lindgren Children's Hospital in 2009-2014 with rotavirus, influenza, respiratory syncytial virus (RSV), or chickenpox. We compared demographic and socioeconomic factors between case groups using logistic regression with rotavirus cases as reference. Results There were differences in the median age at admission; RSV cases were younger (0.4 years), influenza (2.4 years) and chickenpox cases (2.7 years) older than rotavirus cases (1.2 years). RSV, influenza and chickenpox cases lived in families with more children than rotavirus cases. RSV and influenza cases were more likely to have underlying chronic conditions. Mothers of RSV cases were more likely to be born in Sweden. Further socioeconomic differences were not robustly confirmed in sensitivity analyses. Conclusion We found a few differences in demographic factors between children hospitalised with the four common infections, which were mainly explained by the epidemiology and transmission patterns of these infections.