BPP scores by age at first hospitalisation diagnosis with otitis media (OM) in Danish conscripts. The group comprised conscripts without a hospitalisation with OM. The cross marks the median of a BPP score, and the box marks the upper and lower quartiles. The whiskers extend 1.5 times the interquartile range. Observations outside that range are plotted individually. The horizontal line shows sample median BPP, which equals 44.0.