Lessons learned: no increase despite clinical suspicion of acute mastoiditis.

Based on clinical information from one Norwegian hospital in 2005, an increase in childhood acute mastoiditis was postulated, but later nationally disproved. Our purpose was to explore the discrepancy between the clinically raised suspicion and Norwegian treatment data. Complete Norwegian data on children aged 0-16 hospitalized for acute mastoiditis in the period 1999-2005 was analyzed to study national variation in incidence by hospital, treatment region and age of hospitalization. In children below age 16 hospitalization rates for acute mastoiditis ranged from 4.9 to 6.3 from 1999 to 2005 and did not did not show an increase. The proportion of children below age two was stable throughout the study period. Although the number of children at Rikshospitalet (the National Hospital) varied from 6 to 21 during the study period, the pattern of childhood hospitalizations for acute mastoiditis in the region showed no variation in the same period of time. In conclusion, our study did not find evidence for an increase in acute mastoiditis hospitalizations. The postulated increase is likely a result of the reduction of otolaryngologic university departments from two to one in Oslo in 2004 and corresponding work-load increase at the remaining hospital, Rikshospitalet. In our opinion, health information presented as popular science may contribute to confusion rather than increasing understanding of complicated health issues.