"The longitudinal Hjørring-population-study". Results at 6 years of follow-up

A prospectively planned, epidemiologic and longitudinal study of 329 children born in 1972 and living in a Danish provincial municipality was undertaken. All had tympanometric screening by the age of 3, 6 and 9 years. The screenings took place in January 1976, January 1979, and January 1982. The aims of the study were to compare the point prevalences of abnormal tympanometry in a normal population and to evaluate the prognosis of the different curve-types at 6 years of follow-up. Accordingly there is major improvement in middle ear status during the first three years in school. Type A tympanograms have a better prognosis than all other types. Tympanograms with light (type C1) and severe (type C2) negative middle ear pressure have similar prospects. Patients with the poorest prognosis have type B tympanograms, 70% of type B tympanograms at age 9 years were also type B at age 3 years.