Puhakka «Puhakka H. Pieni tympanometri parantaa lasten väli...»1 studied the usefulness of a small portable tympanometer in the diagnosis of otitis by comparing it with a normal-size tympanometer, otomicroscope and, if necessary, tympanocentesis in 277 children (altogether 553 ears, the mean age of children was approximately 5 years). A false-positive result (tympanogram abnormal, but no middle ear effusion) was obtained in 7% of the children and a false-negative result (tympanogram normal with middle ear effusion present) in 3% of the children.
In a study by van Balen and de Melker «van Balen FA, de Melker RA. Validation of a portab...»2 a portable tympanometer was compared with a normal tympanometer and with tympanocentesis in children (n = 142) referred for insertion of ventilation tubes. Compared with a normal-size tympanometer, the sensitivity of the portable device was 96% (95% CI 93 to 99) and specificity 81% (95% CI 71 to 91). Compared with tympanocentesis findings the sensitivity of the portable device was 94% (95% CI 90 to 98) but specificity only 48% (95% CI 37 to 59).
A study by Koivunen et al «Koivunen P, Alho OP, Uhari M, Niemelä M, Luotonen ...»3 included 162 children (age range 7 months to 8 years) who had been referred for the insertion of ventilation tubes or for adenoidectomy. Compared with tympanocentesis findings the sensitivity of the portable tympanometer was 79% and specificity 93% in children who cooperated well.
In a study by Helenius et al «...»4 515 children aged 6-35 months at primary care were followed at symptomatic and asymptomatic visits. At symptomatic visits, different peaked tympanograms were associated with a healthy middle ear as follows: type A in 78%, type C1 in 62%, type C2 in 54% and type Cs in 18% of examinations. In contrast, any peaked tympanogram was related to healthy middle ear in 67% of examinations. Flat (type B) tympanogram was related to otitis media with effusion in 44% and to acute otitis media in 56% of examinations, respectively. At asymptomatic visits, the peaked tympanograms together were associated with a healthy middle ear in 87% of otoscopic examinations. Flat tympanogram indicated otitis media with effusion as well in 87% of examinations.