Table 1

 Characteristics of the seven trials included in the IPD meta-analyses

Treatment groupsNo. of patientsAge at inclusion (y)Inclusion criteriaOutcome measurementsRisk factorsFollow up
VT, ventilation tube; Adeno, adenoidectomy; ATE, adenotonsillectomy; QoL, quality of life; AOM, acute otitis media; URTI, upper respiratory tract infections.
Maw, 1986/199371. VT in one ear 2. Adeno + VT in one ear 3. ATE + VT in one ear2282–9Referred to ORL Bilateral type B tymp >25 dB HLAudiometry TympanometrySex, parental smoking, age of onset6 and 12 months, 2, 3, 4, 5, 7 and 10 years
Black, 199031. Bilateral myringotomy 2. VT in one ear 3. Adeno 4. Adeno + VT one ear1274–9Audiometry TympanometryAge, sex, social class (father’s occupation), history of symptoms7 weeks, 6, 14 and 24 months
Rach, 1991101. VT both ears 2. Watchful waiting in both ears492–3Population screening Bilateral type B tymp Persistent for 6 monthsTympanometry Comprehensive and expressive language (Reynell)Sex, race, breast feeding, season, day-care, passive smoking, age, URTI, family size, AOM, number of siblings, birth weight6 and 12 months
Dempster, 199341. Adeno + VT one ear 2. Adeno 3. VT in one ear 4. No surgery784–9Bilateral type B tymp ⩾25 dB H Persistent for 3 monthsAudiometry TympanometrySex, age6 and 12 months
Maw, 199981. VT both ears 2. Watchful waiting both ears1861–4.5Bilateral type B/C2 tymp Persistent for 3 months >25 dB HL at 4 kHzAudiometry Tympanometry Comprehensive and expressive language (Reynell) Mental development BehaviourSex, age, race, SES (postal code, manual group), season, number of siblings, AOM, URTIs, breast feeding, attending day-care, passive smoking6 weeks, 9 and 18 months
Rovers, 200011,121. VT in both ears 2. Watchful waiting in both ears1871–2Bilateral type B tymp Persistent for 4–6 monthsAudiometry Tympanometry Comprehensive and expressive language (Reynell) QoLSex, SES (educational level mother), season, siblings, AOM, URTIs, attending day-care, breast feeding, birth weight, passive smoking
3, 6, 9, and 12 months
TARGET, 2001251. VT in both ears 2. Adeno + VT in both ears 3. Watchful waiting in both ears3763.5–7Bilateral type B/C2 tymp >20 dB HL & ABG >10 Persistent for 3 monthsAudiometry Tympanometry Symptom scores Behaviour Parental QoL Child QoLSex, age, race, SES (postal code, manual group), season, number of siblings, AOM, URTIs, breast feeding, passive smoking, attending day-care3, 6, 12, 18, and 24 months
Total1234