LANDMARK: When to place tympanostomy tubes based on developmental outcomes later in childhood

Article: Tympanostomy tubes and developmental outcomes at 9 to 11 years of age

Take Home Points:

Prompt insertion, compared to delayed insertion of tympanostomy tubes, in children, who are younger than 3 years old and have persistent asymptomatic middle ear effusion, does not improve developmental outcomes (up to 9 – 11 years old).
Watchful waiting is beneficial in these children prior to insertion of tympanostomy tubes (for 6 additional months if the effusion is bilateral or 9 additional months if the effusion is unilateral).

The Details:

Study Type: Multi-institution prospective randomized controlled trial
Inclusion:
- Initial Study: Children, ages 2 to 61 days (June 1991 – December 1995), whose only household language was English.
  - These children were followed until 3 years of age.
  - 6350 children enrolled.
- Clinical Trial (selected from the initial study group): Children 2 months – 3 years old with either persistent or intermittent middle ear effusion. 588 children were deemed eligible for randomization if they had an effusion that met either of the below criteria.
  - Persistent – At least 90 days if bilateral or 135 days if unilateral.
  - Intermittent – At least 67% of the preceding 180 day period if bilateral or for the preceding 270 day period if unilateral.

From the initial group, patients were divided into the following four groups:
- Eligible for randomization – randomized to early treatment group (216 children).
- Eligible for randomization – randomized to delayed treatment group. Tubes inserted 6 (bilateral effusion) or 9 (unilateral effusion) months later (213 children).
- Eligible for randomization – consent withheld and thus treatment by parental choice (parents declined to grant consent for randomization. They still, however, continued to be part of the original study and were followed after treatment). (159 children).
- Ineligible for randomization (5762 children)
  - Subgroup of 241 children randomly selected for the observational study.
  - Study to (1) assess the correlation between duration of effusion in these children and outcomes, (2) compare outcomes to those children who underwent randomization.
Randomization
- Patients were stratified by site, age and bilateral vs unilateral effusion.
- Within each stratum, patients were then assigned (by block randomization) to either early insertion of tympanostomy tubes or delayed treatment (6 months or later for bilateral effusions but 9 months or later for unilateral)

Children underwent one assessment between their 9th and 12th birthdays. Assessment included an assortment of tests designed to evaluate: (1) literacy, (2) phonological awareness, (3) attention, impulsivity, and psychosocial function and (4) intelligence and academic achievements

Results:
- Clinical Trial: There were no significant differences in the mean scores between the early vs delayed treatment groups that favored the early treatment group (even after adjusting for a range of potential confounders including age, sex, when the patient was randomized and category of effusion). Similarly, there were no significant differences in mean scores between those who were randomized and those whose parents declined randomization.
- Subgroup of children not eligible for randomization: A longer duration of effusion correlated to lower scores on 4/19 formal test measures and 16/28 measures based on parent/teacher reports (only after adjusting for demographic variables). However, the percentage of variance of scores attributed to the duration of effusion was low (mean 3%).

Limitations:
- Results only applicable to healthy children. They did not take into account children with a range of complicating conditions such as for example Down syndrome or sensorineural hearing loss.
- The group that was deemed not eligible for randomization had a higher socioeconomic status than the group that was eligible. This may have been one source of confounding.

Summary contributed by Elizabeth Shay