Condition category
Infections and Infestations
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Dr Anne G.M. Schilder


Contact details

University Medical Centre Utrecht
Wilhelmina Children's Hospital
Department of Otorhinolaryngology
PO Box 85090
3508 AB
+31 (0)30 250 4004

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

The effectiveness of adenotonsillectomy in children NATAN project: Nederlands AdenoTonsillectomie project, Tonsillectomy & Adenoidectomy in the Netherlands



Study hypothesis

Adenotonsillectomy in children with mild to moderate symptoms of throat infections or adenenotonsillar hypertrophy prevents upper airway infections and fever episodes.

Ethics approval

Approval received from the Medical Ethical Committee on the 10th January 2000 (ref: 99-49).

Study design

Randomised, active controlled, parallel group, multicentre trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet


Throat infections, Adenotonsillectomy, Adenotonsillar hypertrophy


Interventions are adenotonsillectomy within six weeks versus watchful waiting.

During the study, the child's temperature was measured daily with a validated infrared tympanic membrane thermometer with an electronic device built in that stored the date and first temperature measurement of each day. Thermometer data were collected by the study physician during scheduled follow-up visits at 3, 6, 12, 18 and 24 months.

During the study, parents kept a diary of complaints of upper respiratory infections in their child, i.e., sore throat, pain/difficulty at swallowing, cough, rhinorrhoea, earache and otorrhoea. They also noted absence from day-care or school due to upper respiratory infections, and resource use such as prescription and over the counter medication, out-patient visits, additional surgical interventions and out-of-pocket expenses such as babysitters and travel expenses.

Diary data were collected by the study physician during scheduled follow-up visits at 3, 6, 12, 18 and 24 months. On the basis of these data incidences of throat infections, sore throat, upper respiratory infections, absence from day-care or school due to upper respiratory infections and costs were calculated.

At inclusion and the scheduled follow-up visits at 3, 6, 12, 18 and 24 months disease-specific and health-related quality of life questionnaires (43-item TNO-AZL Preschool children Quality of Life [TAPQoL], 56-item TNO-AZL Child Quality of Life [TACQoL], and Child Health Questionnaire - Parent Form 50 [CHQ-PF50]) were filled out. An ear, nose and throat examination was performed including tympanometry and length and weight were measured. These data were used to establish the effect of adenotonsillectomy on middle ear status, sleeping and eating pattern, length and weight and health-related quality of life.

Serum samples were collected at baseline and at one-year follow-up to evaluate changes in serum immunoglobulin levels in relation to surgery and occurrence of Upper Respiratory Infections (URIs).

Oropharyngeal swabs were taken at baseline and at 3 and 12 months follow-up to study the effect of adenotonsillectomy on carriage of potential pathogenic bacteria in the oropharynx at 3 and 12 months follow-up and the association between carriage of these potential pathogens and the number of throat infections during the 12 months follow-up.

Intervention type



Not Specified

Drug names

Primary outcome measures

Incidence of fever (a temperature of 38.0°C or higher) for at least one day, measured in number of episodes and days. An episode was considered finished when at least one day was without fever. New episodes were those occurring after a fever-free interval of at least seven days.

Secondary outcome measures

Secondary outcome measures were:
1. Throat infections
2. Sore throat days and episodes
3. Upper respiratory infections
4. Otitis media
5. Sleeping and eating pattern
6. Length and weight
7. Absence from day-care or school due to upper respiratory infections
8. Health-related quality of life
9. Costs
10. Immunological parameters
11. Oropharyngeal microbial flora

Secondary outcomes were measured during follow-up visits at 3, 6, 12, 18 and 24 months.

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

Children aged 2 to 8 years indicated for adenotonsillectomy according to current medical practice. These included children with recurrent throat infections (three or more episodes per year) or other indications such as obstructive complaints or recurrent upper respiratory infections.

Participant type


Age group



Not Specified

Target number of participants


Participant exclusion criteria

Children with:
1. A history of seven or more throat infections in the preceding year, or five or more in each of the two preceding years, or three or more in each of the three preceding years (Paradise criteria)
2. High suspicion of obstructive sleep apnoea, i.e. Brouillette's Obstructive Sleep Apnoea (OSA) score of more than 3.5
3. Down's syndrome
4. Craniofacial malformation, such as cleft palate
5. Documented immunodeficiency, other than Immunoglobulin A (IgA) or Immunoglobulin G subclass two (IgG2) deficiencies

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

University Medical Centre Utrecht
3508 AB

Sponsor information


University Medical Centre Utrecht (UMCU) (Netherlands)

Sponsor details

P.O. Box 85500
3508 GA

Sponsor type

Hospital/treatment centre



Funder type


Funder name

The Dutch Health Care Insurance Board (CVZ) (Netherlands) - knowledge development programme (programma Ontwikkelingsgeneekunde)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

1. 2004 results in
2. 2007 results in
3. 2009 results in

Publication citations

  1. Results

    van Staaij BK, van den Akker EH, Rovers MM, Hordijk GJ, Hoes AW, Schilder AG, Effectiveness of adenotonsillectomy in children with mild symptoms of throat infections or adenotonsillar hypertrophy: open, randomised controlled trial., BMJ, 2004, 329, 7467, 651, doi: 10.1136/bmj.38210.827917.7C.

  2. Results

    Buskens E, van Staaij B, van den Akker J, Hoes AW, Schilder AG, Adenotonsillectomy or watchful waiting in patients with mild to moderate symptoms of throat infections or adenotonsillar hypertrophy: a randomized comparison of costs and effects., Arch. Otolaryngol. Head Neck Surg., 2007, 133, 11, 1083-1088, doi: 10.1001/archotol.133.11.1083.

  3. Results

    Rovers MM, Hoes AW, Klinkhamer S, Schilder AG, Influence of single-trial results on clinical practice: example of adenotonsillectomy in children., Arch. Otolaryngol. Head Neck Surg., 2009, 135, 10, 970-975, doi: 10.1001/archoto.2009.150.

Additional files

Editorial Notes