Effectiveness of adenotonsillectomy in children with mild symptoms
of throat infections or adenotonsillar hypertrophy: open,
randomised controlled trial
Birgit K van Staaij, Emma H van den Akker, Maroeska M Rovers, Gerrit Jan Hordijk, Arno W Hoes, Anne G M
Objective To assess the effectiveness of adenotonsillectomy in
children with mild symptoms of throat infections or
Design Open, randomised controlled trial.
Setting 21 general hospitals and three academic centres in the
Participants 300 children aged 2-8 years requiring
Intervention Adenotonsillectomy compared with watchful
Main outcome measures Episodes of fever, throat infections,
upper respiratory tract infections, and health related quality of
Results During the median follow up period of 22 months,
children in the adenotonsillectomy group had 2.97 episodes of
fever per person year compared with 3.18 in the watchful
waiting group (difference − 0.21, 95% confidence interval
− 0.54 to 0.12), 0.56 throat infections per person year
compared with 0.77 ( − 0.21, − 0.36 to − 0.06), and 5.47 upper
respiratory tract infections per person year compared with 6.00
( − 0.53, − 0.97 to − 0.08). No clinically relevant differences were
found for health related quality of life. Adenotonsillectomy was
more effective in children with a history of three to six throat
infections than in those with none to two. 12 children had
complications related to surgery.
Conclusion Adenotonsillectomy has no major clinical benefits
over watchful waiting in children with mild symptoms of throat
infections or adenotonsillar hypertrophy.
Tonsillectomy,with or without adenoidectomy,is a common pro-
cedure in children in western countries, yet the indications for
surgery remain uncertain, as reflected by the large variation in
surgical rates across countries. In 1998, for example, 115 per
10 000 children underwent adenotonsillectomy in the Nether-
lands,65 per 10 000 in England,and 50 per 10 000 in the United
We previously reported that in the Netherlands 35% of chil-
dren underwent adenotonsillectomy for frequent throat infec-
tions (seven or more a year) or obstructive sleep apnoea, and the
remainder for less frequent throat infections,mild adenotonsillar
hypertrophy, or indications such as upper respiratory tract infec-
tions.2Although frequent throat infections and obstructive sleep
apnoea are considered adequate indications for adenotonsillec-
tomy in children,3–8evidence for the benefits of surgery in
children with milder symptoms is lacking.2 9–12We carried out a
randomised controlled trial to assess the effectiveness of
adenotonsillectomy in children with mild symptoms of throat
infections or adenotonsillar hypertrophy.
Participants and methods
We carried out an open,multicentre,randomised controlled trial
between March 2000 and February 2003. Otorhinolaryngolo-
gists from 21 general hospitals and three academic centres in the
Netherlands were asked to complete a questionnaire on all their
patients aged 2 to 8 years with indications for adenotonsillec-
tomy according to current medical practice. They were asked to
give the indication they considered most important for surgery:
recurrent throat infections (three or more a year) or other indi-
cations such as obstructive problems or recurrent upper respira-
tory tract infections.
We excluded children with a history of seven or more throat
infections in the preceding year, with five or more in each of the
previous two years, or with three or more in each of the previous
three years (Paradise criteria),3and children with suspected
obstructive sleep apnoea—that is, Brouillette’s obstructive sleep
apnoea score of more than 3.5.13Other exclusion criteria were
Down’s syndrome, craniofacial malformations such as cleft
palate, and immunodeficiency, other than deficiencies of IgA or
Children whose parents gave informed consent were randomly
assigned to either adenotonsillectomy within six weeks or watch-
ful waiting. Randomisation was by a computer generated list of
four numbers in each block and fixed blocks within each hospi-
When children were entered in the study, the study doctors
completed a disease specific questionnaire on the basis of infor-
mation provided by the parents. This elicited information on the
number of throat infections and upper respiratory tract
infections experienced by the children in the previous year;
obstructive symptoms during sleep13; eating patterns; previous
ear, nose, and throat operations; and risk factors for upper respi-
ratory tract infections.
The participating hospitals and members of the executive steering commit-
tee are on bmj.com
Cite this article as: BMJ, doi:10.1136/bmj.38210.827917.7C (published 10 September 2004)
BMJ Online First bmj.com
page 1 of 6
The parents completed two generic health related quality of
life instruments: the TNO-AZL preschool children quality of life
questionnaire (TAPQoL for children aged 2 to 5 years and TAC-
QoL for children aged 5 years or older) and the child health
questionnaire parental form (CHQpf50).14 15
underwent an ear, nose, and throat examination and had their
height and weight measured.
The parents kept a diary of upper respiratory tract infections in
their child, which included sore throat, pain or difficulty in swal-
lowing, cough, rhinorrhoea, earache, and otorrhoea. They also
noted absences from day care or school due to upper respiratory
tract infections, and they measured the child’s temperature daily
with a validated tympanic membrane thermometer.16To avoid
information bias, we had an electronic device built into the ther-
mometer, which stored the date and first measurement of each
day. The study doctors collected the diary and thermometer data
during follow up visits at 3,6,12,18,and 24 months.At these vis-
its, the disease specific and health related quality of life question-
naires were again completed. An ear, nose, and throat
examination was carried out, and the child’s height and weight
otorhinolaryngologists were encouraged to manage sore throats
and upper respiratory tract infections during follow up
according to regular practice.
Primary and secondary outcomes
Our primary outcome was the 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 occur-
ring after a fever-free interval of at least seven days.
Secondary outcomes were throat infections, sore throat,
upper respiratory tract infections, absence from day care or
school due to upper respiratory tract infections, health related
quality of life, patterns of sleep and eating, height, and weight. A
throat infection was defined as sore throat or pain or difficulty in
swallowing combined with fever. A sore throat was defined as
sore throat or pain or difficulty in swallowing with or without
fever. Upper respiratory tract infections were defined as one or
more symptoms of sore throat, pain or difficulty in swallowing,
cough, rhinorrhoea, earache, and otorrhoea with or without
fever. Throat infections, sore throats, and upper respiratory tract
infections were measured in episodes and days. We also included
sore throats and upper respiratory tract infections immediately
We calculated absence from day care or school due to upper
respiratory tract infections on the basis of data from the diaries.
We used the generic questionnaires to assess health related qual-
ity of life.14 15Sleeping patterns were evaluated by Brouillette’s
obstructive sleep apnoea score and by the percentage of children
experiencing snoring, difficulties breathing at night, or apnoea.13
Eating patterns were assessed by difficulties in eating solids.
Our sample size calculation was based on a clinically relevant
reduction of fever episodes and throat infections after adenoton-
sillectomy of 25%. Assuming a mean baseline (standard
deviation) incidence of 4 (2) fever episodes and throat infections
each year, and taking ? = 0.05 and a power of 0.80, we
determined that we would need 104 children in each group. To
allow for subgroup analyses, we aimed at including 300 children.
We calculated the effects of adenotonsillectomy on fever,sore
throat, and upper respiratory tract infections as differences in
incidence and incidence rate ratios per person year, with 95%
confidence intervals. Scores on health related quality of life
instruments were linearly transformed into scales of 0-100. For
the mean number of fever episodes we calculated a short term
(0-6 months) and long term (6-24 months) effect. We also evalu-
ated health related quality of life, sleep and eating patterns,
height, weight, and short and long term effects at six and 24
months. We used ?2tests and Student’s t tests to evaluate
differences in percentages and mean values between the groups.
We used the Bonferroni correction to adjust for multiple testing
and the Mantel-Haenzel test to adjust for potential confounders.
Children assessed for eligibilty
Allocated to adenotonsillectomy
Allocated to watchful waiting
Did not undergo adenotonsillectomy
within six weeks (n=7)
Lost to follow up (n=18)
Completed trial (n=133)
223.9 person years analysed
Completed trial (n=124)
217.3 person years analysed
within six weeks (n=3)
Cross over (n=41)
Cross over and lost to follow up (n=6)
Lost to follow up (n=19)
Exclusions (more than one reason in some cases):
Met exclusion criteria (n=221)
Parents insisted on surgery (n=512)
Parents refused surgery (n=51)
Parents considered participation too time consuming (n=83)
Doctor insisted on surgery (n=41)
Flow of participants through trial
page 2 of 6
BMJ Online First bmj.com
As the estimates of effect were not influenced by these
adjustments, we present the estimates of crude effect.
To detect possible modification from effects, we carried out
subgroup analyses according to the burden of upper respiratory
tract symptoms in the year before entry to the trial and age. We
analysed interactions with Poisson regression. All analyses were
performed on an intention to treat basis.
Between March 2000 and August 2002 we enrolled 300 children
in our study; 151 were allocated to adenotonsillectomy and 149
to watchful waiting (fig 1).Characteristics at baseline were similar
between the two groups (table 1). Overall, 43 children (18 from
the adenotonsillectomy group) were lost to follow up. Reasons
were non-medical (n = 36), serious comorbidity (n = 1), or
unknown (n = 6). Fifty children allocated to watchful waiting
underwent adenotonsillectomy and seven allocated to adenoton-
sillectomy did not undergo surgery. Median follow up was 22.0
months in the adenotonsillectomy group and 22.4 months in the
watchful waiting group.
Children in the adenotonsillectomy group had 0.21 fewer
episodes of fever (95% confidence interval –0.12 to 0.54) per
person year (table 2).During the first six months of follow up,the
number of episodes was lower in children in the adenotonsillec-
tomy group. From six to 24 months there was no difference
between the groups.
Compared with the watchful waiting group, children in the
adenotonsillectomy group had, per person year, fewer throat
infections (0.21,95% confidence interval 0.06 to 0.36),fewer sore
throats (0.60, 0.30 to 0.90), fewer days with sore throat (5.91, 5.24
to 6.57), and fewer upper respiratory tract infections (0.53, 0.08
to 0.97; see table 2).
Absence from day care or school due to upper tract respira-
tory infections was comparable between the groups (difference
0.09, –0.27 to 0.44).
At six months, small significant differences were found for
some domains of the health related quality of life questionnaires,
but these were not clinically relevant. We found no differences in
other domains and at 24 months (figs 2 and 3).
At six months, Brouillette’s scores were lower for children in
the adenotonsillectomy group (fig 4). At 24 months there was no
Table 1 Personal and clinical characteristics of 300 participants at baseline
according to treatment allocation. Values are numbers (percentages) unless
Mean (SD) age (months)
Indication for surgery:
Recurrent throat infections
Median No (range) of throat
infections in previous
Median duration (months) of
throat infections (range)*
Median No (range) of
episodes with rhinorrhoea
or cough in previous year
Median No (range) of
episodes of otitis media in
Median obstructive sleep
apnoea score (range)†
Previous ear, nose, and throat surgery:
Mean (SD) weight (kg)
Mean (SD) height (cm)
Breastfed for >1 month
Exposure to tobacco smoke
Day care attendance¶:
No of siblings:
Father’s level of education:
Mother’s level of education:
Watchful waiting group
3 (0 to 6)
3 (0 to 6)
13 (0 to 50)12 (0 to 60)
12 (0 to 24)10 (0 to 24)
0 (0 to 12)0 (1to 6)
–1.7 (–3.83 to 2.55)–1.7 (–3.83 to 2.56)
49 (89.1)49 (89.1)
*Children with recurrent throat infections (n=143).
†Brouilette’s obstructive sleep apnoea score: ≤1 (none), –1.0 to 3.5 (possible), >3.5 (highly
‡Protruding beyond pillars but not meeting uvula, or meeting uvula.
§History of eczema, hay fever, recurrent wheeze, or asthma.
¶Aged <4 years (n=110).
Table 2 Incidence of fever, throat infections, sore throats, and upper
respiratory tract infections per person year for children with mild symptoms
of throat infections or adenotonsillar hypertrophy after adenotonsillectomy or
No of days
ratio (95% CI)
2.973.180.94 (0.84 to 1.04)–0.21
(–0.54 to 0.12)
(–1.06 to –0.18)
5.315.93 0.90 (0.83 to 0.97)
No of days
0.560.770.73 (0.58 to 0.92)–0.21
(–0.36 to –0.06)
(–0.73 to –0.34)
0.83 1.360.61 (0.51 to 0.73)
No of days
2.252.85 0.79 (0.70 to 0.89)–0.60
(–0.90 to –0.30)
(–6.57 to –5.24)
9.8115.710.62 (0.59 to 0.66)
No of days
1.591.880.85 (0.73 to 0.98)–0.29
(–0.53 to –0.04)
(–1.16 to –0.49)
2.813.63 0.77 (0.70 to 0.86)
No of days
5.47 6.000.91 (0.84 to 0.99)–0.53
(–0.97 to –0.08)
(–13.47 to –10.05)
78.1689.920.87 (0.85 to 0.89)
BMJ Online First bmj.com
page 3 of 6
difference between the groups. Fewer children in the adenoton-
sillectomy group experienced snoring and difficulties in eating at
six months, whereas there were no differences at 24 months
(data not shown). Height and weight of children in both groups
remained similar during follow up (data not shown).
The effects of adenotonsillectomy were more pronounced in
children who had had three to six throat infections in the year
before entry to the trial than in those with none to two throat
infections: fever episodes (difference − 1.07 (95% confidence
interval − 1.59 to − 0.56) v 0.34 ( − 0.08 to 0.77),P = 0.01;table 3)
and days with sore throat per person year (difference − 11.33
( − 12.48 to − 10.17) v − 2.38 ( − 3.19 to − 1.60), P = 0.01). Age
did not influence the effectiveness of adenotonsillectomy.
Complications of surgery
Of the 195 children who underwent adenotonsillectomy (145 in
the adenotonsillectomy group and 50 in the watchful waiting
group), 12 (6%) had complications related to surgery. Seven chil-
dren (4%) had primary haemorrhage: two (1%) were managed
surgically,five (3%) were managed non-surgically;and three (2%)
were admitted for overnight observation. None of these children
needed a blood transfusion. Five children (3%) had postopera-
tive nausea, which was managed by antiemetics and intravenous
Adenotonsillectomy for mild symptoms of throat infections or
adenotonsillar hypertrophy in children has little clinical benefit
over watchful waiting. Surgery marginally reduced the number
of episodes of fever,throat infections,and upper respiratory tract
infections per person year.The effects of surgery were more pro-
nounced in children who had had three to six throat infections in
the year before entry to the trial than in those with none to two
throat infections. No clinically relevant differences were found
for health related quality of life.
Short term effect
During the first six months of follow up the incidence of fever
was significantly lower in the adenotonsillectomy group than in
the watchful waiting group, but was the same from six to 24
months. Sleep and eating patterns initially improved more in
children in the adenotonsillectomy group, but by 24 months the
differences had disappeared. The reduction of problems in the
first six months might explain why parents and doctors are usu-
ally satisfied with adenotonsillectomy.12 17 18
Our trial has several limitations. Firstly, we excluded children
with frequent throat infections or obstructive sleep apnoea,
which are generally considered adequate indications for surgery.
Our results are therefore generalisable only to children with
Secondly, 50 children (34%) changed from watchful waiting
to surgery. Similar rates have been reported.3 19–22In surgical tri-
At 6 months
At 24 months
children aged 2-5 years
Health related quality of life (preschool children quality of life questionnaire; TAPQoL) six and 24 months after adenotonsillectomy or watchful waiting for
At 6 months
At 24 months
and 24 months after adenotonsillectomy or watchful waiting
Health related quality of life (child health questionnaire parental form) six
Follow up (months)
Median obstructive sleep apnoea score
036 12 1824
adenotonsillectomy or watchful waiting
Median Brouillette’s obstructive sleep apnoea scores for children after
page 4 of 6
BMJ Online First bmj.com
als,only the children in the watchful waiting group are allowed to
change treatment group because of persisting problems. Per
protocol analyses that exclude children who change groups will
therefore underestimate the effect of treatment. Conversely, ana-
lysing children on the basis of time spent in a treatment arm
might overestimate or underestimate this effect. For these
reasons we chose an intention to treat analysis.
Thirdly, we measured health related quality of life with
generic questionnaires because disease specific instruments for
children with tonsil and adenoid disease were not available when
we started our study.23We chose the TAPQoL and TACQoL pre-
school children quality of life questionnaires because they
include domains relevant for children with tonsil and adenoid
disease.14We did not expect large improvements during follow
up, because the scores of our study population at baseline were
similar to those of healthy children.
Finally, not all eligible children entered the trial, which might
have influenced the generalisability of our results. In an earlier
study, however, we found no major differences between included
children and those who were eligible but not included.24
Strengths of the study
Previous trials are potentially limited by information bias. This is
due to the absence of an objective outcome measure and
because the parents of children in the watchful waiting group are
more likely to report sore throat or upper respiratory tract infec-
tions than parents of children in the intervention group.3 19–22 25
These lead to an overestimation of the intervention effect.26 27
The major strength of our study is the inclusion of the objective
primary outcome of fever measured daily by a validated
thermometer that automatically stored data.16Fever is an impor-
tant physical sign in many diseases of children, and most
episodes of fever in children under 8 years of age are caused by
upper respiratory tract infections.28 29We found that adenotonsil-
lectomy did not significantly reduce the number of fever
episodes but did have a small but statistically significant effect on
the number of throat infections.
The power of our study was large enough to allow for
subgroup analyses, providing a tool for clinicians to identify chil-
dren who are likely to benefit from adenotonsillectomy.
We thank the participants and their parents; our colleagues and nurses in
the participating hospitals; Nelly van Eden for secretarial support; Patrick
Poels,Ward Videler,Charlotte van Krevel,and Wytske Richard for help with
the conduct of the trial and recruitment of the patients; and Frank Leus for
Contributors: BKvS and EhvdA planned the study; collected, analysed, and
interpreted the data; and wrote the paper equally. MMR analysed and inter-
preted the data. GJH contributed to the initial concept and design of the
study and interpreted the data. AGMS and AWH designed, planned, and
supervised the study and interpreted the data. The manuscript was
prepared by BKvS and EHvdA and commented on by all authors. AGMS is
Funding: Dutch Health Care Insurance Board (OG-99-060).
Competing interests: None declared.
Ethical approval:This study was approved by the medical ethics committees
of all participating hospitals.
1Van den Akker EH, Hoes AW, Burton MJ, Schilder AGM. Large international
differences in (adeno)tonsillectomy rates. Clin Otolaryngol 2004;29:161-4.
Van den Akker EH, Schilder AG, Kemps YJ, van Balen FA, Hordijk GJ, Hoes AW. Cur-
rent indications for (adeno)tonsillectomy in children: a survey in the Netherlands. Int J
Pediatr Otorhinolaryngol 2003;67:603-7.
Paradise JL, Bluestone CD, Bachman RZ, Colborn DK, Bernard BS, Taylor FH, et al.
Efficacy of tonsillectomy for recurrent throat infection in severely affected children.
Results of parallel randomized and nonrandomized clinical trials. N Engl J Med
Nieminen P,Tolonen U,Lopponen H.Snoring and obstructive sleep apnea in children:
a 6-month follow-up study. Arch Otolaryngol Head Neck Surg 2000;126:481-6.
De Serres LM,Derkay C,Astley S,Deyo RA,Rosenfeld RM,Gates GA.Measuring qual-
ity of life in children with obstructive sleep disorders. Arch Otolaryngol Head Neck Surg
Flanary VA. Long-term effect of adenotonsillectomy on quality of life in pediatric
patients. Laryngoscope 2003;113:1639-44.
Scottish Intercollegiate Guidelines Network.1999.www.sign.ac.uk/guidelines (accessed
20 May 2004).
American Academy of Otolaryngology-Head and Neck Surgery. 2000. Clinical indica-
tors for otolaryngology—head and neck surgery. 2000. www.entlink.net/practice/
products/indicators/tonsillectomy.html (accessed 17 Jun 2004).
Blair RL, McKerrow WS, Carter NW, Fenton A. The Scottish tonsillectomy audit. Audit
10 Donnelly MJ, Quraishi MS, McShane DP. Indications for paediatric tonsillectomy: GP
versus consultant perspective. J Laryngol Otol 1994;108:131-4.
11 Capper R, Canter RJ. Is there agreement among general practitioners, paediatricians
and otolaryngologists about the management of children with recurrent tonsillitis?
Clin Otolaryngol 2001;26:371-8.
12 Faulconbridge RV, Fowler S, Horrocks J, Topham JH. Comparative audit of
tonsillectomy. Clin Otolaryngol 2000;25:110-7.
13 Brouillette R, Hanson D, David R, Klemka L, Szatkowski A, Fernbach S, et al. A
diagnostic approach to suspected obstructive sleep apnea in children. J Pediatr
14 Fekkes M,Theunissen NC,Brugman E,Veen S,Verrips EG,Koopman HM,et al.Devel-
opment and psychometric evaluation of the TAPQoL: a health-related quality of life
instrument for 1-5-year-old children. Qual Life Res 2000;9:961-72.
15 Raat H, Bonsel GJ, Essink-Bot ML, Landgraf JM, Gemke RJ. Reliability and validity of
comprehensive health status measures in children: the child health questionnaire in
relation to the health utilities index. J Clin Epidemiol 2002;55:67-76.
16 Van Staaij BK, Rovers MM, Schilder AG, Hoes AW. Accuracy and feasibility of daily
infrared tympanic membrane temperature measurements in the identification of fever
in children. Int J Pediatr Otorhinolaryngol 2003;67:1091-7.
Table 3 Differences in incidence of fever, throat infections, upper respiratory tract infections, and days with sore throat in subgroups of children after
adenotonsillectomy or watchful waiting for mild symptoms of throat infections or adenotonsillar hypertrophy
No of throat infections†:
Fever (95% CI)
−0.21 (−0.54 to 0.12)
Throat infections (95%
−0.21 (–0.36 to –0.06)
Days with sore throat
–5.91 (–6 57 to –5.24)
Upper respiratory tract
infections (95% CI)
–0.53 (–0.97 to –0.08)
−0.84 (−1.33 to −0.35)0.10–0.38 (–0.62 to –0.13)0.12–9.70 (–10.79 to –8.61)0.06–0.33 (–0.99 to 0.34)0.79
0.27 (−0.18 to 0.72)–0.08 (–0.28 to 0.11) –3.19 (–4.04 to –2.35) –0.63 (–1.24 to –0.02)
0.34 (−0.08 to 0.77)
−1.07 (–1.59 to −0.56)
0.01–0.03 (–0.21 to 0.15)
–0.49 (–0.75 to –0.22)
0.05–2.38 (–3.19 to –1.60)
–11.33 (–12.48 to –10.17)
0.01 –0.27 (–0.86 to 0.32)
–0.92 (–1.61 to –0.23)
*Values of interaction term in Poisson regression analysis.
†In year before entry to trial.
What is already known on this topic
Frequent throat infections and obstructive sleep apnoea are
adequate indications for adenotonsillectomy
Evidence of the benefits of adenotonsillectomy in children
with milder symptoms is lacking
What this study adds
Adenotonsillectomy has no major clinical benefits over
watchful waiting in children with mild symptoms of throat
infections or adenotonsillar hypertrophy
BMJ Online First bmj.com
page 5 of 6
17 Wolfensberger M, Haury JA, Linder T. Parent satisfaction 1 year after adenotonsillec-
tomy of their children. Int J Pediatr Otorhinolaryngol 2000;56:199-205.
18 Conlon BJ, Donnelly MJ, McShane DP. Improvements in health and behaviour follow-
ing childhood tonsillectomy:a parental perspective at 1 year.Int J Pediatr Otorhinolaryn-
19 McKee WJE. A controlled study of the effects of tonsillectomy and adenoidectomy in
children. Br J Prev Soc Med 1963;17:49-69.
20 Mawson SR, Adlington P, Evans M. A controlled study evaluation of adeno-
tonsillectomy in children. J Laryngol Otol 1967;81:777-90.
21 Mawson SR, Adlington P, Evans M. A controlled study evaluation of adeno-
tonsillectomy in children. Part II. J Laryngol Otol 1968;82:963-79.
22 Paradise JL,Bluestone CD,Colborn DK,Bernard BS,Rockette HE,Kurs-Lasky M.Ton-
sillectomy and adenotonsillectomy for recurrent throat infection in moderately
affected children. Pediatrics 2003;110:7-15.
23 Stewart MG,Friedman EM,Sulek M,deJong A,Hulka GF,Bautista MH,et al.Validation
of an outcomes instrument for tonsil and adenoid disease. Arch Otolaryngol Head Neck
24 Van den Akker EH, Rovers MM, van Staaij BK, Hoes AW, Schilder AG. Representative-
ness of trial populations: an example from a trial of adenotonsillectomy in children.
Acta Otolaryngol 2003;123:297-301.
25 McKee WJE. The part played by adenoidectomy in the combined operation of tonsil-
lectomy with adenoidectomy.Second part of a controlled study in children.Br J Prev Soc
26 Van der Graaf Y. Clinical trials: study design and analysis. Eur J Radiol 1998;27:108-15.
27 McLeod RS. Issues in surgical randomized controlled trials. World J Surg
28 Eskerud JR,Laerum E,Fagerthun H,Lunde PKM,Naess A.Fever in general practice.1.
Frequency and diagnoses. Fam Pract 1992;9:263-9.
29 Soman M. Characteristics and management of febrile young children seen in a univer-
sity family practice. J Fam Pract 1985;21:117-22.
(Accepted 6 July 2004)
Julius Center for Health Sciences and Primary Care, University Medical Center
Utrecht, PO Box 85060, 3508 AB Utrecht, Netherlands
Birgit K van Staaij general practitioner
Maroeska M Rovers clinical epidemiologist
Arno W Hoes professor
Department of Otorhinolaryngology, Wilhelmina Children’s Hospital, University
Medical Center Utrecht, PO Box 85090, 3508 AB Utrecht, Netherlands
Emma H van den Akker otorhinolaryngologist
Anne G M Schilder otorhinolaryngologist
Department of Otorhinolaryngology, Head and Neck Surgery, University Medical
Center Utrecht, 3584 CX Utrecht, Netherlands
Gerrit Jan Hordijk professor
Correspondence to: A G M Schilder A.Schilder@wkz.azu.nl
page 6 of 6
BMJ Online First bmj.com