***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: One hundred and fifty children aged between 2 and 9 years with bilateral SOM were allocated at r and om to three groups : Adeno-tonsillectomy ( 47 cases ) , adenoidectomy ( 47 cases ) and neither procedure ( 53 cases ) . A further 42 children were allocated to either adenoidectomy or no surgery . In all only one ear was treated at r and om by myringotomy and insertion of a ventilation tube . The unoperated ear was examined six weeks , six months , nine months , one , two and three years post-operatively for otoscopic clearance of the effusion , impedance change and improvement in mean hearing threshold . Thus the effects on middle ear status of adenoidectomy alone and in combination with tonsillectomy were assessed . There was a significant clearance of middle ear fluid , change from no peak to peak impedance measurement and hearing gain as a result of both procedures with a late trend favouring the combined operation . Neither pre-operative tonsils size nor the number of attacks of tonsillitis affect outcome . However there is a relationship between age and radiographic post-nasal space airway size with clearance of the effusion one year after surgery . These findings permit recommendation for adenoidectomy with improved expectation for resolution of SOM if cases are selected with reference to these two variables . They also suggest in which cases the operation should not be recommended . Despite the trends in outcome favouring combined operations , the extra morbidity associated with the addition of tonsillectomy does not at present justify recommendation for removal of the tonsils in addition to adenoidectomy for cases with SOM . Tonsillectomy in these children should be assessed on grounds of tonsillar pathology per se and not on the status of the middle ear CONTEXT Adenoidectomy and adenotonsillectomy are commonly performed in US children to reduce the occurrence of persistent or recurrent otitis media , but evidence supporting the efficacy of the operations is limited . OBJECTIVES To test the efficacy of adenoidectomy and adenotonsillectomy in children with persistent or recurrent otitis media who had not previously undergone tube placement and to compare the relative efficacy of adenoidectomy alone vs adenotonsillectomy in such children . DESIGN Two parallel r and omized clinical trials . SETTING AND PARTICIPANTS A total of 461 children aged 3 to 15 years were enrolled at Children 's Hospital of Pittsburgh , Pa , between April 1980 and April 1994 . Four hundred ten children were observed for up to 3 years . INTERVENTIONS Children without recurrent throat infection or tonsillar hypertrophy ( 304 enrolled ; 266 followed up ) were r and omized to either an adenoidectomy , adenotonsillectomy , or control group ;  children who had such conditions ( 157 enrolled ; 144 followed up ) were r and omized to an adenotonsillectomy or control group . MAIN OUTCOME MEASURES Occurrence rate of episodes of acute otitis media by treatment group and estimated proportion of time with otitis media . RESULTS In both trials , most subjects were eligible because of recurrent acute otitis media , with or without persistent otitis media with effusion .  A total of 47 children assigned to surgical treatment groups had no surgery . The efficacy of surgery in both trials was modest and limited mainly to the first follow-up year . The largest differences in that year were found in the 3-way trial between the adenotonsillectomy group and the control group : mean annual rate of episodes of acute otitis media , 1.4 vs 2.1 ( P<.001 ) ; and mean estimated percentage of time with otitis media , 18.6 % vs 29.9 % ( difference , 11.3 % ; 95 % confidence interval , 4.4%-18.2 % ; P=.002 ) . Perioperative and postoperative complications or other adverse events occurred not infrequently , especially among subjects undergoing adenotonsillectomy ( 14.6 % ) . CONCLUSIONS Our study showed limited and short-term efficacy of both adenoidectomy and adenotonsillectomy ; given the risks , morbidity , and costs of these procedures , these data suggest that neither operation should ordinarily be considered as a first surgical intervention in children whose only indication is recurrent acute otitis media The  treatment of deafness secondary to glue ear by grommet insertion  is compared to To investigate the mechanism whereby adenoidectomy influences the subsequent course of patients with chronic otitis media with effusion , we analyzed , on the basis of adenoid size , the outcomes of 476 children r and omly assigned to receive , after paracentesis and aspiration of the middle ear , either no treatment , tympanostomy tubes , adenoidectomy , or both . The two groups receiving adenoidectomy did significantly better than those who did not , and the effect was independent of adenoid size . This suggests that reduction of the adenoidal bacterial reservoir may be the mechanism whereby adenoidectomy is effective A prospect i ve study was conducted of the effects of adenoidectomy and adenotonsillectomy on established otitis media with effusion unresponsive to medical treatment . The operations were performed at r and om with a controlled no surgery group on a cohort of 103 children with the condition and the results assessed six weeks , three months , six months , nine months , and one year later . After adenoidectomy the rate of resolution of the condition increased from 39 % at six weeks to 72 % at one year ; and after adenotonsillectomy the rate increased from 59 % at six weeks to 62 % at one year . In the no surgery group the rate increased from 16 % at six weeks to 26 % at one year . Compared with the no surgery group the effect of adenoidectomy alone at one year was highly significant ( p less than 0.001 ) , and similarly the effect of  adenotonsillectomy  was significant ( p less than 0.01 ) . There was , however , no increased benefit from the addition of tonsillectomy compared with adenoidectomy alone . Thus there was resolution of 36 - 46 % of chronic effusions as a result of adenoidectomy OBJECTIVE --To measure the time to spontaneous resolution of severe chronic otitis media with effusion ( glue ear ) in children and study the effects of adenoidectomy , adenotonsillectomy , and ventilation tubes ( grommets ) . DESIGN --R and omised controlled study over 12 years . SETTING --Paediatric otorhinolaryngology clinics and in-patient unit . SUBJECTS--228 children aged 2 - 9 years with pronounced hearing loss from glue ear and persistent bilateral middle ear effusions confirmed on three occasions over three months . INTERVENTIONS --Children were r and omly allocated to adenotonsillectomy , adenoidectomy , or neither procedure . In all groups a Shepard type ventilation tube was inserted in one r and omly chosen ear . Follow up was annually for five years and then less often for up to seven years four months . For analysis the two operated groups were combined . MAIN OUTCOME MEASURES --Otoscopic clearance of fluid , change in tympanogram , and improvement in mean audiometric hearing threshold . RESULTS --Survival analysis showed appreciable otoscopic and tympanometric resolution of fluid with ventilation tubes alone and adenoidectomy alone compared with no surgery . Further improvement was seen after combination of both treatments . Mean audiometric hearing thresholds improved with fluid resolution . Resolution was delayed in younger children and in those whose parents smoked , irrespective of treatment . Whereas a single insertion of a Shepard tube resolved the glue for a mean ( SD ) period of 9.5 ( 5.2 ) months , the effect of adenoidectomy was sustained throughout follow up . CONCLUSIONS --Treatment of glue ear considerably shortened the time to fluid resolution , combined adenoidectomy and tube insertion being better than either procedure alone . Resolution was longer in younger children and those whose parent(s ) smoked , irrespective of treatment OBJECTIVE --To assess the effect of five different surgical treatments for glue ear ( secretory otitis media ) on improvement in hearing and , assuming one or more treatments to be effective , to identify the appropriate indications for surgery . DESIGN --R and omised controlled trial of children receiving ( a ) adenoidectomy , bilateral myringotomy , and insertion of a unilateral grommet ; ( b ) adenoidectomy , unilateral myringotomy , and insertion of a unilateral grommet ; ( c ) bilateral myringotomy and insertion of a unilateral grommet ; and ( d ) unilateral myringotomy and insertion of a grommet .  Children were followed up at seven weeks , six months , 12 months , and 24 months by symptom history and clinical investigations . SETTING --Otolaryngology department in an urban hospital . PATIENTS --149 Children aged 4 - 9 years who were admitted for surgery for glue ear and who had no history of previous operations on tonsils , adenoids , or ears and no evidence of sensorineural deafness . Inadequate follow up information on levels of hearing and on middle ear function was obtained from 22 . MAIN OUTCOME MEASURES --Mean hearing loss ( dB ) of the three worst heard frequencies between 250 and 4000 Hz , results of impedance tympanometry , and parental views on their child 's progress . RESULTS --In the 127 children for whom adequate information was available ears in which a grommet had been inserted performed better in the short term ( for at least six months ) than those in which no grommet had been inserted , irrespective of any accompanying procedure . Most of the benefit had disappeared by 12 months . Adenoidectomy produced a slight improvement that was not significant , though was sustained for at least two years . The ears of children who had had an  adenoidectomy  with myringotomy and grommet insertion , however , continued to improve so that two years after surgery about 50 % had abnormal tympanometry compared with 83 % of those who had had only myringotomy and grommet insertion , and 93 % of the group that had had no treatment . Logistic regression analyses identified preoperative hearing level as the single best predictor of good outcome from surgery . Other variables contributed little additional predictive power . CONCLUSIONS --If the principal objective of surgery for glue ear is to restore hearing then our study shows that insertion of grommets is the treatment of choice . The addition of an adenoidectomy will increase the likelihood of restoration of normal function of the middle ear but will not improve hearing . When deciding appropriate indications for surgery , a balance has to be made between performing unnecessary operations and failing to treat patients who might benefit from surgical intervention . Preoperative audiometry scores might be the best predictor in helping to make this decision OBJECTIVES To test the effect of adenoidectomy in connection with tympanostomy compared with tympanostomy only in preventing otitis media in children younger than 2 years . DESIGN Prospect i ve trial with r and omized and nonr and omized arms . SETTING Primary care study clinics . PARTICIPANTS AND INTERVENTIONS The study participants were selected from 2497 children who had been enrolled in the Finnish Otitis Media Vaccine Trial at the age of 2 months . A total of 306 children , aged 1 to 2 years , who had experienced recurrent episodes of otitis media were r and omized into 2 treatment groups : tympanostomy with or without adenoidectomy . Of the 306 children , 137 were operated on according to r and om basis ( r and omized trial ) . The 169 children whose parents declined participation in the r and omized trial were operated on according to the parents ' preferences ( nonr and omized trial ) . All children were followed up until 2 years of age . The mean follow-up time was 7 months . MAIN OUTCOME MEASURE The rate of acute otitis media episodes . RESULTS The average reduction in the rate of all acute otitis media episodes in the adenoidectomy group was 19 % ( 95 % confidence interval [ CI ] , -14 % to 43 % ) among children enrolled in the r and omized trial and 25 % ( 95 % CI , -13 % to 50 % ) in the nonr and omized trial . The reduction in the r and omized trial was mainly due to reduction in the rate of pneumococcal otitis media ( 58 % , 95 % CI , 16%-79 % ) . CONCLUSION In children younger than 2 years , concurrent adenoidectomy during the insertion of tympanostomy tubes does not seem to have a major advantage over the insertion of tympanostomy tubes alone in preventing otitis media To study the effectiveness of adenoidectomy and tympanostomy tubes in the treatment of chronic otitis media with effusion , we r and omly assigned 578 4- to 8-year-old children to receive one of the following : Bilateral myringotomy and no additional treatment ( group 1 ) , tympanostomy tubes ( group 2 ) , adenoidectomy and myringotomy ( group 3 ) , or adenoidectomy and tympanostomy tubes ( group 4 ) . The 491 who accepted surgical treatment were evaluated at 6-week intervals for up to 2 years . Treatment effect was assessed by four main outcomes : Time with effusion , time with hearing loss , time to first recurrence of effusion , and number of surgical re-treatments . For the groups ( in order ) , the mean percent of time with any effusion in either ear was 49 , 35 , 30 , 26 ( p < .0001 ) ; the mean percent of time with hearing thresholds 20 dB or greater was 19 , 10 , 8 , and 7 ( p < .0001 ) in the better ear ; and 38 , 30 , 22 and 22 in the worse ear ( p < .0001 ) ; the median number of days to first recurrence was 54 , 222 , 92 , and 240 ( p < .00 
    Output:
    
Regarding AOM , the results of none of the trials including this outcome indicate a significant beneficial effect of adenoidectomy .
Our review shows a significant benefit of adenoidectomy as far as the resolution of middle ear effusion  in children with OME is concerned .
However , the benefit to hearing is small and the effects on changes in the tympanic membrane are unknown .