Rationale and design of surgical trials for otitis media with effusion

Signs of developmental stuttering up to age eight and at 12 plus

Clinicians who are familiar with the general DSM-IV-TR scheme may want to know how to identify whether a child does, or (equally importantly) does not, stutter and what differences there are in the presenting signs for children of different ages. This article reviews and discusses topics in the research literature that have a bearing on these questions. The review compared language, social-environmental and host factors of children who stutter across two age groups (up to age eight and 12 plus). Dysfluency types mainly involved repetition of one or more whole function words up to age eight whereas at age 12 plus, dysfluency on parts of content words often occurred. Twin studies showed that environmental and host factors were split roughly 30/70 for both ages. Though the disorder is genetically transmitted, the mode of transmission is not known at present. At the earlier age, there were few clearcut socio-environmental influences. There were, however, some suggestions of sensory (high incidence of otitis media with effusion) and motor differences (high proportion of left-handed individuals in the stuttering group relative to norms) compared to control speakers. At age 12 plus, socio-environmental influences (like state anxiety) occurred in the children who persist, but were not evident in the children who recover from the disorder. Brain scans at the older age show some replicable abnormality in the areas connecting motor and sensory areas in speakers who stutter. The topics considered in the discussion return to the question of how to identify whether a child does or does not stutter. The review identifies extra details that might be considered to improve the classification of stuttering (e.g. sensory and motor assessments). Also, some age-dependent factors and processes are identified (such as change in dysfluency type with age). Knowing the distinguishing features of the disorder allows it to be contrasted with other disorders which show superficially similar features. Two or more disorders can co-occur for two reasons: comorbidity, where the child has two identifiable disorders (e.g. a child with Down Syndrome whose speech has been properly assessed and classed as stuttering). Ambiguous classifications, where an individual suffering from one disorder meets the criteria for one or more other disorders. One way DSM-IV-TR deals with the latter is by giving certain classification axes priority over others. The grounds for such superordinacy seem circular as the main role for allowing this appears to be to avoid such ambiguities.

A comprehensive model for the aetiology of otitis media with effusion

Otitis media with effusion is highly prevalent among young children. Adverse effects of this disorder are mainly restricted to the group of children with a history of recurrent or persistent otitis media with effusion. Early identification, assessment and intervention might prevent these adverse effects. Up to now it is not possible to distinguish these children from those with transient otitis media with effusion. This article presents a comprehensive model for the aetiology of otitis media with effusion. Eustachian tube functioning and the immunological response to environmental pathogens are the two core elements. This model can be used to formulate specific hypotheses about the interaction of several factors that may lead to the early identification of children who are likely to develop persistent or recurrent otitis media with effusion.

Generalizability of trial results based on randomized versus nonrandomized allocation of OME infants to ventilation tubes or watchful waiting

The objective was to study the generalizability of trial results by comparing randomized patients to eligible but nonrandomized patients who received the same management. Implementation of trial results is only justifiable when the results can be generalized to the total domain population. The design was a multicentre randomized controlled trial on the effect of early screening and treatment with ventilation tubes on infants with otitis media with effusion. Randomized (n = 187) and nonrandomized eligible patients (n = 133) were followed up. The study population comprised children who were detected by auditory screening at the age of 9-12 months and who were subsequently diagnosed with persistent bilateral otitis media with effusion for 4-6 months. A significant difference was found in the distribution of some prognostic factors: more randomized children had older siblings, did not attend day care and had mothers with a lower educational level than the nonrandomized children. These factors, however, did not modify the outcome. No differences were found in mean hearing levels between the randomized and nonrandomized children: in both the randomized and nonrandomized children ventilation tubes improved the hearing level, especially after 6 months. However, in the long term (12 months), the hearing levels were equal again. The results of the randomized and nonrandomized patients were comparable. The results of this trial appear to be generalizable to the total domain population. The procedure of following up both randomized and nonrandomized patients is recommended when there is concern about selective participation and reduced generalizability.

Generalisability of clinical trials in otitis media with effusion

OBJECTIVE

The impact of a randomised controlled trial (RCT) upon practice depends on its external validity (generalisability). This paper summarises and illustrates a framework for judging and augmenting external validity, emphasising its application to treatment trials in otitis media with effusion (OME) so as to permit stronger inferences in the future.

METHODS

The external validity of two surgical trials in the field of OME (TARGET, UK and KNOOP-3, the Netherlands) has been examined within a framework emphasising effect modification, in four specific ways: (1) comparison of the demographic characteristics of the trial population with the domain population; (2) studying the distributions on possible effect modifiers (i.e. variables conditioning the benefit from intervention); (3) studying whether effect modification occurs in the analyses; and (4) comparing outcome measures between the randomised and the eligible but non-randomised children.

RESULTS

For neither KNOOP-3 and TARGET were large discrepancies found between randomised and non-randomised children for any of the demographic variables. Differences in distributions along possible effect modifiers were found, but the overlaps were large enough for it still to be possible to study whether these factors indeed modified the outcome. Results for the randomised and non-randomised but eligible patients were similar. The results of both trials therefore appear to be generalisable to their domain populations.

CONCLUSIONS

A superficial contrast in the results (KNOOP null, TARGET positive) does not amount to a contradiction, because of differences in the clinical question appropriate to the respective age and populations defined. Attention to quality of design and external validity of randomised controlled trials should achieve higher applicability.

The effect of short-term ventilation tubes versus watchful waiting on hearing in young children with persistent otitis media with effusion: a randomized trial

OBJECTIVE

To study the effect of short-term ventilation tubes in children aged 1 to 2 yr with screening-detected, bilateral otitis media with effusion (OME) persisting for 4 to 6 mo, as compared with watchful waiting.

DESIGN

Multi-center randomized controlled trial (N = 187) with two treatment arms: short-term ventilation tubes versus watchful waiting. Young children underwent auditory screening; those with persistent (4 to 6 mo) bilateral OME were recruited.

RESULTS

The mean duration of effusion over 1-yr follow-up was 142 days (36%) in the ventilation tube (VT) group versus 277 days (70%) in the watchful waiting (WW) group. After 6 mo of follow-up, the pure-tone average in the VT group was 5.6 dB A better than that in the WW group. After 12 mo, most of the advantage in the VT group had disappeared. After the insertion of ventilation tubes, the children with poorer hearing levels at randomization improved more than the children with better hearing levels. The largest difference in hearing levels was found between the children in the VT group whose ventilation tubes remained in situ and the children in the WW group. In the VT children with recurrence of OME, the hearing levels again increased, but remained slightly lower than those in the infants with persistent OME in the WW group.

CONCLUSIONS

Ventilation tubes have a beneficial effect on hearing in the short run (6 mo); this effect, however, largely disappears in the long run (12 mo). This is probably due to partial recurrent OME in the VT group and to partial spontaneous recovery in the WW group.

Influences on clinical practice: the case of glue ear

A case study of clinical practice in children with glue ear is presented. The case is part of a larger project, funded by the North Thames Research and Development Programme, that sought to explore the part played by clinicians in the implementation of research and development into practice in two areas: adult asthma and glue ear in children. What is striking about this case is the differences found in every area of the analysis. That is, diversity was found in views about diagnosis and treatment of glue ear; the organisation of related services; and in the reported practice of our interviewees, both between particular groupings of clinical staff and within these groupings. The challenge inherent in the case is to go beyond describing the complexity and differences that were found, and look for patterns in the accounts of practice and tease out why such patterns may occur.

Timing for removal of tympanic ventilation tube in children

The medical records of 220 ears of 137 pediatric patients (85 male and 52 female) in which three kinds of ventilation tubes were inserted for treating otitis media with effusion (OME) were reviewed. The tubes selected were the Shepard grommet (75 ears), Goode-T (39 ears), and Paparella type II tube (106 ears). The criteria for tube placement were as follows: (1) continuous conductive hearing loss with over 25 dB air-bone gap, (2) resistance to conservative therapy for over 6 months, and (3) retracted and glue-colored tympanic membrane with type B tympanogram. The tubes that remained in place for over 18-24 months were removed intentionally in combination with a freshening of the perforation edge and tape-patch technique using Steri-Strip tape (3M) for preventing permanent eardrum perforation, because the incidence of persistent perforation became higher after long-term intubation. Shepard grommets tended to be extruded earlier, while Paparella type II tubes tended to stay longer. The OME recurrence rate decreased 12 months or more after tubal insertion. There was a tendency for the recurrence rate to decrease the longer the tube stayed in the eardrum. The number of recurrences decreased when the patient's age at the tube removal or extrusion was 7-8 years old. Adenoidectomy did not influence the recurrence rate of OME. Although the Goode-T and Paparella tube II tubes showed high perforation rates, the perforation rate after extrusion or removal of the tube was decreased by the use of the tape patch technique in combination with a freshening of the perforation edge. From these findings, it was concluded that the appropriate intubation period for the treatment of OME in children is over 12 months with the use of a long-term tube, and that if the patient's age at the time of tube insertion was below 6 years, it might be better that the removal of the tube is postponed until the patient is 8 years of age.

Surgery for glue ear: the English epidemic wanes

OBJECTIVES

To describe the progress of the epidemic of surgery for glue ear since 1983 and trends in the use of different operative procedures.

DESIGN

Analysis of routine hospital data.

SETTING

Thirteen health districts in the Oxford and East Anglian regions.

MAIN MEASURES

Annual rates of surgery in children under 10 years of age.

RESULTS

The rate of surgery for glue ear reached a peak in 1986 since when it has declined by 12.6%. The rate peaked in all 13 districts but at different times over a six year period (1984-1989/90). Following the peak, district rates plateaued in eight districts and declined in five. These changes have been accompanied by: an increase in the proportion of operations confined to the tympanic membrane since 1983 (from 40% to 60%); an increase in the use of grommets after myringotomy (from 50% to 94% since 1980); and an increased use of day surgery for ear-only operations (from about 10% in the late 1970s to 50% in 1987/88).

CONCLUSIONS

The previously reported epidemic of surgery for glue ear is waning. This seems to be a result of changes in the clinical judgment of general practitioners and surgeons as to its use and possibly of a reduced demand from parents.

Current indications for tympanostomy tubes

Current indications for TT placement are (1) persistent SOM that has not responded to a 6 to 12-week course of medical treatment. This includes full and prophylactic doses of antimicrobials (and corticosteroids, as indicated); (2) recurrent AOM (at least three episodes in 6 months or four episodes in 12 months) that does not respond to, or recurs after, antimicrobial prophylaxis; (3) complications of AOM such as meningitis, facial nerve paralysis, coalescent mastoiditis, or brain abscess; and (4) complications of eustachian tube dysfunction such as tympanic membrane retraction with hearing loss, ossicular erosion, and/or retraction pocket formation. It must be emphasized that TT placement in children does not "cure" the condition that led to the surgical intervention. Rather, the TT maintains aeration of the middle ear until the child grows and his eustachian tube function normalizes. These recommendations for TT placement are to be regarded as guidelines, not as absolute requirements. They must be applied individually to each patient and his/her unique situation. Certain factors may influence timing of TT placement and lead to modification of the guidelines as they apply to each child.

Sex and grommet operations

Sex differences in patients having grommet operations in Scotland were analysed to provide further evidence on whether girls should be managed differently from boys. In children treated at less than one year, 64% were boys, but this proportion declined with age and, after the age of 13 years, became less than 50%. The median age at treatment and the repeat operation rate were similar for both sexes. Different management according to the sex of the patient does therefore not appear to be justified.

A randomized study of the surgical management of children with persistent otitis media with effusion associated with a hearing impairment

The object of this study was to compare the effect on the hearing of the insertion of a grommet, with or without adenoidectomy, against a non-surgically managed control ear in children with persistent hearing impairment due to otitis media with effusion. Seventy-eight children (44 boys, 34 girls, mean age 5.8 years) with documented bilateral otitis media with effusion associated with a bilateral hearing impairment (pure tone average air conduction thresholds over 0.5, 1 and 2 kHz of > or = 25 dB HL) over a three month period were admitted to a randomized, controlled trial. Each child was randomized to have or not to have an adenoidectomy. The ears in each child were then randomly allocated to have a grommet (tympanostomy tube) inserted. The children's hearing status was reviewed six and 12 months post-operatively. During follow-up, should a child redevelop a persistent bilateral hearing impairment (as defined above) for three months they were managed with a hearing aid. Thus no child had repeat insertion of a grommet. Surgery of each type had an effect on the hearing and the presence of otitis media with effusion at six months post-operatively but not at 12 months when it was no different from natural resolution. If resolution of the otitis media with effusion is the outcome measure, then adenoidectomy alone is significantly better than no surgery but only in boys rather than in girls. Even in boys it only resolves about 60 per cent of effusions. However, when combined with a grommet (one insertion) adenoidectomy gives no greater resolution (89 per cent compared with 86 per cent).(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous resolution of severe chronic glue ear in children and the effect of adenoidectomy, tonsillectomy, and insertion of ventilation tubes (grommets)

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

Randomised 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 randomly allocated to adenotonsillectomy, adenoidectomy, or neither procedure. In all groups a Shepard type ventilation tube was inserted in one randomly 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.

The paediatric otological caseload resulting from improved screening in the first year of life

Improved test technique by health visitors has been shown to lead to higher accuracy in the screen of hearing aimed traditionally at prelingual sensorineural deafness. However, it gives greatly increased referrals of children having otitis media with effusion (OME) around the end of the first year of life. Two samples of children (n = 29 and 61) were tested in a children's hearing assessment clinic with properly documented testing techniques and trained personnel. The samples were each formed on a fixed population base, one before and one after screen improvements. This enabled characterization of two outcome groups within each sample (severe/persistent enough to refer to ENT vs discharged, despite slight hearing impairment). The average audiometric criterion for onward referral to ENT rose only very little, despite the increased assessment caseload resulting from more detections by the screen. This usefully permitted the conclusion that the number of true cases found due to the screen and assessed as lying beyond a specifiable degree of severity (average cut-off approximately 47 dB(A) or 35 dBHTL) had increased not through lower criteria for referral to ENT, but through the improvements to the screen. The increase was from approximately 0.4% to 1.3% of the base population screened. Thus a change materially enhancing the sensitivity and positive predictive value of a screen considerably enlarges the eventual otological caseload of children with middle-ear disease thought to justify concern at around the end of their first year. If done properly, screening is hence in practical terms about OME, not about prelingual sensorineural hearing impairment. This conclusion presses the urgency of evaluation and consensus on the otological management of the young child with OME.