Validation of a portable tympanometer for use in primary care

Validation of a Bilateral Simultaneous Computer-Based Tympanometer

Purpose This study aimed to investigate the accuracy of bilateral simultaneous tympanometric measurements using a tympanometer with two pneumatic systems inside circumaural ear cups. Method Fifty-two adults (104 ears), with a mean age of 32 years (SD = 12.39, range: 18-60 years) were included in this study. A within-subject repeated-measures design was used to compare tympanometric measurements yielded with the investigational device in unilateral and bilateral simultaneous conditions compared with an industry-standard tympanometer. Results No significant bias (p > .05) was found between the mean of the differences of tympanometric measurements yielded by the two devices, except for a significant bias (p < .05) of the mean of the differences for ear canal volume measurements (0.05 cm³). The Bland-Altman plots showed overall good agreement between the tympanometric measurements between the two instruments. In all 104 ears, the tympanogram types of the KUDUwave TMP were compared with the reference device. The results were highly comparable with a sensitivity and specificity of 100% (95% CI [86.8%, 100%]) and 92.3% (95% CI [84.0%, 97.1%]), respectively. Conclusions The investigational device is a suitable instrument for unilateral or bilateral simultaneous tympanometric measurements in adults and demonstrates the potential of decentralized and accessible tympanometry services.

Aspectos diagnósticos da otite média com derrame na faixa etária pediátrica

OBJETIVOS: apresentar e discutir aspectos diagnósticos da otite média com derrame (OMD) na prática clínica da atenção primária à saúde. MÉTODOS: foram pesquisadas as bases de dados Medline, Lilacs e SciELO (1994-2004). Identificados 523 artigos, dos quais 30 foram considerados para o presente trabalho. RESULTADOS: os estudos revelaram disparidade entre as definições, inconsistência no quadro clínico e falta de padronização dos critérios diagnósticos. Isto contribuiu para a inadequação diagnóstica da OMD. As evidências que levaram ao diagnóstico de efusão foram: a) pelo menos duas anormalidades do tímpano relacionadas à coloração, opacificação e mobilidade; e/ou b) membrana timpânica (MT) tipicamente retraída, côncava, e com alteração da coloração; e/ou c) mobilidade reduzida ou ausente na otoscopia pneumática (OP). A OP mostrou ser mais acurada que a otoscopia simples (OS), sendo considerada como método de escolha para o diagnóstico clínico da OMD. Quando houver dúvida na otoscopia pneumática, pode-se indicar a timpanometria, que aumenta a acurácia deste diagnóstico. CONCLUSÕES: na prática clínica, o diagnóstico da OMD deve ser realizado, primariamente pela otoscopia pneumática, em toda criança com suspeita de OMD. Em caso de dúvida deve-se indicar a timpanometria.

Comparison of old, professional and consumer model acoustic reflectometers in the detection of middle-ear fluid in children with recurrent acute otitis media or glue ear

OBJECTIVE

Acoustic reflectometry is an alternative method of determining the probability of middle-ear fluid. Its sensitivity and specificity are comparable to those of pneumatic otoscopy and tympanometry. The relative superiority between the first-generation model and second-generation spectral gradient acoustic reflectometers (introduced for both professional and consumer use) has not been studied. This study aimed to assess the diagnostic performance of three different acoustic reflectometry devices, and to evaluate the intercorrelation of the results.

METHODS

Fifty children (100 ears) aged <7 years undergoing ambulatory otomicroscopic myringotomy in anesthesia were examined with three different acoustic reflectometers, and the results were compared to the myringotomy findings (gold standard method). Specificity, sensitivity and positive and negative predictive values of each instrument in detecting middle-ear fluid were determined. The intercorrelations between the three devices were assessed descriptively (percentage agreement) and statistically (kappa correlation).

RESULTS

Second-generation professional and consumer spectral gradient acoustic reflectometers performed equally well in detecting middle-ear fluid (specificities 84 and 85%, sensitivities 83 and 77%, respectively) and were superior to the old model. Accordingly, the results obtained with professional and consumer models correlated well with each other (kappa 0.60) but not with those of the first-generation device. Acoustic reflectometry is not reliable when performed in anesthesia with the patient lying down.

CONCLUSIONS

Newer spectral gradient acoustic reflectometers perform better than the older first-generation model. In this study, the consumer model gave the same information as professional model, but its diagnostic validity in the hands of layman consumers needs to be confirmed.

Tympanometry by nurses--can allocation of tasks be optimised?

OBJECTIVE

Acute otitis media and secretory otitis media are the most common pediatric infectious disease with a substantial impact on especially primary health care. If nurses could perform and interpret tympanometries, family practitioners workload could be reduced. We wanted to investigate the ability of nurses to perform tympanometry and evaluate the amount of training required.

METHODS

Prospective study comparing results from tympanometry with results at myringotomy at a University Central Hospital was conducted. Nurses at the Paediatric Ear, Nose, and Throat Department performed tympanometry prior to myringotomy. Sensitivity and specificity of tympanometries versus myringotomy were calculated. Nurses' opinions about tympanometry and training required were evaluated.

RESULTS

During a 1-year period, 199 children were enrolled in the study and 392 tympanograms were analyzed. Sensitivity of tympanograms to detect middle-ear fluid was 0.54, and specificity 0.82. Secretion occurred in 22.5% of children with type A curves and 45.3% of those with type C curves. Nurses evaluated their training in tympanometry as adequate. CONSCLUSIONS: A single training session in tympanometry is inadequate to qualify nurses to perform tympanometry independently. Thorough research and testing to evaluate the quality of such training is required to produce reliable tympanograms.

Spectral gradient acoustic reflectometry in the diagnosis of middle-ear fluid in children

Diagnosis of otitis media is based on detection of middle-ear fluid (MEF) and is both important and difficult to achieve. Also non-infectious MEF is important to detect, since it can compromise hearing. In this prospective, blinded study, spectral gradient acoustic reflectometry (SG-AR) was evaluated as an indicator of MEF among children. Sensitivity, specificity and positive and negative predictive values of SG-AR in detecting MEF were calculated in children undergoing ambulatory surgery for recurrent or secretory otitis media using otomicroscopic myringotomy as the reference method of confirming middle-ear status. Final study material consisted of 376 ears. Pattern recognition of SG-AR curves reached the best combination of sensitivity and specificity (69 and 97%, respectively), and the best combination of positive (PPV) and negative (NPV) predictive values (93 and 83%, respectively), in detection of MEF. With a spectral gradient value of <80 degrees , the sensitivity was 75% and specificity 71%. With <50 degrees , PPV was 78%, and with >or=100 degrees , NPV was 86%. The diagnostic power of SG-AR was comparable to that reported with pneumatic otoscopy and tympanometry. It was equally effective in detecting both MEF cases and healthy ears. Pattern recognition seems to improve its performance. We recommend the use of pattern recognition of SG-AR as a screening method for MEF among children.

Detection of middle-ear fluid in children with spectral gradient acoustic reflectometry: a screening tool for nurses?

OBJECTIVE

To evaluate the validity of spectral gradient acoustic reflectometry (SG-AR) in the hands of nurses in screening children for middle-ear fluid (MEF).

DESIGN

Prospective, blinded study.

SETTING

A satellite study within the Finnish Otitis Media Vaccine Trial in primary care in 1995-99.

PATIENTS

Some 739 ear examinations among a cohort of 271 children under the age of 2 years during different healthcare contacts (acute sick visits, check-up visits after otitis media, and scheduled healthy control visits at 24 months of age).

MAIN OUTCOME MEASURES

Specificity, sensitivity and positive and negative predictive values of SG-AR performed by nurses in detecting MEF using pneumatic otoscopy by trained physicians as a reference.

RESULTS

SG-AR was successful in 585 (79%) ears. None of the cut-off points assessed resulted in both excellent sensitivity and specificity. Nevertheless, at the sick visits, positive predictive values at 50 and 60 degrees were as high as 94% and 89%, respectively. However, negative predictive value for the cut-off point of 100 degrees was considerably lower, at 75%. At the non-acute visits, negative predictive values were excellent.

CONCLUSION

SG-AR is a useful device for nurses in screening MEF among children. It detects ears with both very high and very low probability of MEF and is especially effective in detecting MEF during sick visits and in ruling out MEF among non-acute patients. We recommend the use of the SG-AR cut-off point of 60 degrees as a sign of MEF when screening sick children, and the cut-off point of 100 degrees as a sign of a healthy ear among non-symptomatic patients.

Long-term prognosis of acute otitis media in infancy: determinants of recurrent acute otitis media and persistent middle ear effusion

OBJECTIVES

Children under 2 years of age with acute otitis media are known to have a relatively poor prognosis. The objective of this study was to assess whether known determinants for recurrent acute otitis media and persistent middle ear effusion after an episode of acute otitis media during childhood also apply to children under 2 years.

STUDY DESIGN

prospective study of 210 children under 2, with identification of potential prognostic determinants. Univariate and multivariate logistic regression analyses were applied to evaluate which parameters independently contributed to the prediction of both outcome measures (recurrent acute otitis media and persistent middle ear effusion). A prognostic function was developed, and the area under the receiving operating characteristic (ROC) was used to estimate the predictive ability of the prognostic models.

POPULATION

children under 2 years of age with an episode of acute otitis media in family practice.

OUTCOMES MEASURED

recurrent acute otitis media and persistent middle ear effusion.

RESULTS

For the outcome recurrent acute otitis media data from 210 children were used and winter season, male sex, passive smoking and persistent symptoms for more than 10 days at presentation were independent prognostic determinants. For the outcome persistent middle ear effusion data from 190 children were used and winter season, bilateral disease at entry, a sibling history of recurrent acute otitis media, and a previous episode of acute otitis media independently predicted the outcome. No sufficiently discriminatory prognostic model could be constructed for either outcome measure.

CONCLUSION

Prediction of recurrent acute otitis media or persistent middle ear effusion in individual young children remains poor.

Evidence assessment of the accuracy of methods of diagnosing middle ear effusion in children with otitis media with effusion

OBJECTIVES

We report the findings of an evidence assessment on the accuracy of methods of diagnosing middle ear effusion in children with otitis media with effusion (OME).

METHODS

We searched Medline (1966-January 2000), the Cochrane Library (through January 2000), and Embase (1980-January 2000) and identified additional articles from reference lists in proceedings, published articles, reports, and guidelines. Excluded were nonhuman studies; case reports; editorials; letters; reviews; practice guidelines; non-English-language publications; and studies on patients with immunodeficiencies, craniofacial anomalies (including cleft palate), primary mucosal disorders, or genetic conditions. From each eligible study, we calculated the sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and prevalence of OME in the cohort. We determined the number of studies for each comparison of a diagnostic method and a reference standard listed within the scope of our assessment. For comparisons with 3 or more studies, we derived random effects estimates of sensitivity, specificity, and prevalence rate. Using the pooled estimates, we plotted the performance of each diagnostic test in terms of sensitivity and (1 - specificity) and identified the best performer among the tests included in the comparison.

RESULTS

Among 8 diagnostic methods, pneumatic otoscopy had the best apparent performance with a sensitivity of 94% (95% confidence interval: 92%-96%) and a specificity of 80% (95% confidence interval: 75%-86%). However, examiner qualifications were reported inconsistently, and training was not specified.

CONCLUSIONS

The finding that pneumatic otoscopy can do as well as or better than tympanometry and acoustic reflectometry has significant practical implications. For the typical clinician, pneumatic otoscopy should be easier to use than other diagnostic methods. The important question may be what degree of training will be needed for the clinician to be as effective with pneumatic otoscopy as were the examiners in the studies reviewed in this report.

Negative pressure tympanograms in children less than 2 years of age--different bacterial findings in otitis media by tympanometric results

OBJECTIVE

The interpretation of negative pressure tympanograms as indicators of the presence of middle ear fluid has been ambiguous. Our purpose was to assess the occurrence and implications of negative pressure tympanograms and to study their association with bacterial pathogens in otitis media.

METHODS

Altogether 329 infants were enrolled at a well-baby clinic for the Finnish Otitis Media Cohort Study, a longitudinal prospective cohort study. The children were closely followed in a special study clinic from 2 to 24 months of age for respiratory diseases, especially acute otitis media. Children were examined at the study clinic with tympanometry and pneumatic otoscopy whenever visiting the study clinic for respiratory disease. Myringotomy with aspiration was performed if middle ear fluid was suspected in otoscopy. Occurrence of middle ear fluid in ears with negative pressure tympanograms (less than -100 daPa) was assessed. Nested case control design matched by visit type (acute or follow-up visit) and month of visit was used for analysis of association of bacterial pathogens and tympanometric results.

RESULTS

Middle ear fluid was encountered in 15% of ears with negative tympanometric peak pressure, a lower proportion than described previously. In otitis media with a negative tympanometric peak pressure, 71% of bacterial cultures remained negative for the main pathogens, compared to 36% in matched controls (P<0.001). Especially Streptococcus pneumoniae but also Haemophilus influenzae were rarely found in samples from negative pressure ears. Moraxella catarrhalis was equally often found.

CONCLUSIONS

Negative pressure tympanogram is a poor indicator for the presence of middle ear fluid. Furthermore, if otitis media is diagnosed with negative tympanometric peak pressure negative middle ear bacterial culture for the main pathogens is highly probable. Expectant follow-up might be more appropriate than routine antibiotic treatment.

Does early detection of otitis media with effusion prevent delayed language development?

OBJECTIVE

To consider whether earlier detection of otitis media with effusion (OME) in asymptomatic children in the first 4 years of life prevents delayed language development.

METHODS

MEDLINE and other databases were searched and relevant references from articles reviewed. Critical appraisal and consensus development were in accordance with the methods of the Canadian Task Force on Preventive Health Care.

RESULTS

No randomised controlled trials assessing the overall screening for OME and early intervention to prevent delay in acquiring language were identified, although one trial evaluated treatment in a screened population and found no benefit. The "analytic pathway" approach was therefore used, where evidence is evaluated for individual steps in a screening process. The evidence supporting the use of tools for early detection such as tympanometry, microtympanometry, acoustic reflectometry, and pneumatic otoscopy in the first 4 years of life is unclear. Some treatments (mucolytics, antibiotics, steroids) resulted in the short term resolution of effusions as measured by tympanometry. Ventilation tubes resolved effusions and improved hearing. Ventilation tubes in children with hearing loss associated with OME benefited children in the short term, but after 18 months there was no difference in comparison with those assigned to watchful waiting. Most prospective cohort studies that evaluated the association between OME and language development lacked adequate measurement of exposure or outcome, or suffered from attrition bias. Findings with regard to the association were inconsistent.

CONCLUSIONS

There is insufficient evidence to support attempts at early detection of OME in the first 4 years of life in the asymptomatic child to prevent delayed language development.

Interrater agreement on tympanometry in infants

Two-hundred and forty-two tympanograms of infants were interpreted according to a standard operating procedure independently by an audiologist and ten study doctors from the Finnish Otitis Media Vaccine Trial. The interrater agreement among the study doctors according to Kappa index was excellent (kappa = 0.80). The agreement was significantly better on curves taken during pre-scheduled healthy visits than during sick visits due to respiratory infection (p < 0.001). In addition concurrent knowledge of the clinical ear status significantly improved the agreement on abnormal curves (flat B-curves and failed F-curves, p < 0.001). The clinical differences between the groups were minor. The age of the infant had no effect on interpretation. The agreement between the audiologist and the study doctors was also excellent (kappa = 0.77). Excellent agreement can be achieved in infant tympanometry through adequate instruction and training.

Diagnostic value of tympanometry in infants in clinical practice

One hundred and twenty-one visits of 58 infants (2-11 months of age) were evaluated in the Finnish Otitis Media Vaccine Trial. Infants were examined with tympanometry (Grason-Stadler GSI 38 Autotymp) and pneumatic otoscopy by one study doctor. Diagnosis of otitis media was verified by myringotomy in 74% of cases. Tympanometry was technically successful in 94% of ears. The success rate was statistically significantly higher (P < 0.05) among infants less than 7 months of age than those above 7 months. The sensitivity of tympanometry (type B) to detect ears with middle ear fluid was 0.70 and the specificity 0.98 with a positive predictive value of 0.93 and negative predictive value of 0.94. The sensitivity was somewhat lower in the younger age group (0.61); specificity and positive and negative predictive values were good in both age groups. The high success rate and high negative and positive predictive values of tympanometry make it a useful aid for assuring the correct diagnosis of otitis media in infants in routine clinical practice.

Tympanometry by general practitioners: reliable?

BACKGROUND

The diagnosis of otitis media with effusion (OME) is difficult using only medical history and otoscopy. Tympanometry may, therefore, be helpful in the diagnosis and follow-up of OME in general practice. Studies regarding the reliability of tympanogram production and validation of tympanogram outcome have been performed.

OBJECTIVE

To gain insight into the usability of microtympanometry and the degree of agreement and accuracy of tympanogram classification in general practice.

METHODS

Data were collected in the offices of 49 general practitioners (GP's). The usability of the microtymp was monitored against a checklist. GP's (39) classified 47 tympanograms according to Jerger's modified classification, designating them as 'OME', 'no OME' or 'interpretion impossible'. The gold standard was the consensus over the 47 tympanograms reached by three doctors very experienced in tympanometry.

RESULTS

Of the general practitioners, 61% handled the microtymp faultlessly. The overall inter-observer agreement was moderate to substantial; with respect to the gold standard 74% of the general practitioners had a satisfactory to almost perfect agreement. These results were achieved after instruction and training; longer practice produced no significant improvement in the agreement.

CONCLUSION

After training and instruction microtympanometry is a reliable diagnostic instrument in general practice. The classification of tympanograms is satisfactory. Classification problems arise when the curve is not a good one. Additional criteria for the assessment of the curves are proposed.

Double-blind randomised trial of co-amoxiclav versus placebo for persistent otitis media with effusion in general practice

BACKGROUND

The treatment of persistent otitis media with effusion (OME) remains controversial, but this condition is the commonest reason for children to require ear, nose, and throat (ENT) surgery. Trials of antibiotics are inconclusive, are often weak methodologically, and have not been done in general practice. Our aim was a trial of an antibiotic for OME in such a population.

METHODS

433 children, aged 6 months to 6 years, with OME from 57 general practices entered a 3-month watchful waiting period. Of 223 (52%) with persistent bilateral OME, 162 were randomised double-blind to receive co-amoxiclav suspension (20 mg/kg amoxicillin, 5 mg/kg clavulanate potassium) or matching placebo, orally three times a day for 14 days. All cases also received xylometazoline 0.25% decongestant nosedrops thrice daily. Of the 61 not randomised, 13 children were referred to an ENT surgeon and parents refused consent in 48 cases. The main outcome measures were persistent OME in both ears and in one or both ears, as assessed clinically and by tympanometry. Analysis was by intention-to-treat.

FINDINGS

79 children in the treatment group and 70 in the placebo group were analysed for efficacy. 3 withdrew in the co-amoxiclav group (2 lost to follow-up, 1 due to side-effects); 6 withdrew in the placebo group (5 and 1, respectively). In addition, 4 tympanograms were uninterpretable in the controls. Compliance was over 90% in both groups. Persistent OME in both ears and in one or both ears were found at significantly lower rates in the co-amoxiclav group than in the controls at the 2-week follow-up: 53 vs 84% and 77 vs 93%, respectively. Odds ratios adjusted for sex, history of adenoidectomy, and upper respiratory tract infection at follow-up were 0.25 (95% CI 0.11, 0.58, p = 0.001) and 0.30 (0.10, 0.89, p = 0.03), respectively. Parents of children in the co-amoxiclav group reported significantly more side-effects than those of control children (44 vs 22%, p = 0.03). Side-effects were mostly gastrointestinal and mild.

INTERPRETATION

Our study in a general-practice setting confirmed the positive short-term effect of antibiotic treatment for persistent middle-ear infection. Before referral to an ENT surgeon, children with persistent OME presenting to general practitioners could be considered for such treatment, depending on the individual child and possible adverse sequelae.