Optimizing intracochlear electrical stimulation to suppress tinnitus.

OBJECTIVES: Research on tinnitus suppression by intracochlear electrical stimulation has gained interest over the past few decades and it has become easier to apply since the introduction of cochlear implants (CI). This study attempted to gain more insight into optimal stimulation characteristics for tinnitus suppression. DESIGN: Eleven subjects with unilateral CI and tinnitus were recruited from our CI clinic. Electrical stimulation, independent of acoustic sounds, was generated using their CI. The current prospective (single blinded) experimental study systematically assessed two stimulation parameters, namely current level and the anatomical stimulation site inside the cochlea and their short-term effect on tinnitus. RESULTS: Approximately one-third of the tested conditions were successful in which case tinnitus loudness was reduced by at least 30%. At least one successful condition was achieved for nine subjects (82%). Complete suppression was achieved in 6 out of 107 tested conditions (6%). The effect of subthreshold electrical stimulation on tinnitus suppression did not differ significantly from above threshold electrical stimulation. However, a positive relation between mean percentage tinnitus suppression and current level was observed. Pitch-matched electrical stimulation did not appear to suppress tinnitus better than other tested conditions. CONCLUSIONS: The majority of the subjects were able to experience tinnitus reduction through intracochlear electrical stimulation independent of acoustic sounds. Tinnitus can be reduced with audible or even inaudible, subthreshold stimuli. Clear trends in optimal stimulation characteristics were not found. Optimal stimulus characteristics for tinnitus reduction therefore appear to be highly subject-specific.

Amplitude Modulation Detection and Speech Recognition in Late-Implanted Prelingually and Postlingually Deafened Cochlear Implant Users.

OBJECTIVES: Many late-implanted prelingually deafened cochlear implant (CI) patients struggle to obtain open-set speech understanding. Because it is known that low-frequency temporal-envelope information contains important cues for speech understanding, the goal of this study was to compare the temporal-envelope processing abilities of late-implanted prelingually and postlingually deafened CI users. Furthermore, the possible relation between temporal processing abilities and speech recognition performances was investigated. DESIGN: Amplitude modulation detection thresholds were obtained in eight prelingually and 18 postlingually deafened CI users, by means of a sinusoidally modulated broadband noise carrier, presented through a loudspeaker to the CI user's clinical device. Thresholds were determined with a two-down-one-up three-interval oddity adaptive procedure, at seven modulation frequencies. Phoneme recognition (consonant-nucleus-consonant [CNC]) scores (percentage correct at 65 dB SPL) were gathered for all CI users. For the prelingually deafened group, scores on two additional speech tests were obtained: (1) a closed-set monosyllable-trochee-spondee test (percentage correct scores at 65 dB SPL on word recognition and categorization of the suprasegmental word patterns), and (2) a speech tracking test (number of correctly repeated words per minute) with texts specifically designed for this population. RESULTS: The prelingually deafened CI users had a significantly lower sensitivity to amplitude modulations than the postlingually deafened CI users, and the attenuation rate of their temporal modulation transfer function (TMTF) was greater. None of the prelingually deafened CI users were able to detect modulations at 150 and 200 Hz. High and significant correlations were found between the results on the amplitude modulation detection test and CNC phoneme scores, for the entire group of CI users. In the prelingually deafened group, CNC phoneme scores, word scores on the monosyllable-trochee-spondee test, and speech tracking scores correlated significantly with the mean amplitude modulation detection threshold of the modulation frequencies between 5 and 100 Hz and with almost all separate amplitude modulation thresholds. High correlations with these speech measures were also found for the attenuation rate of and the surface area below the TMTF. In postlingually deafened CI users, CNC phoneme scores only correlated significantly with the 100-Hz and 150-Hz amplitude modulation thresholds, as well as with the attenuation rate of and surface area below the TMTF. CONCLUSIONS: Prelingually deafened CI users were less sensitive to temporal modulations than postlingually deafened CI users, and the attenuation rate of their TMTF was steeper. For all CI users, subjects with better amplitude modulation detection skills tended to score better on measures of speech understanding. Significant correlations with low modulation frequencies were found only for the prelingually deafened CI users and not for the postlingually deafened CI users.

Informed consent and nurses' roles: a survey of Indonesian practitioners.

BACKGROUND: In Southeast Asia, the process of obtaining informed consent is influenced by both culture and policy at the hospital and national level. Both physicians and nurses play vital roles in this process, but physicians influence the roles of nurses. OBJECTIVES: Since the physicians and nurses often have different perspectives, it is important to investigate their views about the informed consent process and nurses' roles therein and whether there is a difference between ideal and experienced practice (reality), and whether this differs across hospitals. METHODS: A questionnaire was developed and a survey was conducted among physicians and nurses. Using exploratory factor analysis a three factor structure was determined: 'nurses' roles', 'barriers in informed consent', and 'adequacy of information'. Non-parametric tests were applied to compare nurses and physicians, and hospital setting. PARTICIPANTS AND RESEARCH CONTEXT: Responses were obtained from 129 physicians and 616 nurses from two Indonesian hospitals. Those hospitals differ in ownership, location, and size. ETHICAL CONSIDERATION: The study was reviewed by the hospital ethical committee. Participation was voluntary and confidentiality was ensured by keeping the responses anonymous. FINDINGS: Physicians and nurses differ significantly on all three factors. The scores reflecting disparity between ideal and reality regarding nurses' roles varied across professions, while barriers in informed consent differed between hospitals. DISCUSSION: The differences between ideal and reality indicated that improvement in the informed consent process and nurses' roles therein is called for. Varying views between physicians and nurses on nurses' roles may hinder collaboration. The differences between hospital settings showed interventions may have to be customized for different settings. CONCLUSION: Views on nurses' roles vary across professions. Views on barriers in informed consent vary across hospitals. Therefore interprofessional education is needed to promote interprofessional collaboration and intervention to improve informed consent practice should be tailored to the hospital context.

Functional impairment of the auditory pathway after perinatal asphyxia and the short-term effect of perinatal propofol anesthesia in lambs.

BACKGROUND: Sensorineural hearing loss (SNHL) is a common feature in the postasphyxial syndrome in newborns. Several anesthetic drugs have been proposed to attenuate secondary neuronal injury elicited by hypoxia-ischemia. We hypothesized that propofol anesthesia reduces auditory impairment after perinatal asphyxia in comparison with isoflurane. METHODS: Twenty-three pregnant ewes were randomized to propofol or isoflurane anesthesia and sedation. The lambs underwent in utero umbilical cord occlusion (isoflurane n = 5; propofol n = 7) and were compared with sham-treated animals (isoflurane n = 5; propofol n = 6) at a gestational age of 133 d. For 8 h after delivery by cesarean section, repeated auditory brainstem responses (ABRs) were recorded to obtain hearing thresholds, peak amplitudes, latencies, and interpeak latencies. RESULTS: Significantly elevated mean thresholds, diminished amplitudes, and elevated latencies were observed in the asphyxia group relative to the control group through the observation period. Comparison of anesthetic treatment in the asphyxia group revealed a significantly lower elevation in threshold and less impairment in the ABR amplitudes and latencies during propofol anesthesia as compared with isoflurane anesthesia. CONCLUSION: Our results support the hypothesis that anesthesia with propofol has a preventive effect on the functional changes to the auditory pathway in the event of perinatal asphyxia.

Screening for hearing loss versus parental concern regarding hearing problems: Subsequent referral and treatment for otitis media in the Netherlands.

OBJECTIVE: The present study investigates whether general practitioner (GP) consultation initiated by failing the population hearing screening at age nine months or GP consultation because of parental concern over ear/hearing problems was more important in deciding on referral and/or surgical treatment of otitis media (OM). DESIGN: A questionnaire covering the history between birth and 21 months of age was used to obtain information on referral after failing the hearing screening, GP consultations for ear/hearing problems, and subsequent referral to a specialist and possible surgical treatment at an ENT department. SETTING: The province of Limburg, the Netherlands. SUBJECTS: Healthy infants invited for the hearing screening at age nine months, who responded in an earlier study called PEPPER (Persistent Ear Problems, Providing Evidence for Referral, response rate 58%). MAIN OUTCOME MEASURES: The odds of a child being surgically treated for OM. RESULTS: The response rate for the present questionnaire was 72%. Of all children tested, 3.9% failed the hearing screening and were referred to their GP. Of all 2619 children in this study, 18.6% visited their GP with ear/hearing problems. Children failing the hearing screening without GP consultation for ear/hearing problems were significantly more often treated surgically for OM than children passing the hearing screening but with GP consultation for ear/hearing problems. CONCLUSION: Objectified hearing loss, i.e. failing the hearing screening, was important in the decision for surgical treatment in infants in the Netherlands.

Risk factors for failing the hearing screen due to otitis media in Dutch infants.

Hearing loss from otitis media (OM) can affect young children's development. Some children with persistent OM-related hearing loss and associated problems can benefit from treatment, but researchers and clinicians are still unclear on how to identify them best. The present study aims to determine which factors are most related to the hearing loss in OM, as a first step towards an effective case-finding instrument for detecting infants with persistent OM-related hearing loss. The full PEPPER ('Persistent Ear Problems, Providing Evidence for Referral') item pool includes a wide range of risk factors for OM in a single questionnaire, and is easily completed by parents or guardians. The questionnaire was sent to all children invited for the universal hearing screen at age 9 months in Limburg, The Netherlands. Repeatedly failing of the hearing screen was used as outcome marker indicative of OM-related chronic hearing loss. Univariate analyses were conducted to determine statistically significant risk factors predicting 'fail' cases at this hearing screen. Five items were found as individually predictive of hearing screen failure and subsequent referral: 'having severe cold symptoms', 'attending day care with >4 children', 'having siblings', 'severe nasal congestion' and 'male gender'. Suitably worded parental questions document risk factors for OM-related hearing loss in infants, broadly consistent with past general literature on OM risk factors, but more focused. The findings justify further optimising and evaluation of an additive or multiplicative combination of these questions as a means for selecting and routing an infant with diagnosed or suspected OM to further care.

Evaluation Criteria for Chromosome Instability Detection by FISH to Predict Malignant Progression in Premalignant Glottic Laryngeal Lesions.

Background: The definition of objective, clinically applicable evaluation criteria for FISH 1c/7c in laryngeal precursor lesions for the detection of chromosome instability (CI). Copy Number Variations (CNV) for chromosomes 1 and 7 reflect the general ploidy status of premalignant head and neck lesions and can therefore be used as a marker for CI. Methods: We performed dual-target FISH for chromosomes 1 and 7 centromeres on 4 µm formalin-fixed, paraffin-embedded tissue sections of 87 laryngeal premalignancies to detect CNVs. Thirty-five normal head and neck squamous cell samples were used as a control. First, the chromosome 7:1 ratio (CR) was evaluated per lesion. The normal range of CRs (≥0.84 ≤ 1.16) was based on the mean CR +/− 3 x SD found in the normal population. Second, the percentage of aberrant nuclei, harboring > 2 chromosomes of chromosome 1 and/or 7 (PAN), was established (cut-off value for abnormal PAN ≥ 10%). Results: PAN showed a stronger correlation with malignant progression than CR (resp. OR 5.6, p = 0.001 and OR 3.8, p = 0.009). PAN combined with histopathology resulted in a prognostic model with an area under the ROC curve (AUC) of 0.75 (s.e. 0.061, sensitivity 71%, specificity 70%). Conclusions: evaluation criteria for FISH 1c/7c based on PAN ≥ 10% provide the best prognostic information on the risk of malignant progression of premalignant laryngeal lesions as compared with criteria based on the CR. FISH 1c/7c detection can be applied in combination with histopathological assessment.

Speech perception after early-life otitis media with fluctuating hearing loss.

The present study examined the effect of early-life otitis media and its associated fluctuating hearing loss on categorical speech perception in 7-year-old Dutch children. The middle ear status of these children had been followed prospectively in their first 2 years of life. Identification and discrimination of speech sounds differing in place of articulation were tested at school age and outcomes were significantly related to otitis media-related hearing loss. Results revealed that phoneme identification and discrimination were affected by early-life hearing loss. It is not otitis media per se, but rather the relative severity of hearing loss resulting from early-life otitis media which is related to poorer categorical speech perception abilities in school-age children.

Frequency shifts with age in click-evoked otoacoustic emissions of preterm infants.

A previous study [Brienesse et al. (1997). Pediatr. Res. 42, 478-483] demonstrated a positive shift with increasing postmenstrual age (PMA) in the frequencies of synchronized spontaneous otoacoustic emissions (SSOAEs) in preterm infants. We used a mixed model approach to describe a shift with PMA in the spectra of click-evoked otoacoustic emissions (CEOAEs) measured in a group of 22 preterm infants. The rate in shift in CEOAE spectral components was found to be frequency dependent, with a mean estimate of 10 Hz/week for frequencies around 2 kHz and 30 Hz/week for frequencies around 4.25 kHz. This rate decreased with increasing PMA. Because SSOAEs are often part of the CEOAE response, a comparison was made between the shifts in SSOAEs and CEOAEs in a sub-group of 16 preterm infants. The results indicate that the shifts found for both types of OAE are similar, which supports a common mechanism for this change in OAE-characteristic. At present it is not clear to what extent developmental processes in the cochlea and the middle ear can account for these frequency shifts in the spectra of CEOAEs and SSOAEs during the preterm period.

Stapedius muscle fibre characterization in the noise exposed and auditory deprived rat.

In skeletal muscle, interventions that unload the muscle cause slow-to-fast myosin heavy chain (MHC) conversions, whereas fast-to-slow conversions are seen when the muscles are engaged in resistance training and endurance exercise. The stapedius muscle (SM) is reported to prevent cochlear damage by noise. This theory may be supported by showing comparable changes of muscle fibre composition when ears are exposed to longstanding noise (SM training). Comparable changes after sound deprivation (SM unloading) would suggest that the SM needs a certain degree of daily activity evoked by environmental sound to sustain its normal composition. We investigated the difference in myosin composition of SM fibres from rats exposed to noise, from auditory deprived rats and from rats exposed to low level ambient noise (control group). Consecutive complete SM cross-sections were processed by enzymehistochemistry to determine acid/alkali lability of myofibrillar adenosine triphosphatase (mATPase) and by immunohistochemistry using MHC antibodies. Fibres were assigned to mATPase type I, IIA, IIX or 'Miscellaneous' categories. Per mATPase category, the fibres were attributed to groups with specific MHC isoform compositions. Auditory deprivation lasting nine weeks was accomplished by closure of the external meatus at the age of three weeks. A slow-to-fast shift was seen in these rats when compared to the control group. The noise exposed group was exposed to 65-90dB sound pressure level during a period lasting nine weeks from the age of three weeks onwards. A shift from an overwhelming presence of type mATPase IIX, as seen in the control group, to type mATPase IIA occurred in the noise exposed group. Also, more MHC IIA/IIX hybrid fibres were found in the mATPase IIX category. An adaptive response to the acoustic environment in the characteristics of the fibres of the SM, comparable to the response in skeletal muscles on unloading and training activity, can be ascertained. This supports the theory that the SM plays an active role in modulating external acoustic energy on entry to the cochlea. Our results are also in favour of another postulated function of the SM, the unmasking of high-frequency signals in low-frequency background noise.

Intrauterine Lipopolysaccharide-Induced Chorioamnionitis in a Sheep: Does It Affect the Auditory System?

BACKGROUND: Fetal exposure to in utero inflammation such as chorioamnionitis is related to central nervous system injury. We hypothesized that chorioamnionitis can provoke inflammatory changes in the perilymph and alter hearing outcome. METHODS: Pregnant ewes were randomized into 2 groups: intrauterine injection with lipopolysaccharide (LPS; n = 19) or saline (n = 21). In the first experiment, fetal perilymph samples were taken for cytokine analysis. In the second experiment, consecutive bone-conducted auditory brain stem responses were obtained from 1 to 7 months after birth. RESULTS: Perilymph samples showed a significant elevation in interleukin 8 in the LPS group. Auditory brain stem response analysis demonstrated higher response thresholds and a prolongation of absolute peak V and interpeak intervals I to V and III to V in the LPS group compared to sham treatment. CONCLUSION: Our study confirms the hypothesis that an intrauterine inflammation by LPS can result in a fetal perilymphatic inflammatory response and functional impaired hearing outcomes after birth in a sheep model.

Chromosome instability predicts progression of premalignant lesions of the larynx.

The histopathology of premalignant laryngeal lesions does not provide reliable information on the risk of malignant transformation, hence we examined new molecular markers which can easily be implemented in clinical practice. Dual-target fluorescence in situ hybridisation (FISH) for chromosome 1 and 7 centromeres was performed on tissue sections of laryngeal premalignancies in 69 patients. Chromosome instability was indicated by numerical imbalances and/or polysomy for chromosomes 1 and 7. Additionally, immunostainings for p53, Cyclin D1 and (p)FADD expression were evaluated. Malignant progression was recorded. Eighteen patients with carcinoma in situ (CIS) were treated after diagnosis and excluded from follow-up. Chromosome instability was strongly associated with a high risk of malignant transformation, especially in lower grade lesions (hyperplasia, mild and moderate dysplasia; odds ratio = 8.4, p = 0.004). Patients with lesions containing chromosome instability showed a significantly worse 5-year progression-free survival than those with premalignancies without chromosome instability (p = 0.002). Neither histopathology nor the protein markers predicted progression in univariate analysis, although histopathological diagnosis, p53 and FADD contributed positively to chromosome instability in multivariate analysis. Chromosome instability is associated with malignant progression of laryngeal premalignancies, especially in lower grade lesions. These results may contribute to better risk counselling, provided that they can be validated in a larger patient set.

Evaluation of the Hearing Aid Rehabilitation Questionnaire in Dutch: Examination of its Psychometric Properties and Potential Use as a Screening Instrument.

Items pertaining to hearing and hearing aids from the Hearing Aid Rehabilitation Questionnaire were applied to a heterogeneous sample of Dutch patients aged 55 years and more to evaluate their potential use in hearing screening. Subjects aged 55+ were recruited from a large general practitioners practice to participate. Three groups were formed: a group of 63 persons with a hearing aid, a group of 64 without a hearing aid but with sufficient hearing impairment to qualify for hearing aid reimbursement, and a group of 85 non-hearing impaired persons. Factor and reliability analyses revealed a structure with two scales regarding hearing, namely functionality and social hearing and three scales pertaining to hearing aids, namely hearing aid stigma, pressure to be assessed and not wanting a hearing aid. Scale validity was assessed with pure tone averages over the frequencies 1, 2 and 4 kHz and with a visual analogue scale for subjective hearing. The derived scales can be applied reliably in audiological assessment in an adult hearing screen setting to detect experienced hearing problems as well as attitudes related to hearing and hearing aids.

Shared care for hearing complaints: guideline effects on patient flow.

RATIONALE, AIMS AND OBJECTIVES: A national guideline was proposed to enable shared care in hearing complaints and therefore to change patient flows. In this study the effect of this guideline is evaluated. METHODS: From a total of 3500 patients with hearing complaints, consulting the Ear Nose and Throat Department of a large non-university hospital in the Netherlands in 2002, a random sample of 1000 patients was selected. Patient flow was simulated according to guideline criteria with as main outcome measures: the effect of the guideline on patient flow. RESULTS: Simulation of the consensus guideline did not really alter patient flow, with 89% to 97% of the patients still being referred to the Ear Nose and Throat specialist or Audiological Centre. Age, ear operations in the past and asymmetric hearing loss are the most important factors determining whether a person is labelled as a patient in need of medical care. CONCLUSION: The present study emphasizes the importance of designing evidence-based guidelines for shared care.

Prevalence of intestinal parasitic infections in preschool-children from vulnerable neighborhoods in Bogotá / Prevalencia de parásitos intestinales en niños preescolares de barrios vulnerables de Bogotá

Introduction: Intestinal parasitic infections (IPIs) are neglected tropical diseases, even though their prevalence is high in many developing countries. The public health impact of IPIs is substantial, in particular for children due to the negative effect on growth and development. Objectives: This study examines the prevalence and risk factors of IPIs in preschool-children from at-risk neighborhoods, including those from internally displaced families. Materials and Methods: A cross-sectional study among 239 preschool-children from two vulnerable neighborhoods in Bogotá. Fecal samples were collected and microscopically examined (direct and Ritchie technique) and data regarding related factors was obtained through a questionnaire. Results: A prevalence of 26.4% for pathogenic parasites (Giardia duodenalis, Blastocystis spp, Trichuris trichiura, Ascaris lumbricoides, and Hymenolepis nana) was found. Logistic regression resulted in four risk factors: siblings ≤5 years (OR 2.33 [1.077-5.021]), stray dogs (OR 2.91 [0.867-9.767]), household members (OR 2.57 [1.155-5.706]) and child's sex (OR 2.17 [1.022-4.615]). Discussion: IPI presence in preschool children is an important health issue in Bogotá which should be addressed. A high protozoan prevalence was found compared to helminthes. Implementing policies addressing risk factors could be a first step in decreasing IPI prevalence.

Introducción: Infecciones parasitarias intestinales (IPI) son enfermedades tropicales desatendidas, a pesar de que su prevalencia es alta en muchos países en desarrollo. El impacto en la salud pública de los IPI es importante, especialmente para los niños debido al efecto negativo sobre el crecimiento y el desarrollo. Objectivos: Este estudio examina la prevalencia y factores de riesgo de IPI en niños preescolares de barrios en riesgo, incluidos los de las familias desplazadas. Materiales y Métodos: estudio transversal entre 239 niños preescolares de dos barrios vulnerables de Bogotá. Se recogieron muestras fecales y se examinaron microscópicamente utilizando dos técnicas (directa y Ritchie). Se aplicó cuestionario para indagar factores relacionados con el parasitismo intestinal. Resultados: Se encontró una prevalencia de 26,4% de parásitos intestinales patógenos (Giardia duodenalis, Blastocystis spp, Trichuris trichiura, Ascaris lumbricoides y Hymenolepis nana). La regresión logística resultó en cuatro factores de riesgo: hermanos ≤5 años (OR 2.33 [1.077-5.021]), los perros callejeros (OR 2.91 [0.867-9.767]), los ocupantes de la casa (OR 2.57 [1.155-5.706]) y el sexo del niño/a (OR 2.17 [1.022-4.615]). Discusión: La presencia del IPI en los niños preescolar es un problema de salud importante en Bogotá y que debe abordarse. Una alta prevalencia de protozoos se encontró comparado con helmintos. La implementación de políticas que aborden los factores de riesgo podría ser un primer paso en la disminución de la prevalencia del IPI. El antecedente de desplazamiento no cambio ni el tipo de parásito ni la prevalencia de parasitismo.

Bone-anchored hearing aid: a comparison of surgical techniques.

OBJECTIVE: To determine which bone-anchored hearing aid (BAHA) implantation surgical technique is associated with the fewest major postoperative complications and shortest time between surgery and use of the BAHA. The techniques evaluated were 1) a free retroauricular "full-thickness" skin graft, 2) a pedicled parieto-occipital epidermal graft, 3) a dermatome-pedicled parieto-occipital dermal graft, and 4) two broad pedicled local epidermal skin envelopes/skin flaps. STUDY DESIGN: Retrospective case study. SETTING: Tertiary referral center. PATIENTS: One hundred forty-three patients who received a BAHA at Maastricht University Medical Center between November 1996 and January 2007. Number and mean age of patients in each group: Technique 1 (n = 30; mean age, 55 yr), Technique 2 (n = 45; mean age, 54 yr), Technique 3 (n = 47; mean age, 55 yr), and Technique 4 (n = 21; mean age, 54 yr). MAIN OUTCOME MEASURES: Cumulative proportion of implants that remained free of major complications versus follow-up interval, time between surgery and use of BAHA. RESULTS: Technique 4 (2 broad pedicled local epidermal envelopes/skin flaps) has a significantly higher proportion of implants that remained free of major complications during first year of follow-up (91%; p = 0.021). Pairwise comparisons revealed that Technique 4 also has a significantly shorter time until use (2 mo) than Techniques 1 (2.5 mo), 2, and 3 (both 2.3 mo). CONCLUSION: Two broad pedicled, local epidermal envelopes/flaps are associated with significantly fewer major complications and have one of the shortest times between surgery and use of the BAHA. The use of a dermatome is not associated with fewer major complications. We recommend Technique 4 as the preferred standard in BAHA surgery to minimize complications, postoperative medication, discomfort, and cost.

Willingness to pay for a hearing aid: comparing the payment scale and open-ended question.

RATIONALE & OBJECTIVES: Different question formats elicit different willingness-to-pay (WTP) results, but there is no consensus on which method elicits the most valid WTP. In spite of the methodological controversies, WTP is a potentially valuable tool in health economics to value health services. Our general objective was to provide additional evidence on the validity of two WTP elicitation formats: the open-ended question and the payment scale. METHODS: We elicited WTP for a hearing aid among hearing aid users (n = 108), using both a payment scale and an open-ended question. We compared the results from both formats. We tested criterion validity by comparing both formats with the actual out-of-pocket payment. Construct validity was tested by examining whether WTP was consistent with positive income elasticity. RESULTS: The WTP results elicited with the payment scale and open-ended question were not statistically significantly different. Both formats showed good criterion validity, although the open-ended question showed a stronger association with the actual out-of-pocket payment. The open-ended format showed better construct validity, as it was influenced by family income. CONCLUSION: The results of the present study showed that the open-ended question was more valid than the payment scale question. We, therefore, recommend that in future WTP studies on hearing aids the open-ended question is used to directly elicit WTP values. The same recommendation may apply to other studies where respondents are familiar with costs or payments for the intervention under evaluation.

Psychometric evaluation of the OM8-30 questionnaire in Dutch children with otitis media.

The Dutch translation of the OM8-30 questionnaire, originally developed in the UK on a large clinical sample, has been applied for validation in an ENT sample, with the aim of assessing otitis media impact and identifying treatment needs in children suffering from chronic otitis media (OM) and/or upper respiratory tract infections (URTI). Caregivers of 246 children completed the OM8-30 and also the generic Strengths and Difficulties Questionnaire (SDQ), prior to otolaryngologist consultation. Factor analysis confirmed the hypothesized six-factor structure, accounting for 55.5% of the variance. The internal consistency was satisfactory to good for all of the physical and developmental facets (alpha-values > or = 0.68). The correlation matrix with the SDQ scales and total difficulties score showed significant relationships for almost all of the OM8-30 developmental facets and sub-aggregate (Ps < 0.01), supporting the concurrent validity of the OM8-30 as a measure of impact in otitis media. This first examination of the Dutch OM8-30 shows that the psychometric characteristics are sufficiently good for the assessment of disease impact, and that this can be subdivided into impact on physical health and on developmental aspects. Recommendations for further research include the study of confounders such as hearing, age and previous operations so that these can be adjusted out, and the determination of which subgroup of children may benefit from tympanostomy tubes.

Societal effects of hearing aid fitting among the moderately hearing impaired.

The objective of this study was to evaluate hearing aid fitting from a societal viewpoint, rather than the more traditional patient perspective. The effects of hearing aid fitting on generic quality of life (EuroQol), social functioning (SF36), auditory disability, productivity at paid and unpaid labour, and medical consumption, were assessed in a prospective study among 80 moderately hearing-impaired first-time hearing aid applicants. The study showed that hearing aid fitting solved problems with paid employment, but did not seem to affect unpaid work. Use of medical services remained relatively stable after first-time hearing aid fitting. The Amsterdam Inventory proved to be a useful questionnaire to assess the effects on hearing disability. No effects of hearing aid fitting on generic quality of life could be determined with the EuroQol, while hearing aid fitting did lead to an improvement in one aspect of generic quality of life; namely social functioning.

Changing characteristics of first-time hearing aid applicants in The Netherlands in the past decade.

This study assessed changes in the characteristics of first-time hearing aid applicants in the past decade. Age, gender, date, type and ear of first hearing aid and audiometry were determined for a sample of 705 first-time hearing aid applicants. Thirteen cohorts resulted, according to the year of first visit to the dispenser. Differences in age, hearing loss, gender and type and ear of first hearing aid between cohorts were analysed. The mean age of first-time hearing aid users increased from 59.52 years in 1987 to 71.84 years in 1999. The mean pure-tone average hearing loss in the better ear (1, 2 and 4kHz) decreased from 69.06 dB in 1987 to 51.86dB in 1999. Relatively more males than females were fitted with hearing aids. Our conclusions are that people are being fitted with hearing aids at older ages and with smaller degrees of hearing loss.