Ellen Kvestad

Epidemiology, natural history, and risk factors: Panel report from the Ninth International Research Conference on Otitis Media

The 2007 Recent Advances in Otitis Media Research Conference Panel Report provides an update on otitis media (OM) research published from 2003 to 2007. This report summarizes important trends in disease incidence and prevalence, describes established and newly identified risk factors for acute and chronic OM and OM with effusion, and conveys information on newly discovered genetic factors. In this report, researchers have described declining rates of OM diagnosis, antibiotic prescriptions, offices visits for OM, and middle ear surgery since the licensure and routine use of pneumococcal conjugate vaccine in infants. The panel report also recommends short and long term goals for current and future OM research.

Acute mastoiditis: predictors for surgery.

To estimate the incidence of acute mastoiditis and identify predictors for mastoid surgery, a retrospective case record study of 38 children hospitalised for acute mastoiditis in Oslo from 1989 to 1998 was performed. Median age at diagnosis was 18 months and 13 (34%) of the children received mastoidectomy. Compared to the period 1970-1979, the incidence of mastoidectomy was significantly reduced. Only seven children (18%) had experienced acute otitis media prior to the current episode. Symptom duration of 6 days or more prior to hospitalisation and elevated white blood cell counts and C-reactive Protein were predictive for mastoidectomy ((OR = 5.0 (1.0-22.8), (OR = 24.5 (2.5-240) and OR = 10.5 (1-108.8)). Furthermore, total time from symptom onset to hospital discharge was significantly higher in children who received mastoidectomy. We suggest early referral to an otolaryngologic department in children suspected of acute mastoiditis.

Respiratory infections in schoolchildren: co-morbidity and risk factors

Aims: To assess co-morbidity and risk factors for otitis media, tonsillopharyngitis, and lower respiratory infections in school children. Methods: Logistic regression analysis of co-morbidity and risk factors for airway infections in a population based sample of 10 year old children living in Oslo, Norway. Main outcome measures: otitis media, tonsillopharyngitis, and lower respiratory infections in past 12 months. Results: Airway infections in 10 year old children were common, and significant co-morbidity was found between the various airway infections. Home dampness was a risk factor for all infections, adjusted odds ratios ranging from 1.2 (95% CI 1.0 to 1.5) to 1.4 (95% CI 1.1 to 1.6) for otitis media and tonsillopharyngitis respectively. Atopic disease was a constitutional risk factor, particularly strong for lower airway infections (adjusted odds ratio 2.4, 95% CI 1.8 to 3.1). African or Asian ethnicities were associated with the airway infections, adjusted odds ratios ranging from 1.2 (95% CI 0.9 to 1.7) to 1.7 (95% CI 1.2 to 2.3). Conclusions: Respiratory tract infections were common in 10 year old children. There was substantial co-morbidity between upper and lower airway infections. Environmental and constitutional factors were identified and positively associated with the infections. Results support the hypothesis of 1957 that the whole respiratory tract is one unit.

Panel 1 Epidemiology, Natural History, and Risk Factors

Background The First International Symposium on Recent Advances in Otitis Media (OM) with Effusion was held in Columbus, Ohio, in 1975. The symposium has been organized in the United States every 4 years since, followed by a research conference to (a) assess major research accomplishments, (b) identify important research questions and opportunities, (c) develop consensus on definitions and terminology, and (d) establish priorities with short- and long-term research goals. One of the principal areas reviewed quadrennially is Epidemiology, Natural History, and Risk Factors. Objective To provide a review of recent literature on the epidemiology, natural history, and risk factors for OM. Data Sources and Review Methods A search of OM articles in English published July 2007 to June 2011 was conducted using PubMed and related databases. Those with findings judged of importance for epidemiology, public health, and/or statistical methods were reviewed. Results The literature has continued to expand, increasing understanding of the worldwide burden of OM in childhood, complications from treatment failures, and comorbidities. Novel risk factors, including genetic factors, have been examined for OM susceptibility. Population-based studies in Canada, the United States, and other countries confirmed reductions in OM prevalence. Although most studies concentrated on acute OM (AOM) or OM with effusion (OME), a few examined severe chronic suppurative OM (CSOM), a major public health problem in developing countries and for certain indigenous populations around the world. Conclusions and Implications for Practice Recent publications have reinforced earlier epidemiological findings, while extending our knowledge in human population groups with high burden of OM.

Otitis Media: Genetic Factors and Sex Differences

Although genetic factors are recognised as major contributors to otitis media, the presence of sex differences in heritability needs clarification. The aim of this study was to estimate the relative contribution of genetic and environmental effects in otitis media liability with particular focus on sex differences. Data from a cohort of Norwegian twins born between 1967 and 1979 with repeated measures on recurrent childhood otitis media were analysed. Altogether the sample included 4247 twin pairs. The tetrachoric correlations for monozygotic twins were .71 and .65 for males and females respectively. In dizygotic twins the correlations were .35 and .25 for males and females, respectively, and was.34 in opposite sexed pairs. The contribution of genetic and environmental effects was analyzed using structural equation modeling. The best fitting model showed that additive genetic effects explained 72% and 61% of the variance in males and females, respectively. The remaining variance was attributed to individual environmental effects. A model specifying equal heritability estimates for males and females yielded an almost equivalent fit. We found substantial genetic effects for liability to otitis media. There is no evidence that different sets of genes influence liability in males and females, but there may be sex differences in the relative importance of genetic effects.

Occupation and the risk of bothersome tinnitus: results from a prospective cohort study (HUNT)

Objectives Estimates of occupation-specific tinnitus prevalence may help identify high-risk occupations where interventions are warranted. The authors studied the effect of occupation on prevalence of bothersome tinnitus and estimated the attributable fraction due to occupation. The authors also studied how much of the effect remained after adjusting for noise exposure, education income, hearing thresholds and other risk factors. Design A prospective cohort study. Setting A health survey of the Nord-Trøndelag county of Norway. Participants A sample of the general adult population (n=49 948). Primary outcome measure The primary outcome measure is bothersome tinnitus. Results Occupation had a marked effect on tinnitus prevalence. The effect of occupation on tinnitus was reduced in men by controlling for self-reported occupational noise exposure and in women by controlling for education and income. Adding hearing loss as a predictor increased the effect of occupation somewhat. In men, age-adjusted prevalence ratios of tinnitus ranged from 1.5 (workshop mechanics) to 2.1 (crane and hoist operators) in the 10 occupations with highest tinnitus prevalence. In women, the most important contribution to the tinnitus prevalence was from the large group of occupationally inactive persons, with a prevalence ratio of 1.5. Conclusion This study found a moderate association between occupation and bothersome tinnitus.

Childhood Otitis Media: A Cohort Study With 30-Year Follow-Up of Hearing (The HUNT Study).

Objectives: To study the extent to which otitis media (OM) in childhood is associated with adult hearing thresholds. Furthermore, to study whether the effects of OM on adult hearing thresholds are moderated by age or noise exposure. Design: Population-based cohort study of 32,786 participants who had their hearing tested by pure-tone audiometry in primary school and again at ages ranging from 20 to 56 years. Three thousand sixty-six children were diagnosed with hearing loss; the remaining sample had normal childhood hearing. Results: Compared with participants with normal childhood hearing, those diagnosed with childhood hearing loss caused by otitis media with effusion (n = 1255), chronic suppurative otitis media (CSOM; n = 108), or hearing loss after recurrent acute otitis media (rAOM; n = 613) had significantly increased adult hearing thresholds in the whole frequency range (2 dB/17–20 dB/7–10 dB, respectively). The effects were adjusted for age, sex, and noise exposure. Children diagnosed with hearing loss after rAOM had somewhat improved hearing thresholds as adults. The effects of CSOM and hearing loss after rAOM on adult hearing thresholds were larger in participants tested in middle adulthood (ages 40 to 56 years) than in those tested in young adulthood (ages 20 to 40 years). Eardrum pathology added a marginally increased risk of adult hearing loss (1–3 dB) in children with otitis media with effusion or hearing loss after rAOM. The study could not reveal significant differences in the effect of self-reported noise exposure on adult hearing thresholds between the groups with OM and the group with normal childhood hearing. Conclusions: This cohort study indicates that CSOM and rAOM in childhood are associated with adult hearing loss, underlining the importance of optimal treatment in these conditions. It appears that ears with a subsequent hearing loss after OM in childhood age at a faster rate than those without; however this should be confirmed by studies with several follow-up tests through adulthood.

Labyrinthine Fistula Detection: The Predictive Value of Vestibular Symptoms and Computerized Tomography

A retrospective case record study of 20 patients in Oslo operated on for chronic otitis media with labyrinthine fistula between 1986 and 1999 was performed in order to estimate the incidence of, and identify predictors for, labyrinthine fistulas. The incidence of fistula was 0.3 per 100 000, with a median age at diagnosis of 37 years. The median duration of chronic otitis media prior to labyrinthine fistula detection was significantly correlated with age at surgery. Subjective hearing loss (90%), otorrhoea (65%) and dizziness (50%) were presenting symptoms. Modified canal-wall-down mastoidectomy was performed in all patients. Preoperative hearing levels could not predict postoperative hearing outcome. Positive signs of fistula were found in only 4 patients (20%). Correspondingly, computerized tomography (CT) diagnosed the fistula in 11 patients (55%). The seven patients presenting without dizziness and with a negative CT scan and fistula test were characterized by lower age, absence of previous middle ear surgery, lower preoperative pure-tone thresholds for bone conduction and better hearing outcome after surgery. In conclusion, the identification of a younger group of patients presenting with fewer symptoms indicates that fistulas should be suspected in all patients undergoing surgery for chronic middle ear and mastoid disease.A retrospective case record study of 20 patients in Oslo operated on for chronic otitis media with labyrinthine fistula between 1986 and 1999 was performed in order to estimate the incidence of, and identify predictors for, labyrinthine fistulas. The incidence of fistula was 0.3 per 100 000, with a median age at diagnosis of 37 years. The median duration of chronic otitis media prior to labyrinthine fistula detection was significantly correlated with age at surgery. Subjective hearing loss (90%), otorrhoea (65%) and dizziness (50%) were presenting symptoms. Modified canal-wall-down mastoidectomy was performed in all patients. Preoperative hearing levels could not predict postoperative hearing outcome. Positive signs of fistula were found in only 4 patients (20%). Correspondingly, computerized tomography (CT) diagnosed the fistula in 11 patients (55%). The seven patients presenting without dizziness and with a negative CT scan and fistula test were characterized by lower age, absence of previous middle ear surgery, lower preoperative pure-tone thresholds for bone conduction and better hearing outcome after surgery. In conclusion, the identification of a younger group of patients presenting with fewer symptoms indicates that fistulas should be suspected in all patients undergoing surgery for chronic middle ear and mastoid disease.

Heritability of hearing loss.

Background: Hearing impairment is one of the most common permanent disabilities in the western world. Although hearing ability normally declines with age, there is great individual variation in age of onset, progression, and severity, indicating that individual susceptibility plays a role. The aim of the present study was to explore the relative importance of genetic and environmental effects in the etiology of impaired hearing. Methods: From August 1995 to June 1997, the total adult population of Nord-Trøndelag County, Norway, was invited to take part in the Nord-Trøndelag Health Study. The survey included as an integrated project the Nord-Trøndelag Hearing Loss Study with pure-tone audiometry assessment of the standard frequencies 0.25, 0.5, 1, 2, 3, 4, 6, and 8 kHz on 51,574 participants aged 20 to 101 years. We obtained information from Statistics Norway identifying 11,263 sibling pairs. After age stratification, we assessed similarity in hearing thresholds between siblings using polychoric correlations. The contribution of genetic effects in hearing ability was calculated. Results: The upper limit of the heritability of hearing loss was 0.36. We found little evidence for sex differences in the relative importance of genetic effects. Conclusions: There is a substantial genetic contribution to individual variation in hearing thresholds.

Otologic Facial Palsy: Etiology, Onset, and Symptom Duration

To estimate the occurrence of otogenic facial palsy, we performed a retrospective case record study of all patients hospitalized for otogenic facial palsy in the period 1989 to 1999 at Ullevål University Hospital, which is the only referral hospital for patients with otologic sequelae in Oslo. The facial palsy was a complication of acute otitis media in 10 patients (56%), of acute mastoiditis in 3 patients (17%), of secretory otitis media in 3 patients (17%), and of chronic otitis media in 2 patients (11%). In half of the patients, complete facial palsy was found at the time of diagnosis. Sixteen patients (89%) reported a gradual onset of the facial palsy. The mean duration of otologic symptoms before the onset of facial palsy was 3 days (range, 1 to 9 days), and the median time to remission was 9 weeks (range, 2 to 96 weeks). Total remission was achieved in all patients who received follow-up. Although most patients recover within a few weeks, some patients have long-lasting facial palsy. Multicenter studies are needed to increase the sample size and to identify predictors of facial palsy duration.