Kari Jorunn Kværner

Distribution and Heritability of Recurrent Ear Infections

The distribution of recurrent ear infections was obtained from a population-based sample of 2,750 pairs of Norwegian twins born between 1967 and 1974. The lifetime prevalence of self-reported recurrent ear infections was 8.9%, with a significant predominance of female cases. The mean age of onset was 4.2 years, with a gradual decrease in occurrence from 2 to 7 years of age. Among monozygotic pairs, the rate of tetrachoric correlation between co-twins was almost identical in males (0.73, SE 0.08) and females (0.74, SE 0.06), but among the dizygotic pairs the correlation was clearly higher in males (0.53, SE 0.12) than in females (0.20, SE 0.12). The value in the unlike-sexed dizygotic twins (0.25, SE 0.05) was intermediate to that of the like-sexed male and female dizygotic pairs. The relative contribution of genes and environment to variability in the predisposition to develop otitis media was estimated by means of structural equation modeling. Variation in liability to ear infections was mainly explained by additive genetic and dominance factors in females, for whom heritability was estimated at 74%. The remaining 26% of the variation in liability was explained by individual environmental factors. In males, 45% of the variation could be accounted for by genetic factors, 29% by common familial environment, and the remaining 26% by individual environmental effects.

Prevalence of Secondary Chronic Headaches in a Population-Based Sample of 30-44-Year-Old Persons. The Akershus Study of Chronic Headache

We studied secondary chronic headaches (≥ 15 days/month for at least 3 months) in a random sample of 30 000 persons aged 30-44 years. They received a mailed questionnaire. Those with self-reported chronic headache within the last month and/or year were invited to an interview and examination by a neurological resident. The criteria of the International Classification of Headache Disorders (ICHD-II) were applied. The questionnaire response rate was 71%, and the participation rate of the interview was 74%. Of the 633 participants, 298 had a secondary chronic headache. The 1-year prevalence of secondary chronic headache was 2.14%, i.e. chronic posttraumatic headache 0.21%, chronic headache attributed to whiplash injury 0.17%, post-craniotomy headache 0.02%, medication-overuse headache (MOH) 1.72%, cervicogenic headache 0.17%, headache attributed to chronic rhinosinusitis 0.33% and miscellaneous headaches 0.04%. The majority of those with ICHD-II-defined secondary chronic headache had MOH, while about one-third had other secondary headaches often in combination with MOH.

A Norwegian population‐based study on the risk and prevalence of obstructive sleep apnea The Akershus Sleep Apnea Project (ASAP)

The Berlin Questionnaire (BQ) is a widely used screening tool for obstructive sleep apnea (OSA), but its performance in the general population setting is unknown. The prevalence of OSA in middle‐aged adults is not known in Norway. Accordingly, the aims of the current study were to evaluate the utility of the BQ for OSA screening in the general population and to estimate the prevalence of OSA in Norway. The study population consisted of 29 258 subjects (aged 30–65 years, 50% female) who received the BQ by mail. Of these, 16 302 (55.7%) responded. Five‐hundred and eighteen subjects were included in the clinical sample and underwent in‐hospital polysomnography. Screening properties and prevalence were estimated by a statistical model that adjusted for bias in the sampling procedure. Among the 16 302 respondents, 24.3% (95% confidence interval (CI) = 23.6–25.0%) were classified by the BQ to be at high‐risk of having OSA. Defining OSA as an apnea–hypopnea index (AHI) ≥5, the positive predictive value of the BQ was estimated to be 61.3%, the negative predictive value 66.2%, the sensitivity 37.2% and the specificity 84.0%. Estimated prevalences of OSA were 16% for AHI ≥ 5 and 8% for AHI ≥ 15. In conclusion, the BQ classified one out of four middle‐aged Norwegians to be at high‐risk of having OSA, but the screening properties of the BQ were suboptimal. The estimated prevalence of OSA was comparable to previous estimates from general populations in the USA, Australia and Europe.

Female medical leadership : cross sectional study

Objective: To assess the relation between male and female medical leadership. Design: Cross sectional study on predictive factors for female medical leadership with data on sex, age, specialty, and occupational status of Norwegian physicians. Setting: Oslo,Norway. Subjects: 13844 non-retired Norwegian physicians. Main outcome measure: Medical leaders, defined as physicians holding a leading position in hospital medicine, public health, aacademic medicine, or private health care. Results: 14.6% (95% confidence interval 14.0% to 15.4%) of the men were leaders compared with 5.1% (4.4% to 5.9%) of the women. Adjusted for age men had a higher estimated probability of leadership in all categories of age and job, the highest being in academic medicine with 0.57(0.42to 0.72) for men aged over 54years compared with 0.39(0.21to 0.63) for women in the same category. Among female hospital physicians there was a positive relation between the proportion of women in their specialty and the probability of leadership. Conclusion: Women do not reach senior positions as easily as men. Medical specialties with high proportions of women have more female leaders.

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.

Otitis media across nine countries: disease burden and management.

OBJECTIVE To assess the perceived disease burden and management of otitis media (OM) among an international cohort of experienced physicians. METHODS A cross-sectional survey conducted in France, Germany, Spain, Poland, Argentina, Mexico, South Korea, Thailand and Saudi Arabia. Face-to-face interviews conducted with 1800 physicians (95% paediatricians, 5% family practitioners).Main outcome measures were the perceived burden on clinical practice (number of cases, complications and referrals) and first- and second-line management strategies for OM. Results are expressed as mean and range across the nine countries over three continents. RESULTS Respondents estimated an average annual caseload of 375 (range 128-1003) children under 5 years of age with OM; 54% (range 44-71%) with an initial episode and 38% (range 27-54%) with recurrent OM (ROM). OM with complications was estimated to be approximately 20 (range 7-49) cases per year and an estimated 15% (8-41%) of children with OM was recalled as needing specialist referral. There was high awareness of Streptococcus pneumoniae and Haemophilus influenzae as causative bacterial pathogens: 77% (range 65-91%) and 74% (range 68-83%), respectively, but less recognition of non-typeable H. influenzae (NTHi); 59% (range 45-67%). Although concern over antimicrobial resistance was widespread, empirical treatment with antibiotics was the most common first-line treatment (mean 81%, range 40-96%). The burden of disease is substantial enough that many physicians would consider vaccination to prevent OM (mean score 5.1, range 4.3-6.2 on 1-7 scale). CONCLUSIONS This large, multinational survey shows that OM remains a significant burden for clinical practice. Despite awareness of shortcomings, antimicrobial therapy remains the most frequent treatment for OM.

Prenatal and postnatal parental smoking and acute otitis media in early childhood.

Aim:  To explore the associations between acute otitis media in early childhood and prenatal and postnatal tobacco smoke exposure.

Recurrent Acute Otitis Media: The Significance of Age at Onset

In order to assess the relationship between recurrent acute otitis media (rAOM) and age at first acute otitis media (AOM) episode, a prospective cohort of 3754 Norwegian children born in 1992-1993 was followed from birth to 2 years. Recurrent acute otitis media was defined by the criterion of four or more episodes of AOM during a 12-month period. Approximately 5.4% of the children experienced rAOM before the age of 2. Furthermore, children whose first AOM episode occurred before the age of 9 months were at a significantly higher risk for developing rAOM compared to children whose first AOM episode was 10-12 months. In children who had the first ear infection during the first 9 months of life, one-quarter developed rAOM before the age of 2. Multiple logistic regression analysis adjusted for confounding showed that gender and a familial history of atopy were significantly associated with rAOM. In conclusion, the present study found an association between age at first AOM episode and the later subsequent AOM proneness. Additionally, both gender and a family history of atopy seemed to predispose towards otitis-proneness.