Risk Factors For Otitis Media Research Articles

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...

Prevalence and risk factors of otitis media with effusion in Trabzon, a city in northeastern Turkey, with an emphasis on the recommendation of OME screening

This cross-sectional study was undertaken to assess the prevalence and risk factors for otitis media with effusion (OME) in Trabzon, a city in northeastern Turkey, and evaluate the need for screening for OME in the normal population. In kindergartens, daycare centers, public and private schools in the rural and central areas of Trabzon, 1,077 children aged between 5 and 12 years were examined. OME prevalence was 11.14% (120/1,077). Young age, attendance at kindergarten/daycare, low economical status, the mother's working status (housewife), history of snoring and acute otitis media, antibiotic use in the previous 3 months and active upper respiratory tract infection (URTI) were found to be the risk factors for OME. A history of hearing loss reported by the parents and teachers was found significant in the diagnosis of OME despite the low predictive value. When the parents suspected that their child had experienced hearing loss (in 36 cases), they did not refer them to a healthcare facility. To conclude, the approach to OME in developing countries should be more interventional as healthcare coverage is usually low and behavioral factors such as the demand for healthcare is poor.

Risk factors for otitis media with effusion in Chinese schoolchildren: A nested case–control study and review of the literature

To identify the risk factors for otitis media with effusion (OME) in Chinese schoolchildren and analyse the results with reference to the review of the literature. The study subjects were 6-7-year-old children drawn from a school-screening program for OME in Hong Kong. Both positive and negative screens attended a hospital clinic for further assessment with repeated otoscopic examination and tympanometry as well as pure tone audiometry within 3 weeks after the initial school-screening. During the visit, parents were interviewed to provide information with regard to the children's birth history, neonatal history, socio-economic background, otological history, past health, and medical history. These data formed the basis in the estimation of potential risk factors for OME. In the univariate analysis of 127 cases and 173 controls, significantly elevated odds ratios (OR) for OME were detected on the symptoms of atopy (OR = 2.21, p = 0.04), hearing loss (OR = 4.13, p = 0.001), nasal obstruction (OR = 1.94, p = 0.005), rhinorrhoea (OR = 1.61, p = 0.04), tonsillitis in the past 12 months (OR = 1.82, p = 0.02), and previous history of acute otitis media (OR = 6.89, p < 0.001). However, only three of them were found to be significant in the multivariate logistic regression model: nasal obstruction (OR = 1.67, 95% CI: 1.01-2.75); acute tonsillitis (OR = 1.68, 95% CI: 1.00-2.80), and previous acute otitis media episodes (OR = 5.75, 95% CI: 2.60-12.69). Risk factors identified in the Chinese schoolchildren for OME were comparable with previous western reports. A previous attack of acute otitis media was a major determinant for middle ear effusion.

Comparison of caregiver otitis media risk factor knowledge in suburban and urban primary care environments

There are many risk factors for otitis media. Some of these, such as passive tobacco smoke exposure and childcare arrangements; have the potential to be modified. The purpose of this study is to assess caregiver knowledge deficits about risk factors associated with otitis media and their willingness to modify behaviors associated with those risks. This study is a prospective survey study investigating knowledge deficits of parents or guardians of children ages 6-36 months about the risk factors of otitis media. The patients were consecutively drawn from a suburban and an urban pediatric practice. Any difference in survey results between these two groups was also assessed. Participants completed a survey of 21 questions with content including demographic and OM risk factor data. A total of 401 caregivers completed surveys, with 213 from an urban pediatric practice and 188 from a suburban practice. There was a significant difference in the ethnic distributions of the two populations. The suburban population had a significantly greater family history of ear infections, number of ear infections in the past 12 months, and number of previous ventilation tubes placed. The urban population had a significantly greater number of smokers in the household and decreased knowledge about day care as a risk for OM. The urban population's question responses suggested a greater willingness to change day care arrangements to reduce the risk of otitis media. Both populations demonstrated knowledge deficits regarding risk factors associated with OM and both populations exhibited willingness to modify behaviors to reduce risk. These findings demonstrate that there are opportunities for improving education regarding OM risk factors and that this education could potentially reduce risk for OM and in turn reduce the incidence of OM in children.

Racial/ethnic disparities in the diagnosis of otitis media in infancy

Objective: Otitis media (OM) is an extremely common pediatric diagnosis. Several risk factors have been associated with OM, but the relationship between OM and race/ethnicity remains controversial. We sought to define the relationship between OM diagnosis and race/ethnicity in infants. Methods: By multivariable logistic regression, we evaluated the association between OM diagnosis and race/ethnicity in 11,349 non-low-birthweight infants who were participants in a prospective cohort study of infant care practices. Results: As in previous studies, breastfeeding was associated with a decreased risk of OM diagnosis while other factors were independently associated with a substantially increased risk of OM diagnosis: out-of-home daycare, multiple children living in the home, and mother’s multiparity. Daycare was associated with a “dose effect” in that the risk of OM diagnosis increased with an increasing number of children in the daycare. While the crude analysis suggested little relation of OM diagnosis and race/ethnicity, the association was confounded by several covariates including maternal marital status, number of children living in the home, breastfeeding status, and maternal age. After adjustment for relevant confounders, Black (OR 0.74; 95% CI 0.61–0.89) and Asian infants (OR 0.77; 95% CI 0.57–1.0]) were less likely to be diagnosed with OM than White infants. Conclusions: This large prospective study confirms previous risk factors for OM and demonstrates a strong “dose effect” of the size of daycare centers on OM. The study also demonstrates that the association between race/ethnicity and OM diagnosis is confounded by social factors. After adjusting for such factors, Black and Asian infants are less likely to be diagnosed with OM than White infants. The reason for this racial disparity remains unknown.

Trends in otitis media among children in the United States.

The prevalence of repeated otitis media (OM) increased during the 1980s, but it is unknown if the increase has continued. To determine trends in the prevalence of OM, early-onset OM, and repeated OM among US children from 1988 to 1994 and to identify factors that may explain any observed changes. The Third National Health and Nutrition Examination Survey was administered in 2 phases: phase I (1988-1991) and phase II (1991-1994), each comprising a national probability sample. OM (ever having had OM), early-onset OM (first episode at <12 months of age), and repeated OM (>or=3 episodes) were assessed for 8261 children <6 years of age. After controlling for risk factors for OM, the prevalence of OM from phase I to phase II increased from 66.7% to 69.7% (odds ratio [OR] = 1.1; 95% confidence interval [CI] =.99, 1.1), early-onset OM increased from 41.1% to 45.8% (OR = 1.1; 95% CI = 1.03, 1.2), and repeated OM increased from 34.8% to 41.1% (OR = 1.2; 95% CI = 1.1, 1.4). This observed increase corresponds to 561,000 and 720,000 more children having early-onset OM and repeated OM, respectively. Child care use, early breastfeeding termination, asthma, and access to health care did not significantly increase from phase I to phase II. The prevalence of early-onset OM and repeated OM was higher for affluent children, but the greatest increase in prevalence was among impoverished children. There was an increase in allergic conditions from phase I to phase II for poor children (22.6% to 30.2%). The prevalence of early-onset OM and repeated OM continued to increase among preschool children in the United States. Further research to investigate this increasing prevalence should explore changes in management practice and an increase in prevalence of allergic conditions among poor children.

Meconium-stained amniotic fluid is not a risk factor for otitis media.

It has recently been hypothesised that large amounts of amniotic fluid cellular content (AFCC) in the middle ear may lead to chronic inflammation and predispose young children to recurrent middle ear infections. Because children born with meconium-stained amniotic fluid (MSAF) have higher AFCC in the middle ear, we performed a retrospective cohort study to determine whether children born with MSAF had a higher risk of OM during infancy. Children born between May 1998 and April 2000 formed two groups based on the absence or presence of MSAF at birth as documented in the hospital birth records. In April 2002, home visits were made to take tympanometric measurements and administer a questionnaire on OM history and possible confounders. Logistic regression models were constructed to assess odds ratios (OR) as a measure of the effect of MSAF on OM and to adjust for potential confounders. There were no differences in the point prevalence of a type-B tympanogram at the home visit (OR 0.81; 95% confidence interval: 0.38-1.76). Also, no statistically significant association was found between the proportion of children with OM diagnosed in the 1st year of life (OR 0.86, 95% confidence interval: 0.27-2.73) and in the proportion of children that had ever been diagnosed with OM (OR 0.91, 95% confidence interval: 0.40-2.91). It can be concluded that children born with MSAF do not constitute a high-risk group for OM in early childhood. A long-term OM effect, especially in severe MSAF cases, cannot be excluded.

Blood Group in Otitis media with Effusion

The aim of the present study was to assess whether blood group ABO is a risk factor for otitis media with effusion (OME). In a screening program 889 children were studied with pneumatic otoscopy, tuning fork tests, audiometry, impedance measures and blood group tests. Among these children, there were 51 children with OME at the time of examination (5.7%), and 838 healthy children. Multivariate logistic regression risk for OME was compared between children with different blood groups, taking sociodemographic and history-related risk factors into account. Blood group and OME were found to be statistically related. Considering children of blood group A as a reference, children with blood group O had a statistically significant lower risk of OME. Children with blood group B did not have lower risk. Children with blood group AB had lower relative risk for OME, but not significantly so. Examining Rhesus factor as a predictor for OME, no relationship was found. It is concluded that blood group O (and possibly AB) plays a preventive role, while blood group A or B are burdensome for OME.

Microbiologic findings and risk factors for antimicrobial resistance at myringotomy for tympanostomy tube placement—a prospective study of 601 children in Toronto

Context: There is limited information on the identity and antibiotic susceptibility of bacterial pathogens in children with chronic otitis media whose repeated antibiotic use may place them at increased risk of antibiotic-resistant bacteria. Objective: To determine, at myringotomy for tympanostomy tube placement, (1) the prevalence of bacteria, (2) the extent and patterns of antibiotic resistance, and (3) the risk factors associated with the presence and resistant status of pathogens. Design: Prospective, multi-site, cohort study. Setting and patients: Children undergoing myringotomy for tympanostomy tube placement between November 1, 1999 and March 31, 2000 in seven hospitals in Toronto, Ontario, were identified. If fluid was present, aspirates were submitted for bacteriologic testing. A follow-up telephone questionnaire was administered to patient caregivers in order to identify risk factors for the presence of (1) culturable pathogens and (2) resistant pathogens. Main outcome measures: The identification and prevalence of bacteria cultured from the middle ears of subjects, and the degree of nonsusceptibility to commonly prescribed antibiotics. Results: Among 601 patients (mean age 3.9 years, 60.7% male), both a telephone interview ( n=544) and an ear specimen ( n=527) were obtained for 478. Pathogens were found in middle ear effusions of 37% of the children in the study; including at least one ‘definite’ pathogen in 189 children (31.4%), and a further 32 children (5.3%) with at least one ‘possible’ pathogen. Definite pathogens included Haemophilus influenzae in 17% of the children, followed by Moraxella catarrhalis (9%) and Streptococcus pneumoniae (6%); ampicillin nonsusceptibility was found in 40, 100 and 24%, respectively. Overall, 123 children (20.5%) were found to have definite pathogens with resistance to ampicillin/penicillin, trimethoprim-sulfamethoxazole, or clarithromycin/erythromycin. Patient characteristics included premature birth and/or long length of stay in the nursery (23%), first infection before the age of 6 months (26%), put to bed with a bottle (28%), household smoker (34%), in out-of-home child care (38%), history of eczema, bronchiolitis and/or asthma (39%), and use of pacifiers (40%). Household characteristics were smoking (34%), married/common law parents (85%), and 60% had completed college or university; in 26% both parents were born outside of Canada; 73% of children were Caucasian. Of the 75% who responded to the question regarding income, 42% had household income over $60,000 (CAN). Risk factors for the presence of a pathogen and for a resistant pathogen in mulivariate analysis included younger age, lower maternal education, day care centre attendance, no previous adenoidectomy and bilateral, primarily winter infections as well as amoxicillin use in the previous 6 months. Conclusion: Modifiable risk factors for otitis media including household smoking and pacifier use are present in many children undergoing tympanostomy tube placement; child care centre attendees are over-represented. Multiple antibiotic courses were commonly prescribed prior to surgery. H. influenzae and M. catarrhalis are important pathogens and therapy in clinical failures should be directed against them. The 7-valent protein conjugate polysaccharide vaccine (Prevnar™) would have covered 73% of the serotypes of S. pneumoniae isolated in this study.

A longitudinal study of risk factors for otitis media in African American children.

Otitis media with effusion (OME) is a common health care problem for children. The purpose of this study was to examine factors that place children at risk for OME such as age, type of child care, number of people in the household, and smoking in the household. Eighty-six African American children, enrolled in center-based child care in infancy, entered the study at a mean age of 8.2 months and were followed prospectively until 48 months of age. Ear status was documented biweekly using pneumatic otoscopy and tympanometry. Data on risk factors were collected every 6 months. Results indicated that children had a marked decrease in the proportion of time with OME between 6 and 48 months. The rate of OME decline was faster in the first 2.5 years than in subsequent years. Children in center-based child care showed a slightly slower rate of decline than did children in non-center-based care. Longitudinal analysis indicated that the age of the child and the number of other children in the household were significant predictors of OME. For each additional child under 12 years of age in the home, there was a 2% increase in the proportion of time with OME. While attendance in group child care predicted a risk for OME, children's age and the number of other children in the household were still contributing risk factors for OME.

Cell biology of tubotympanum in relation to pathogenesis of otitis media — a review

The sterility of the eustachian tube and tympanic cavity of normal individuals is maintained not only by the adaptive immune system, but also by the mucociliary system and the antimicrobial molecules of innate immunity. Mucin production and periciliary fluid homeostasis are essential for normal mucociliary function and dysfunction of this system is an important risk factor for otitis media. The secreted antimicrobial molecules of the tubotympanum include lysozyme, lactoferrin, beta defensins, and the surfactant proteins A and D (SP-A, SP-D). Defects in the expression or regulation of these molecules may also be the major risk factor for otitis media.

Risk Factors for Otitis Media and Carriage of Multiple Strains of Haemophilus influenzae and Streptococcus pneumoniae

We studied genetic diversity in Streptococcus pneumoniae and Haemophilus influenzae in throat culture isolates from 38 children attending two day-care centers in Michigan. Culture specimens were collected weekly; 184 S. pneumoniae and 418 H. influenzae were isolated from the cultures. Pulsed-field gel electrophoresis identified 29 patterns among the S. pneumoniae isolates and 87 among the H. influenzae isolates. Of the cultures, 5% contained multiple genetic types of S. pneumoniae, and 43% contained multiple types of H. influenzae. Carriage of multiple H. influenzae isolates, which was associated with exposure to smoking, history of allergies, and age 36 to 47 months, may increase risk for otitis media in children.

Risk factors of otitis media with effusion during infancy

Associations of possible risk factors with prevalence of otitis media with effusion (OME) were prospectively studied in a cohort of 250 infants, aged 0–2 years. In order to determine OME, otoscopy and tympanometry were performed at 3-monthly intervals beginning at term date. Eighteen epidemiologically relevant features were inventoried by means of standardized questionnaires. Multivariate analysis controlled for possible confounding factors. Prevalence of OME was most strongly associated with age ( P-value<0.001). Other factors significantly associated with the prevalence of OME ( P-value<0.05) were gestational age, birth weight, breastfeeding, day-care attendance, number of siblings, season, and parent-reported ear infection, hearing loss, mouth breathing and common cold. No significance was found for gender, date of birth, passive smoking, family history of otitis media, parental socio-economic status and histories of snoring and consultation of a physician. In conclusion: both intrinsic and extrinsic factors appear to play an important role in the prevalence of OME. Some of the risk factors appeared to be time–dependent.

Changing perspectives on otitis media: Diagnosis, risk factors, management, and prevention

This review summarizes recent information on the diagnosis, epidemiology, management, and prevention of otitis media, focusing on practical implications for pediatric clinicians and researchers. New perspectives are offered on the following four clinically important aspects of otitis media: (1) use of tympanometry in diagnosis, (2) sociodemographic risk factors, (3) management, and (4) methods of prevention. The limited positive predictive value of tympanometry in infants and young children and the uncertain validity of research in which tympanometry alone is used for diagnosing middle-ear effusion are discussed. New evidence indicates that by far the most important sociodemographic risk factors for otitis media are low socioeconomic status and repeated exposure to large numbers of other children, whether at home or in a child care facility. The rising prevalence of multiplyresistant strains of Streptococcus pneumoniae , a phenomenon promoted by extensive antimicrobial usage, makes it advisable to curtail antimicrobial treatment to the extent possible without risking avoidable morbidity or avoidable tube placement. Concerning prevention, curtailing the use of antimicrobials for prophylaxis is recommended and alternative clinical approaches are reviewed.

Epidemiology and Treatment of Otitis Media with Effusion in Children in the First Year of Primary School

In this multicentre study we evaluated the prevalence and risk factors of otitis media with effusion (OME) in Italian school-children and the effectiveness of medical treatment of chronic OME with a new cephalosporin, ceftibuten. During two winter periods, 3413 children, aged 5 to 7 years, were examined for the presence of OME by means of pneumotoscopy and a portable, hand-held tympanometer. The prevalence of asymptomatic OME was 14.2%, with no difference as regards sex, age, month of examination or geographic area. Younger children had significantly more bilateral than unilateral effusion. A recent episode of acute otitis media and previous tonsillectomy or adenoidectomy were associated with an increased risk of OME in multivariate logistic regression models. The presence of OME was unrelated to such factors as birthweight, prematurity, sibling or parental history of allergy, duration of daycare attendance, family history of ear infections. After 12 weeks, 26.6% of children with OME still had middle-ear fluid: 52 were randomized to ceftibuten (9 mg/kg q.d. for 14 days) and 59 to no treatment (nasal saline drops allowed). Children treated with ceftibuten had a significantly better resolution of middle-ear effusion after 4 and 8 weeks. As mass screening programmes for OME in the year of school entry are questioned, a focus only on children with known risk factors seems advisable. Ceftibuten can be useful in reducing the duration of middle-ear effusion.

Knowledge and attitudes about otitis media risk: implications for prevention.

To investigate maternal knowledge and attitudes about otitis media (OM) risk, to estimate the prevalence of risk factors in the first year of life, and to identify barriers to the reduction of risk factors (eg, formula feeding, day care attendance, and exposure to passive smoke). Questionnaires mailed to a systematic sample of 504 Minnesota women >/=18 years old identified through 1994 birth certificates. Eighty percent returned a completed survey. According to maternal report, 29% of infants (age 8 to 13 months) had recurrent OM (>/=3 episodes) and 2% had tympanostomy tubes. Forty-six percent attended day care, 29% had >/=1 smoking parent, and 49% breastfed for </=2 months. Women were more knowledgeable about OM signs and symptoms than about risk factors. Mean OM knowledge score (the sum of correct true-false responses) was 7.0 (standard deviation = 1.6). Using multiple linear regression, knowledge score was significantly related to marital status, education, age, area of residence, breastfeeding (months), and number of cigarettes smoked per day by the mother, but not to infant or sibling OM history or day care attendance (R = .23). Infant history of OM (odds ratio, 1.9; 95% confidence interval, 1.1 to 3.2) and white race (odds ratio, 0.3; 95% confidence interval, 0. 1 to 0.8), but not the presence of risk factors, were significantly related to having received clinicians' advice about OM prevention advice. OM education and prevention programs should target pregnant women and new mothers with OM risk factors, and those who are young, single, and less educated.

Risk factors for otitis media with effusion in children 0 to 2 years of age

Purpose: To determine the possible risk factors associated with the occurrence of otitis media with effusion. Patients and Methods: Two hundred eighty-nine children born between July 1987 and October 1988 were studied up to the age of 24 months. The enrollment of the children took place during their regular check-up visits at three different health-care centers. Results: Having older siblings was the most important risk factor, for both the time elapsed until the first occurrence and for the probability of otitis media with effusion at each visit. Other significant risk factors for the probability at each visit were: having had acute otitis media before the visit or before the previous visit, age, a positive family history of otitis media, and upper respiratory tract infections (URTI). Conclusion: Having older siblings is the most important risk factor for otitis media with effusion in this ape group.

Otitis media in 2253 Pittsburgh-area infants: prevalence and risk factors during the first two years of life.

As part of a long-term study of possible effects of early-life otitis media on speech, language, cognitive, and psychosocial development, we set out to delineate the occurrence and course of otitis media during the first 2 years of life in a sociodemographically diverse population of infants, and to identify related risk factors. We enrolled healthy infants by age 2 months who presented for primary care at one of two urban hospitals or one of two small town/rural and four suburban private pediatric practices. We intensively monitored the infants' middle-ear status by pneumatic otoscopy, supplemented by tympanometry, throughout their first 2 years of life; we monitored the validity of the otoscopic observations on an ongoing basis; and we treated infants for otitis media according to specified guidelines. We followed 2253 infants until age 2 years. The proportions developing > or = 1 episode of middle-ear effusion (MEE) between age 61 days (the starting point for data analysis) and ages 6, 12, and 24 months, respectively, were 47.8%, 78.9%, and 91.1%. Overall, the mean cumulative proportion of days with MEE was 20.4% in the first year of life and 16.6% in the second year of life. Tympanostomy-tube placement was performed on 1.8% and 4.2% of the infants during the first and second years of life, respectively. By every measure, the occurrence of MEE was highest among urban infants and lowest among suburban infants; these differences were greatest in the earliest months of life. Overall, unadjusted mean cumulative proportions of days with MEE were higher among boys than girls, higher among black than white infants, and higher among Medicaid than private health insurance enrollees. Cumulative proportions of days with MEE varied directly with the number of smokers in the household and with the number of other children to whom infants were exposed, whether at home or in day care, and varied inversely with birth weight, maternal age, level of maternal education, a socioeconomic index, and duration of breastfeeding. After adjustment, using multivariate analysis, the only variables that each remained independently and significantly related to the cumulative proportion of days with MEE were: during the first year of life, study site grouping, sex, the socioeconomic index, breastfeeding for > or = 4 months, the number of smokers in the household, and an index rating the degree of exposure to other children at home or in day care; and during the second year of life, sex, the socioeconomic index, and the child exposure index. The duration of breastfeeding and the degree of exposure to tobacco smoke contributed little to the explained variance; most was attributable to differences in the socioeconomic index and the child exposure index. Contrary to findings in many previous reports, the prevalence of otitis media during the first 2 years of life among lower-socioeconomic-status black infants appears to be as high as, if not higher than among lower-socioeconomic-status white infants, and certainly higher than among middle-class white infants. Among middle-class white infants the prevalence may also be higher than commonly assumed. The most important sociodemographic risk factors for otitis media appear to be low socioeconomic status and repeated exposure to large numbers of other children, whether at home or in day care.

The relationship between otitis media and intrauterine growth: a co-twin control study

The association between intrauterine growth, as measured by weight and gestational age, and the occurrence of recurrent ear infections was studied using data from a population-based sample of 7992 Norwegian twins. Perinatal measures were collected from the Medical Birth Registry, and reports of recurrent ear infections were based on questionnaires completed when the twins were aged 18–25 years. First, the individual effects of birth weight and gestational age on the occurrence of otitis media (OM) were estimated. Birth weight among individuals who reported OM was significantly lower than for controls, with a mean weight difference of 86 g. The average difference in gestational age was 3 days shorter among individuals with a positive history of OM. Next, the effect of birth weight was estimated using the co-twin control method. Among MZ twins, within-pair differences in birth weight reflect environmental differences experienced in utero. Among DZ pairs, birth weight differences may be due to genetic and environmental differences. Among OM-discordant pairs, the co-twin without a history of OM is a matched control for comparisons of intra-pair differences in birth weight. When within-pair birth weight differences were compared, the co-twin without a history of OM was used as the matched control. Results indicated that lower birth weight may be a risk factor for OM. The average birth weight difference among OM-discordant pairs was 48 g, with the control twin weighing significantly more than the twin with a history of OM.

Public health impact of various risk factors for acute otitis media in northern Finland.

The aim of this study was to assess the excess risk attributable to alterable risk factors for acute otitis media in Finnish children, including day care attendance, parental smoking, and a short duration of breastfeeding. Data on a population-based cohort of 2,512 children were gathered from medical records and questionnaires from 1985 to 1988. Excess (attributable) fractions for the risk factors were calculated among 825 children (target population) followed for 2 years, from a dynamic logistic model fitted to the entire cohort (estimation data). In theory, one child out of every five affected in the exposed population would have escaped otitis media completely if he/she had been moved from nursery day care to home care, and two out of every five affected could have escaped recurrent episodes in this way. The corresponding figures for family day care were lower: one and two children out of every six affected, respectively. Cessation of parental smoking and breastfeeding would have smaller effects. The impacts were more modest in the whole population. Nevertheless, approximately 14% of all of the otitis media episodes would have been avoided if all of the children had been cared for at home. These figures are hypothetical, since it is unlikely that use of day care outside the home can be avoided altogether, but they offer further evidence of the notable role of day care attendance as a risk factor for otitis media.