Ear infections in children are a major health problem and may be associated with hearing impairment [
Research has shown that Aboriginal ethnicity [
Other risk factors for ear infections include younger maternal age [
To our knowledge, there is no Canadian data available to compare prevalence rates associated with risk factors of ear infection in Aboriginal children or rural and urban Canadian school-aged children. However, we are currently conducting two cohort studies, one with rural children and the second with First Nations children living in two reserve communities in Saskatchewan. The objective of this paper was to determine the prevalence and associated risk factors for ear infection in children 6–17 years old living in rural areas of the province or residing on-reserve.
The term “Aboriginal peoples” refers to descendants of the original inhabitants of North America. The Canadian constitution recognizes three groups of Aboriginal people: Indians (commonly referred to as First Nations who are registered Indians under the Indian Act of Canada), Métis, and Inuit. These are three separate peoples with unique heritages, languages, cultural practices, and spiritual beliefs [
The rural population was defined as consisting of those persons living in towns and municipalities outside the commuting zone of larger urban centres with population of 10,000 or more [
Data obtained from the child components of baseline surveys from the Saskatchewan Rural Health Study (SRHS) [
The overall description of the SRHS and details of the study designs for the adult and child components were described elsewhere [
The study participants received a study package from the home room teacher to be taken home to their parents for completion. The package contained (i) the information letter; (ii) the baseline questionnaire to be completed by a parent or guardian; (iii) a consent form (parent or guardian); (iv) an assent form and information letter (child); and (v) a return envelope. Parents were asked to send the completed questionnaire, signed parental consent, and assent forms sealed in the return envelope to the home room teacher within two weeks. The completed or not returned sealed study packages were retrieved from the schools by the research team at the end of four weeks. A reminder letter was sent home two weeks after the initial contact. A total of 5667 study packages were distributed to students in Grades 1 to 12 in the study area schools and 2757 (49%) were returned, with 42% of the forms being completed (
Overall description of the FNLHP and details of the study design for the adult component were described elsewhere [
A parents/caregivers’ information session (supper night) was held at each school site prior to beginning the survey. An elder from each community was invited to attend the supper night who provided traditional knowledge and advice related to facilitating this project. During the gathering of information about the survey, consent and assent processes were discussed. Information about the survey, parent/caregiver and child involvement was provided through the school newsletters.
Prospective participants received a personally addressed study package from the classroom teacher to be taken home to their parents/caregivers. The package contained (i) cover letter and questionnaire to be completed by a parent or caregiver; (ii) parent-child information letter and consent/assent forms; and (iii) a return envelope. Parents or caregivers were asked to return the completed or uncompleted questionnaire, signed parental consent, and assent forms in a sealed envelope to the classroom teacher at the school within two weeks. For each survey returned, parents or caregivers received a $5 gift card. The completed, sealed study packages were retrieved from the schools by the research nurses after the two-week return date. A total of 603 study packages were distributed to students in Kindergarten (6 years old) to Grade 12 in the study area and 363 (60.2%) study packages were returned, with 58.2% of completed surveys (
Approval for the study protocols was obtained from the Biomedical Research Ethics Board at the University of Saskatchewan (# Bio: 10-177 for the SRHS and # Bio: 13-27 for the FNLHP) and permission to conduct the surveys was obtained from the directors of each school division in June, 2010, and from the school principals in December, 2010, for the SRHS, and in January, 2012, for the FNLHP.
In both studies, child study questionnaire included items describing sociodemographics, health status of the child, childhood diseases and infections, other illnesses, the lifestyle and home environment, health risk behaviours, access to health care factors, and family history of respiratory health.
Information was collected on the following variables.
There were 2082 Caucasian children who participated in SRHS aged 6–17 years. There were 351 First Nations children who participated in the FNLHP aged 6–17 years. For this paper, a new variable, ethnicity, First Nations or Caucasian, was created. Hence, the study population contains data from 2433 children that was used for analysis. Mean age and standard deviation of the study population were
Table
Comparison of proportions among Caucasian and First Nations children.
Variables | Caucasians |
First Nations |
|
---|---|---|---|
Ear infection | 1204 (57.8) | 153 (43.6) |
|
Tonsillitis | 624 (30.0) | 67 (19.1) |
|
Had operation to remove the tonsils | 194 (9.3) | 13 (3.7) |
|
Doctor diagnosed asthma | 314 (15.1) | 61 (17.4) | 0.270 |
Sex | |||
Male | 1025 (49.2) | 165 (47.0) | 0.441 |
Female | 1057 (50.8) | 186 (53.0) | |
Obese | |||
Yes | 123 (5.9) | 45 (12.8) |
|
No | 1959 (94.1) | 306 (87.2) | |
Mother’s highest education | |||
<Grade 12 | 97 (4.7) | 87 (24.8) |
|
≥Grade 12 | 1985 (95.3) | 264 (75.2) | |
Child breastfed longer than three months | 835 (40.1) | 202 (57.5) |
|
Mother smoked during pregnancy | 414 (19.9) | 181 (51.6) |
|
First born | 809 (38.9) | 93 (26.5) |
|
Exposure to passive smoking | 260 (12.5) | 154 (43.9) |
|
Any respiratory allergy | 608 (29.2) | 71 (20.2) |
|
Difficulty of accessing regular or on-going health care in past 12 months | 152 (7.3) | 17 (4.8) | 0.094 |
The univariate relationships between the environmental factors and personal factors or covariates and ear infection using unadjusted logistic regression are shown in Table
Bivariable logistic regression analysis of the association of physician diagnosed ear infection on personal and environmental factors (
Ever diagnosed with ear infection | Unadjusted |
||
---|---|---|---|
Yes/total | (%) | (95% CI) | |
Environmental factors | |||
Exposure to passive smoking | |||
Yes | 226/414 | 54.6 | 0.94 (0.76, 1.17) |
No | 1131/2019 | 56.0 | 1.00 |
During past 12 months, water or dampness | |||
Yes | 576/1015 | 56.7 | 1.07 (0.91, 1.26) |
No | 781/1418 | 55.1 | 1.00 |
House damage caused by dampness | |||
Yes | 403/720 | 56.0 | 1.01 (0.85, 1.20) |
No | 954/1713 | 55.7 | 1.00 |
Signs of mold or mildew in home | |||
Yes | 300/542 | 55.4 | 0.98 (0.81, 1.18) |
No | 1057/1891 | 55.9 | 1.00 |
Number of people in home | |||
≤4 people | 718/1286 | 55.8 | 1.00 (0.86, 1.18) |
>4 people | 639/1147 | 55.7 | 1.00 |
|
|||
Personal factors | |||
Age, in years | |||
6–11 | 766/1319 | 58.1 |
|
12–17 | 591/1114 | 53.1 | 1.00 |
Sex | |||
Male | 669/1190 | 56.2 | 1.04 (0.88, 1.22) |
Female | 688/1243 | 55.3 | 1.00 |
Obese | |||
Yes | 103/168 | 61.3 | 1.28 (0.93, 1.76) |
No | 1254/2265 | 55.4 | 1.00 |
Ethnicity | |||
First Nations/Métis | 153/351 | 43.6 |
|
Caucasian | 1204/2082 | 57.8 | 1.00 |
Mother’s education | |||
<High school | 90/184 | 48.9 |
|
≥High school | 1267/2249 | 56.3 | 1.00 |
Mother smoked during pregnancy | |||
Yes | 330/595 | 55.5 | 0.98 (0.82, 1.18) |
No | 1027/1838 | 55.9 | 1.00 |
Breastfed longer than three months | |||
Yes | 551/1037 | 53.1 |
|
No | 806/1396 | 57.7 | 1.00 |
First born | |||
Yes | 540/902 | 59.9 |
|
No | 817/1531 | 53.4 | 1.00 |
Tonsillitis | |||
Yes | 550/691 | 79.6 |
|
No | 807/1742 | 46.3 | 1.00 |
Asthma | |||
Yes | 242/375 | 64.5 |
|
No | 1115/2058 | 54.2 | 1.00 |
Any respiratory related allergy | |||
Yes | 429/679 | 63.2 |
|
No | 928/1754 | 52.9 | 1.00 |
Birth weight# | |||
Underweight (<2500 g) | 89/143 | 62.2 | 1.25 (0.88, 1.78) |
Overweight (>4000 g) | 203/353 | 57.5 | 1.03 (0.82, 1.29) |
Normal (≥2500 g to 4000 g) | 1031/1814 | 56.8 | 1.00 |
Results of multivariate logistic regression analysis adjusted for covariates are presented in Table
Adjusted odds ratios (95% confidence intervals) based on multivariate logistic regression for associations with physician diagnosed ear infection.
Variable |
|
---|---|
Age, in years | |
6–11 |
|
12–17 | 1.00 |
Sex | |
Male | 1.00 (0.84, 1.19) |
Female | 1.00 |
Obese | |
Yes | 1.29 (0.92, 1.81) |
No | 1.00 |
Mother smoked during pregnancy | |
Yes | 1.12 (0.91, 1.38) |
No | 1.00 |
Tonsillitis | |
Yes |
|
No | 1.00 |
Any respiratory related allergy | |
Yes |
|
No | 1.00 |
Asthma | |
Yes |
|
No | 1.00 |
Ethnicity | |
First Nations/Métis |
|
Caucasian | 1.00 |
First born in the family | |
Yes |
|
No | 1.00 |
Breastfed longer than three months | |
Yes |
|
No | 1.00 |
Otitis media (OM) or middle ear infection is a common disease among children under the age of 6 years. According to Kong and Coates [
Our results showed a greater prevalence of ear infection among Caucasian children compared with First Nations children (43.6% for First Nations/Métis children and 57.8% for Caucasian children). The association between ethnicity and ear infection has been reported previously [
Many studies showed that breastfeeding has a protective effect on the development of otitis media [
Studies have shown that ear infection develops significantly more often in boys than in girls [
An early meta-analysis of risk factors for acute otitis media reported that having at least one sibling significantly increased the risk of having an ear infection [
Recently, the relationship between otitis media and obesity has been discussed [
It is a well-known factor that exposure to cigarette smoke is a risk factor for the development of ear infection among children [
In addition to the risk factors mentioned above, several comorbid conditions were associated with ear infection. There is limited research on the effect of allergy in the pathogenesis of otitis media in younger children [
Two studies looked at the association between ear infection and asthma [
This study has several strengths and several limitations. Very few Canadian studies have examined the risk factors of ear infections among Caucasian and First Nations children together. This combined study surveyed a large number of children allowing robust results. This study included children from rural Saskatchewan and First Nations from two reserves in Saskatchewan. On the other hand, the two studies had moderate response rates (SRHS: 42.0%; FNLHP: 58.2%). First Nations children for this paper were coming from two sources and they were from two reserves in Saskatchewan (Community A:
In general, due to the cross-sectional nature of the study, one of the major limitations was the parent-reported survey recall-bias of disease history. No detailed information on income status and daycare attendance was available. Although we have obtained information of whether or not this child was breastfed and duration of breastfeeding, we have not collected the information on feeding practices (e.g., exclusive breastfeeding, formula, or both).
These results suggested that significant determinants of ear infection were younger age; self-reported physician-diagnosed tonsillitis and asthma; any respiratory allergy; first born; and ethnicity. Breastfeeding longer than three months was protective. While ear infection was a prevalent condition of childhood, children of First Nations heritage living in rural communities were less likely to have a history of ear infections when compared to their rural Caucasian counterparts.
The authors declare that they have no conflict of interests.
Chandima P. Karunanayake authored most of the paper, carried out the statistical analysis, reviewed the literature, reviewed the citations, and created the abstract and paper. James A. Dosman, Punam Pahwa, Sylvia Abonyi, and Jo-Ann Episkenew are the Coprincipal Investigators of the First Nations Lung Health Project (FNLHP). Chandima P. Karunanayake, Donna C. Rennie, Joshua A. Lawson, Sylvia Abonyi, Jo-Ann Episkenew, James A. Dosman, and Punam Pahwa contributed to grant writing, development of study design, questionnaire development, and study coordination. Vivian Ramsden provided input into the writing of the paper and edited the paper. Laura McCallum and Kathleen McMullin managed the study data collection. Laura McCallum, P. Jenny Gardipy, Jeremy Seeseequasis, and Arnold Naytowhow served as “content experts” for the research project engaged in document review/editing and support during the data collection phase of the survey. All other coauthors significantly contributed to paper preparation. The Saskatchewan Rural Health Study Team and the First Nations Lung Health Project members contributed during the grant writing and questionnaires development and with conducting the survey. All authors read and approved the final paper.
The First Nations Lung Health Project was funded by a grant from the Canadian Institutes of Health Research “Assess, Redress, Re-assess: Addressing Disparities in Respiratory Health among First Nations People,” CIHR MOP-246983-ABH-CCAA-11829. The Saskatchewan Rural Health Study was funded by a grant from the Canadian Institutes of Health Research “Saskatchewan Rural Health Study,” Fund no. MOP-187209-POP-CCAA-11829. The First Nations Lung Health Project Team consists of James A. Dosman, M.D., Designated Principal Investigator, University of Saskatchewan, Saskatoon, SK, Canada; Dr. Punam Pahwa, Ph.D., Coprincipal Investigator, University of Saskatchewan, Saskatoon, SK, Canada; Jo-Ann Episkenew, Ph.D., Coprincipal Investigator, Indigenous People’s Health Research Centre, University of Regina, SK, Canada; Sylvia Abonyi, Ph.D., Coprincipal Investigator, University of Saskatchewan, Saskatoon, SK, Canada. Coinvestigators were Mark Fenton, M.D., John Gordon, Ph.D., Bonnie Janzen, Ph.D., Chandima P. Karunanayake, Ph.D., Malcolm King, Ph.D., Shelly Kirychuk, Ph.D., Niels Koehncke, M.D., Joshua A. Lawson, Ph.D., Greg Marchildon, Ph.D., Lesley McBain, Ph.D., Donna C. Rennie, Ph.D., Vivian Ramsden, RN, Ph.D., and Ambikaipakan Senthilselvan, Ph.D. Collaborators were Amy Zarzeczny, B.A., LL.M.; Louise Hagel, M.S., Breann Davis, M.D., John Dosman, M.D., Roland Dyck, M.D., Thomas Smith-Windsor, M.D., and William Albritton, M.D., Ph.D. External Advisor was Janet Smylie, M.D., M.P.H.; Project Manager: Kathleen McMullin, MEd. Community Partners were Jeremy Seeseequasis, B.A.; P. Jenny Gardipy, M.P.H.; Arnold Naytowhow; Laura McCallum, RN. The Saskatchewan Rural Health Study Team consists of James A. Dosman, M.D., Designated Principal Investigator, University of Saskatchewan, Saskatoon, SK, Canada; Dr. Punam Pahwa, Ph.D., Coprincipal Investigator, University of Saskatchewan, Saskatoon, SK, Canada; Dr. John Gordon, Ph.D., Coprincipal Investigator, University of Saskatchewan, Saskatoon, SK, Canada; Yue Chen, Ph.D., University of Ottawa, Ottawa, Canada; Roland Dyck, M.D., University of Saskatchewan, Saskatoon, SK, Canada; Louise Hagel, Project Manager, University of Saskatchewan, Saskatoon, SK, Canada; Bonnie Janzen, Ph.D., University of Saskatchewan, Saskatoon, SK, Canada; Chandima P. Karunanayake, Ph.D., University of Saskatchewan, Saskatoon, SK, Canada; Shelley Kirychuk, Ph.D., University of Saskatchewan, Saskatoon, SK, Canada; Niels Koehncke, M.D., University of Saskatchewan, Saskatoon, SK, Canada; Joshua A. Lawson, Ph.D., University of Saskatchewan, Saskatoon, SK, Canada; William Pickett, Ph.D., Queen’s University, Kingston, ON, Canada; Roger Pitbaldo, Ph.D., Professor Emeritus, Laurentian University, Sudbury, ON, Canada; Donna C. Rennie, RN, Ph.D., University of Saskatchewan, Saskatoon, SK, Canada; Ambikaipakan Senthilselvan, Ph.D., University of Alberta, Edmonton, AB, Canada. The authors are grateful for the contributions from elders, community leaders, school boards, school principals, and teachers that facilitated the engagement necessary for the study and all parents and children who donated their time to participate.