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Epidemiology of Acute Otitis Media in Children in An Urban Population
Auris·Nasus·Larynx (Tokyo) 12 (Supp!. I) S 105-S 107, 1985
EPIDEMIOLOGY OF ACUTE OTITIS MEDIA IN CHILDREN IN AN URBAN POPULATION Leif INGVARSSON, M.D., Kaj LUNDGREN, M.D., and Bertil OLOFSSON, Ph.D. Department of Otolaryngology, University of Lund, Malmo General Hospital, Malmo, Sweden
The epidemiology of acute otItIs media (AOM) in children is still to a great deal inadequately explored (HINCHCLIFFE, 1972; McELDOWNEY and KESSNER, 1972; MANNING et al., 1974). Most earlier studies have been carried out in small selected groups of children. A few great incidence studies over I year have been published earlier (Medical Research Council, 1957; PUKANDER, 1982). There are very few cohort studies penetrating the relationship between AOM and demographic, medical and socio-economic factors (PUKANDER, 1982; PATERSON and MACLEAN, 1970; TEELE et al., 1980). Prospective investigations in a sufficiently large cohort of unselected children from a weel-defined population have been recommended (KUDRJAVCEV and SCHOENBERG, 1979). Malmo, Sweden, is a well-defined geographic unit with unique conditions for epidemiologic studies. The aim of the present investigation was to study the incidence rate of AOM in children in a prospective cohort study with a special reference to children with recurrent episodes of AOM early in life. Materials and Methods Since 1977 all cases of AOM diagnosed by a doctor in children born in 1977 or later and living in Malmo, Sweden, have been registered (lNGVARSSON et al., 1982). Malmo is the leading industrial and commercial center in southern Sweden with 235,000 inhabitants and with 2,200-2,700 children in each age class. All doctors working in acute pediatric medical practice are participating. Episodes of AOM are defined as the presence of reddened and bulging eardrums with or without spontane-
ous perforation. Information on the patient's name, ten-digit birth number, and date and place of diagnosis is forwarded from the ENT and Pediatrics departments at the General Hospital and from all individual physicians in the city (general practitioners, otologists, pediatricians, and physicians on duty). This information is completed from official computerized data files containing information about the patients' dwelling in the city, type of housing and type of day-care at the time of diagnosis. All information is computerized and processed in a specially designed statistical program (PERSSON, 1981). Preliminary results from the cohort studies have been published earlier (INGVARSSON et al., 1982, 1984; LUNDGREN et al., 1984). The following presentation includes the results from the first 7 years of registration, 1977 to 1983-the present study end-point, including all children born in 1977 or later. The study is planned to go on for 10 years. In the cohort study a special interest is focused on children with recurrent episodes of AOM early in life. Preliminary results from a study of these children will also be given. Results In Malmo totally 16,611 children, 8,683 boys and 7,928 girls, were born 1977-1983. The highest incidence rate, about 45 episodes of AOM per 100 children at risk, was registered in the one-year-old boys. Corresponding figures for the girls were 37 episodes per 100 at risk. At the age of 6 years the annual incidence for boys and girls was 8 episodes per 100 at risk.
L. INGVARSSON et al.
S 106
Table 1. Age at the first episode of AOM in relation to the total number of episodes per child. Age (years) at the first episode of AOM No. of episodes per child
Total
::;;2
<1 No.
%
No.
%
No.
%
1 2-3 4--5 6-16
295 430 200 130
28 41 19 12
407 411 128 35
41 42 13 4
650 257 30 5
69 27.5 3 0.5
Total
1,055
100
981
100
942
100
No.
%
1,352 1,098 358 170
45 37 12 6
2,978
100
p
The cumulative incidence rate (CIR) of the first episode of AOM in relation to sex during the first 7 years of life in all the children born 1977-1983 in Malmo was studied. At the age of about 3 years 50% of all the boys had got at least 1 episode of AOM. At the age of 3 years and 7 months 50% of the girls had got their first episode of AOM. At the age of 7 about 65-70% of all the children had got at least 1 episode of AOM. The greatest risk to get the first episode was seen between 6-11 months of life. Table 1 illustrates the total number of episodes of AOM per child and the relation between the age at the first episode and the total number of episodes per child during their first 4 years oflife in children born 19771979. One thousand three hundred fifty-two children (45%) did only get 1 episode and 170 (6%) were registered for 6 to 16 episodes. In the children who had experienced their first episode before the age of 1 year 130 (12%) were registered for 6 or more episodes. Corresponding figures for the children aged 1 and for those aged 2 years or more at the first episode, respectively were 35 (4%) and 5 (0.5%). The difference between the groups is statistically significant (p < 0.00 1). All children born 1977-1981 in Malmo, diagnosed for 6 or more episodes of AOM during their first 2 years of life ("otitis-prone children"), were studied separately. The otitis-prone group of children consists of 252 children, 154 boys (61%) and 98 girls (39%). A control group of children (252), with the
same age- and sex-distribution as the otitisprone group, was chosen by chance among the children in the city. The hospital records from the ENT and Pediatrics departments for all these 504 children have been investigated concerning ambulatory visits, hospital admittances, different ENT-operations and other diagnosed diseases. A few preliminary results will be given here. The group of otitis-prone children was registered for a mean number of ambulatory visits at the ENT and Pediatrics departments of 39 per child compared to 9 visits per child for the children in the control group. Eighty children (32%) in the otitis-prone group and 31 children (12%) in the control group had been admitted at least once in the ENTdepartment. The figures concerning hospital admittances in the Pediatric department were 154 (61%) and 92 (37%) for the 2 groups, respectively. The difference between the 2 groups is statistically significant (p < 0.001). A registration of different diseases diagnosed at the ENT and Pediatrics departments revealed that in the otitis-prone group 133 children (53%) had been diagnosed for broncho/pulmonary diseases at least once. Corresponding figures in the control group were 80 children (32%). Gastrointestinal diseases had been diagnosed in the otitisprone group and in the control group in 111 (44%) and 82 children (33%), respectively. Concerning allergic symptoms or diseases the figures for the 2 groups were 91 (36%) and 43 (17%) children, respectively. The difference
Lecture
concerning diagnosed diseases between the 2 groups is statistically significant (p
References HINCHCLIFFE, R.: Epidemiological aspects of otitis media. In Otitis Media: Proceedings of the National Conference (Glorig, A., and Gerwin, K., eds.), pp. 36-43, Charles C. Thomas, Springfield, 1972. INGVARSSON, L., LUNDGREN, K., and OLOFSSON, B.: Epidemiology of acute otitis media in childrenA cohort study in an urban population. In Recent Advances in Otitis Media with Effusion (Lim, D. J., Bluestone, C. D., Klein, J. 0., and Nelson, J.D., eds.), pp. 19-22, B. C. Decker Inc., Philadelphia, Toronto, 1984. INGVARSSON, L., LUNDGREN, K., OLOFSSON, B., and
Bacteriology
S 107
WALL, S.: Epidemiology of acute otitis media in children. Acta Otolaryngol. (Stockh.) supp!. 388: 1982. KUDRJAVCEV, T., and SCHOENBERG, B. S.: Otitis media and developmental disability. Epidemiologic considerations. Ann. Otol. Rhinal. Laryngal. supp!. 60: 88-98, 1979. LUNDGREN, K., INGVARSSON, L., and OLOFSSON, B.: Epidemiologic aspects in children with recurrent acute otitis media. In Recent Advances in Otitis Media with Effusion (Lim, D. J., Bluestone, C. D., Klein, J. 0., and Nelson, J. D., eds.), pp.2225, B. C. Decker Inc., Philadelphia, Toronto, 1984. MANNING, P., AVERY, M. E., and Ross, A.: Purulent otitis media: Differences between populations in different environments. Pediatrics 53: 135136, 1974. McELDOWNEY, D., and KESSNER, D. M.: Review of the literature. Epidemiology of otitis media. In Otitis Media: Proceedings of the National Conference (Glorig, A., and Gerwin, K., eds.), pp. 11-25, Charles C. Thomas, Springfield, 1972. Medical Research Council: Acute otitis in general practice. Lancet 2: 510-514, 1957. PATERSON, J. E., and MACLEAN, D. W.: Acute otitis media in children. A medical social study from general practice. Scott. Med. J. 15: 289-296, 1970. PERSSON, T.: New Mathematical Statistics Package, Department of Mathematical Statistics, Institute of Technology, University of Lund, Lund, Sweden, 1981. PUKANDER, J.: Occurrence of Acute Otitis Media, Department of Clinical Sciences, University of Tampere, Finland, Acta Universitatis Tamperensis, Series A, Vo!. 135, 1982. TEELE, D. W., KLEIN, J. 0., and ROSNER, B. A.: Epidemiology of otitis media in children. Ann. Otol. Rhinal. Laryngol. supp!. 68: 5-6, 1980.
EPIDEMIOLOGY OF ACUTE OTITIS MEDIA IN CHILDREN IN AN URBAN POPULATION Leif INGVARSSON, M.D., Kaj LUNDGREN, M.D., and Bertil OLOFSSON, Ph.D. Department of Otolaryngology, University of Lund, Malmo General Hospital, Malmo, Sweden
The epidemiology of acute otItIs media (AOM) in children is still to a great deal inadequately explored (HINCHCLIFFE, 1972; McELDOWNEY and KESSNER, 1972; MANNING et al., 1974). Most earlier studies have been carried out in small selected groups of children. A few great incidence studies over I year have been published earlier (Medical Research Council, 1957; PUKANDER, 1982). There are very few cohort studies penetrating the relationship between AOM and demographic, medical and socio-economic factors (PUKANDER, 1982; PATERSON and MACLEAN, 1970; TEELE et al., 1980). Prospective investigations in a sufficiently large cohort of unselected children from a weel-defined population have been recommended (KUDRJAVCEV and SCHOENBERG, 1979). Malmo, Sweden, is a well-defined geographic unit with unique conditions for epidemiologic studies. The aim of the present investigation was to study the incidence rate of AOM in children in a prospective cohort study with a special reference to children with recurrent episodes of AOM early in life. Materials and Methods Since 1977 all cases of AOM diagnosed by a doctor in children born in 1977 or later and living in Malmo, Sweden, have been registered (lNGVARSSON et al., 1982). Malmo is the leading industrial and commercial center in southern Sweden with 235,000 inhabitants and with 2,200-2,700 children in each age class. All doctors working in acute pediatric medical practice are participating. Episodes of AOM are defined as the presence of reddened and bulging eardrums with or without spontane-
ous perforation. Information on the patient's name, ten-digit birth number, and date and place of diagnosis is forwarded from the ENT and Pediatrics departments at the General Hospital and from all individual physicians in the city (general practitioners, otologists, pediatricians, and physicians on duty). This information is completed from official computerized data files containing information about the patients' dwelling in the city, type of housing and type of day-care at the time of diagnosis. All information is computerized and processed in a specially designed statistical program (PERSSON, 1981). Preliminary results from the cohort studies have been published earlier (INGVARSSON et al., 1982, 1984; LUNDGREN et al., 1984). The following presentation includes the results from the first 7 years of registration, 1977 to 1983-the present study end-point, including all children born in 1977 or later. The study is planned to go on for 10 years. In the cohort study a special interest is focused on children with recurrent episodes of AOM early in life. Preliminary results from a study of these children will also be given. Results In Malmo totally 16,611 children, 8,683 boys and 7,928 girls, were born 1977-1983. The highest incidence rate, about 45 episodes of AOM per 100 children at risk, was registered in the one-year-old boys. Corresponding figures for the girls were 37 episodes per 100 at risk. At the age of 6 years the annual incidence for boys and girls was 8 episodes per 100 at risk.
L. INGVARSSON et al.
S 106
Table 1. Age at the first episode of AOM in relation to the total number of episodes per child. Age (years) at the first episode of AOM No. of episodes per child
Total
::;;2
<1 No.
%
No.
%
No.
%
1 2-3 4--5 6-16
295 430 200 130
28 41 19 12
407 411 128 35
41 42 13 4
650 257 30 5
69 27.5 3 0.5
Total
1,055
100
981
100
942
100
No.
%
1,352 1,098 358 170
45 37 12 6
2,978
100
p
The cumulative incidence rate (CIR) of the first episode of AOM in relation to sex during the first 7 years of life in all the children born 1977-1983 in Malmo was studied. At the age of about 3 years 50% of all the boys had got at least 1 episode of AOM. At the age of 3 years and 7 months 50% of the girls had got their first episode of AOM. At the age of 7 about 65-70% of all the children had got at least 1 episode of AOM. The greatest risk to get the first episode was seen between 6-11 months of life. Table 1 illustrates the total number of episodes of AOM per child and the relation between the age at the first episode and the total number of episodes per child during their first 4 years oflife in children born 19771979. One thousand three hundred fifty-two children (45%) did only get 1 episode and 170 (6%) were registered for 6 to 16 episodes. In the children who had experienced their first episode before the age of 1 year 130 (12%) were registered for 6 or more episodes. Corresponding figures for the children aged 1 and for those aged 2 years or more at the first episode, respectively were 35 (4%) and 5 (0.5%). The difference between the groups is statistically significant (p < 0.00 1). All children born 1977-1981 in Malmo, diagnosed for 6 or more episodes of AOM during their first 2 years of life ("otitis-prone children"), were studied separately. The otitis-prone group of children consists of 252 children, 154 boys (61%) and 98 girls (39%). A control group of children (252), with the
same age- and sex-distribution as the otitisprone group, was chosen by chance among the children in the city. The hospital records from the ENT and Pediatrics departments for all these 504 children have been investigated concerning ambulatory visits, hospital admittances, different ENT-operations and other diagnosed diseases. A few preliminary results will be given here. The group of otitis-prone children was registered for a mean number of ambulatory visits at the ENT and Pediatrics departments of 39 per child compared to 9 visits per child for the children in the control group. Eighty children (32%) in the otitis-prone group and 31 children (12%) in the control group had been admitted at least once in the ENTdepartment. The figures concerning hospital admittances in the Pediatric department were 154 (61%) and 92 (37%) for the 2 groups, respectively. The difference between the 2 groups is statistically significant (p < 0.001). A registration of different diseases diagnosed at the ENT and Pediatrics departments revealed that in the otitis-prone group 133 children (53%) had been diagnosed for broncho/pulmonary diseases at least once. Corresponding figures in the control group were 80 children (32%). Gastrointestinal diseases had been diagnosed in the otitisprone group and in the control group in 111 (44%) and 82 children (33%), respectively. Concerning allergic symptoms or diseases the figures for the 2 groups were 91 (36%) and 43 (17%) children, respectively. The difference
Lecture
concerning diagnosed diseases between the 2 groups is statistically significant (p
References HINCHCLIFFE, R.: Epidemiological aspects of otitis media. In Otitis Media: Proceedings of the National Conference (Glorig, A., and Gerwin, K., eds.), pp. 36-43, Charles C. Thomas, Springfield, 1972. INGVARSSON, L., LUNDGREN, K., and OLOFSSON, B.: Epidemiology of acute otitis media in childrenA cohort study in an urban population. In Recent Advances in Otitis Media with Effusion (Lim, D. J., Bluestone, C. D., Klein, J. 0., and Nelson, J.D., eds.), pp. 19-22, B. C. Decker Inc., Philadelphia, Toronto, 1984. INGVARSSON, L., LUNDGREN, K., OLOFSSON, B., and
Bacteriology
S 107
WALL, S.: Epidemiology of acute otitis media in children. Acta Otolaryngol. (Stockh.) supp!. 388: 1982. KUDRJAVCEV, T., and SCHOENBERG, B. S.: Otitis media and developmental disability. Epidemiologic considerations. Ann. Otol. Rhinal. Laryngal. supp!. 60: 88-98, 1979. LUNDGREN, K., INGVARSSON, L., and OLOFSSON, B.: Epidemiologic aspects in children with recurrent acute otitis media. In Recent Advances in Otitis Media with Effusion (Lim, D. J., Bluestone, C. D., Klein, J. 0., and Nelson, J. D., eds.), pp.2225, B. C. Decker Inc., Philadelphia, Toronto, 1984. MANNING, P., AVERY, M. E., and Ross, A.: Purulent otitis media: Differences between populations in different environments. Pediatrics 53: 135136, 1974. McELDOWNEY, D., and KESSNER, D. M.: Review of the literature. Epidemiology of otitis media. In Otitis Media: Proceedings of the National Conference (Glorig, A., and Gerwin, K., eds.), pp. 11-25, Charles C. Thomas, Springfield, 1972. Medical Research Council: Acute otitis in general practice. Lancet 2: 510-514, 1957. PATERSON, J. E., and MACLEAN, D. W.: Acute otitis media in children. A medical social study from general practice. Scott. Med. J. 15: 289-296, 1970. PERSSON, T.: New Mathematical Statistics Package, Department of Mathematical Statistics, Institute of Technology, University of Lund, Lund, Sweden, 1981. PUKANDER, J.: Occurrence of Acute Otitis Media, Department of Clinical Sciences, University of Tampere, Finland, Acta Universitatis Tamperensis, Series A, Vo!. 135, 1982. TEELE, D. W., KLEIN, J. 0., and ROSNER, B. A.: Epidemiology of otitis media in children. Ann. Otol. Rhinal. Laryngol. supp!. 68: 5-6, 1980.