OTITIS-MEDIA IN 2253 PITTSBURGH-AREA INFANTS - PREVALENCE AND RISK-FACTORS DURING THE FIRST 2 YEARS OF LIFE

Objective. As part of a long-term study of possible effects of early-l ife otitis media on speech, language, cognitive, and psychosocial deve lopment, we set out to delineate the occurrence and course of otitis m edia during the first 2 years of life in a sociodemographically divers e population of infants, and to identify related risk factors. Methods . We enrolled healthy infants by age 2 months who presented for primar y care at one of two urban hospitals or one of two small town/rural an d 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 tr eated infants for otitis media according to specified guidelines. Resu lts. We followed 2253 infants until age 2 years. The proportions devel oping greater than or equal to 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%. Overal l, the mean cumulative proportion of days with MEE was 20.4% in the fi rst year of life and 16.6% in the second year of life. Tympanostomy-tu be 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 oc currence of MEE was highest among urban infants and lowest among subur ban infants; these differences were greatest in the earliest months of life. Overall, unadjusted mean cumulative proportions of days with ME E were higher among boys than girls, higher among black than white inf ants, and higher among Medicaid than private health insurance enrollee s. Cumulative proportions of days with MEE varied directly with the nu mber 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 var ied inversely with birth weight, maternal age, level of maternal educa tion, a socioeconomic index, and duration of breastfeeding. After adju stment, using multivariate analysis, the only variables that each rema ined independently and significantly related to the cumulative proport ion of days with MEE were: during the first year of life, study site g rouping, sex, the socioeconomic index, breastfeeding for greater than or equal to 4 months, the number of smokers in the household, and an i ndex rating the degree of exposure to other children at home or in day care; and during the second year of Life, sex, the socioeconomic inde x, and the child exposure index. The duration of breastfeeding and the degree of exposure to tobacco smoke contributed little to the explain ed variance; most was attributable to differences in the socioeconomic index and the child exposure index. Conclusions. Contrary to findings in many previous reports, the prevalence of otitis media during the f irst 2 years of life among lower-socioeconomic-status black infants ap pears to be as high as, if not higher than among lower-socioeconomic-s tatus white infants, and certainly higher than among middle-class whil e infants. Among middle-class white infants the prevalence may also be higher than commonly assumed. The most important sociodemographic ris k factors for otitis media appear to be low socioeconomic status and r epeated exposure to large numbers of other children, whether at home o r in day care.