Socio-economic status and hearing loss in chronic suppurative otitis media in Nigeria

Background: Hearing loss is reported in about 50% of cases of chronic suppurative otitis media (CSOM). Aim: To report the prevalence, type and severity of hearing loss in CSOM and identify risk factors. Methods: A prospective study of hearing loss in CSOM was undertaken in University College Hospital, Ibadan, two general hospitals and two primary health care centres, all in densely populated, semi-urban areas in south-west Nigeria. Controls were selected from school children, hospital workers' children and children whose parents were visiting the hospitals, all of whom claimed that there had been no episode of otitis media in the past. An oral questionnaire was administered to all, followed by audiometry and examination of the ear, nose and throat in study children. Results: There were 189 CSOM subjects and 100 controls aged between 4 and 150 months [mean (SD) 59.25 (44.55), 173 girls and 116 boys, M: F 1.5: 1]. The prevalence of hearing loss in CSOM was 89/189 (47%) and was conductive in 73/89 (82%) and sensorineural (SHL) in 16/89 (18%). Of the subjects with hearing loss, 72% had had otitis media during the 1st year of life. Of the 89, 61 (69%) were of low social class, 13/37 (35%) were middle class and 15/63 (24%) upper class. The duration of CSOM ranged from 4 weeks to 12 years [mean (SD) 4 yrs (2.04)] and from 5 to 12 years in those with SHL [mean (SD) 9 yrs (6.21)]. There was significant correlation between socio-economic status and hearing loss (r=0.138, p=0.02) while no correlation was found with upper respiratory infection (r=0.054, p=0.36), age of onset (r=0.037, p=0.62) or frequency of attacks (r=-0.068, p=0.35). Conclusion: About one fifth of patients with CSOM have SHL. Early diagnosis and management of CSOM is imperative to improve outcome. CSOM is strongly associated with low socio-economic status.