Risk Factors of Hearing Impairment among

Background: Hearing impairment among lower primary school children is common especially in the Sub Saharan Africa. Some host related and environmental factors can influence its development. The factors may vary depending on the environment of the child and circumstances that surround the child’s birth and neonatal history. The aim of this study was to determine the risk factors associated with hearing impairment among lower primary school children as seen in Port Harcourt, Nigeria. Methodology: Hearing assessment was carried out in lower primary school children in Port Harcourt City between January 10th and May 21st, 2010. A multi-staged sampling technique was used to recruit pupils from lower primary schools for the study. A total of 802 school children, consisting of 405 (50.5%) males and 397 (49.5%) females, were screened for hearing impairment using pure tone audiometry. The data of each child screened was entered into forms provided by the researchers. The data was then entered into the database of a software package designed for collection, completion and reporting, the EPI_INFO (version 6) and SPSS11.0 statistical packages for epidemiology. The age and sex distribution of the study population; the social class; the prevalence of hearing impairment in relation to age, sex, social class; the risk factors of hearing impairment and its relationship with hearing impairment were determined from the data collected. These data were presented as charts and tables in simple proportions, and comparisons of sub groups carried out with chi square test. Statistical significance at 95% confidence interval was p value < 0.05. Results: A total of 802 pupils were screened. The number of pupils was almost equally distributed in all the age groups; 281 pupils (35.0%) were between 5-7 years whereas 253 pupils (31.6%) were > 10 years. There were 405 males (50.5%) and 397 (49.5%) females, giving a male: female ratio of 1.02:1. Majority of the pupils were from social class III (268 pupils, 33.4%). The prevalence of hearing impairment in lower primary school children in Port Harcourt was found to be 29.4%. Of the 236 pupils with hearing impairment 76 pupils (52%) had Conductive Hearing Loss (CHL), 35 (24%) had Mixed Hearing loss (MHL) and 35 (24%) had Sensorineural Hearing Loss (SNHL). Of the 236 pupils with hearing loss, 128 (54.1%) had unilateral hearing loss while 108 (45.9%) had bilateral hearing loss. Hearing impairment was significantly more prevalent (32.8%) among children in the older age group (>10 years) than in children 5-7 years of age (24.2%). Females had a significantly higher prevalence (34.0%) than males (24.9%), p=0.003. Hearing impairment was most prevalent among children from the social class V (43.5%) and least in class I and II (27.0%), the difference however, was not statistically significant (p=0.138). Conductive hearing loss was the most common type of hearing impairment seen amongst these children (52.0%). Majority (58.9%) of the children had slight hearing impairment (16-25 dB HL). Bilateral hearing loss was seen in 54.1% of the children with hearing impairment while 32.8% had unilateral hearing loss of the various identified risk factors, history of neonatal fever (24.6%), ear pain (23.7%) and neonatal convulsions (11.4%) were significantly associated with hearing impairment (p<0.050). Conclusion: This study had shown that the female gender, older age group > 10years, neonatal jaundice, otalgia and neonatal convulsions are risk factors for hearing impairment among lower primary school children in Port Harcourt.