Pattern of hearing loss in a tertiary hospital in the north western Nigeria

Background: Hearing impairment is a major public health problem in developing countries. According to the World Health Organization,approximately 15% of the world's adult population has some degree of hearing loss. About one­third of those who are affected have disabling hearing loss and two­third of them live in developing countries. Aim: This study aims to determine the causes and pattern of hearing loss in Zaria, North Western Nigeria. Materials and Methods: This was a retrospective study conducted at ear, nose,and throat unit of Ahmadu Bello University Teaching Hospital Zaria, Kaduna Nigeria. The hospital is a tertiary health­care facility in North Western Nigeria and is a referral center to many primary, secondary, tertiary and private health facilities in Nigeria. The records of all patients who were managed for hearing loss in our unit over a period of 5 years between January 2011 and December 2015 were reviewed. Information obtained from the case files included demographic characteristics, main presenting symptoms, and causes of hearing loss. Findings of pure tone audiograms, tympanograms, and otoacoustic emission were also recorded. The data obtained were analyzed using statistical package for Social Science Version 21. Results: Of the 277 patients who presented with hearing loss,only 144 met the inclusion criteria. There were 86 (59.7%) males and 58 (40.3%) females with sex ratio (M:F) of 1.4:1. The mean age was 29.9 years with standard deviation of ±2.18. The most common cause of hearing loss was presbyacusis 24 (16.7%) followed by ototoxicity 14 (9.7%), most of the patients 91 (63.2%) had bilateral hearing loss while 53 (36.8%) had unilateral hearing loss. Majority 112 (77.8%) had sensorineural hearing loss, followed by 24 (16.7%) conductive and mixed 8 (5.5%). Majority of the patients 94 (64.3%) had mild to moderately severe with the remaining 50 (34.7%) having severe to profound hearing losses, respectively. Tympanometric findings showed that 118 (90.8%) and 11 (8.5%) had Types A and B tympanograms, respectively. Conclusion: Majority of the patients were adult with bilateral mild to moderately severe sensorineural hearing loss. Age­related hearing loss was the most common cause of hearing loss followed by ototoxicity