Validation of the Use of Hear Screen, a Mobile Phone Application as a Screening Tool for Hearing Loss at the Kenyatta National Hospital

Abstract

Background: Approximately 466 million people suffer from disabling hearing loss in the world. The greatest burden is seen in Pacific Asia and sub Saharan Africa with a prevalence of 9% in the latter. There is a huge gap in hearing care occasioned by constraints in number of and access to trained personnel and infrastructure especially in Kenya and other developing countries. The World Health Organization has recognized mobile health as part of the solution to bridge this gap. Objective: To validate the mobile phone based application Hear screen as a screening tool for hearing loss at the Kenyatta National Hospital. Methodology: This was a prospective study conducted in the Ear Nose and Throat department at Kenyatta National hospital on 40 patients referred for conventional Pure Tone Audiometry test which is the gold standard hearing test. Convenient sampling was done. A Repeated measures within subject study design was used where mobile based audiometry thresholds in 0.5 to 8 KHz frequency with ambient noise of quiet office (35dB) and normal clinic set up(45dB) was compared to conventional audiometry (21dB). Data Collection and Analysis: Data was collected and univariate analysis was carried out to determine the mean age with standard deviation. Hearing was compared across all frequencies in all modalities with proportion and 95% confidence interval determined. Regression analysis was done to compare agreement of smartphone and convectional PTA and presented on two way scatter plots. T tests were also carried out to determine if the mean time taken in testing was statistically different for the tests. Fishers test was done to determine whether age or level of education influenced the preference for the mode of testing. Results: The mean age of the study population was 42 years with 35% males and 65% females. There was no statistical difference between smartphone and conventional PTA across all frequencies with a regression coefficient of 1.26 and a p value of < 0.01.Time taken to do the tests had no statistical difference p <0.01. Majority of the respondents preferred to use conventional audiometry with no correlation (p value of 1.00) between this preference and their age or level of education. Conclusion: Heartest the threshold version of hearscreen provides thresholds comparable to convectional PTA in both the quiet office set up and normal clinic set up and can thus be used reliably as a screening tool. Recommendations: Smart phone based audiometry should be used as a method of screening in resource depleted settings.