Diagnostic accuracy of non‐specialist versus specialist health workers in diagnosing hearing loss and ear disease in Malawi

Abstract

Objective To determine whether a non‐specialist health worker can accurately undertake audiometry and otoscopy, the essential clinical examinations in a survey of hearing loss, instead of a highly skilled specialist (i.e. ENT or audiologist). Methods A clinic‐based diagnostic accuracy study was conducted in Malawi. Consecutively sampled participants ≥ 18 years had their hearing tested using a validated tablet‐based audiometer (hearTest) by an audiologist (gold standard), an audiology officer, a nurse and a community health worker (CHW). Otoscopy for diagnosis of ear pathologies was conducted by an ENT specialist (gold standard), an ENT clinical officer, a CHW, an ENT nurse and a general nurse. Sensitivity, specificity and kappa (κ) were calculated. 80% sensitivity, 70% specificity and kappa of 0.6 were considered adequate. Results Six hundred and seventeen participants were included. High sensitivity (>90%) and specificity (>85%) in detecting bilateral hearing loss was obtained by all non‐specialists. For otoscopy, sensitivity and specificity were >80% for all non‐specialists in diagnosing any pathology except for the ENT nurse. Agreement in diagnoses for the ENT clinical officer was good (κ = 0.7) in both ears. For other assessors, moderate agreement was found (κ = 0.5). Conclusion A non‐specialist can be trained to accurately assess hearing using mobile‐based audiometry. However, accurate diagnosis of ear conditions requires at least an ENT clinical officer (or equivalent). Conducting surveys of hearing loss with non‐specialists could lower costs and increase data collection, particularly in low‐ and middle‐income countries, where ENT specialists are scarce.

Rationale for a Rapid Methodology to Assess the Prevalence of Hearing Loss in Population-Based Surveys

“…Pure tone audiometry can now be conducted using validated smartphone-based tests which are automated [27]. The advantages of smartphone-based tests over screening audiometers in survey settings is portability, and ability for non-specialist staff to undertake the tests [28]. Therefore, the presence of audiologists in the field may not be required, although this needs further verification.…”

Field-testing of a rapid survey method to assess the prevalence and causes of hearing loss in Gao’an, Jiangxi province, China

“…Then, a pilot study of the survey protocol was undertaken in Malawi to determine the appropriate cluster size, and whether the data collection protocol needed adaptations. Finally, a clinic-based diagnostic accuracy study was undertaken in Malawi to determine whether non-specialist health workers, instead of highly skilled professionals, could undertake the hearing test and ear examination [27]. The next section gives an overview of the developed methodology.…”

“…at least 30 people), two testers were required. The diagnostic accuracy study in Malawi found that non-specialist health workers can be trained to accurately assess hearing [27]. One ear examiner: to complete an ear examination using otoscopy and assign causes (Ear Nose and Throat (ENT) specialist).…”

“…One ear examiner: to complete an ear examination using otoscopy and assign causes (Ear Nose and Throat (ENT) specialist). Pilot work in Malawi suggested at least an ENT clinical officer (mid-cadre health worker with 18 months of clinical training) is required to be in the field [27].…”

Rationale and feasibility of a combined rapid assessment of avoidable blindness and hearing loss protocol

“…In 2013-2014, all-age population-based surveys of disability were undertaken in one district each in India (Mahbubnagar District) and Cameroon (Fundong Health District). [15,16] These surveys measured VI and HI using both self-reported and clinical tools. Sample size calculations resulted in a target sample size of 4056 participants of all-ages in 51 clusters of 80 people.…”