INTRODUCTION
Common causes of conductive hearing loss are chronic middle ear diseases (CMED), such as chronic otitis media (COM) with or without cholesteatoma. Without adequate treatment, hearing loss can lead to severely limited communication skills with a negative impact on health-related quality of life (HRQoL).1 Furthermore, CMED may severely affect HRQoL due to symptoms such as discharge from the ear, otalgia and dizziness.2 Standardized reporting of HRQoL, but also objective outcomes, such as hearing or surgical techniques, is needed when establishing individual or new therapeutic approaches, including new materials or prostheses as well as novel surgical techniques.3 Concerning the evaluation of surgical treatments of CMED, it has been shown that the outcome of surgery is influenced by the structures involved into the disease, such as the ossicles.4,5 It has to be assumed that postoperative hearing improvement by reducing the air-bone gap is an important but not the only factor influencing HRQoL.2Therefore, focusing on the audiological outcome as an objective evaluation of the surgical success may lead to misinterpretations.1 The assessment of HRQoL has gained importance both in clinical studies and in clinical practice and has become an important indicator for the assessment of therapeutic success.6–12 Standardized questionnaires are used to assess the individual impairment covering everyday situations, communication or social contacts and accompanying symptoms such as tinnitus.13,14 The Zurich Chronic Middle Ear Inventory (ZCMEI-21) is a validated disease-specific tool for assessing disease-specific symptoms of CMED and their impact on HRQoL.6,10,15,16 The ZCMEI-21 features a complete assessment of ear-related symptoms and a comprehensive survey of psychosocial impairment.6 Recent clinical applications of the ZCMEI-21 led to the assumption, that HRQoL varies among different types of CMED.17,18 This may be explained by different types of CMED presenting with differing severity of single symptoms such as discharge, vertigo or hearing loss. This study therefore aimed to (i) investigate characteristics of HRQoL and (ii) evaluate the association between HRQoL and hearing among different types of CMED. Since not every CMED necessarily is treated surgically, e.g. persistent mastoid cavities without cholesteatoma or postinflammatory meatal fibrosis (PIMF), HRQoL questionnaires may assist the counselling of the patients and find the correct treatment.