Figure 1.

Simplified Schematic Diagram of the Markov Model

1. Process of hearing aid fitting. 2. Incidence and detection of pathology. 3. Successful treatment of pathology. 4. Becoming ex-user. 5. Detecting undetected pathology. ^*Hearing aid users are subdivided into users with a poor and a good quality hearing aid fitting. ^**The pathology state is subdivided into “acoustic neuroma,”“chronic otitis media,”“otosclerosis,” and “psychosocial problems.” These pathologies can be either detected or undetected. For detected acoustic neuroma, before and after treatment states are distinguished. Pathology states are further subdivided into hearing aid users and nonusers, as is illustrated for the no pathology states