The results were calculated using a measure called “effect size”, which is a way of quantifying the size of the difference between the two groups. For the difference in quality of life scores between groups, the effect size was calculated to be 0.24. This can be interpreted as a “small” effect. In other words, treatment including CBT gave a small improvement in quality of life compared with usual care.
Assessment of psychological processes related to tinnitus involves measurement of tinnitus severity and distress (i.e., nature and extent of tinnitus-related problems), measured subjectively by validated self-report tinnitus questionnaires. These questionnaires measure the degree of psychological distress and handicap associated with tinnitus, including effects on hearing, lifestyle, health and emotional functioning. A broader assessment of general functioning, such as levels of anxiety, depression, stress, life stressors and sleep difficulties, is also important in the assessment of tinnitus due to higher risk of negative well-being across these areas, which may be affected by or exacerbate the tinnitus symptoms for the individual. Overall, current assessment measures are aimed to identify individual levels of distress and interference, coping responses and perceptions of tinnitus in order to inform treatment and monitor progress. However, wide variability, inconsistencies and lack of consensus regarding assessment methodology are evidenced in the literature, limiting comparison of treatment effectiveness. Developed to guide diagnosis or classify severity, most tinnitus questionnaires have been shown to be treatment-sensitive outcome measures.
Health care professionals who incline to offer patients an option or strategy to deal with tinnitus are confronted with the variability inherent to this disorder.5 The cause of tinnitus can vary, although people who experience tinnitus have usually first developed hearing loss due to ageing or from exposure to loud noise that caused peripheral auditory damage. In fact, the number of tinnitus sufferers that develop the constant ringing due to hearing loss may be even higher than thought, as some tinnitus sufferers only appear to have normal hearing when thresholds at frequencies below 8 kHz are measured. Less frequently, tinnitus may also occur after a head or neck injury, or due to the presence of an acoustic neuroma. Certain medications may also contribute to the development of tinnitus through effects on hair cells in the inner ear or via mechanisms that are not yet well understood.6 This variety in cause has been the first part of the challenge in developing a “cure” or effective treatment for tinnitus. However, even for the largest group of tinnitus sufferers (those who may develop tinnitus due to hearing damage), effective treatments have been hard to come by.
Exposure to loud noise. Loud noises, such as those from heavy equipment, chain saws and firearms, are common sources of noise-related hearing loss. Portable music devices, such as MP3 players or iPods, also can cause noise-related hearing loss if played loudly for long periods. Tinnitus caused by short-term exposure, such as attending a loud concert, usually goes away; both short- and long-term exposure to loud sound can cause permanent damage.