The Agency for Healthcare Research and Quality (AHRQ) has published its technology assessment for cochlear implants for sensorineural hearing loss, and the 114-page report notes that while the data generally show good outcomes over baseline hearing scores, those same data offer little in the way of guidance as to which patients are good candidates for a cochlear implant.

The report states that the data are derived largely from studies of three such implants marketed in the U.S., the Nucleus 5 from Cochlear (Denver), the Harmony HiRes 90K from Advanced Bionics (Valencia, California), and the Maestro from Med-El (Durham, North Carolina). In the discussion section, the report says that the data for unilateral implants indicate "significant gains in speech perception and health-related quality-of-life (QoL) in adults," and that gains in speech perception were sustained for both implant-only patients and patients whose implants were augmented by the use of additional hearing aids.

Studies of unilateral implants suffered, the report says, due to "low to insufficient level evidence regarding relationships between pre-operative patient characteristics and post-operative health-related" QoL outcomes. Another area of deficiency cited by AHRQ was the data supporting efficacy in unilateral implants as assessed by baseline scores for open-set sentence tests. The authors of the report were referring to patients who scored greater than 40% but less than or equal to 50%, as well as those whose scores fell in the interval of greater than 50% up to and including 60%.

As for bilateral implants, the report says that the data indicate improved speech perception in adults compared with those with only one implanted ear regardless of the use of augmentative devices, "particularly in noisy conditions." The report notes that speech perception is better even in noisy conditions "apparently with intact ears or with cochlear implants," but that the benefit of two implants over one in quiet conditions was not clearly demonstrated by the data. However, some of the reviewed studies indicated that patients with two implants apparently enjoyed a diminished head shadow effect, which the report acknowledges is suggestive of the possibility that real world performance with two implants may be better than in controlled studies.

The report remarks that while published studies "revealed significant gains in terms of speech perception outcomes, this did not translate to consistent gains in the perceived performance as assessed through a series of health-related" QoL measures in three of the studies examined for bilateral implants. The report states further that a paucity of data and "inconsistent benefits in terms of health-related QoL outcomes preclude any definitive conclusions" about QoL outcomes for bilateral implants.

By Mark McCarty, Medical Device Daily Washington Editor
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