Stress Biomarkers in People Waiting for Cochlear Implants

Abstract

Background: Previous Research (Guitar, 2010) compared the health of those on the cochlear implant waiting list to the health of those with cochlear implants. The conditions investigated included only those which are potentially stress mediated according to well-accepted models of pathology. People on the waiting list had a greater number of physical health problems, experienced them for longer or more frequently, took medication for more conditions, had poorer mental health and had poorer self rated health. It was concluded that the stress of hearing loss and/or of waiting for a cochlear implant had a negative impact on health, though the drivers were not clearly understood: the findings did not provide evidence of either the psychological factors that would have led to feelings of stress or the physiological factors that would mark stress. Aims: To investigate the psychological and physiological correlates of stress in people on the cochlear implant waiting list in comparison with people who have a cochlear implant. Method: The study was cross sectional and used a mixed quantiative and qualitative methodology. I compared correlates of stress in patients on the waiting list for cochlear implants to those with cochlear implants. Biological markers of stress measured were: blood pressure, heart rate and heart rate variability. Sleep quality was assessed as both a marker of stress and a contributing factor for stress. These outcome measures were compared to hearing handicap scores and time spent on waiting list to assess whether one of these apparent stressors had more impact than the other. A qualitative approach was used to gain insight into the perceptions, feelings and experiences surrounding the stress of hearing handicap. Results: Those on the cochlear implant waiting list had higher levels of stress, as indicated by poorer sleep quality and reduced parasympathetic modulation of nocturnal heart rate, suggesting a state of autonomic hyperarousal. Moreover, there was a significant association between poor sleep quality and hearing handicap, but not time spent on the waiting list. Interviews revealed that profound hearing loss had a significant and adverse effect on numerous aspects of the participants' lives, including their sense of identity, interpersonal relationships, work, leisure and ability to perform day-to-day activities whereas in people with cochlear implants, these negative experiences were attenuated. Conclusion: Those using a cochlear implant were less stressed than those on the cochlear implant waiting list, primarily due to decreased hearing handicap. This provides support for a mechanism through which profound hearing loss may be causing poor health, and implies that the principle stressor is not the waiting but the need to live with the difficulties imposed by losing hearing and feeling in a state of personal isolation.