Client, Hearing aid and Subjective Variables as Predictors of Hearing Aid Success

1
Client, Hearing aid and Subjective Variables as
Predictors of Hearing Aid Success

• Suzanne C Purdy
• National Acoustic Laboratories
• and
• J Chris K Jerram
• Audiology Section, The University of Auckland

Presented at Audiological Society of Australia
Conference, Adelaide, Australia, 6-9 June 2000
2
Topics

• Aim
• Outcome measures
• Predictors of outcome
• Methodology
• Results
• Conclusions

3
Overall Aim

• To determine demographic, technical and
  subjective predictors of hearing aid outcome

4
Measuring Hearing Aid Outcome

• Hours of hearing aid use
• Satisfaction
• Overall (Dillon et al 1997 Purdy Jerram 1998)
• Profile (SADL, Cox Alexander 1999)
• Benefit
• Objective (aided-unaided real ear SPL / speech )
• Subjective (APHAB, Cox Alexander 1995)

5
Measuring Hearing Aid Outcome

• Psychosocial
• depression
• social activity
• personal relationships
• health status
• cognitive status
• life satisfaction
• emotional stability
• anxiety

• Mulrow et al 1990
• Bridges Bentler 1998
• Garsteki Erler 1998
• Crandell 1998
• Kochkin Rogin 2000

6
Predictors of Hearing Aid Outcome

• Demographic factors
• age
• degree of hearing loss
• gender
• Poor health, impaired cognition, social
  isolation, central auditory deficits in the
  elderly impact on hearing aid success
• Greater hearing loss ? more aid use, poorer
  performance, greater benefit

7
Predictors of Hearing Aid Outcome

• Hearing instrument factors
• age of instrument
• hearing aid style
• technology (compression,
  multiple memories / microphones / channels)
• Better satisfaction with newer instruments and
  higher performance instruments
• Higher benefit in noise with dual microphone
  technology

8
Predictors of Hearing Aid Outcome

• Subjective factors
• personal adjustment to hearing loss
• attitude to hearing aids
• expectations of hearing aids
• personality
• Better outcomes if more outward-looking
  personality, less depressed, more positive
  attitude towards hearing aids

9
Methodology 1.

• 12 private,
  7 public clinics
• n225 consent forms
• Questionnaires received back from n200 (89)
• personal adjustment to hearing loss
• hearing aid attitudes and expectations
• unaided listening (Modified APHAB)
• Hearing aid fitting and trial

10
Methodology 2.

• Post-fitting questionnaires n162 (81)
• aided listening (Modified APHAB)
• overall satisfaction
• hours of use
• Demographic, hearing loss and hearing aid details
  from audiologists

11
Statistical Analysis

• Internal reliability of questionnaires
• Relationship between outcome measures
• Ordinal logistic regression analysis to
  investigate the effects on outcome of
  age, gender, employment status,
  public/private clinic, prior aid experience,
  degree of hearing loss, monaural/bilateral
  fitting, aid style, aid I/O characteristics,
  high tech features, personal adjustment to
  hearing loss, attitudes to hearing aids, aid
  expectations

12
Questionnaires 1.

• Communication Profile for the Hearing Impaired
  (CPHI) Personal Adjustment
• Acceptance of Loss
• Stress
• Denial

Sometimes Im ashamed of my hearing loss When
I have trouble hearing, I feel frustrated When
I cant understand whats being said, I feel
tense and anxious
13
Questionnaires 2.

• Hearing Attitudes in Rehabilitation (HARQ) Factor
  1. Hearing Aid Stigma

It would make me feel old to wear a hearing
aid If I wear an aid, people will probably
think Im a bit stupid
14
Questionnaires 3.

• Seyfried (1990) Expectations Questionnaire

My hearing aids will fit comfortably My
hearing aids will make speech sounds more
distinct
15
Subject Characteristics

• 81 men, 81 women
• 31-88 years (mean 70.5, sd 10.8 years)
• 47 public, 53 private
• 62 some prior hearing aid experience
• Sensorineural hearing loss

16
Average Pure Tone Audiogram
17
Hearing Aid Fitting (n162)

• 26 1-4 hrs use
• 69 4 hrs use
• Bilateral 59
• BTE 22
• ITE/ITC 73
• CIC 5

18
Hearing Aid Outcomes
19
Significant Predictors of Outcomes
20
Better CPHI Acceptance of Loss and higher
Expectations associated with more aid use
21
Conclusions 1.

• Questionnaires internal reliability
• good after elimination of some items from
  Expectations and Attitudes scales
• Relationships between outcomes
• people who were more satisfied and had higher
  benefit wore their aids more
• satisfaction most strongly related to benefit in
  difficult listening situations

22
Conclusions 2.

• Demographic factors not significant
• High tech affected outcome
• WDRC aids associated with higher difficult
  listening benefit but milder losses
• Multiple memory associated with higher
  satisfaction and higher easy listening benefit
  (multiple channel also ?easy listening benefit)
• On average satisfaction was highest (82) for
  multiple microphone aids but not significant due
  to few subjects (n15)

23
Conclusions 3.

• Attitude not predictive of outcome
• Higher expectations associated with more hearing
  aid use and greater benefit in easy and difficult
  listening situations
• Better personal adjustment to hearing loss
  (Acceptance of Loss subscale) associated with
  more hearing aid use

This research was supported by the Deafness
Research Foundation of New Zealand.