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Benefit from, satisfaction with, and cost-effectiveness of three different hearing aid technologies |
Newman C W, Sandridge S A |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology The study examined the use of three different hearing aid (HA) technologies in conventional HA users with adult onset of sensorineural hearing loss. The three behind-the-ear HA technologies were from the same manufacturer and were: a one-channel linear conventional analogue HA (HA-A); a 2-channel, non-linear HA (HA-B); and a 7-band, 2-channel digital signal processing HA (HA-C).
Economic study type Cost-effectiveness analysis.
Study population The study population comprised conventional HA users aged at least 21 years with adult onset of sensorineural hearing loss.
Setting The setting was secondary care (audiology clinic). The economic study was carried out in Cleveland, OH, USA.
Dates to which data relate The authors did not state the dates over which the resource use and effectiveness data were collected, or the price year.
Source of effectiveness data The effectiveness data were derived from a single study.
Link between effectiveness and cost data The costing was performed on the basis of the average retail price of both monaural and binaural fittings.
Study sample Power calculations were not used to determine the sample size. The study sample consisted of 25 adults with a mean age of 69.2 years (range: 47 - 84), who wore each HA technology for at least a 1-month period and participated in a minimum of five sessions. The participants were fitted with the HA according to previous HA use, in order to decrease the potential confounding effects of a monaural user adjusting to binaural amplification. Eleven participants were fitted monaurally while 14 were fitted binaurally.
Study design This was a prospective cohort study carried out in single centre. The duration of follow-up was a minimum of one month for each HA worn. No loss to follow-up was reported.
Analysis of effectiveness The clinical outcomes were audibility and speech recognition, communication disability, psychological handicap, satisfaction with sound quality features (SQ-Sat) and listening conditions (LC-Sat), and preference ratings.
Objective and subjective measures were used to gauge aided and unaided outcomes in terms of laboratory measures and self-report measures.
The laboratory measures, i.e. the testing of audibility and speech recognition, included: the Audibility Index (AI), which used 50 and 80 dB HL input levels; and the Speech Perception in Noise (SPIN) test, which consisted of 25 high-predictability (HP) items and 25 low-predictability (LP) items)
The self-report measures included: the Abbreviated Profile of Hearing Aid Benefit (APHAB), which involved the measurement of communication disability and consisted of four 6-item scales; and the Hearing Handicap Inventory (HHIE), which involved the measurement of psychological handicap and consisted of 25 items.
An adjustment was made for the potential order effects by counterbalancing across participants.
Effectiveness results The aided outcomes were significantly better than the unaided outcomes for each HA technology in terms of AI (p<0.0001), SPIN LP and HP scores (p<0.0001), HHIE (p<0.0001), and APHAB for the sub-groups of ease of communication, reverberation and background noise (p<0.0001).
In terms of the mean AIs for the 50 dB input, there were no statistically-significant differences among the HA technologies. The HA-A had significantly higher mean AIs for the 80 dB input in comparison to the HA-C: 33 versus 24% (p=0.0035).
Compared with the HA-A, the HA-C had significantly higher scores in terms of SPIN test for the LP and HP scores: 54.16 versus 44.16% (p=0.0066) and 91.68 versus 83.52% (p=0.0142), respectively.
The three HAs were not significantly different in terms of any of the APHAB sub-groups with respect to HA benefit (unaided minus aided; p>0.05), or HHIE total benefit score (unaided minus aided; F=1.01; p=0.3728).
The three technologies were not significantly different in terms of SQ-Sat (F=0.38, p=0.6838) and LC-Sat (F=0.37, p=0.6925).
The HA-C was preferred by 48% of the participants, compared with 28% for the HA-B and 24% for the HA-A, when the participants did not know the purchase prices of the devices. The corresponding values after knowing the purchase prices were 32, 36 and 32%, respectively.
Clinical conclusions The digital signal processing HA (HA-C) yielded significantly higher word recognition scores on the SPIN test, although no differences were observed among the test HAs for the standardised self-report measures. In contrast, however, more than 75% of the participants preferred the "higher end" instruments.
Measure of benefits used in the economic analysis The measures of patient's benefit were the SPIN-LP, HHIE or modified HHIE (HHIA) scores.
Direct costs The costs were not discounted due to the short timeframe of the study. The quantities of resource use were related to the HA instruments used. The cost items were reported separately. The cost analysis covered the average retail price of both monaural and binaural fittings. The cost analysis appeared to have been conducted from the perspective of the patient. The price year was unclear.
Statistical analysis of costs No statistical analysis of costs was performed.
Indirect Costs Indirect costs were not considered.
Sensitivity analysis No sensitivity analysis was conducted.
Estimated benefits used in the economic analysis The benefit score in terms of SPIN-LP was 34 for the HA-C, versus 32 and 24 for the HA-B and HA-A, respectively.
The corresponding values in terms of HHIE or HHIA were 16.7 for the HA-C, 14.8 for the HA-B, and 12.1 for the HA-A.
Cost results The HA-C had an average cost of $3,732, compared with $1,660 for the HA-B and $1,192 for the HA-A.
Synthesis of costs and benefits The average and incremental cost per unit (C/U) of benefit in terms of SPIN-LP, HHIE or HHIA scores were calculated as the measures of cost-effectiveness.
The average cost-effectiveness ratio in terms of SPIN-LP scores was $109.76 for the HA-C, versus $51.88 and $49.67 for the HA-B and HA-A, respectively.
The corresponding values in terms of HHIE or HHIA were $223.47 for the HA-C, $112.16 for the HA-B, and $98.51 for the HA-A.
In terms of SPIN-LP scores, the incremental cost-effectiveness ratios for pair-wise comparisons were $58.50 for HA-A and HA-B, $1,036 for HA-B and HA-C, and $254 for HA-A and HA-C.
The corresponding values in terms of HHIE or HHIA scores were $173.33 for HA-A and HA-B, $1,090.53 for HA-B and HA-C, and $552.17 for HA-A and HA-C.
Authors' conclusions The cost-effectiveness analysis in the present report suggests that HA-A is the most cost-effective, having the least C/U effectiveness for both SPIN-LP and HHIE or HHIA. Yet, HA-B provides improved benefit for marginal increase in cost. Thus it could be argued that HA-B is the most cost-effective among the test instruments. There is little doubt, however, that HA-C is the least cost-effective in this study.
CRD COMMENTARY - Selection of comparators The reason for the choice of the comparator was clear and was justified in the context of the study. You, as a user of the database, should consider if the three behind-the-ear HA technologies are relevant in your own setting.
Validity of estimate of measure of benefit Many clinical measures were estimated and the patient's HA preferences were assessed. Appropriate statistical analyses, such as analyses of variance for repeated measures, were performed in order to address the issue of internal validity. A larger sample size might have increased the robustness of the findings.
Validity of estimate of costs It would have been useful to have more information about the perspective of the analysis in order to assess if all relevant cost components were included.
Other issues The authors highlighted numerous other investigations on effectiveness and cost-effectiveness of HAs in order to report on "newer" technologies. The authors stated that the observations of this study might have been influenced by the clinical measures adopted, and thus, may be limited to the sample population studied. Incremental cost-effectiveness ratios, rather than average cost-effectiveness ratios, should be regarded as the relevant indicator in comparing the three HA technologies. It is interesting to note that, without knowledge of purchase price, 48% of the participants preferred the HA-C technology, while knowing the purchase price, only 32% of the participants still favoured this technology.
Implications of the study This information could be used to design more efficient studies aimed at analysing cost-effectiveness, and for performing sensitivity analyses.
Source of funding Funded by the American Speech-Language-Hearing Foundation (ASHF) through a clinical research grant.
Bibliographic details Newman C W, Sandridge S A. Benefit from, satisfaction with, and cost-effectiveness of three different hearing aid technologies. American Journal of Audiology 1998; 7(2): 115-128 Indexing Status Subject indexing assigned by NLM MeSH Adult; Audiometry; Communication; Cost-Benefit Analysis; Disabled Persons; Hearing Aids /economics; Hearing Loss, Sensorineural; Hearing Tests; Middle Aged; Patient Satisfaction; Severity of Illness Index AccessionNumber 21999007602 Date bibliographic record published 28/02/2002 Date abstract record published 28/02/2002 |
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