|
A cost-effectiveness analysis of the high risk register and auditory brainstem response |
Friedland D R, Fahs M C, Catalano P J |
|
|
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 High risk register (HRR) screening and auditory brainstem response (ABR) testing for hearing impairment of newborns.
Economic study type Cost-effectiveness analysis.
Study population A cohort of newborn infants, extrapolated from data on approximately 16,500 infants.
Setting Hospital. The study was carried out in New York City, New York, USA.
Dates to which data relate For the intervention, the effectiveness and resource use data were collected from infants born at a tertiary care institution between 1990 and 1993. The data for the control were obtained from a literature review (no further details provided). The price year was not clearly reported.
Source of effectiveness data Effectiveness data were derived from a single study.
Link between effectiveness and cost data The costing was undertaken retrospectively on the same patient sample as that used in the effectiveness analysis.
Study sample From approximately 16,500 newborns delivered at the institution during a three-year period, approximately 420 (2.5%) failed the HRR and were then referred to the audiology department. It was estimated that 381 newborn infants of this latter group were tested with ABR whereas 39 patients did not undergo any testing. No power calculations were reported.
Study design This was a retrospective uncontrolled cohort study with follow-up of six months to one year. This study was carried out in a single centre.
Analysis of effectiveness The primary health outcome used in the study was the number of clinically significant sensorineural hearing-loss (enough to interfere with the acquisition of speech and language skills) diagnoses. The reference test used in the analysis was the follow-up sound field (SF) exam and tympanogram test.
Effectiveness results At the Mount Sinai Hospital 410 infants were identified as high risk from the HRR, of whom 391 underwent the ABR. 40.2% failed the ABR, compared to the estimated 16% expected from the base model. Of those, only 0.26% had sensorineural hearing loss compared to 1.27% predicted from the base model.
Clinical conclusions The programme at MSH did not perform as well as might have been expected from studies reported in the literature.
Modelling A decision model was used to calculate costs and benefits associated with the protocol investigated by using data from the clinical study. The model incorporated the different components associated with the protocol, and these can be summarised as follows:
(a) in-hospital exams at birth, and
(b) the outpatient follow-up at six months to one year.
Measure of benefits used in the economic analysis The benefit measure was the number of hearing-loss cases detected. A decision model was used to estimate those numbers.
Direct costs The number of tests and time spent for each test were reported separately from the costs. The costs of the nursing screening examination with ABR, complete work-up at first follow-up visit and all other follow-up examinations were estimated. For the hospital perspective analysis, the cost per test was estimated from audiologist salaries, whereas for the government's perspective that estimate came from Medicaid reimbursement rates. Capital costs (purchase and maintenance of equipment) were also included in the analysis with the associated quantities being reported. It was assumed that clinical staffing and physical plant were not affected by the screening programme. A decision model was used to calculate total costs. The price year of the capital cost was 1990 whereas that of the rest of the cost components was not clearly reported. The analysis included marginal costs only.
Sensitivity analysis No sensitivity analysis was performed.
Estimated benefits used in the economic analysis The expected number of cases detected per 100,000 newborn infants was 6 with the protocol investigated, whereas the base model yielded 57 cases (range: 12 - 242 cases).
Cost results The overall cost of the intervention protocol was $68,819 from the hospital perspective, and from the government's perspective it was $251,902. The base model cost $495,902 (range: $168,847 -1,377,419).
Synthesis of costs and benefits The cost per diagnosis at MSH was $11,470 (hospital perspective)and $42,278 (government's perspective). The base model cost per diagnosis was $8,678 (range: $5,686 - $13,624).
Authors' conclusions It appears that the poor performance of the MSH (intervention) protocol is due to the low specificity and sensitivity of the HRR, producing a subgroup with low prevalence of true hearing deficit. This generates a costly and ineffective programme as follow-up exams focus on ruling-out false positives rather than correctly identifying true hearing losses. Further evaluation is needed to determine whether changes in the application of the HRR or the use of newer, low-cost tests such as otoacoustic emissions (OAE) may be effective in universal infant hearing screening.
CRD COMMENTARY - Selection of comparators The performance of a screening programme at a single hospital was compared to what would be expected from the literature. It might have been more informative to have included a scenario of outcomes with no screening programme.
Validity of estimate of measure of benefit The validity of the study results can be questioned on the following grounds: the retrospective and uncontrolled nature of the clinical study associated with the intervention's data, and the lack of any information about the methodology used in the literature review to obtain the data for the control.
Validity of estimate of costs The quantities of resource use were reported separately from the costs. The cost analysis did not clearly report the price year used in the analysis. No relevant costs appear to have been excluded from the analysis.
Other issues The conclusions reached by the authors are weakened by the high uncertainty surrounding the results on which they are based. The comparison with previous reports regarding average cost-effectiveness ratios for the ABR test alone (using the same parameters as those included in the present study) supported the results found in the study. The issue of generalisability was not addressed. The results were presented without clearly reporting what the 'base case' model (control) stood for.
Implications of the study Further studies are needed before clear implications can be derived for the cost-effectiveness of universal screening of newborn infants using HRR and ABR to assess those infants for congenital hearing loss.
Bibliographic details Friedland D R, Fahs M C, Catalano P J. A cost-effectiveness analysis of the high risk register and auditory brainstem response. International Journal of Pediatric Otorhinolaryngology 1996; 38(2): 115-130 Indexing Status Subject indexing assigned by NLM MeSH Audiometry, Evoked Response /economics; Cohort Studies; Cost-Benefit Analysis; Decision Trees; Evoked Potentials, Auditory, Brain Stem; Hearing Loss, Sensorineural /congenital /diagnosis; Hospitals, Urban; Humans; Infant, Newborn; Neonatal Screening /economics; New York City; Retrospective Studies; Risk Factors; Sensitivity and Specificity AccessionNumber 21997000300 Date bibliographic record published 30/04/2000 Date abstract record published 30/04/2000 |
|
|
|