Identification of neonatal hearing impairment: Experimental protocol and database management

Objective: The purposes of this article are to describe the overall protoco l for the Identification of Neonatal Hearing Impairment (INHI) project and to describe the management of the data collected as part of this project. A well-defined protocol and database management techniques were needed to en sure that data were 1) collected accurately and in the same way across site s; 2) maintained in a database that could be used to provide feedback to in dividual sites regarding enrollment and the extent to which the protocol wa s complete on individual subjects; and 3) available to answer project quest ions. This article describes techniques that were used to meet these needs. Design: This study was a prospective, randomized study that was designed to evaluate auditory brain stem responses, transient evoked otoacoustic emiss ions, and distortion product otoacoustic emissions as hearing-screening too ls, and to relate neonatal test findings to hearing status, defined by visu al reinforcement audiometry at 8 to 12 mo of age, Measures of middle-ear fu nction also were obtained at some sites as part of the neonatal test batter y, In addition, other clinical and demographic data were gathered to determ ine the extent to which factors, other than auditory status, influenced tes t behavior. Three groups were evaluated: neonatal intensive care unit (NICU ) infants (those who spent 3 or more days in a NICU), well babies with risk factors for hearing loss, and well babies without risk factors. Six center s participated in the trial. The testers for the project included audiologi sts, technicians, audiology graduate students, and medical research staff. The same computerized neonatal test program was applied at each center. Thi s program generated the neonatal test database automatically. Clinical and demographic data were collected by means of concise data collection forms a nd were entered into a database at each site. After the neonatal test, subj ects from the NICU and at-risk, well babies were evaluated with visual rein forcement audiometry starting at 8 to 12 mo of age. All data were electroni cally transmitted to the core site where they were merged into one overall database, This database was exercised to provide feedback and to identify d iscrepancies throughout the course of the study. In its final form, it serv ed as the database on which all analyses were performed. Results and Conclusion: The protocol was a departure from typical hearing s creening procedures in terms of 1) its regimented application of three scre ening measures; 2) the detailed information that was obtained regarding sub ject clinical and demographic factors; and 3) its application of the same p rocedures across six centers having diverse geographic location and subject demographics. A learning curve for successfully executing the study protoc ols was observed. Throughout the study, monthly reports were generated to m onitor subject enrollment, check for data completeness, and to perform data integrity checks. In combination with monthly data reports and checks that occurred throughout the progression of the study, miscellaneous data audit s were performed to check, accuracy of neonatal testing programs and to cro sscheck information entered in the clinical and demographic database. The d ata management techniques used in this project helped to ensure the quality of the data collection process and also allowed for detailed analyses once data were collected, This was particularly important because it enabled us to evaluate not only the performance of individual measures as screening t ools, but also permitted an evaluation of the influence of other variables on screening test results.