Congenital hearing disability--epidemiology and identification: a comparison between two health authority districts

The objective of the present study was to describe some epidemiological aspects of congenital/early acquired (i.e. in the neonatal period) hearing disability (CEHD) in children born between 1980 and 1990, living in two separate health authority districts, i.e. the Copenhagen City/County; in addition, to evaluate the age at identification of the children, the persons raising suspicion of the hearing loss and the pattern of referral; finally, to compare some epidemiological aspects and the age at identification of similarly defined cohorts of children, born 1970-80. Thus the evaluation can be considered as an audit of the primary health care sector concerning children with CEHD. An identical prevalence rate of CEHD was demonstrated, i.e. 1.5/1000 with a better ear hearing level average at 0.5-4 kHz > or = 25 dB (BEHL 0.5-4 kHz) in both regions and unchanged from 1970-80. The median age at identification in the total cohort was 16/18 months in the City/County, respectively, demonstrating a significantly earlier identification of at-risk children in the County with the opposite pattern in the City. The parents were the first to raise suspicion of their child's hearing disability in 50%/57% in the City/County and only minor differences in the pattern of referral was found in the two regions. The frequency of at-risk children among parents/professionals who first suspected the CEHD showed no significant differences; however, the BEHL 0.5-4 kHz in the children was poorer in the group of parents who first raised the suspicion when compared with the group of professionals. Thus the BEHL 0.5-4 kHz is of significance for the age at identification and for the person raising the suspicion of CEHD. Although an improvement in the early identification of CEHD has taken place, when comparing the 1970-80 cohort and 1980-90 cohort, it is concluded that children with CEHD are identified with a substantial delay and that the line of information both concerning high-risk criteria and general information should be continued and intensified towards both parents and professionals.