Independent Validation of an Existing Model Enables Prediction of Hearing Loss after Childhood Bacterial Meningitis

Objective: This study aimed external validation of a formerly developed prediction model identifying children at risk for hearing loss after bacterial meningitis (BM). Independent risk factors included in the model are: duration of symptoms prior to admission, petechiae, cerebral spinal fluid (CSF) glucose level, Streptococcus pneumoniae and ataxia. Validation helps to evaluate whether the model has potential in clinical practice. Study design: 116 Dutch school-age BM survivors were included in the validation cohort and screened for sensorineural hearing loss (>25 dB). Risk factors were obtained from medical records. The model was applied to the validation cohort and its performance was compared with the development cohort. Validation was performed by application of the model on the validation cohort and by assessment of discrimination and goodness of fit. Calibration was evaluated by testing deviations in intercept and slope. Multiple imputation techniques were used to deal with missing values. Results: Risk factors were distributed equally between both cohorts. Discriminative ability (Area Under the Curve, AUC) of the model was 0.84 in the development and 0.78 in the validation cohort. Hosmer-Lemeshow test for goodness of fit was not significant in the validation cohort, implying good fit concerning the similarity of expected and observed cases. There were no significant differences in calibration slope and intercept. Sensitivity and negative predicted value were high, while specificity and positive predicted value were low which is comparable with findings in the development cohort. Conclusions: Performance of the model remained good in the validation cohort. This prediction model might be used as a screening tool and can help to identify those children that need special attention and a long follow-up period or more frequent auditory testing

Estudo retrospectivo de crianças e jovens com deficiência auditiva: caracterização das etiologias e quadro audiológico Retrospective study of hearing impaired children and teenager: characterizing the etiologies and audiological aspects

OBJETIVO: conhecer os fatores de risco para deficiência auditiva e obter informações sobre o tempo transcorrido entre suspeita, diagnóstico e intervenção em crianças e jovens deficientes auditivos atendidos no Serviço de Audiologia Educacional, DERDIC-PUC-SP. MÉTODOS: estudo retrospectivo de 162 prontuários de deficientes auditivos com idade entre um e 17 anos e 6 meses, atendidos de 1999 a 2002. Para registro dos dados utilizou-se a adaptação do protocolo elaborado no Fórum de Reabilitação Aural do Encontro Internacional de Audiologia, no Brasil. RESULTADOS: 54% dos sujeitos eram do sexo masculino e 46% do feminino; 60% tinham idade entre três e oito anos e 11 meses; 43% tiveram a suspeita da deficiência auditiva no primeiro ano de vida. Em 25% dos casos, o diagnóstico ocorreu logo após a suspeita, em 34% ocorreu um intervalo de até um ano; 11% iniciaram atendimento fonoaudiológico após diagnóstico, 54% demoraram até um ano e 27% demoraram mais de um ano. Trinta e dois por cento apresentaram etiologia desconhecida, 18% genética, 17% presumida multifatorial, 15% meningite, 9% rubéola congênita. CONCLUSÃO: a prevalência da etiologia desconhecida aponta para a necessidade do aprofundamento no diagnóstico etiopatológico (estudos genéticos, de imagens e laboratoriais) como rotina para se obter as causas da deficiência auditiva. Observou-se que mesmo após as campanhas de vacinação, a rubéola ainda foi a maior causa de deficiência auditiva congênita e a meningite a maior causa das deficiências auditivas adquiridas após o nascimento. Constatou-se um longo intervalo de tempo entre suspeita, confirmação e início da intervenção fonoaudiológica.<br>PURPOSE: to become aware of the risks factors for hearing impairment and describe the time gap between the suspicions of the hearing loss, the diagnostic and the beginning of the rehabilitation for a group of hearing impaired children and teenagers from an institution in São Paulo, Brazil - DERDIC PUC-SP, that took part in a rehabilitation program from 1999 to 2002. METHODS: a retrospective study of 162 files of hearing impaired children between 12mo and 17:6 yrs old, the questionnaire elaborated by The Aural Rehabilitation Forum which occurs annually during the International Audiology Meeting in Brazil was used. RESULTS: the results showed 54% male and 46% female subjects; 60% between 3 and 8:11 years old; 43% had the suspicions of the hearing loss in the first year of life; for 25% of the subjects the diagnostic was carried out just after the suspicions; 34% finished the diagnostic one year after the suspicions; 11% began rehabilitation just after the diagnostic, 54% after a year and 27% more than a year. 32% had unknown etiology, 18% genetic causes, 17% presumed multiple factors, 15% meningitis, 9% congenital rubella. CONCLUSION: the prevalence of unknown etiology shows the need for deepening the diagnosis, and as a routine, carry out genetics, images and laboratories studies, in order to know the etiologies of the hearing loss. Even though after implementing immunization campaigns, rubella was the most prevalent cause of the congenital hearing loss and meningitis was the most prevalent cause of acquired hearing loss. A precious time for the child development was lost because of the time gap between suspicions, diagnostic and rehabilitation