The burden of influenza in children under 5 years admitted to the Children's Hospital at Westmead in the winter of 2006.

OBJECTIVE: Active surveillance to determine influenza disease burden in children admitted to hospital with influenza-like illness (ILI). METHODS: A prospective hospital-based cohort study conducted June-October 2006 in children <5 years hospitalised at The Children's Hospital at Westmead with ILI (fever and respiratory symptoms). Influenza and other viral infections were diagnosed either by antigen detection using immunofluorescence or nucleic acid amplification testing of nasopharyngeal aspirates. Data were collected using researcher-administered questionnaires. Main outcome measures include proportion of hospitalisations with influenza, vaccination and treatment, risk factors for influenza and associated medical and social burdens. RESULTS: Data on 275 children with ILI aged <5 years were analysed. Thirty-one (11%) children with ILI had influenza (22 had influenza A and 9 had influenza B). Thirty-five percent were under 6 months of age and 61% under 1 year. Twenty-nine percent of children with influenza A were born prematurely. The mean duration of hospital stay for influenza was 2.8 days (95% confidence interval 2.1-3.4) and 26% had a lumbar puncture. Although 68% received intravenous antibiotics, only 3% (one case) was given an antiviral. Eighty-four percent had visited their local doctor before admission and all came through the emergency department. On average, in one-third (32%) of families of children with influenza a parent developed, ILI during admission or soon after hospital discharge resulted in an average of 3.2 days of work absenteeism. Only 3.5% (7/199) of children older than 6 months with ILI received any influenza vaccination. CONCLUSIONS: Both the burden of influenza in childhood morbidity and its social impact are substantial. There is considerable room for improvement in both the prevention and early recognition (trigger treatment with antivirals) of influenza. Our data will inform decisions regarding the value of a universal influenza vaccine programme.

How useful are hospital morbidity data for monitoring conditions occurring in the perinatal period?

BACKGROUND: There is currently no published information on the full range of morbid conditions affecting mothers and newborns in Australia. Hospital morbidity data collections are a possible source of this information, but have not been widely utilised due to concerns about data quality. AIMS: To assess the accuracy and reliability of perinatal morbidity reporting to the New South Wales Inpatient Statistics Collection (NSW ISC). METHODS: A sample of 1000 records relating to 500 mothers and 500 newborns were randomly selected from the NSW ISC for the financial year 1999-2000 and compared with information obtained from medical records. Sensitivities and specificities were calculated for conditions of clinical relevance. RESULTS: There was a wide range of sensitivities among the 41 conditions selected, indicating a variable level of under-enumeration. Only 17 (41%) had a sensitivity of 80% or more. Sensitivities were more than 95% for gestational diabetes, prolonged pregnancy, perineal laceration, single live birth, low birth weight, and intracranial haemorrhage. However, numbers are small and confidence intervals wide for some of these conditions. Specificities were generally high. Neonatal conditions tended to be more accurately reported than maternal conditions. The pattern of results was similar to that reported for state perinatal data collections. CONCLUSIONS: While hospital administrative data are readily available, data quality is a valid concern. However, if the data are viewed critically and information on accuracy is available, they can be a useful resource for monitoring the health of mothers and babies.