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Improvement in outcome for very low birthweight children: apparent or real
Author(s) -
Kitchen William H,
Doyle Lex W,
Rickards Anne L,
Ford Geoffrey W,
Kelly Elaine A,
Callanan Catherine
Publication year - 1992
Publication title -
medical journal of australia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 131
eISSN - 1326-5377
pISSN - 0025-729X
DOI - 10.5694/j.1326-5377.1992.tb137075.x
Subject(s) - medicine , pediatrics , confidence interval , cohort , odds ratio , cohort study , prospective cohort study
Objective To determine whether improvement in the survival rate of infants with a birthweight of less than 1501 g was accompanied by an increase in the rate of neurological impairment or disability among the survivors. Design, setting and patients Two cohorts of consecutive very low birthweight infants (birthweight <1501 g) in one tertiary perinatal centre were followed prospectively to eight years of age; for both cohorts, comparison groups of children of birthweight more than 1501 g were randomly selected from hospital births. Interventions The first cohort was born before the introduction of assisted ventilation (1966–1970), the second after assisted ventilation was well established (1980–1982). Main outcome measures Comparisons between cohorts, at eight years of age, of the survival rates and the rates of severe sensorineural impairments and disabilities. Results The survival rate for very low birthweight infants to eight years of age almost doubled between these cohorts, from 37.1% to 67.8% (odds ratio [OR], 3.4; 95% confidence interval [CI], 2.5–4.7; χ 2 = 57.6; P <<0.0001). The biggest gain was the increase in non‐disabled survivors at eight years of age, from 52.6% in the first cohort to 80.8% in the second cohort (OR, 3.5; 95% CI, 2.2–5.7; χ 2 = 26.7; P <0.0001). Furthermore, the rate of severe disabilities in survivors fell substantially, from 13.6% to 4.1% (OR, 0.31; 95% CI, 0.14–0.69; χ 2 = 8.3; P <0.01). Of specific impairments, the rate of severe sensorineural deafness fell substantially (3.2% to 0%: OR, 0.14; 95% CI, 0.02–0.81; χ 2 = 4.8; P <0.05), as did the rate of severe intellectual impairment (13.0% to 2.7%: OR, 0.25; 95% CI, 0.11–0.57; χ 2 = 10.7; P < 0.002). Only the rate of cerebral palsy increased, but not significantly (2.6% to 6.8%; OR, 2.6; 95% CI, 0.89–7.6; χ 2 = 3.0). Conclusions It has been possible to improve the survival rate of very low birthweight infants over time without increasing the number of severely disabled survivors. Whether the long‐term outcome for these infants is continuing to improve with more recent advances in perinatal care remains to be determined.