Costs and health utilities associated with extremely preterm birth: Evidence from the EPICure study
Petrou S., Abangma G., Johnson S., Wolke D., Marlow N.
Objective: To estimate costs and health utilities associated with extremely preterm birth at approximately 11 years of age using evidence from a whole population study (the EPICure study). Methods: The study population comprised surviving children born at 20 through 25 completed weeks of gestation in all 276 maternity units in the United Kingdom and Republic of Ireland from March through December 1995 and a control group of classmates born at full term, matched for age, sex, and ethnic group. Estimates of utilization of health, social, and education services were combined with unit costs derived from primary and secondary sources. Generalized liner regression was used to estimate the impact of extremely preterm birth on public sector costs during the 11th year of life. Suboptimal levels of function for each of the eight attributes of the Health Utilities Index Mark III (cognition, vision, hearing, speech, ambulation, dexterity, emotion, and pain) and multiplicative multi-attribute utility scores were compared between the extremely preterm children and their classmates. Tobit regressions were performed to explore the effects of gestational age at birth on the Health Utilities Index Mark III multiattribute utility score. Results: Mean (standard deviation [SD]) public sector costs over the 12-month period were £6484 (£5548) for the combined extremely preterm group and £4007 (£2537) for their classmates, generating a mean cost difference of £2477 (bootstrap 95% confidence interval [CI] £1605, £3360) that was statistically significant (P < 0.001). The generalized linear models revealed that compared to birth at term, birth at ≤23 completed weeks, 24+0-24+6 weeks and 25 +0-25+6 weeks gestation increased public sector costs by an average of £2417 (95% CI £60, £4774; P = 0.044), £1528 (95% CI £129, £2927; P = 0.032) and £1501 (95% CI £428, £2574; P = 0.006), respectively. In all eight attributes of the Health Utilities Index Mark III, there were significantly higher proportions of suboptimal levels of function among the extremely preterm children (P ≤ 0.05). The mean (SD) multiattribute utility score for the extremely preterm children as a cohort was 0.789 (0.264), compared to 0.956 (0.102) for the classmates born at term, a mean difference in utility score of 0.167 (95% CI 0.124, 0.209) that was statistically significant (P < 0.001). The Tobit regressions revealed that, compared to birth at term, birth at ≤23 completed weeks, 24+0-24+6 weeks and 25+0-25+6 weeks gestation reduced the Health Utilities Index Mark III multi-attribute utility score by an average of 0.312 (95% CI 0.169, 0.455; P < 0.001), 0.337 (95% CI 0.235, 0.439; P < 0.001) and 0.243 (95% CI 0.159, 0.327; P < 0.001), respectively. Conclusions: The results of this study should be used to inform the development of future economic evaluations of interventions aimed at preventing extremely preterm birth or alleviating its effects. © 2009, International Society for Pharmacoeconomics and Outcomes Research (ISPOR).