Authors (including presenting author) :
Lee SYR, Chan CM, Chan WH, Chan LK, Lee KP
Affiliation :
Department of Paediatrics and Adolescent Medicine, Pamela Youde Nethersole Eastern Hospital
Introduction :
It has been the practice of the neonatologists reviewing survival rates of premature infants in their own centres and comparing the survival rates with other centres. Examples include the Vermont Oxford Network and the Australian New Zealand Neonatal Network. The survival rate could be an indicator of standard of care. Through this exercise, neonatal units may strive for service improvement and have local data for counseling mothers with imminent premature delivery.
Objectives :
To find out the survival rates of premature infants born in our hospital from 2006 to 2020 and compare our survival rates with other parts of the world.
Methodology :
We used CDARS (a search engine of clinical information system of the Hospital Authority) and retrieved data of premature infants with gestation less than 28 weeks born in our hospital. Stillbirth was excluded. Survival was defined as survival to discharge from the birth episodes. The survival figures were compiled in the two periods: years 2006 to 2012 and years 2014 – 2020 because there was reform in management structure in the year 2013. From the Medline, we looked for studies with survival rates of premature infants (livebirth) born at gestation less than 28 weeks. For the sake of comparison with our own data, among all these studies, we selected those studies having survival rates in two periods across the 2000s and the 2010s. We also tried to pick publications by other local hospitals in Hong Kong. We also looked for meta-analysis with pooled data from various countries in the world.
Result & Outcome :
There were two cohorts from PYNEH in two periods: 2006 -2012 and 2014-2020. From the literature, we identified a publication of a cohort from the Queen Mary Hospital (QMH), Hong Kong. We selected studies from USA,Sweden and the Australia New Zealand Network (ANZ) illustrating the survival rates across the two recent decades. We identified a meta-analysis of 65 studies from 20 countries spanning the period 2000 to March 2017.
In PYNEH, there was improved survival across the two periods (2006 – 2012 versus 2014 – 2020) except for the 27-week neonates. The survival rates of these two periods were 50% and 62.5% at 24 weeks, 56.3% and 72.2% at 25 weeks, 76.3% and 100% at 26 weeks, 92.9% and 88.5% at 27 weeks respectively. From the meta-analysis, the 95% confident intervals of survival rate were 48 -59.6 at 24 weeks, 68.7 to 78.6 at 25 weeks, 81 -86.6 at 26 weeks, 87.4 – 92.3 at 27 weeks. Using these 95% confident intervals as the standard, in the period 2006 – 2017, the survival rates were below the standard at the gestation of 25 and 26 weeks. However, in the period 2014 – 2020, we were above the standard at the gestation of 24 and 26 weeks and within the standard at 25 and 27 weeks. Our survival rates in the period from 2014 to 2020 were similar to that of QMH. The survival rates of PYNEH and QMH were: 62.5% and 64% at 24 weeks, 72.2% to 73% at 25 weeks, 100% to 90% at 26 weeks and 88.5% and 93% at 27 weeks respectively.
We examined the survival rates of USA in two periods: 2003 to 2007 and 2008 to 2012, Swedish data in two periods: 2004 to 2007 and 2014 to 2016, and the survival rates of the ANZ network in year 2007 and year 2018. All these three localities showed improvement in survival rates especially at the lower gestation. The improvement across time was slight in the ANZ network as the survival rates in 2007 were already quite impressive leaving less room for improvement. The survival rates in 2007 and 2018 were: 66.3% and 70.1% at 24 weeks, 83.5% and 82.5% at 25 weeks, 89.5% and 92.1% at 26 weeks, 92.2% and 93.4% at 27 weeks respectively.
Conclusion:
Like USA, Sweden and the ANZ network, the survival rates of premature infants improved in the last two decades in PYNEH. Currently we had survival rates meeting / exceeding the 95% confident intervals of the largest pooled data published in 2019.
