Why do Outcomes of Critical Congenital Heart Disease in New Zealand Differ by Ethnicity?

Abstract

Critical congenital heart disease (CCHD) are life-threatening inborn structural heart abnormalities. Indigenous Māori and Pacific CCHD survival is inferior to European infants in New Zealand (NZ). Knowledge of why ethnic disparity in CCHD survival occurs in NZ is sparse. Therefore, this research aims to understand the contributors of inequitable infant survival in CCHD by ethnic group to inform healthcare advances in NZ. A multi-ethnic, multisource grounded theory was applied, intertwining Indigenous (Kaupapa Māori), Pacific (Talanoa) and Western worldviews, underpinned by the dialectical pluralism philosophical paradigm. Three sources informed the grounded theory:

A scoping review and a systematic integrative literature review; A national retrospective cohort study of CCHD cases (excluding terminations) over 14 years with survival and Cox regression analysis and An interview study of CCHD parent and healthcare professional experiences, with transcripts assessed for key concepts.

The theory of navigating the disjuncture of a narrowly responsive healthcare system is presented. The scoping and systematic review revealed a dearth of NZ knowledge and unequal CCHD mortality risk burdens by ethnic groups. The cohort analysis (n = 1,039) confirmed inequitable CCHD survival by ethnicity with multivariable analysis identifying independent drivers to explain this difference: specific cardiac diagnoses; lower birthweight; comfort care management, and higher levels of deprivation. The interview study (n = 57 interviews, n = 25 parents, n = 20 healthcare professionals) identified three categories: 1) Minoritised groups experience disparate healthcare quality; 2) healthcare systems are under-resourced to provide equitable support for the differential needs of grieving parents, and 3) healthcare systems could engage minoritised families more optimally in shared decision making. Professionals seem positioned to acknowledge and support equitable changes in healthcare. Results suggest inequities in CCHD infant survival by ethnic group in NZ are attributed to disparate upstream health determinants and healthcare systems mediating differential quality experiences. Updates in health equity policy and practice are recommended if parity in infant survival for all is to be achieved. Increasing the knowledge base into mechanisms underlying broader inequities and interventions to reduce disparities is warranted.