Isolated clubfoot in the Northern Territory of Australia: birth prevalence and population description

Abstract

Background: Clubfoot prevalence in the Aboriginal and Torres Strait Islander population (hereafter Indigenous population) is reportedly higher than globally. This study enumerates and describes the isolated (also 'idiopathic') clubfoot population in Australia's Northern Territory (NT), where 30% of the population is Indigenous.

Methods: In this retrospective study, medical records were searched to identify all cases in the NT born in 2009-22 inclusive. Birth prevalence was calculated by using established methods. Logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs) comparing characteristics of Indigenous with non-Indigenous babies with clubfoot.

Results: The birth prevalence of isolated clubfoot (150 cases/53 591 births) was 2.80/1000 (95% CI: 2.35-3.25). For 109 Indigenous babies, the prevalence was five times higher (5.99, 95% CI: 4.87-7.12) than for non-Indigenous babies (1.16, 95% CI: 0.84-1.56) and three times higher in Indigenous males (4.11, 95% CI: 3.35-4.86) than females (1.42, 95% CI: 0.96-1.88). Among babies with clubfoot, Indigenous babies with clubfoot were more likely to be male (OR = 2.68; 95% CI: 1.22-5.90; P = 0.014), from remote or very remote localities (OR = 14.24; CI: 5.98-33.90; P < 0.001), and have younger mothers (OR = 13.88; 95% CI: 3.90-49.39; P < 0.001).

Conclusion: The prevalence of isolated clubfoot in Australia's NT is higher than global estimates and other Australian reports, and disproportionately affects Indigenous babies. An Australian clubfoot register would be invaluable to improve the national understanding of prevalence patterns. Given the disproportionate prevalence in Indigenous babies, culturally responsive service provision, clinical outcomes, and experiences of their families warrant investigation.

Keywords: Australian Aboriginal and Torres Strait Islander Peoples; Northern Territory; clubfoot; congenital abnormalities; prevalence.

Figure 1.

Isolated clubfoot case ascertainment screening flowchart. ^aPhysiotherapy databases include all patients treated with serial casting for congenital abnormalities, not just clubfoot. ^bNT Midwives Collection includes the Congenital Anomalies Register within the NTPR. Entries were included that recorded ‘clubfoot’, ‘talipes’, ‘CTEV’, or related terms within the condition description. ^cCoding data for admissions during the study period in NT Health hospitals according to ICD-10-AM 6th–12th editions. ^dRepeated admissions for individuals resulted in duplicates within the coding data.