Chunhuan Lao

Background: Systemic lupus erythematosus (SLE) is a complex autoimmune condition with a high level of morbidity, mortality and healthcare costs. In New Zealand prevalence of the condition has been increasing over time, although studies to date are based on national administrative datasets or hospital records. Objective: We aimed to estimate the prevalence of SLE based on primary care medical records in New Zealand and to evaluate the differences in age, gender and ethnicity. Methods: Potential SLE cases were identified through electronic primary care records from 1 January 2000 to 20 March 2024. All records were manually reviewed to identify the diagnosis based on 2019 European League Against Rheumatism/American College of Rheumatology classification criteria. Prevalence was based on definite and probable cases. Results: Sixty-eight SLE cases were identified (55 definite, 6 probable, 7 possible) from a total practice population of 96,348. The crude prevalence of SLE estimated using primary care records was 63.3 per 100,000 people in 2024. The World Health Organization age-standardised prevalence was 52.9 per 100,000 people in 2024. SLE prevalence generally increased with advancing age. Women were five times more likely than men to have SLE (RR 5.36, 95% CI 2.63 – 10.93. Pacific people had the highest age-standardised prevalence of SLE (94.1), followed by Asian (58.7), European/Others (48.3) and Māori (42.9 per 100,000). Conclusion: The use of primary care medical records builds on national studies based primarily on administrative databases. Prevalence of SLE is highest in the elderly (>85 years), females and Pacific people based on primary care data in New Zealand.

Aims: To describe pregnancy outcomes in those with systemic lupus erythematosus (SLE) in Aotearoa/New Zealand. Methods: We conducted a retrospective population-based cohort study using linked national datasets from 2005 to 2022. Multivariable logistic regression estimated associations between birth outcomes and timing of SLE diagnosis, end-stage kidney disease (ESKD), ethnicity, maternal age, deprivation quintile and year of parturition. Results: Among 2450 females with SLE, 1532 were aged 18–45 years. There were 971 births, with a live birth rate of 96.1%. Preterm birth occurred in 19.3%, caesarean section in 36.6%, and induction in 48.1%. Births occurring after the diagnosis of SLE were associated with higher odds of preterm birth (OR 1.77, 95%CI 1.17–2.71), induction (OR 2.21, 95%CI 1.58–3.11) and ESKD (OR 23.7, 95%CI 4.05–450). Conclusions: SLE is associated with increased obstetric risk in New Zealand, particularly for pregnancies after diagnosis, and among those with ESKD, with trends toward higher risk in Māori and Pacific ethnicities.

Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory condition that affects the joints, skin, eyes, lungs, heart, blood vessels, and nervous system. Aim: This study aims to estimate the incidence and prevalence of RA in New Zealand and compare the mortality of RA patients with the general population. Methods: Patients with a SNOMED CT code for RA in 2018–2025 were identified from the Pinnacle dataset. The WHO (World Health Organization) age-standardised rate (ASR) of incidence and prevalence of RA were calculated by ethnicity and gender (women and men). The standardised mortality ratio (SMR) was estimated to compare the relative rate of observed deaths in RA patients with the expected deaths in the general population. Results: We identified 3831 RA patients during the study period. The age-standardised incidence of RA was 26.9 (95% CI: 22.8–30.9) per 100,000 population. Women (34.8, 95% CI: 28.3–41.3, per 100,000) had around twice the incidence of RA than men (18.2, 95% CI: 13.5–22.9). The age-standardised prevalence of RA was 417.5 (95% CI: 402.8–432.1) per 100,000 population. The prevalence was 583.0 (95% CI: 558.8–607.2) per 100,000 for women and 237.6 (95% CI: 221.8–253.3) for men. Asians had the highest age-standardised incidence but the lowest age-standardised prevalence among all ethnic groups. The SMR of all the incident RA patients compared to the general population was 1.07 (95% CI: 0.80–1.34). Discussion: The prevalence of RA in general practice aligns with rates observed in secondary care settings. The upward trend in RA prevalence raises concerns about escalating healthcare system burdens, including increased costs and resource demands. The rise in RA prevalence was driven by increasing incidence among Asian populations.

Aims: Lupus nephritis (LN) is common in systemic lupus erythematosus (SLE) and is associated with adverse renal outcomes and premature mortality. There is limited data examining LN outcomes in Aotearoa New Zealand and none examining outcomes since mycophenolate mofetil (MMF) became subsidised for use in class III/IV LN induction. We describe a cohort of adults with biopsy-confirmed LN over an 18-year period in two regions of Aotearoa New Zealand, including LN characteristics, treatment, and outcomes. Methods: Cases were identified from laboratory databases and relevant data extracted from patient records. Response was defined per Kidney Disease, Improving Global Outcomes (KDIGO) with overall renal response (ORR) defined as at least partial response (PR). Outcomes among patients with class III/IV LN were explored by induction treatment and timing of MMF restrictions. Results: One hundred cases were identified, including 74 with class III/IV LN. Most (85/100) were women, living in urban areas (78%), with ethnicities including Māori (25%), Pacific (13%) and NZ European (38%). The median age at LN diagnosis was 38 years (range 18-74) and the median time between SLE diagnosis and renal biopsy was 2 years. In the MMF-restricted period, MMF was used for induction in class III/IV LN in 43% (12/28) of cases, and in 72% (33/46) of cases in the MMF-unrestricted period ( p = .01). In the MMF-unrestricted period, use of high dose cyclophosphamide stopped (18% to 0%), complete response (CR) rates doubled (14% to 33%, p = .08) whereas rates of ORR did not show statistically significant change (39% to 50%, p = .37). At last-observed follow up (mean 7 years from biopsy) 26/74 (36% cases) had poor outcomes with no renal response. Conclusion: In this LN cohort in Aotearoa New Zealand, half of people with LN class III/IV do not achieve early renal response and over one-third have poor outcomes over less than a decade of follow up. Subsidy of MMF substantively increased its use and patients in this time period had better rates of good LN outcomes. These data suggest considerable unmet need for effective treatments for LN and that funding of effective medicine for LN increases their use and improves LN outcomes.

Objectives: This study aims to estimate the annual medical costs of systemic lupus erythematosus (SLE) in New Zealand (NZ). Methods: SLE patients were linked to the Australia and New Zealand Dialysis and Transplant Registry, Pharmaceutical Collection, National Minimum Dataset, National Non-Admitted Patients Collection and Mortality Collection. National direct medical costs of SLE in 2006-2021 and annual costs per patient were estimated. Generalized linear model was used to examine the impact of various factors on medical costs, including ethnicity, gender, age, socioeconomic status and presence of end-stage kidney disease (ESKD). Results: The annual national costs of SLE were stable over time, around NZ$12 million. The average costs were NZ$8,324 (US$5,277, €5,011) per patient per year, with the costs for patients with ESKD being nine times higher than patients without ESKD (NZ$47,143 vs NZ$5,091). The costs per patient for Māori and Pacific were both around twice the costs for European/Others (NZ$13,124 and NZ$11,842 vs NZ$6,153), but the difference attenuated after adjustment for ESKD and other factors. Among patients without ESKD, Asian, males and patients living in the most deprived areas were associated with higher costs. For patients with ESKD, Māori and patients living in the most deprived areas had higher costs. Conclusions: The annual national costs of SLE were stable over time. The increase in pharmaceutical costs were offset by decrease in hospitalisation costs. Costs for patients with ESKD were nine times higher than costs for patients without ESKD. Interventions for slowing the disease progression and preventing ESKD can reduce medical costs.

Objectives: This study aims to explore the treatment pattern of systemic lupus erythematosus (SLE) in Aotearoa/New Zealand. Methods: SLE patients were linked to the pharmaceutical dispensing data. The use of publicly funded anti-malarials, immunomodulators, biologics, glucocorticoids and bisphosphonates were compared by gender, ethnicity, age group, socioeconomic status and year of SLE identification. Adherence to hydroxychloroquine was examined using the medication possession ratio (MPR), with a MPR of ≥0.8 considered as high adherence. Results: Of the 2631 SLE patients, 73.8% used hydroxychloroquine, 64.1% used immunomodulators/biologics and 68.0% used 5 mg or more prednisone daily for at least 90 days. Women were more likely to use hydroxychloroquine than men. Asian patients had a different treatment pattern than other ethnic groups, and Māori were less likely to use hydroxychloroquine. The proportions of patients using different treatments decreased with age. Of the patients using hydroxychloroquine, 54.5% had high adherence. For patients over 40 years old and on long term prednisone, 47.3% had bisphosphonates and this figure was 17.8% for patients under the age of 40 years old. Patients with better socioeconomic status had a higher probability of using bisphosphonates than patients with lower socioeconomic status. Conclusions: Adherence to hydroxychloroquine in these patients varied and was lower in men and in Māori. Prednisone is commonly prescribed and used long term. Half of those over the age of 40 years old co-administered bisphosphonate. Further research is needed to identify the reasons for these discrepancies on SLE treatments by gender, ethnicity, age and socioeconomic status.

Background: This study aims to examine the treatment patterns of end-stage kidney disease (ESKD) among SLE patients and to compare the outcome of hemodialysis (HD) and peritoneal dialysis (PD). Methods: SLE patients identified from the national administration dataset in 2005–2021 were linked to the Australia and New Zealand Dialysis and Transplant Registry to identify ESKD cases. The adjusted odds ratio of having PD instead of HD as the first treatment for ESKD for Asian, Māori, and Pacific compared with European/others was estimated with the logistic regression model. The adjusted hazards ratio of all-cause mortality for patients having PD first compared with HD first was calculated. Results: Two hundred ten ESKD patients with SLE were identified. Two thirds (137/210) of the ESKD patients had HD as the first treatment, and one third (68, 32.4%) had PD first. Around 60% of Asian patients had PD as the first treatment, compared with 30% in other ethnic groups. The adjusted odds ratio of having PD as the first treatment for Asian patients compared with European/others was 3.00 (95% confidence interval, 1.16–7.73). The adjusted hazards ratio of all-cause mortality for patients in the PD group compared with the HD group was 0.60 (95% confidence interval, 0.37–0.97). Conclusions: Asian patients with ESKD were more likely to have PD as the first treatment. The optimal dialysis type for ESKD patients with SLE might be different from ESKD patients caused by other diseases. ESKD patients with SLE receiving PD first had superior outcomes than patients receiving HD first.

Objectives: The objective of this study is to investigate the influence of diabetes on breast cancer‐specific survival among women with breast cancer in Aotearoa/New Zealand.Methods: This study included women diagnosed with invasive breast cancer between 2005 and 2020, with their information documented in the Te Rēhita Mate Ūtaetae—Breast Cancer Foundation National Register. Breast cancer survival curves for women with diabetes and those without diabetes were generated using the Kaplan–Meier method. The hazard ratio (HR) of breast cancer‐specific mortality for women with diabetes compared to women without diabetes was estimated using the Cox proportional hazards model.Results: For women with diabetes, the 5‐year and 10‐year of cancer‐specific survival were 87% (95% CI: 85%–88%) and 79% (95% CI: 76%–81%) compared to 89% (95% CI: 89%–90%) and 84% (95% CI: 83%–85%) for women without diabetes. The HR of cancer‐specific mortality for patients with diabetes compared to those without diabetes was 0.99 (95% CI: 0.89–1.11) after adjustment for patient demographics, tumor characteristics, and treatments. Age at cancer diagnosis and cancer stage had the biggest impact on the survival difference between the two groups. When stratified by cancer stage, the cancer‐specific mortality between the two groups was similar.Conclusions: While differences in survival have been identified for women with diabetes when compared to women without diabetes, these are attributable to age and the finding that women with diabetes tend to present with more advanced disease at diagnosis. We did not find any difference in survival between the two groups due to differences in treatment.