Hidden figures and misnomers: a case for disaggregated Asian health statistics in Aotearoa New Zealand to improve health outcomes

People of Asian ethnicity in Aotearoa New Zealand currently constitute 15% of the population. The majority are migrants. The current sources of data to monitor Asian health in New Zealand are routine population surveys and administrative data. This article highlights the effect of "masking" due to the use of a single "Asian" category for reporting health indicators. Issues regarding the use of the "Other Asian" category in administrative data are also discussed. This discourse provides an impetus to raise questions on how we should be developing policies, strategies and investments to make visible the hidden figures of Asian health statistics in New Zealand. Given that Asian population will become the second largest ethnic group in New Zealand, practical steps need to be taken to strengthen the New Zealand health strategy and enable equitable investment in Asian health.

The effectiveness of goal setting on glycaemic control for people with type 2 diabetes and prediabetes: A systematic review and meta-analysis

AIM

This review assessed the effectiveness of interventions using a goal-setting approach on glycaemic control for people diagnosed with prediabetes or type 2 diabetes.

DESIGN

A systematic review guided by the Joanna Briggs Institute methodology for conducting systematic reviews of primary research studies was conducted.

DATA SOURCES

Randomized controlled trials and experimental studies with a minimum follow-up period of 6 months were considered for inclusion. The primary outcome was change in glycaemic control as measured by glycated haemoglobin (%) and/or fasting plasma glucose (mg/dl). A systematic search of seven electronic databases was completed in October 2020.

REVIEW METHODS

Papers meeting the inclusion criteria were critically appraised using the Joanna Briggs Institute tools for critical appraisal followed by data extraction. A Grading of Recommendations Assessment, Development and Evaluation assessment was conducted to assess the overall certainty of the evidence. Fixed-effect meta-analyses were completed to demonstrate the mean effect for each outcome of interest.

RESULTS

Twenty one studies were included in this review. Goal setting was more effective than usual care for glycaemic control in prediabetes at 6 months and at 12 months for fasting plasma glucose (mg/dl) and glycated haemoglobin (%). Goal setting was more effective than usual care for glycaemic control in type 2 diabetes for fasting plasma glucose (mg/dl) at 6 months, fasting plasma glucose (mg/dl) at 12 months, glycated haemoglobin (%) at 6 months and glycated haemoglobin (%) at 12 months.

CONCLUSION

The evidence suggests goal setting is effective in supporting people to achieve glycaemic targets in prediabetes and type 2 diabetes.

Minimization of bias in measures of gestational weight gain

Gestational weight gain (GWG) is an important predictor of adverse pregnancy outcomes including gestational diabetes, preterm birth, delivery by caesarean and post-partum weight retention. The Institute of Medicine guidelines on GWG are widely adopted, and GWG is widely researched as an outcome of interest in lifestyle interventions during pregnancy. However, estimation of prepregnancy weight and measurement of weight prior to delivery introduce bias into measures of GWG. This review discusses the sources of bias in measures of GWG and the potential effect of bias on the relationship between adverse pregnancy outcomes associated with GWG. Bias in measures of GWG can be minimized by using measured weight at the first antenatal appointment in early pregnancy rather than self-reported prepregnancy weight and by adjusting for gestational age when the last weight is collected earlier than the delivery date. Bias owing to gestational age is an important potential confounder in the relationship between GWG and adverse pregnancy outcomes.

Built environment changes and active transport to school among adolescents: BEATS Natural Experiment Study protocol

INTRODUCTION

Natural experiments are considered a priority for examining causal associations between the built environment (BE) and physical activity (PA) because the randomised controlled trial design is rarely feasible. Few natural experiments have examined the effects of walking and cycling infrastructure on PA and active transport in adults, and none have examined the effects of such changes on PA and active transport to school among adolescents. We conducted the Built Environment and Active Transport to School (BEATS) Study in Dunedin city, New Zealand, in 2014-2017. Since 2014, on-road and off-road cycling infrastructure construction has occurred in some Dunedin neighbourhoods, including the neighbourhoods of 6 out of 12 secondary schools. Pedestrian-related infrastructure changes began in 2018. As an extension of the BEATS Study, the BEATS Natural Experiment (BEATS-NE) (2019-2022) will examine the effects of BE changes on adolescents' active transport to school in Dunedin, New Zealand.

METHODS AND ANALYSIS

The BEATS-NE Study will employ contemporary ecological models for active transport that account for individual, social, environmental and policy factors. The published BEATS Study methodology (surveys, accelerometers, mapping, Geographic Information Science analysis and focus groups) and novel methods (environmental scan of school neighbourhoods and participatory mapping) will be used. A core component continues to be the community-based participatory approach with the sustained involvement of key stakeholders to generate locally relevant data, and facilitate knowledge translation into evidence-based policy and planning.

ETHICS AND DISSEMINATION

The BEATS-NE Study has been approved by the University of Otago Ethics Committee (reference: 17/188). The results will be disseminated through scientific publications and symposia, and reports and presentations to stakeholders.

TRIAL REGISTRATION NUMBER

ACTRN12619001335189.

What predicts regression from pre-diabetes to normal glucose regulation following a primary care nurse-delivered dietary intervention? A study protocol for a prospective cohort study

INTRODUCTION

Pre-diabetes is a high-risk state for the development of type 2 diabetes mellitus (T2DM) and cardiovascular disease. Regression to normoglycaemia, even if transient, significantly reduces the risk of developing T2DM. The primary aim of this mixed-methods study is to determine if there are clinically relevant differences among those with pre-diabetes and excess weight who regress to normoglycaemia, those who have persistent pre-diabetes and those who progress to T2DM following participation in a 6-month primary care nurse-delivered pre-diabetes dietary intervention. Incidence of T2DM at 2 years will be examined.

METHODS AND ANALYSIS

Four hundred participants with pre-diabetes (New Zealand definition glycated haemoglobin 41-49 mmol/mol) and a body mass index >25 kg/m² will be recruited through eight primary care practices in Hawke's Bay, New Zealand. Trained primary care nurses will deliver a 6-month structured dietary intervention, followed by quarterly reviews for 18 months post-intervention. Clinical data, data on lifestyle factors and health-related quality of life (HR-QoL) and blood samples will be collected at baseline, 6 months, 12 months and 24 months. Sixty participants purposefully selected will complete a semi-structured interview following the 6-month intervention. Poisson regression with robust standard errors and clustered by practice will be used to identify predictors of regression or progression at 6 months, and risk factors for developing T2DM at 2 years. Qualitative data will be analysed thematically. Changes in HR-QoL will be described and potential cost savings will be estimated from a funder's perspective at 2 years.

ETHICS AND DISSEMINATION

This study was approved by the Northern A Health and Disability Ethics Committee, New Zealand (Ethics Reference: 17/NTA/24). Study results will be presented to participants, published in peer-reviewed journals and presented at relevant conferences.

TRIAL REGISTRATION NUMBER

ACTRN12617000591358; Pre-results.

A cost-effectiveness analysis of the Prediabetes Intervention Package (PIP) in primary care: a New Zealand pilot programme

AIMS

To estimate the cost-effectiveness of the Prediabetes Intervention Package (PIP), a multilevel primary care nurse-delivered prediabetes lifestyle intervention programme was piloted in Hawke's Bay, New Zealand. The goal of the intervention was weight loss and prevention of progression from prediabetes to type 2 diabetes.

METHODS

A cost-effectiveness evaluation was conducted from a health funder perspective using 2015 NZ$ with costs and per kilogram (kg) weight change at six months analysed at an individual participant level. Missing six-month data were imputed using multiple imputation adjusted for baseline characteristics. Change in weight was calculated following intention-to-treat principles. Three lower-cost scenarios were modelled.

RESULTS

Using multiple imputation and bootstrapping, there was a statistically significant median difference in weight between the intervention and control groups of 1.87kg (95% CI 0.54, 3.15) at six months. The incremental cost-effectiveness ratio (ICER) was NZ$170.90 (95% CI 100.37, 553.93) per 1kg of weight loss. ICERs for the lower-cost scenarios ranged from NZ$95.33 (95% CI 56.12, 308.36) to $NZ120.74 (95% CI 71.04, 391.60).

CONCLUSION

The primary care nurse-delivered PIP intervention is likely to be a cost-effective weight loss strategy for preventing or delaying progression to type 2 diabetes in people with prediabetes.

Characteristics and cardiovascular risk of new cases of type 2 diabetes in Otago, New Zealand, 1998-2004

We compared clinical and metabolic characteristics and estimated cardiovascular risk for 2073 new cases of type 2 diabetes enrolled on the Otago Diabetes Register, 1998-2004 by age at diagnosis (<40 years, 40-59 years, 60-79 years, >79 years). Data were extracted and means or proportions calculated. 5-year cardiovascular risk was estimated using New Zealand risk equation tables. The <40 year age group had the highest proportion of current smokers (27%). Weight, body mass index and diastolic blood pressure decreased significantly with increasing age from 104.2 kg, 35.9 kg/m(2) and 80.5 mmHg, respectively, for the <40 year age group to 71.6 kg, 26.9 kg/m(2) and 76.2 mmHg, respectively, for the > or =80 year age group (p<0.01). The reverse trend was observed for systolic blood pressure. HbA1c and triglycerides were significantly higher and HDL-cholesterol significantly lower in the <40 year age group compared with other groups (p<0.001). Estimated 5-year risk of cardiovascular disease was lower in the young age group when compared with older age groups despite, overall, having the worst array of modifiable clinical risk factors. A new approach to assessment and communication of cardiovascular risk and aggressive treatment of modifiable risk factors is likely to be necessary to prevent potentially serious diabetes complications at a young age.

Under-reporting of diabetes on death certificates among a population with diabetes in Otago Province, New Zealand

AIMS

To estimate the degree of under-reporting of diabetes on death certificates, and to describe the population of patients enrolled on the Otago Diabetes Register known to have died during the 6-year period to 31 December 2003.

METHODS

The Otago Diabetes Register was established in 1998, as part of the Otago Diabetes Project, to monitor and evaluate diabetes care in the Otago region, New Zealand. Demographic and clinical data, including vital status, type of diabetes and year of diagnosis, diabetes complications, diabetes medication and clinical examination, and biochemistry test results were collected annually from general practice medical records. Copies of death certificate information were obtained from the national Births, Deaths and Marriages office, Department of Internal Affairs for 508 enrolled diabetic patients known to have died before 31 December 2003. Causes of death were coded using ICD-10. Date, place, and causes of death were added to the Otago Diabetes Register.

RESULTS

The mean age at death was 78 years (SD=9.7) and the average duration of diagnosed diabetes was 12.1 (SD=8.6) years. Diabetes was mentioned on the death certificates of just over half (55.1%) of the 508 diabetic patients. More of those using insulin only, or oral hypoglycaemic and insulin therapies combined, before death had diabetes mentioned on their death certificate, 67.8% and 81.0%, respectively, compared with those taking oral hypoglycaemics only (55.7%) or diet only treatment (38.0%). Almost 50% of deaths were due to a circulatory system disorder, either cardiovascular or cerebrovascular disease. Five men with type 1 diabetes, all aged less than 50 years, died from diabetic ketoacidosis or hypoglycaemia.

CONCLUSION

Diabetes is under-reported on death certificates in New Zealand. Improvements in the completion of death certificates are necessary, if the impact of the diabetes epidemic on mortality is to be monitored appropriately.

Insulin resistance in a rural Maori community

AIM

To determine the prevalence of insulin resistance, impaired fasting glycaemia, impaired glucose tolerance, and diabetes mellitus in a rural Maori community, and to compare different methods for identifying individuals with insulin resistance.

METHODS

589 randomly selected individuals from the Ngati Porou Hauora Register aged 25 years and over and resident on New Zealand's East Coast north of Gisborne were invited to participate in the study. A questionnaire was administered, anthropometric measures made, and blood samples taken for an oral glucose tolerance test and biochemical analysis. Impaired fasting glycaemia, impaired glucose tolerance, and diabetes mellitus were defined according to World Health Organization (WHO) diagnostic criteria, and among those persons with normal glucose tolerance, insulin resistance was calculated according to the McAuley formula and three other recognised methods for calculating insulin sensitivity.

RESULTS

The overall age-standardised prevalence of diabetes (both known and newly diagnosed) was 10.6% and the age-standardised prevalence of insulin resistance was 37.0%. Age-specific diabetes rates were high among the older age groups, peaking at 34.1% for 60-69 year olds, whereas age-specific insulin resistance rates were high among the young age groups with the highest rate (44.3%) occurring among 30-39 year olds. Persons identifying as insulin-resistant reported higher rates of gout and family history of diabetes--and were found to have a higher waist circumference, blood pressure, and lower high-density lipoprotein (HDL) cholesterol than those without a glucose metabolism disorder.

CONCLUSION

Diabetes is a common disorder among this population, but insulin resistance is even more prevalent, especially among young age groups. This is considerable cause for concern given that insulin resistance is believed to be the underlying cause of most cases of type 2 diabetes mellitus, and is confirmed by these data to be associated with a high degree of cardiovascular risk.

Establishing a regional diabetes register and a description of the registered population after one year

AIM

To establish a regional diabetes register in order to determine baseline data with which to monitor diabetes care in Otago, New Zealand.

METHODS

All general practitioners (GPs) in Otago were invited to participate in the project. Diabetic patients were identified from GP diabetes registers and invited to participate in the project. Written consent was obtained before any data were transferred from general practices to the Otago Diabetes Register. An Access-based computer programme was developed to record and analyse patient data.

RESULTS

In 1998, 1693 consenting diabetic patients were enrolled on the Otago Diabetes Register. The ratio of male to female patients was almost 1:1; the median age was 67 years; 11.9% had Type 1 diabetes and 86.5% had Type 2 diabetes; 44.5% were treated with hypoglycaemic tablets only and 25.6% were treated with insulin only. For those aged over 16 years, the mean systolic BP was 140.6 mmHg and the mean diastolic BP was 78.7 mmHg. 65.4% had undergone a retinal examination within the previous two years and 36.2% a feet examination within the previous year.

CONCLUSIONS

The 1998 data will be used to monitor changes in diabetic care over time. Ongoing patient recruitment and data collections will also assist with informing funding decisions for diabetes services and improving diabetes information in New Zealand.

The development of a national agreed minimum diabetes dataset for New Zealand

The development of a minimum diabetes dataset (MDD) for monitoring diabetes in New Zealand was intended to facilitate diabetes quality initiatives. Existing published datasets were reviewed and a draft MDD for New Zealand was distributed to all 147 specialist, general practice and relevant community groups. Data definitions were either identical or compatible with other datasets and dataset items included if there were at least six supportive replies. All groups were followed up by letter and telephone. A total of 26 (18%) replies were received. Comments were reviewed and the recommended MDD finalised. There was agreement that this dataset would be embedded into the software of at least three commercially available patient management systems. In conclusion, developling an agreed national MDD was difficult, in spite of its potential utility for local, regional and national collation of diabetes data allowing those involved to generate a picture of diabetes and its outcomes.

An evaluation of the National Cervical Screening Programme Otago site

AIM

To evaluate progress of the Otago Cervical Screening Programme towards achieving its goal of reducing cervical cancer incidence and mortality using data routinely collected by the National Cervical Screening Register (NCSR), and to investigate whether all data required for this task are available from the NCSR.

METHOD

Non-identifying data for Otago women aged 20-69 years were obtained from the New Zealand National Cervical Screening Register for the period 1 July 1993 to 30 June 1996. For each five-year age group, proportion screened in three years, short interval re-screening estimates and age-specific reporting rates for squamous atypia of uncertain significance (ASCUS), low-grade intraepithelial lesions (LGIL) and high-grade intraepithelial lesions (HGIL) were calculated. Age-specific reporting rates were also calculated for 20-69 year-old New Zealand women for the same period and compared to the Otago rates.

RESULTS

The proportion of eligible women screened was 82.5%, slightly less than the target 85%. Women aged 55 years or more were underscreened, short interval rescreening was more common among younger women, age-specific reporting rates for ASCUS, LGIL and HGIL had increased since 1991/92, and the rate of HGIL was higher than expected in the 20-34 year age group.

CONCLUSIONS

In order to maximise the effectiveness and efficiency of the Otago Cervical Screening Programme, it is recommended that participation amongst older women be increased and frequent screening be reduced in the younger age groups. Unexpected elevated rates of HGIL amongst 20-34 year-old women were not adequately explained and require further investigation. Not all data required for an outcome evaluation were available through the NCSR.