Diabetes
| Diabetes single map | PHO analysis |
The goal of this Atlas of Healthcare Variation domain is to investigate the quality of care given to people with diabetes. The data is not intended to form a basis for judgement or definitive statements of quality, rather to raise questions about potential areas for quality improvement.
The indicators were developed with the help of an expert advisory group.
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Key messages
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Diabetes
(Data updated June 2024)
This Atlas domain has been updated using data from the updated Virtual Diabetes Register (VDR) for 2022. Changes made in this update include the following:
- The use of primary health organisation (PHO) enrolment data as the denominator for the diabetes prevalence indicator, replacing Stats NZ estimated population projections. This ensures alignment and consistency with the Health New Zealand VDR web tool. However, we acknowledge that some population groups are more likely to be unenrolled compared with others. For more information on access to primary care by demographics, please see www.tewhatuora.govt.nz/for-health-providers/primary-care-sector/primary-health-organisations/enrolment-with-a-general-practice-and-primary-health-organisation.
- Given the high prevalence of diabetes among the Indian population, we have replaced the Asian ethnic group with Indian. This enables us to gain an in-depth understanding of variations within the Indian population and offers some insights into the quality of care provided.
- To better capture diabetes prevalence among younger age groups, we have subdivided the 0‒24 years group into two categories: 0‒14 and 15‒24 years.
- To better capture the diversity in hypoglycaemic medication usage, we have incorporated additional pharmacological indicators including newer medicines like dulaglutide and empagliflozin.
- Due to unavailability of complete laboratory claims data for certain years (for some districts), laboratory indicators have been excluded from this update.
- Note that individuals recorded in the VDR but not enrolled in a PHO are excluded from analyses. This approach ensures consistency in the numerator and denominator for calculations.
Diabetes prevalence is markedly higher in some population subgroups than in others
The prevalence of diabetes increased significantly with age, ranging from 0.2 percent in those aged 0–14 years to 17.9 percent in those aged 75 years and older. In 2022, diabetes prevalence varied more than two-fold by Health New Zealand district, from 9.4 percent to 27.9 percent of a district population aged 65–74 years, and more than three-fold in those aged 45–64 years (5.2‒17.9 percent).
The Pacific population had the highest estimated rate of diabetes at 12.5 percent, followed by the Indian population (9.5 percent) and the Māori population (7.0 percent). The European/other ethnic group had the lowest rate of diabetes at 5.4 percent. On average, 48.2 percent of Pacific peoples aged 65–74 years were estimated to have diabetes compared with 12.5 percent of people of European/other ethnicity aged 65–74 years.
In 2022, within the Pacific population, diabetes prevalence differed among various ethnic subgroupings. For example, among those aged 65‒74 years, those who identified as Fijian had the highest prevalence at 56.7 percent, followed by Tongan (56.5 percent), Tokelauan (54.1 percent), Samoan (47.7 percent), Niuean (45.5 percent) and Cook Island Māori (41.3 percent). Those who had identified as Other Pacific Island (37.9 percent) and Pacific Island Not Further Defined (36.2 percent) had the lowest prevalence.
Good glycaemic control and cardiovascular risk factor management are important for positive outcomes
If haemoglobin A1c (HbA1c) in a person with diabetes does not meet an agreed target with dietary and lifestyle changes, drug therapy is recommended. Insulin and metformin are well proven. Evidence suggests good glycaemic control benefits microvascular outcomes.[1] The provision of comprehensive cardiovascular risk management for people with diabetes (such as blood pressure and lipid management) has been shown to improve macrovascular outcomes substantially while good glycaemic control has a smaller and very delayed effect.
The use of any hypoglycaemic medication varied around 1.5-fold by district
Given both the lack of available data on clinical parameters and the inability to split data by diabetes type, the indicators of medication use are not intended to suggest an ‘ideal’ rate of use, rather they provide a high-level view. Wide variation may raise questions such as, do districts with lower-than-average rates of medication use have lower or higher rates of diabetes complications?
Without HbA1c results available nationally, 67.7 percent of people with diabetes received any hypoglycaemic medication in 2022. Use was highest in those aged 0‒14 years (75.6 percent) and 65–74 years (74.2 percent). This varied around 1.5-fold by Health New Zealand district, from between 65.2 percent to 83.4 percent of those aged 65‒74 years with diabetes regularly receiving those medicines in 2022.
Metformin remains the standard initial drug treatment for type 2 diabetes. As expected, use increased with age. On average, 9.6 percent of people with diabetes aged 15‒24 years regularly received metformin compared with 58.2 percent of those aged 65–74 years in 2022. Males (52.8 percent) were more likely to regularly receive metformin than females (46.4 percent).
Newer medicines, including sodium-glucose co-transporter 2 (SGLT-2) inhibitors such as empagliflozin, have been available since February 2021. Glucagon-like peptide-1 (GLP-1) receptor agonists, such as dulaglutide, have been available since September 2021. These medicines are fully funded for the treatment of people with poorly controlled type 2 diabetes (individuals with HbA1c levels > 53 mmol/mol) who are at high risk of, or have established cardiovascular disease, diabetic kidney disease or heart failure, or who are of Māori or Pacific ethnicity. As these medicines are new and only funded for some people, these rates should be interpreted with caution. Since we define regular dispensing as people receiving medication for three or four quarters in a year, it is possible to miss individuals who started these medicines later in the year.
The regular dispensing of newer medication empagliflozin increased from 6.7 percent in 2021 to 13.3 percent in 2022, with higher rates of dispensing among people in the 45‒64 years age group (16.9 percent) followed by those aged 65‒74 years (15.7 percent). Rates of dispensing are higher among males (15.5 percent) compared with females (10.9 percent). The regular dispensing of empagliflozin varied more than two-fold by district for those aged 45‒64 years, ranging from 8.0 percent to 21.4 percent.
In 2022, the regular dispensing of dulaglutide was at 2.6 percent with the peak among people with diabetes aged 45‒64 years (3.4 percent). These rates varied by ethnicity: for example, Māori aged 45‒64 years (5.9 percent) have higher rates compared with other ethnic groups (Pacific peoples at 2.4 percent, Indian population at 1.6 percent and European/other at 3.1 percent). Rates also varied five-fold by district ranging from 1.2 percent to 6.1 percent across all age groups. For instance, the regular dispensing of dulaglutide among Pacific peoples aged 45‒64 years living in the Counties Manukau district was lower compared with other districts such as Hutt Valley and Hawke's Bay, despite higher rates of diabetes among Pacific peoples aged 45‒64 years living in the Counties Manukau district (33.6 percent).
Insulin therapy is used for both type 1 and type 2 diabetes. Overall, 20.3 percent of people with diabetes regularly received insulin in 2022. Across all ages, people of European/other ethnicity had the highest rate of insulin dispensing (22.0 percent) with people of Indian ethnicity having the lowest rate (12.5 percent). As might be expected, insulin dispensing was highest in the 0–14 and 15‒24-year age groups with diabetes, with 72.1 percent and 54.8 percent of these regularly dispensed insulin among the 0‒14 years and 15‒24 years groups, respectively.
Intensive management of high blood pressure and microalbuminuria
On average, 52.9 percent of people with diabetes received angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blockers (ARB) medicines in 2022. This is a slight reduction from 53.1 percent in 2021. The 2022 rate varied 1.2-fold by district (49.1‒58.7 percent). People of Indian ethnicity received the fewest ACEI or ARB medicines compared with other ethnic groups.
Intensive management of blood pressure and microalbuminuria is recommended to prevent progression of renal disease in diabetes. ACEI and ARB medicines are first-line treatments. The younger the age at diagnosis, the greater the impact of diabetes on life expectancy; this highlights the importance of glycaemic control, blood pressure management and prevention of kidney disease in younger people with diabetes.
Māori and Pacific peoples have higher rates of ACEI or ARB medicine use at a younger age; however, some data also shows these populations have significantly higher rates of end-stage renal disease. A recent publication from the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) found that Māori and Pacific peoples in Aotearoa New Zealand are at a significantly heightened risk of succumbing to the impacts of diabetic kidney disease reaching kidney failure (Māori 67 percent, Pacific peoples 67 percent), a two-fold greater likelihood than non-Māori non-Pacific (31 percent).[3]
Complications – hospital admissions for diabetic ketoacidosis and hypoglycaemia varied by age
Nationally, the highest rates for admission to hospital for diabetic ketoacidosis were among those aged 0–14 years (12.0 percent), followed by 15–24 years (6.0 percent). At all ages Māori (0.6 percent) experienced higher admission rates followed by European/other (0.4 percent).
The rates for admission to hospital because of hypoglycaemia was also highest in the youngest age group although the count of people was highest in those aged 65 years and over. It is pleasing to note there has been a consistent reduction in admissions to hospital for hypoglycaemia in those aged 0–24 years since 2018.
Complications – lower-limb amputations increased with age
Lower-limb amputation rates increased significantly with age, with 95 percent occurring in those aged 45 years and over. While this rare complication affected only 0.2 percent of the diabetes population in a year, in 2022, this meant 721 people lost part of a lower limb because of their diabetes, 204 of whom underwent major amputation and 517 underwent minor amputation. More detailed information on major and minor amputation levels is available elsewhere.4 In 2022, males (0.3 percent) had statistically significantly more lower-limb amputations than females (0.1 percent).
Note this indicator counts people with diabetes who had one or more amputations in a year. Our analyses excluded people who died during the year. This means that people who had an amputation during the year and died are not included. Also, if someone had multiple amputations within the year, they are counted only once.
People with diabetes occupied more bed-days for any reason
The number of medical and surgical bed-days occupied by people with diabetes for any reason was compared with the total occupied medical and surgical bed-days. Age had a significant effect on occupied bed-days. In 2022, age-specific rates ranged from 2.1 percent among those aged 0–14 years to 27.6 percent among those aged 65–74 years. People with diabetes aged 45–64 years occupied 26.2 percent of total bed-days, compared with a population prevalence of 9.8 percent of people with diabetes in this age group.
On an unadjusted basis, people with diabetes occupied 20.3 percent of total bed-days, despite a population prevalence of diabetes of 6.4 percent. However, some of the differences here are partially explained by the fact that increasing age is strongly associated with bed-day use and the age structure of people with diabetes is older than the general population. However, the extent of the bed occupancy by people with diabetes remains large.
In 2022, among the Indian population aged 65–74 years, 56.4 percent of total bed-days were occupied by those with diabetes while the population prevalence of diabetes in this age group is 44 percent. Among Pacific peoples in the same age group, total bed-days occupied by those with diabetes was 52 percent, compared with a population prevalence of 48 percent. In contrast, people of European/other ethnicity with diabetes aged 65–74 years occupied 22.4 percent of bed-days, with a population prevalence of 12.5 percent in that age group.
- How many of these results can be explained by the predominant type of diabetes?
- Are rates for specific indicators lower or higher than might be expected?
- Is there room for improvement in any of the indicators?
- Do results reflect local differences in care?
This Atlas domain draws on data contained in the VDR, which was developed by the Ministry of Health Manatū Hauora to estimate and track the number of people diagnosed with diabetes.
The VDR combines and filters various sources of health information, including the National Minimum Dataset, the National Non-admitted Patients Collection (outpatients), the Pharmaceutical Collection, the Laboratory Claims Collection and the Primary Health Organisation Enrolment Collection.
The VDR was used to estimate the prevalence of diabetes. The data is based on health service utilisation data that is consistent with diabetes care rather than formal clinical diagnosis or laboratory results, so should be interpreted with some caution. The Atlas does not use any patient-identifiable data.
Please note some of the source data that informs the VDR has not been consistently reported across all districts in Aotearoa New Zealand. Several data gaps have been identified and are likely to affect the accuracy of the VDR (in particular with sensitivity/coverage). So, results at regional level based on the VDR should be interpreted with some caution. Please see VDR: Technical Guide for more information on data quality issues.
The methodology is provided here (1.1MB, docx).
The Pharmaceutical Collection contains claim and payment information from community pharmacists for subsidised dispensing. This collection does not indicate whether a medicine was taken or whether the dose was effective. Over-the-counter medicines are not included. Note our definition of regular medication use only includes people receiving medication for three or more quarters in a year. It should be noted that we did not take into account people who initiate medication later in the year.
In selecting indicators for oral hypoglycaemic medication use, the expert advisory group for this Atlas domain decided to focus on medicines like metformin, sulfonylureas, vildagliptin, empagliflozin and dulaglutide as the medicines for people with type 2 diabetes and insulin as the key medication for people with type 1 diabetes.
There is no ideal rate of medicine use in people with diabetes because it depends on clinical need. However, wide variation between districts or ethnic groups raises questions as to why the rate of medicine use varies.
Analysis does not split by type of diabetes
There were some limitations as to what measures could be presented. It was not possible to reliably split people by type of diabetes; hence the indicators represent a combination of those with type 1 and type 2 diabetes. Generally, most people with diabetes aged 0–24 years will have type 1 diabetes, while around 90 percent and over of those aged 25 years and above will have type 2 diabetes.
The method used in the VDR to identify people with diabetes is less accurate at identifying children than adults with diabetes. A recently published survey highlights that local district data may be a better source for identifying prevalence in children.[5] The National Diabetes Register is currently under development. Once it is live, it will be possible to split results by type 1 and type 2 diabetes.
Some important outcome indicators could not be included
Due to limitations in currently available data, we could not explore certain outcome indicators, including screening for diabetic retinopathy, retinopathy rates and end-stage renal failure. Outcome indicators, including myocardial infarction rates, stroke and other cardiovascular outcomes, are not included in this version of the diabetes Atlas domain, but are likely to be included in future updates. We encourage users to investigate local data in relation to these outcomes to promote improvement and equity initiatives at PHO and general practice level.
Relationship with other Ministry of Health activities
The diabetes Atlas domain links with Te Pae Tata Interim New Zealand Health Plan,[6] which outlines priority actions to improve care for people with diabetes in Aotearoa New Zealand. This includes work towards each Health New Zealand district meeting the 26 quality standards published in 2020.[7] These standards link with many of the measures presented in the diabetes Atlas domain.
Te Tāhū Hauora would like to acknowledge Pharmac – Te Pātaka Whaioranga for supporting this work.
- Ministry of Health and New Zealand Society for the Study of Diabetes. 2021. Type 2 Diabetes Management Guidance. Dunedin: New Zealand Society for the Study of Diabetes. URL: https://t2dm.nzssd.org.nz.
- Ministry of Health. 2020. Diabetes. Wellington: Ministry of Health. URL: www.health.govt.nz/your-health/conditions-and-treatments/diseases-and-illnesses/diabetes.
- Sun T, Davies C, Au E, et al. 2023. 46th Report. Chapter 9: Kidney Failure in Aotearoa New Zealand. Adelaide: Australia and New Zealand Dialysis and Transplant Registry, Adelaide. URL: www.anzdata.org.au.
- van Netten JJ, Bus SA, Apelqvist J, et al. 2024. Definitions and criteria for diabetes-related foot disease (IWGDF 2023 update). Diabetes Metab Res Rev e3654. URL: https://onlinelibrary.wiley.com/doi/10.1002/dmrr.3654.
- Jefferies C, Owens N, Wiltshire E for the Clinical Network for Children with Diabetes in New Zealand, on behalf of the Paediatric Society of New Zealand diabetes clinical network. 2015. Care for children and adolescents with diabetes in New Zealand District Health Boards: Is the clinical resourcing ready for the challenge? NZMJ 128 (1424): 20–7. URL: www.nzma.org.nz/journal/read-the-journal/all-issues/2010-2019/2015/vol-128-no-1424-30-october-2015/6707.
- Health New Zealand – Te Whatu Ora and Te Aka Whai Ora |Māori Health Authority. 2022. Te Pae Tata | Interim New Zealand Health Plan. Wellington: Health New Zealand. URL: www.tewhatuora.govt.nz/whats-happening/what-to-expect/nz-health-plan.
- Ministry of Health. 2014. Quality standards for Diabetes Care 2020. Wellington: Ministry of Health. URL: www.health.govt.nz/system/files/documents/publications/quality-standards-for-diabetes-care-toolkit-2014-nov14-v2.pdf.
- Ministry of Health. 2014. Screening, Diagnosis and Management of Gestational Diabetes in New Zealand: A clinical practice guideline. Wellington: Ministry of Health. URL: www.health.govt.nz/publication/screening-diagnosis-and-management-gestational-diabetes-new-zealand-clinical-practice-guideline.
- International Diabetes Federation diabetes Atlas (eighth edition): www.diabetesatlas.org.
Update to include 2022 data
(Data updated June 2024)
This Atlas domain has been updated using data from the updated Virtual Diabetes Register (VDR) for 2022. Changes made in this update include the following:
- The use of primary health organisation (PHO) enrolment data as the denominator for the diabetes prevalence indicator, replacing Stats NZ estimated population projections. This ensures alignment and consistency with the Health New Zealand VDR web tool. However, we acknowledge that some population groups are more likely to be unenrolled compared with others. For more information on access to primary care by demographics, please see www.tewhatuora.govt.nz/for-health-providers/primary-care-sector/primary-health-organisations/enrolment-with-a-general-practice-and-primary-health-organisation.
- Given the high prevalence of diabetes among the Indian population, we have replaced the Asian ethnic group with Indian. This enables us to gain an in-depth understanding of variations within the Indian population and offers some insights into the quality of care provided.
- To better capture diabetes prevalence among younger age groups, we have subdivided the 0‒24 years group into two categories: 0‒14 and 15‒24 years.
- To better capture the diversity in hypoglycaemic medication usage, we have incorporated additional pharmacological indicators including newer medicines like dulaglutide and empagliflozin.
- Due to unavailability of complete laboratory claims data for certain years (for some districts), laboratory indicators have been excluded from this update.
- Note that individuals recorded in the VDR but not enrolled in a PHO are excluded from analyses. This approach ensures consistency in the numerator and denominator for calculations.
Key findings
Diabetes prevalence is markedly higher in some population subgroups than in others
The prevalence of diabetes increased significantly with age, ranging from 0.2 percent in those aged 0–14 years to 17.9 percent in those aged 75 years and older. In 2022, diabetes prevalence varied more than two-fold by Health New Zealand district, from 9.4 percent to 27.9 percent of a district population aged 65–74 years, and more than three-fold in those aged 45–64 years (5.2‒17.9 percent).
The Pacific population had the highest estimated rate of diabetes at 12.5 percent, followed by the Indian population (9.5 percent) and the Māori population (7.0 percent). The European/other ethnic group had the lowest rate of diabetes at 5.4 percent. On average, 48.2 percent of Pacific peoples aged 65–74 years were estimated to have diabetes compared with 12.5 percent of people of European/other ethnicity aged 65–74 years.
In 2022, within the Pacific population, diabetes prevalence differed among various ethnic subgroupings. For example, among those aged 65‒74 years, those who identified as Fijian had the highest prevalence at 56.7 percent, followed by Tongan (56.5 percent), Tokelauan (54.1 percent), Samoan (47.7 percent), Niuean (45.5 percent) and Cook Island Māori (41.3 percent). Those who had identified as Other Pacific Island (37.9 percent) and Pacific Island Not Further Defined (36.2 percent) had the lowest prevalence.
Good glycaemic control and cardiovascular risk factor management are important for positive outcomes
If haemoglobin A1c (HbA1c) in a person with diabetes does not meet an agreed target with dietary and lifestyle changes, drug therapy is recommended. Insulin and metformin are well proven. Evidence suggests good glycaemic control benefits microvascular outcomes.[1] The provision of comprehensive cardiovascular risk management for people with diabetes (such as blood pressure and lipid management) has been shown to improve macrovascular outcomes substantially while good glycaemic control has a smaller and very delayed effect.
The use of any hypoglycaemic medication varied around 1.5-fold by district
Given both the lack of available data on clinical parameters and the inability to split data by diabetes type, the indicators of medication use are not intended to suggest an ‘ideal’ rate of use, rather they provide a high-level view. Wide variation may raise questions such as, do districts with lower-than-average rates of medication use have lower or higher rates of diabetes complications?
Without HbA1c results available nationally, 67.7 percent of people with diabetes received any hypoglycaemic medication in 2022. Use was highest in those aged 0‒14 years (75.6 percent) and 65–74 years (74.2 percent). This varied around 1.5-fold by Health New Zealand district, from between 65.2 percent to 83.4 percent of those aged 65‒74 years with diabetes regularly receiving those medicines in 2022.
Metformin remains the standard initial drug treatment for type 2 diabetes. As expected, use increased with age. On average, 9.6 percent of people with diabetes aged 15‒24 years regularly received metformin compared with 58.2 percent of those aged 65–74 years in 2022. Males (52.8 percent) were more likely to regularly receive metformin than females (46.4 percent).
Newer medicines, including sodium-glucose co-transporter 2 (SGLT-2) inhibitors such as empagliflozin, have been available since February 2021. Glucagon-like peptide-1 (GLP-1) receptor agonists, such as dulaglutide, have been available since September 2021. These medicines are fully funded for the treatment of people with poorly controlled type 2 diabetes (individuals with HbA1c levels > 53 mmol/mol) who are at high risk of, or have established cardiovascular disease, diabetic kidney disease or heart failure, or who are of Māori or Pacific ethnicity. As these medicines are new and only funded for some people, these rates should be interpreted with caution. Since we define regular dispensing as people receiving medication for three or four quarters in a year, it is possible to miss individuals who started these medicines later in the year.
The regular dispensing of newer medication empagliflozin increased from 6.7 percent in 2021 to 13.3 percent in 2022, with higher rates of dispensing among people in the 45‒64 years age group (16.9 percent) followed by those aged 65‒74 years (15.7 percent). Rates of dispensing are higher among males (15.5 percent) compared with females (10.9 percent). The regular dispensing of empagliflozin varied more than two-fold by district for those aged 45‒64 years, ranging from 8.0 percent to 21.4 percent.
In 2022, the regular dispensing of dulaglutide was at 2.6 percent with the peak among people with diabetes aged 45‒64 years (3.4 percent). These rates varied by ethnicity: for example, Māori aged 45‒64 years (5.9 percent) have higher rates compared with other ethnic groups (Pacific peoples at 2.4 percent, Indian population at 1.6 percent and European/other at 3.1 percent). Rates also varied five-fold by district ranging from 1.2 percent to 6.1 percent across all age groups. For instance, the regular dispensing of dulaglutide among Pacific peoples aged 45‒64 years living in the Counties Manukau district was lower compared with other districts such as Hutt Valley and Hawke's Bay, despite higher rates of diabetes among Pacific peoples aged 45‒64 years living in the Counties Manukau district (33.6 percent).
Insulin therapy is used for both type 1 and type 2 diabetes. Overall, 20.3 percent of people with diabetes regularly received insulin in 2022. Across all ages, people of European/other ethnicity had the highest rate of insulin dispensing (22.0 percent) with people of Indian ethnicity having the lowest rate (12.5 percent). As might be expected, insulin dispensing was highest in the 0–14 and 15‒24-year age groups with diabetes, with 72.1 percent and 54.8 percent of these regularly dispensed insulin among the 0‒14 years and 15‒24 years groups, respectively.
Intensive management of high blood pressure and microalbuminuria
On average, 52.9 percent of people with diabetes received angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blockers (ARB) medicines in 2022. This is a slight reduction from 53.1 percent in 2021. The 2022 rate varied 1.2-fold by district (49.1‒58.7 percent). People of Indian ethnicity received the fewest ACEI or ARB medicines compared with other ethnic groups.
Intensive management of blood pressure and microalbuminuria is recommended to prevent progression of renal disease in diabetes. ACEI and ARB medicines are first-line treatments. The younger the age at diagnosis, the greater the impact of diabetes on life expectancy; this highlights the importance of glycaemic control, blood pressure management and prevention of kidney disease in younger people with diabetes.
Māori and Pacific peoples have higher rates of ACEI or ARB medicine use at a younger age; however, some data also shows these populations have significantly higher rates of end-stage renal disease. A recent publication from the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) found that Māori and Pacific peoples in Aotearoa New Zealand are at a significantly heightened risk of succumbing to the impacts of diabetic kidney disease reaching kidney failure (Māori 67 percent, Pacific peoples 67 percent), a two-fold greater likelihood than non-Māori non-Pacific (31 percent).[3]
Complications – hospital admissions for diabetic ketoacidosis and hypoglycaemia varied by age
Nationally, the highest rates for admission to hospital for diabetic ketoacidosis were among those aged 0–14 years (12.0 percent), followed by 15–24 years (6.0 percent). At all ages Māori (0.6 percent) experienced higher admission rates followed by European/other (0.4 percent).
The rates for admission to hospital because of hypoglycaemia was also highest in the youngest age group although the count of people was highest in those aged 65 years and over. It is pleasing to note there has been a consistent reduction in admissions to hospital for hypoglycaemia in those aged 0–24 years since 2018.
Complications – lower-limb amputations increased with age
Lower-limb amputation rates increased significantly with age, with 95 percent occurring in those aged 45 years and over. While this rare complication affected only 0.2 percent of the diabetes population in a year, in 2022, this meant 721 people lost part of a lower limb because of their diabetes, 204 of whom underwent major amputation and 517 underwent minor amputation. More detailed information on major and minor amputation levels is available elsewhere.4 In 2022, males (0.3 percent) had statistically significantly more lower-limb amputations than females (0.1 percent).
Note this indicator counts people with diabetes who had one or more amputations in a year. Our analyses excluded people who died during the year. This means that people who had an amputation during the year and died are not included. Also, if someone had multiple amputations within the year, they are counted only once.
People with diabetes occupied more bed-days for any reason
The number of medical and surgical bed-days occupied by people with diabetes for any reason was compared with the total occupied medical and surgical bed-days. Age had a significant effect on occupied bed-days. In 2022, age-specific rates ranged from 2.1 percent among those aged 0–14 years to 27.6 percent among those aged 65–74 years. People with diabetes aged 45–64 years occupied 26.2 percent of total bed-days, compared with a population prevalence of 9.8 percent of people with diabetes in this age group.
On an unadjusted basis, people with diabetes occupied 20.3 percent of total bed-days, despite a population prevalence of diabetes of 6.4 percent. However, some of the differences here are partially explained by the fact that increasing age is strongly associated with bed-day use and the age structure of people with diabetes is older than the general population. However, the extent of the bed occupancy by people with diabetes remains large.
In 2022, among the Indian population aged 65–74 years, 56.4 percent of total bed-days were occupied by those with diabetes while the population prevalence of diabetes in this age group is 44 percent. Among Pacific peoples in the same age group, total bed-days occupied by those with diabetes was 52 percent, compared with a population prevalence of 48 percent. In contrast, people of European/other ethnicity with diabetes aged 65–74 years occupied 22.4 percent of bed-days, with a population prevalence of 12.5 percent in that age group.
Questions raised
- How many of these results can be explained by the predominant type of diabetes?
- Are rates for specific indicators lower or higher than might be expected?
- Is there room for improvement in any of the indicators?
- Do results reflect local differences in care?
Method and data source
This Atlas domain draws on data contained in the VDR, which was developed by the Ministry of Health Manatū Hauora to estimate and track the number of people diagnosed with diabetes.
The VDR combines and filters various sources of health information, including the National Minimum Dataset, the National Non-admitted Patients Collection (outpatients), the Pharmaceutical Collection, the Laboratory Claims Collection and the Primary Health Organisation Enrolment Collection.
The VDR was used to estimate the prevalence of diabetes. The data is based on health service utilisation data that is consistent with diabetes care rather than formal clinical diagnosis or laboratory results, so should be interpreted with some caution. The Atlas does not use any patient-identifiable data.
Please note some of the source data that informs the VDR has not been consistently reported across all districts in Aotearoa New Zealand. Several data gaps have been identified and are likely to affect the accuracy of the VDR (in particular with sensitivity/coverage). So, results at regional level based on the VDR should be interpreted with some caution. Please see VDR: Technical Guide for more information on data quality issues.
The methodology is provided here (1.1MB, docx).
Limitations
The Pharmaceutical Collection contains claim and payment information from community pharmacists for subsidised dispensing. This collection does not indicate whether a medicine was taken or whether the dose was effective. Over-the-counter medicines are not included. Note our definition of regular medication use only includes people receiving medication for three or more quarters in a year. It should be noted that we did not take into account people who initiate medication later in the year.
In selecting indicators for oral hypoglycaemic medication use, the expert advisory group for this Atlas domain decided to focus on medicines like metformin, sulfonylureas, vildagliptin, empagliflozin and dulaglutide as the medicines for people with type 2 diabetes and insulin as the key medication for people with type 1 diabetes.
There is no ideal rate of medicine use in people with diabetes because it depends on clinical need. However, wide variation between districts or ethnic groups raises questions as to why the rate of medicine use varies.
Analysis does not split by type of diabetes
There were some limitations as to what measures could be presented. It was not possible to reliably split people by type of diabetes; hence the indicators represent a combination of those with type 1 and type 2 diabetes. Generally, most people with diabetes aged 0–24 years will have type 1 diabetes, while around 90 percent and over of those aged 25 years and above will have type 2 diabetes.
The method used in the VDR to identify people with diabetes is less accurate at identifying children than adults with diabetes. A recently published survey highlights that local district data may be a better source for identifying prevalence in children.[5] The National Diabetes Register is currently under development. Once it is live, it will be possible to split results by type 1 and type 2 diabetes.
Some important outcome indicators could not be included
Due to limitations in currently available data, we could not explore certain outcome indicators, including screening for diabetic retinopathy, retinopathy rates and end-stage renal failure. Outcome indicators, including myocardial infarction rates, stroke and other cardiovascular outcomes, are not included in this version of the diabetes Atlas domain, but are likely to be included in future updates. We encourage users to investigate local data in relation to these outcomes to promote improvement and equity initiatives at PHO and general practice level.
Relationship with other Ministry of Health activities
The diabetes Atlas domain links with Te Pae Tata Interim New Zealand Health Plan,[6] which outlines priority actions to improve care for people with diabetes in Aotearoa New Zealand. This includes work towards each Health New Zealand district meeting the 26 quality standards published in 2020.[7] These standards link with many of the measures presented in the diabetes Atlas domain.
Acknowledgements
Te Tāhū Hauora would like to acknowledge Pharmac – Te Pātaka Whaioranga for supporting this work.
References
- Ministry of Health and New Zealand Society for the Study of Diabetes. 2021. Type 2 Diabetes Management Guidance. Dunedin: New Zealand Society for the Study of Diabetes. URL: https://t2dm.nzssd.org.nz.
- Ministry of Health. 2020. Diabetes. Wellington: Ministry of Health. URL: www.health.govt.nz/your-health/conditions-and-treatments/diseases-and-illnesses/diabetes.
- Sun T, Davies C, Au E, et al. 2023. 46th Report. Chapter 9: Kidney Failure in Aotearoa New Zealand. Adelaide: Australia and New Zealand Dialysis and Transplant Registry, Adelaide. URL: www.anzdata.org.au.
- van Netten JJ, Bus SA, Apelqvist J, et al. 2024. Definitions and criteria for diabetes-related foot disease (IWGDF 2023 update). Diabetes Metab Res Rev e3654. URL: https://onlinelibrary.wiley.com/doi/10.1002/dmrr.3654.
- Jefferies C, Owens N, Wiltshire E for the Clinical Network for Children with Diabetes in New Zealand, on behalf of the Paediatric Society of New Zealand diabetes clinical network. 2015. Care for children and adolescents with diabetes in New Zealand District Health Boards: Is the clinical resourcing ready for the challenge? NZMJ 128 (1424): 20–7. URL: www.nzma.org.nz/journal/read-the-journal/all-issues/2010-2019/2015/vol-128-no-1424-30-october-2015/6707.
- Health New Zealand – Te Whatu Ora and Te Aka Whai Ora |Māori Health Authority. 2022. Te Pae Tata | Interim New Zealand Health Plan. Wellington: Health New Zealand. URL: www.tewhatuora.govt.nz/whats-happening/what-to-expect/nz-health-plan.
- Ministry of Health. 2014. Quality standards for Diabetes Care 2020. Wellington: Ministry of Health. URL: www.health.govt.nz/system/files/documents/publications/quality-standards-for-diabetes-care-toolkit-2014-nov14-v2.pdf.
Recommended reading/suggested links
- Ministry of Health. 2014. Screening, Diagnosis and Management of Gestational Diabetes in New Zealand: A clinical practice guideline. Wellington: Ministry of Health. URL: www.health.govt.nz/publication/screening-diagnosis-and-management-gestational-diabetes-new-zealand-clinical-practice-guideline.
- International Diabetes Federation diabetes Atlas (eighth edition): www.diabetesatlas.org.
Published: 29 Oct 2021
Modified: 2 Jul 2024
