Virtual Diabetes Register (VDR)

Published online: 9 August 2019

Note: The VDR algorithm was updated in 2017 resulting in a small reduction in the total number of people estimated to have diabetes. It is important that the updated numbers are not compared with numbers derived using any previous version of the VDR. Any comparison may result in artificial and inaccurate trends.

Each year the New Zealand Ministry of Health releases national estimates of the prevalence of diabetes based on the VDR. The VDR is an important tool to monitor prevalence of diabetes and support national and local clinical quality improvements.

The VDR contains data about people suspected as having diabetes, identified through their use of diabetes health services. The VDR uses an algorithm to identify these people in data extracted from hospital inpatient and outpatient, laboratory test, and pharmaceutical dispensing data collections. The VDR is collated annually at the end of March and national and regional diabetes prevalence estimates are calculated based on the number of people on the VDR as at 31 December of the previous year. People with diabetes who were deceased and those not enrolled in a PHO were excluded from the totals.

Virtual Diabetes Register 2018 revision

In 2016 the algorithm used to create the VDR was assessed against the Auckland TestSafe repository of actual glycaemic test results. (For more information read the published article: Can administrative health utilisation data provide an accurate diabetes prevalence estimate for a geographical region? - ScienceDirect website).

As a result, improvements to the algorithm were made in early 2017 to create the latest version of the VDR. A comparison of the numbers from the old VDR and the latest version (v686) is shown in the chart below.

Number of people estimated as having diabetes, on the old VDR and the new VDR, 2005–2018

Number of people estimated as having diabetes, on the old VDR and the new VDR, 2005–2018

	Old VDR	New VDR
2005	137,815	136,660
2006	147,525	144,747
2007	158,478	154,334
2008	171,025	165,837
2009	182,745	176,389
2010	196,134	187,860
2011	210,759	200,235
2012	224,908	211,591
2013	238,890	220,866
2014	251,478	228,790
2015	260,458	236,073
2016	-	241,463
2017	-	245,680
2018	-	253,480

Note: People who were either not enrolled in a PHO or deceased, as at 31 December of the relevant year, have been excluded.

It is important to note that numbers produced by the algorithm in the old VDR are now obsolete and should not be used, nor compared to the numbers produced by the new VDR algorithm. From now onwards, please use the numbers published here or request updated numbers or datasets fromdata-enquiries@health.govt.nz.

Number of people in the Virtual Diabetes Register by DHB of domicile, 2010–2017

DHB of domicile	2010	2011	2012	2013	2014	2015	2016	2017	2018
Auckland	18,573	19,647	20,657	21,718	22,836	23,867	24,508	24,586	25,050
Bay of Plenty	9507	9917	10,241	10,433	10,537	10,330	10,391	10,722	11,169
Canterbury	18,103	18,706	19,467	20,075	20,664	21,261	21,959	22,531	23,344
Capital and Coast	9393	10,788	11,899	12,436	12,805	13,119	13,350	13,370	13,823
Counties Manukau	27,845	29,877	32,092	34,430	36,927	39,007	40,266	41,256	42,867
Hawke's Bay	6797	7080	7494	7865	8025	8181	8370	8719	8,836
Hutt Valley	5812	6575	7211	7467	7699	7866	7903	7885	8,126
Lakes	4340	4547	4793	4928	5178	5430	5589	5677	5,676
MidCentral	6814	7453	7797	7953	8120	8331	8446	8719	9,066
Nelson Marlborough	5282	5577	5686	5786	5933	6022	6080	6075	6,089
Northland	8515	8908	9605	10,425	10,734	10,844	10,952	11,115	11,319
South Canterbury	2763	2862	2969	3016	3040	3107	3150	3165	3,155
Southern	12,002	12,672	13,206	13,525	13,578	13,804	14,146	14,355	14,854
Tairāwhiti	2621	2919	3098	3241	3357	3444	3388	3349	3,349
Taranaki	6205	6347	6510	6597	6659	6767	6781	6804	6,977
Waikato	16,548	17,396	18,125	18,895	19,637	20,406	20,998	21767	22,800
Wairarapa	1919	2075	2198	2218	2228	2223	2199	2205	2,305
Waitemata	20,296	22,136	23,651	24,959	25,908	27,020	27,796	28173	29,131
West Coast	1195	1226	1213	1204	1192	1254	1305	1404	1,467
Whanganui	3045	3255	3420	3471	3533	3616	3744	3837	3,981
Unknown/Unassigned	285	272	259	224	200	174	142	113	96
Total	187,860	200,235	211,591	220,866	228,790	236,073	241,463	245,680	253,480

Note: People that were either not enrolled in a PHO or were not alive, as at 31 December of the relevant year, have been excluded.

Source: VDR Dec 2010–2018 (v686)

Notes about VDR 2018:

1. People who weren't enrolled in a PHO, or were dead as at 31/12/2018, have been excluded.
2. Data was extracted on 05/04/2019.
3. NNPAC data from Canterbury DHB was removed for Oct, Nov, and Dec 2018 due to data quality concerns.
4. Any unknown ethnicity information on the NHI was bulk updated from ethnicity data on PHO enrolments in 2018. As a result this has changed the ethnicity distribution in the VDR 2018 when compared to previous years.
5. Chemical ID 4103 Vildagliptin and 4101 Vildagliptin with metformin hydrochloride were added to the list of pharmaceuticals included in the algorithm for the VDR 2018. These pharmaceuticals were not availalble prior to 2018, so do not affect the data in previous VDR years.