University of Waikato researchers have found Māori patients receive fewer prescriptions for a common diabetes medication than non-Māori patients, and have worse blood sugar control as a result.
Type 2 diabetes is a growing problem in New Zealand, affecting an increasing number of young people, and twice as many Māori as non-Māori.
Led by Dr Lynne Chepulis at the University of Waikato Medical Research Centre, the team collected data from 10 general practice clinics around the Waikato, focusing on patients with type 2 diabetes who were regular, ongoing users of metformin.
“Metformin is the medication of choice for treating most patients with type 2 diabetes,” says Dr Chepulis. “But when patients don’t receive the required amount, this can lead to poor blood sugar control and increased risk of complications.”
The researchers studied three measures to assess metformin use: prescriptions from doctors, dispensing by pharmacies, and patients’ glycated haemoglobin scores, a marker of their blood sugar levels over time.
They found Māori received fewer prescriptions than non-Māori, but that there was no difference between Māori and non-Māori in adhering to their prescriptions (obtaining them from a pharmacy). However, prescription adherence was lower for younger patients overall, compared to older patients.
In terms of average blood sugar levels, those who were prescribed the recommended amount of medication, and those who obtained 100% of their prescriptions from the pharmacy, had better results. Given that fewer Māori were prescribed the required amount of metformin, their blood sugar levels were worse on average.
“There are many studies using pharmaceutical data showing that Māori are less likely to use medication for diabetes and other illnesses,” says Dr Chepulis. “However this study includes prescription data from primary care, which is generally difficult to get hold of. Being able to include the primary care data shows that this discrepancy in medication use by Māori is actually due to a lack of prescriptions.
“I believe that we are the first in New Zealand to report on combined prescribing and medication dispensing data for diabetes medication use.”
Dr Chepulis says further research is needed to uncover whether the reduced rate of prescribing metformin to Māori patients is related to patient preferences or health system issues. “Understanding ways to improve outcomes for people with diabetes is very important to the health of Māori in particular, as well as New Zealand’s population as a whole,” she says.
This study was supported by funding from the University of Waikato and the New Zealand Society for the Study of Diabetes.
The paper Metformin Adherence in Patients with Type 2 Diabetes and Association with Glycated Haemoglobin Levels was authored by:
- Dr Lynne Chepulis, University of Waikato
- Christopher Mayo, University of Waikato (Summer Studentship)
- Brittany Morison, University of Waikato
- Dr Rāwiri Keenan, University of Waikato
- Dr Chunhuan Lao, University of Waikato
- Dr Ryan G Paul, University of Waikato, Waikato District Health Board
- Professor Ross Lawrenson, University of Waikato, Waikato District Health Board