EXPERT REACTION: Māori diabetes patients missing out on key medicine

It is well known that there are important disparities between ethnicities in New Zealand for rates of type 2 diabetes and health outcomes related to this. Māori have higher rates compared with New Zealand Europeans, but lower than Pacific people and South Asians.

Metformin is the first line medication therapy for type 2 diabetes and should be prescribed for almost everyone unless it has not been tolerated or is contraindicated.

This paper explores the rates of adherence with Metformin in people with type 2 diabetes in Waikato. As a proxy of actually being able to measure the drug in people, the authors have taken a sophisticated approach of extracting data on dispensing rates of Metformin, but also prescriptions. This enables the differentiation of whether people are actually picking up their prescriptions and a more nuanced analysis of where issues may lie in terms of use of Metformin. 

The main finding is that Māori are less likely to be prescribed metformin than non-Māori, but that when prescribed they are equally likely to collect the prescriptions, and equally likely to get the benefit of that on glycaemic control. 

Having identified this, it raises the question of why they are not receiving prescriptions in the first place. That is beyond the scope of the paper but focuses the attention on establishing this in order to improve outcomes for Māori and improve equity.

This study is really important in showing that, when given a prescription, Māori do pick it up. Previous reports have shown that Māori receive less medication that non-Māori, but it is often explained as Māori not picking up scripts or not wanting medication in the first place. Negative stereotypes and attitudes to Māori persist and are maintained by deficit thinking in relation to Māori. This paper shows that gap is actually getting a prescription in the first place. Māori were less likely to receive the five to seven prescriptions needed to maintain 100% medication cover. Importantly, our study did show that if metformin was prescribed, Māori were just as likely as non-Māori to have the medication dispensed.

It is on us as a health system and providers to fix this. Many will try and explain this away as patients needing to come in and take care and responsibility, but we too have a responsibility to ensure our practices and services are safe and welcoming spaces. Removing barriers to medication is important if we are to tackle the growing burden of uncontrolled diabetes; this affects Māori and Pacific people at much higher rates.

Finally, later this year we will get new medication to control sugars and reduce complications (sodium glucose co-transporter 2 (SGLT-2) inhibitors and glucagon-like peptide-1 receptor (GLP-1) agonists). However, despite pressure from many places, especially Māori doctors and pharmacists, PHARMAC currently will only fund these if certain special criteria are met, creating more barriers and most likely resulting poorer access to these medication by those most in need.

Metformin was introduced as a medication for people with diabetes more than half a century ago. Despite the many newer drugs which are now available for diabetes, it remains one of the most widely used tablet treatments for this condition in New Zealand and worldwide. It is a cornerstone of treatment for the majority of people with type 2 diabetes even when other treatments including insulin are needed.

It is therefore of considerable concern to discover that there appears to be a reduction in metformin coverage in Māori compared with New Zealand Europeans, given the appreciably higher rates of type 2 diabetes amongst Māori. Not only are type 2 diabetes rates high among Māori, but there are ethnic disparities in terms of diabetes-related health outcomes.

The authors present evidence to suggest that this is due principally to the fact that Māori are less likely to receive as many prescriptions for the drug as do New Zealand Europeans and they reflect on possible reasons for this including reduced access to health care. They also mention that ‘Māori may be less adherent to metformin because of other reasons such as a higher rate of side effects.’ This statement concerns me because my own clinical experience suggests that, while gastrointestinal side effects to metformin are indeed common, they can be greatly reduced and adherence improved if patients are given simple advice such as gradually increasing to the full dose from a very small initial dose and having the tablets with food.  

It is clearly important for these findings to be followed up in order to determine the reasons for reduced coverage of this important drug amongst Māori and to ensure that they and, indeed all patients, are getting appropriate advice as to avoid or at least greatly reduce risk of side effects.