Accurate diagnosis is vital in medicine. Patients want better outcomes.

Accurate diagnosis is critical for effective public policy, for the same reason. All too often it is not sought. A misdiagnosis that supports a politically preferred end can be a tragic mistake.

In her Waitangi Day Speech this year, the Prime Minister told Māori that they die younger than everyone else because they are Māori.

In 2018, the then Director-General of Health informed a Treaty of Waitangi Tribunal hearing that “the impact of personal and institutional racism is significant on both the determinants of health and access to and outcomes from health care itself”.

These are assertions of racist causation with a material effect on health outcomes. What evidence supports them?

Earlier this year, the Ministry of Health responded to my twin requests for the most authoritative empirical evidence it had in support of the above statements.

I examine those responses in my report, Every Life is Worth the Same: The Case for Equal Treatment, that The New Zealand Initiative published this week. Des Gorman, professor of medicine at Auckland University, wrote the foreword.

Regrettably and disturbingly, I found obfuscation on a grand scale. Unequal group average outcomes are conflated with inequity and racism. Correlation is taken to be causation. Materiality is merely asserted.

What about the remedy? The Pharmac Review Panel proposed that Pharmac’s spending be skewed to favour the needs of “priority populations”, notably Māori.

That approach treats Māori lives as being of higher value than those not in a priority population. The report illustrates how this might be quantified. It also shows how even Māori might end up worse off.

Official documents justify this racially polarising approach for health care generally. Their main grounds are relatively poor average health outcomes for Māori, ‘equity’, and the Treaty.

Non-Māori outnumber Māori by 40% in the bottom decile of according to New Zealand’s Deprivation Index. To favour Māori over others in this decile violates horizontal equity. To favour Māori in better-off deciles over non-Māori in the lower deciles violates vertical equity.

Nor is the international empirical evidence on such “affirmative action” policies encouraging.

People who do not care for accurate diagnosis cannot care much if their remedy does not work.

Finding remedies that work for all is critical. The previous government’s social investment approach had that focus. The current racially polarising approach does not.