The “Inverse Care Rule” still rules in Dentistry in Australia

Professors Estie Kruger and Marc Tennant write:

The “Inverse Care Rule” still rules in Dentistry in Australia

The definition of the inverse care law was coined in the early 1970′s [1].  The law “The availability of good medical care tends to vary inversely with the need for it in the population served” defined what has been observed for many years.  Today, even after the clarity of its definition, it remains an all-to-often seen occurrence in modern health care.

Modern dentistry is no exception, in fact, in many developed economies, it could be argued that it’s an extreme example of the rule.  In Australian dentistry, all the ingredients for extreme inverse care law have been present for decades.

Oral health care is predominately provided on a fee-for-service basis in the private sector.  In fact, more than 80% of care is provided in this way.  Dentists are, on the whole, small business owners, partners off small businesses, or other types of “employees” of businesses, with the total sector income estimated at near $8billion per annum.

On a national level we see dental practice distribution reflect the economic drivers.  Some of the world’s (and certainly Australia’s) highest densities of dental practices are in the cores of our major cities, whilst at the same time some of the world’s lowest densities are seen in rural and remote Australia. Even within cities, we see practices clustered around areas of high net wealth.

State governments provide relatively small safety-net care systems.  The safety-net service workforce, and thus care provision is fundamentally at the fate of the substantially larger private sector.  Income differences between government and private practice are so substantial that there is forever a drain to the private sector.  In strong economic times the drain is higher, but even in cooler economic times the drain remains.

One recent study found that newly graduated dentists work in the more marginal economic (and health for that matter) communities of our cities (and beyond), but 6 years post-graduation there is a substantial “migration” back to the wealthy areas of cities.

Over the last half a century substantial reductions in disease burden have been achieved through massive improvements in public, and individual health attitudes and prevention.  However in dentistry the effect has, like in many chronic conditions, been most substantial at the higher socioeconomic strata of society.  Oral health, with the advent of community fluoride exposure, is a wonderful example of public preventive strategies being effective, but the effect has magnified remaining differences between rich and poor.  We now see only 5% of 12 year-olds with 5 or more decayed teeth, but these children are, in the vast majority, resident in the marginalised parts of society.  Whilst at the wealthy end, no decay at all is the predominate status for 12 year-olds.

The collision of changed disease distribution, now substantially skewed to the poor and disadvantaged, and a health system predominated by pay-as-you-go care, sees the Inverse Care Rule, rule.

The well and wealthy have deep reservoirs of care available and most aspects of access to care is “easy”, while the poor and marginalised remain with the disease burden and lack of access to care.  Those in the middle are squeezed depending on economic circumstances.

The collision has seen many effects, most notably the dichotomy between the cry for increased need for services and simultaneously the major parts of the professional call for reducing supply of practitioners.  In a cooler economic climate where consumers have reigned in their expenditure it is not unsurprising to see demand for dental care in the middle and wealthy sectors of society reducing; thus the call by small business dental practice to reduce workforce.  But the poor and marginalised face ongoing hardship with high burdens of disease and issues of fundamental access.

Government intervention has to be aimed at levelling the playing field so essential care for the poor is attainable.  Pouring money at the problem at a broad level and without targeting is not effective and history has taught us painful lessons of waste.  Systems that diminish the burden faced by the disadvantaged and marginalised are vital.  We have to be smart and targeted to remain lean and efficient, whilst simultaneously addressing a substantive community need.

To increase care provision, in simple economic terms, needs approaches that enhance the “buying power” for care of the poor, or alternatively diminish the “opportunity cost” for providing care in marginalised communities. These are the only two efficient ways forward within the current governance framework.

Examples of these economic principles are starting to take hold in Australia. The means-testing of subsidies to access care as is in the new Child Dental Benefits Schedule is a targeting mechanism by enhancing the buying power of the poor. The Dental Relocation and Infrastructure Support Scheme, where practitioners are supported to move to more disease heavy regions of Australia, reduces opportunity costs of providing care in these areas.

In summary, we must strengthen the systems that redress the Inverse care law in modern Australian dentistry.  This will reduce overall costs, enhance overall health and strengthen Australia as a just society.

1. The Lancet, 1971:297;405-412 doi:10.1016/S0140-6736(71)92410-X

Marc Tennant and Esite Kruger are from the International Research Collaborative – Oral Health and Equity, The University of Western Australia