Doctors and the health care of their parents

In my ECONS102 class, we talk about how health care is an unusual good, because it simultaneously has four characteristics: (1) derived demand (we demand health care but what we really want is better health); (2) positive externalities (consuming health care makes others better off as well as yourself); (3) information asymmetries (health professionals know much more about health care than patients do); and (4) uncertainty (it is uncertain whether particular health care treatments or procedures will work, or how well they will work, or what would have happened in the absence of the health care).

In relation to information asymmetry, medical knowledge is what we refer to as private information - it is known to the medical practitioner, but not to the patient. That creates a range of problems, including that patients may not always get the care that they need. For example, patients may not know when to seek care, as they may underestimate the seriousness of symptoms.

Could having better access to medical information reduce information asymmetries and improve the quality of health care? That is essentially the question that this recent article by Elisabeth Artmann (Institute for Employment Research, Netherlands), Hessel Oosterbeek (University of Amsterdam), and Bas van der Klaauw (VU University Amsterdam), published in the American Economic Journal: Applied Economics (ungated earlier version here), addresses. They use population registry data from the Netherlands, along with the results of the medical school admissions lotteries over the period from 1988 to 1999, and look at the effect on parents' health care of having a child who becomes a doctor. The idea here is that, if your child becomes a doctor, then that would reduce any information asymmetry in health care, because your child would be able to provide advice that eliminates the asymmetry.

The lottery aspect of the research is important, because it provides an exogenous source of variation in who becomes a doctor - essentially, there is a random component to becoming a doctor, because the lottery determines who is allowed into medical school. In other words, Artmann et al. use winning the first lottery (because students could apply each year afterwards) as an instrument for becoming a doctor. That means that their results can be interpreted as evidence of the causal effects of having a child who is a doctor on parents' health care. Note that this is exactly the same approach as was used in an earlier paper on doctors' prescription drug use (which I discussed here).

The instrumental variables approach is important because simply comparing parents with children who are doctors with parents who do not have children who are doctors is subject to a lot of selection bias. For instance, better-educated parents are more likely to have children who are doctors, and also more likely to have better health outcomes. So, a positive correlation would be observed between having doctor children and health outcomes, even if doctors had no effect on parents' health. Indeed, Artmann et al. demonstrate just such a correlation, finding that:

When we consider the full population independent of children’s level of education, we find strong associations between children having a medical degree and parents’ mortality and health care use. Fathers and mothers of doctors live longer, have lower health care costs, and are less likely to visit a GP, to be hospitalized, or to take any prescription medication. They are, however, slightly more likely to be treated by a specialist. These associations are weaker but still hold when we restrict the sample to parents of children with a college degree.

However, in their instrumental variables analysis, which avoids the problems of selection bias, they find:

...causal effects on mortality that are close to zero and not significantly different from zero. For health care use and costs, most estimates are not significantly different from zero, although for some outcome variables estimates are too imprecise to rule out substantial effects. Taken together, the results indicate that having access to medical expertise and services through a child who is a doctor is not an important cause of differences in parents’ health care use and mortality.

In other words, almost all of the better health outcomes for parents of children who are doctors arises from selection bias. Having a child who is a doctor doesn't improve health outcomes in the Netherlands.

In the Waikato Economics Discussion Group this week, we had an interesting conversation about this paper. The results are clear for the Netherlands, but it is likely that the particular health system matters. In the Netherlands, Artmann et al. write that:

Since the implementation of the Health Insurance Act in January 2006, all Dutch residents are legally obliged to purchase a basic health insurance package from private insurers...

The central government defines the content of the basic package. This covers medical care, including care provided by GPs, hospitals, specialists and midwives, and prescription drugs... Every insured person over age 18 pays an annual deductible of €385 (in 2019) for health care costs... including costs for hospital admission, medical transportation, and prescription drugs but excluding costs for GP consultations, maternity care, home nursing care, and care for children under the age of 18.. Voluntary supplemental health insurance is available for services not included in the basic health insurance package.

The comprehensive and universal nature of available health care in the Netherlands probably matters for whether doctor children can affect the health care (and health outcomes) of their parents. The need for a doctor to intervene on behalf of their parents in the health system is likely to be much lower in the Netherlands than it would be in, say, a typical developing country. We'd expect to see very different results when the health system is not universal. That opens an important question, though: would we see an effect for a country like New Zealand, which has a public health system, where access is rationed through waiting lists, and where a parallel private health system exists. Would having a child who is a doctor mean that parents are added to the waiting list sooner, or are more likely to be re-routed into the private system (at their own cost)? Either of those would suggest better health outcomes for parents of doctor children. It would be interesting to follow this up with other research for New Zealand.

Coming back to the Artmann et al. paper, it would be attractive to draw some conclusions in relation to inequality in access to health care. However, Artmann et al. caution against this, noting that:

...our results apply to parents of individuals who applied for medical school, so these parents have relatively high-educated children. Therefore, our results are not conclusive about equality of health care access in the Netherlands in general.

However, the results do suggest that the quality of health care in the Netherlands is such that, having a child who is a doctor cannot improve the health care that you receive.