Austin Frakt draws our attention to a BMJ article that finds a positive relationship between hospital readmissions and inequality. A number of explanations are offered, but to put it charitably, none are persuasive. Here is a different explanation: If you graph health care spending against income you will generally get a U-shaped curve. (See below.) The reason: poor people are sicker and need more health care and since health care is a luxury good, wealthier people spend more on it. An NCPA study found that for Medicare patients, the highest level of spending was among the highest and lowest income enrollees.
So where you have inequality (poor and rich bunched together) you will get high spending and where you have equality (everybody’s average) you will have low spending.