Wednesday, June 25, 2014

Regional variation in STEMI care, costs and outcomes

From a recent study in Clinical Cardiology:
We used the 2003 to 2010 Nationwide Inpatient Sample databases to identify all patients age greater than or equal to 40 years hospitalized with STEMI. Patients were divided into 4 groups according to region: Northeast, Midwest, South, and West. Multivariable logistic regression was used to identify differences in treatment choice and outcomes (in-hospital mortality, acute stroke, and cardiogenic shock) among the 4 regions.

Of 1 990 486 patients age greater than or equal to 40 years with STEMI, 350 073 (17.6%) were hospitalized in the Northeast, 483 323 (24.3%) in the Midwest, 784 869 (39.4%) in the South, and 372 222 (18.7%) in the West. Compared with the Northeast, patients in the Midwest, South, and West were less likely to receive medical therapy alone and more likely to receive percutaneous coronary intervention and coronary artery bypass grafting. Risk-adjusted in-hospital mortality was higher in the Midwest (odds ratio [OR]: 1.07, 95% confidence interval [CI]: 1.05-1.09, P less than 0.001), South (OR: 1.03, 95% CI: 1.01-1.05, P = 0.001), and West (OR: 1.06, 95% CI: 1.04-1.08, P less than 0.001), as compared with the Northeast. When adjusted further for regional variation in treatment selection, risk-adjusted in-hospital mortality was even higher in the Midwest, West, and South.

Despite higher reperfusion and revascularization rates, STEMI patients in the Midwest, West, and South have paradoxically higher risk-adjusted in-hospital mortality as compared with patients in the Northeast.

Let's try and make sense of these findings in view of what we already knew. We already knew that:

In general an early invasive reperfusion strategy for acute coronary occlusion leads to the best outcomes, and the earlier the better.

Invasive reperfusion strategies are costly.

But this study showed that by region in the US, decreased use of the early invasive strategy was associated with lower mortality and higher cost. It's the opposite of what we knew before. In fact it doesn't make any sense at all. In the discussion section of the paper the authors talk around the paradox but don't come up with a good answer.

I don't have a pat answer but I have an idea. Keep in mind that although STEMI is widely accepted as a surrogate for acute coronary occlusion it's not a very good one. Moreover this is from an administrative database, so the findings must have been captured from coding.

Coding has always been dubious as a way to capture research data but it's even worse in the current environment because it has been loaded with powerful incentives not only for payment but also for public reporting. Increasing the apparent severity through creative coding not only results in better reimbursement but it also makes you look like a better provider on public report cards. There's a lot of creative charting going on these days.

That means 1) there's no telling what these “STEMI” patients really had and 2) the severity adjustment for the mortality is questionable.

Coding has become corrupted. Dream on if you think ICD 10 is going to fix that.

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