The Census Bureau, the authoritative source of health insurance data for more than three decades, is changing its annual survey so thoroughly that it will be difficult to measure the effects of President Obama’s health care law in the next report, due this fall, census officials said.
The changes are intended to improve the accuracy of the survey, being conducted this month in interviews with tens of thousands of households around the country. But the new questions are so different that the findings will not be comparable, the officials said.
An internal Census Bureau document said that the new questionnaire included a “total revision to health insurance questions” and, in a test last year, produced lower estimates of the uninsured. Thus, officials said, it will be difficult to say how much of any change is attributable to the Affordable Care Act and how much to the use of a new survey instrument.
“We are expecting much lower numbers just because of the questions and how they are asked,” said Brett J. O’Hara, chief of the health statistics branch at the Census Bureau.
With the new questions, “it is likely that the Census Bureau will decide that there is a break in series for the health insurance estimates,” says another agency document describing the changes. This “break in trend” will complicate efforts to trace the impact of the Affordable Care Act, it said.
The questionnaire traditionally used by the Census Bureau provides an “inflated estimate of the uninsured” and is prone to “measurement errors,” said a working paper by statisticians and demographers at the agency.
In the test last year, the percentage of people without health insurance was 10.6 percent when interviewers used the new questionnaire, compared with 12.5 percent using the old version. Researchers said that they had found a similar pattern in the data for different age, race and ethnic groups.
In addition, “the percentage of people with private coverage was statistically higher” when the bureau tested the new questionnaire, the working paper said. For reasons that are not clear, people were less likely to respond when interviewers used the new questionnaire.
Another Census Bureau paper said “it is coincidental and unfortunate timing” that the survey was overhauled just before major provisions of the health care law took effect. “Ideally,” it said, “the redesign would have had at least a few years to gather base line and trend data.”
Oh well... let's just consider Obamacare a huge success and get on with the rest of that fundamental transformation promised.