We counted the number of chronic conditions documented in the claims for each beneficiary during 2007. We used the 9 major chronic conditions based on the work of Iezzoni et al,2 (link) as adapted for the 2008 Dartmouth Atlas of Health Care. The conditions were cancer with poor prognosis, chronic obstructive pulmonary disease, coronary artery disease, congestive heart failure, peripheral artery disease, severe liver disease, diabetes with end-organ disease, chronic renal failure, and dementia.
For a beneficiary to be counted as having a chronic condition, the diagnosis had to be either coded on at least 1 hospital discharge abstract following an inpatient stay or on at least 2 claims involving physician contact that were at least 7 days apart. The latter requirement was used to reduce the likelihood of erroneously including “rule out” diagnoses. A beneficiary was counted as either having or not having each of the 9 conditions, and the total number of conditions for each beneficiary was calculated (range, 0–9).
We calculated the mean number of chronic conditions per beneficiary within each of the 306 HRRs to examine the variation in diagnosis frequency across the Medicare population as a whole. The HRRs were sorted in terms of increasing diagnosis frequency and grouped into quintiles based on population counts (ie, approximately 1 million beneficiaries per quintile). Within each quintile, we examined the distribution of the number of chronic conditions diagnosed. To assess system factors that may be related to the likelihood of diagnosis, we examined 4 measures reflecting physician encounters and diagnostic testing: the number of physician visits, the number of different physicians seen, the number of imaging tests obtained, and the number of laboratory tests obtained.
For a beneficiary to be counted as having a chronic condition, the diagnosis had to be either coded on at least 1 hospital discharge abstract following an inpatient stay or on at least 2 claims involving physician contact that were at least 7 days apart. The latter requirement was used to reduce the likelihood of erroneously including “rule out” diagnoses. A beneficiary was counted as either having or not having each of the 9 conditions, and the total number of conditions for each beneficiary was calculated (range, 0–9).
We calculated the mean number of chronic conditions per beneficiary within each of the 306 HRRs to examine the variation in diagnosis frequency across the Medicare population as a whole. The HRRs were sorted in terms of increasing diagnosis frequency and grouped into quintiles based on population counts (ie, approximately 1 million beneficiaries per quintile). Within each quintile, we examined the distribution of the number of chronic conditions diagnosed. To assess system factors that may be related to the likelihood of diagnosis, we examined 4 measures reflecting physician encounters and diagnostic testing: the number of physician visits, the number of different physicians seen, the number of imaging tests obtained, and the number of laboratory tests obtained.
