Using longitudinal claims data for Medicare beneficiaries from 1999–2005, we observed marked heterogeneity by ICD-9 diagnosis code submitted and local Medicare carrier in the proportion of central DXA claims that were denied. This was especially notable for repeat DXA studies performed within 23 months of the prior test. Additionally, in men the proportion of claims denied for the initial DXA study was approximately 1.7-fold greater than for women. Assuming that DXA studies are performed for male and female Medicare beneficiaries with one of the five indications specified in the BMMA, the overall 5–9% rejection rate for the claim submitted for the initial DXA study suggests that providers are unclear as to which ICD-9 diagnosis code to use.
In the face of a federally legislated mandate to provide DXA testing to appropriately qualified individuals, why does regional variation in DXA reimbursement denial exist? The indications for DXA testing seem clear in the BMMA, yet these indications do not intuitively map to specific ICD-9 diagnosis codes. Indeed, DXA tests with a diagnosis code of “Screening for osteoporosis (V82.81)” had an 18% denial rate. However, this diagnosis was relatively common and accounted for 5% of diagnoses submitted with DXA tests. One might assume that simply substituting one of the diagnosis codes associated with menopausal status (≤ 4% rejection rate) would significantly reduce the likelihood that the DXA would be denied. We suspect that the failure of Medicare carriers to provide specific ICD-9 codes for the categories of “qualified DXA individuals” contributed, at least in part, to these differences in reimbursement rates for initial DXA studies. Alternatively, or perhaps conjointly, information on which ICD-9 codes should be used for which qualified conditions may exist for certain carriers [6
], but our results suggest that providers were not aware of it.
Denial rates were much higher for claims submitted on repeat DXA studies performed within 23 months than for the initial DXA study or DXA studies performed at ≥ 23 months. One indication for a repeat bone mass measurement test, to establish a baseline measurement if a different technology will be used to monitor longitudinal change, has no specific ICD-9 code. Other indications for repeat testing that could qualify as “medically necessary” include long term glucocorticoid use and hyperparathyroidism. The ICD-9 codes that could be used for DXAs related to long term glucocorticoid use (although not necessarily specified for this condition) include E932.0 [adrenal steroid adverse events], V58.65 [long term steroid use], V58.69 [long term use of other medications], 255.0 [cushings] and V67.59 [followup examination]. Rejection rates for these diagnosis codes were low, but their use was relatively uncommon. Hyperparathyroidism diagnoses also were uncommon and appeared on < 1% of DXA claims. It is possible that providers are miscoding the diagnosis of people who have these indications for repeat testing, with the result that they are not reimbursed but could have been if they were coded appropriately. It is also possible that physicians are ordering repeat DXA tests for individuals who do not meet one of the specified ‘medically necessary’ indications or that local Medicare carriers interpret “medical necessity” differently when evaluating whether to reimburse a claim submitted for a repeat DXA study within 23 months.
In addition to not providing specific ICD-9 codes for each category of beneficiaries qualified to receive DXA, no specific screening code for women was ever approved by CMS. This contrasts with other nationally mandated preventive services, including mammography and colonoscopy, which have screening codes. With mammograms, for example, all regional Medicare providers are required by federal mandate to accept two simple screening codes for asymptomatic women, with frequency of coverage dependent on date of birth [1
]. In contrast, regional variation in reimbursement for less common services (e.g. deep brain stimulation, toenail debridement) has been previously documented [7
]. An age-appropriate screening code for DXA in female Medicare beneficiaries could potentially decrease the variation in DXA reimbursement identified in our study. Greater transparency or even standardization between local Medicare carriers in specifying which diagnosis codes should be used for persons meeting the various indications outlined in the BMMA, including screening, would likely impart greater certainty that providers will be reimbursed for appropriate testing.
By intent (Federal Register, vol 71, no 231, December 1, 2006, p. 6965), CMS has not provided specific ICD-9 diagnostic codes for the other categories of qualified individuals under the Bone Mass Measurement Act, which has resulted in different ICD-9 codes being accepted by different local Medicare carriers for the same diagnostic criteria. For example, for patients who are on glucocorticoids, E932.0, V58.65, V58.69 or 255.0 may be required depending on the local Medicare carrier. Monitoring response to medical therapy requires the ICD-9 code V67.59 or v58.69, but this is also often carrier dependent. Even codes for estrogen deficiency vary with specific carriers; for example, 627.2 (symptomatic menopausal or female climacteric states) can be used with Palmetto GBA the Medicare carrier in OH, WV and SC, but is not accepted by CIGNA, the carrier in NC, TN and ID. Standardization by CMS of the various ICD-9 diagnostic codes that could be used when submitting claims to the local Medicare carrier would likely impart greater certainty that providers would be reimbursed for appropriate testing.
The strengths of our study include use of data that allow us to generalize our results to the U.S. Medicare fee-for-service population and that provide diagnosis and state-specific detail regarding reimbursement rates. However, our results may not be generalizable to older persons with Medicare managed care coverage (i.e. Medicare Advantage). As another potential limitation, reimbursement determinations were evaluated after DXA claims had been fully resolved; initial rejection rates may have been higher but could have been successfully appealed by providers. An additional limitation is our inability to identify what “should be” the appropriate diagnostic codes for reimbursement as we only have access to claims data, not medical records. As a result, we do not necessarily know the true medical reason for which the DXA was ordered. Finally, consolidation among local Medicare carriers is expected, such that the 17 carriers currently represented in this analysis may be reduced to a smaller number in the future. This consolidation may alter the reimbursement patterns that we observed.
In conclusion, although most central DXA claims were reimbursed for women and when the interval between scans was greater than 23 months, rates of denial were far higher for men and were highly variable when serial testing was ordered at intervals less than 23 months. Greater guidance and transparency in coding policies, as well as enhanced provider awareness of those policies, are needed to improve access to DXA as a covered service for qualified Medicare beneficiaries.