Table 3-9 describes the study population in terms of their demographics and severity levels (APR-DRGs, FY 2008 CMS MS-DRGs, and HCCs). These results are shown for both non-PAC users and PAC users. For beneficiaries using PAC services, the demographics and severity within each setting are presented. The proportions show the characteristics of cases discharged to each PAC setting as their first site following hospital discharge. Severity indicators are presented for 2006 only as these analyses were not conducted on 2005 claims.13 The demographics for 2006 are essentially unchanged from those in 2005, with a few exceptions noted here.
|No PAC Use||PAC Users By First Discharge Destination|
|1. Other includes Asian, Hispanic, North American Native, Unknown, and Other.
SOURCE: RTI analysis of 2005 and 2006 Medicare Claims 5% sample (mmor075b, pcs06).
|Less than 65||19.2||19.7||8.6||8.8||18.1||20.0||8.5||8.7||5.5||8.7||10.2||10.4||14.6||14.4|
|85 Years and Over||12.6||12.8||26.8||27.3||16.6||16.6||16.9||18.9||37.0||37.3||20.5||20.8||20.5||20.6|
|APR-DRG Severity Index:|
|MS-DRG Severity Index|
|Any Medicaid in 2006||23.5||23.1||23.9||23.4||30.2||32.9||15.6||15.4||27.9||27.3||21.1||19.9||27.2||26.7|
In both 2005 and 2006, PAC users were more likely to be female and were older, on average, than non-PAC users. In 2006, approximately 63.0 percent of PAC users were female, compared with only 53.0 percent of non-PAC users. Two-thirds of the PAC users (66.0 percent) were over age 75, compared to only 45.0 percent of the non-PAC users. The age distribution also varied among PAC users by first PAC setting. Beneficiaries discharged to SNFs tended to be older than beneficiaries discharged to other PAC settings. Of beneficiaries discharged to SNFs in 2006, 37.0 percent were aged 85 or older, compared with only 21.0 percent of patients discharged to HHAs and 19.0 percent of patients discharged to IRFs.
Severity of illness was measured by both the APR-DRG severity index and the MS-DRG severity index. Note that as discussed in Chapter 2, the APR-DRGs and MS-DRGs use different methods to assign severity levels. Although it is not possible to directly compare these measures, both have been included in our analysis in order to allow for comparisons to our previous work using the APR-DRGs and to reflect the current Medicare policy in adopting the MS-DRG system.
In both 2005 and 2006, severity of illness as measured by APR-DRG was higher for PAC users than for non-PAC users. In 2006, approximately 35.0 percent of PAC users had APR-DRGs in levels 3 or 4, compared with approximately 20.0 percent of non-PAC users. Of 2006 PAC users, beneficiaries discharged to LTCHs had the highest proportion of patients in APR-DRG level 4 (37.0 percent). This was a 4.0 percent increase in the proportion of level 4 patients discharged to LTCHs compared to 2005. Beneficiaries discharged to HHAs and hospital outpatient therapy were more likely to have lower APR-DRG severity levels, compared with beneficiaries admitted to the inpatient PAC settings.
Severity of illness as measured by the MS-DRG severity index also demonstrated that PAC users were more likely to have CCs and MCCs than non-PAC users. Approximately 44.0 percent of PAC users had either CCs or MCCs, compared with 32.0 percent of non-PAC users. Mirroring the findings for APR-DRGs, beneficiaries discharged to LTCHs had the highest proportion of patients in the MCC MS-DRG severity category (40.0 percent). In comparison, only 15.0 percent of beneficiaries discharged to hospital outpatient therapy and 17.0 percent of beneficiaries discharged to HHA were in the MCC MS-DRG severity category.
One interesting finding shown in this table is that there was a significantly higher proportion of beneficiaries in the lowest MS-DRG severity level (no CCs), compared with the number in the lowest APR-DRG severity level. Wynn and colleagues (2007) have noted that compared with the APR-DRG systems, the MS-DRGs have a much higher percentage of discharges assigned to the lowest severity level. Reasons for this are related to the specifics of the MS-DRG methodology. Beneficiaries are assigned to the lowest MS-DRG group in cases in which there is no CC severity level, where the base DRGs are not divided into severity subgroups, and where the DRGs are split into based on the presence of a MCC only.
The presence of comorbid or complicating conditions was examined using the HCCs. A larger proportion of beneficiaries with at least three HCCs used PAC services (37.0 percent), compared with beneficiaries who did not use PAC services (25.0 percent). Conversely, a larger proportion of beneficiaries with none or one HCC do not use PAC services (49.0 percent) compared with beneficiaries who do use PAC services (39.0 percent).
The distribution of the number of HCCs varied among PAC users by first PAC destination. Of beneficiaries discharged to LTCHs, 32.0 percent had five or more HCCs. The distribution of HCCs was more similar for beneficiaries discharged to other settings of post-acute care. Approximately half of all beneficiaries discharged to IRFs, SNFs, HHAs, or hospital outpatient therapy had one or two HCCs.
The last line of Table 3-9 shows the percentage of beneficiaries with readmissions to acute hospitals during their post-acute episodes by first setting of PAC for 2005 and 2006. Overall, more than 30.0 percent of PAC users had a readmission during a PAC episode in both 2005 and 2006. The patterns of readmission rates by first PAC setting were consistent with the patterns observed for APR-DRGs, MS-DRGs, and HCCs in which beneficiaries discharged to LTCH had more severe conditions and higher rates of hospital readmission compared with beneficiaries discharged to other inpatient settings or to home health or hospital outpatient therapy. Over 43.0 percent of beneficiaries discharged to LTCH had an acute hospital readmission during their PAC episode in 2006. Similar readmission rates were observed in 2006 for beneficiaries discharged to IRFs (30.4 percent), SNFs (31.3 percent), and HHAs (30.1 percent). In contrast, readmission rates for beneficiaries discharged to hospital outpatient therapy were 25.3 percent in 2006.
More specific detail on readmission rates per DRG is presented in Table 3-10. This table shows the percentage of beneficiaries with at least one acute hospital readmission during an episode of PAC, and the mean acute readmission payments, for the top ten DRGs by volume among PAC users. Readmission rates in episodes of care clearly vary by DRG. For beneficiaries in the most common DRG, DRG 544, 14.3 percent of beneficiaries had at least one readmission during PAC episodes compared to 32.6 percent of beneficiaries in DRG 014. The DRG with the highest readmission rate among the top 10 most common DRGs was DRG 127 Heart Failure and Shock in which over 43.0 percent of beneficiaries had at least one acute hospital readmission during their PAC episodes. Mean payments associated with readmissions for beneficiaries in DRG 127 were also the highest among the top 10 DRGs at $17,449. These rates, again, reflect differences between the medical and rehabilitation populations.
|1. NOTE: FY 2006 DRG titles were used in this analysis.
SOURCE: RTI analysis of 2006 Medicare Claims 5% sample (MM2Y097).
|Overall Sample of PAC Users||109,236||$30,028||30.5||$15,636|
|Index Acute Admission DRG1 (Top 10 DRGs for PAC Users)|
|544 Major Joint Replacement or Reattachment of Lower Extremity||15,261||$23,985||14.3||$12,952|
|014 Specific Cerebrovascular Disorders Except TIA||4,882||$33,484||32.6||$13,409|
|089 Simple Pneumonia & Pleurisy Age >17 w CC||4,675||$20,476||31.6||$13,023|
|127 Heart Failure & Shock||4,096||$26,076||43.1||$17,449|
|210 Hip & Femur Procedures except Major Joint Age >17 w CC||3,552||$36,882||30.6||$12,919|
|088 Chronic Obstructive Pulmonary Disease||2,439||$21,118||36.3||$14,888|
|320 Kidney & Urinary Tract Infections Age >17 w CC||2,396||$22,039||31.8||$12,994|
|416 Septicemia Age >17||1,996||$30,627||33.1||$16,956|
|316 Renal Failure||1,848||$28,729||38.4||$16,999|
|296 Nutritional & Misc Metabolic Disorders Age >17 w CC||1,757||$22,852||33.1||$15,078|