In Tables 3-13 through 3-15, episode lengths of stay and Medicare payments during PAC episodes are presented for post-acute care users across all DRGs as well as for post-acute care users in DRG 089 and DRG 544. Within these tables, we show the number of beneficiaries with each claim type, the percent using each type of service, the mean length of stay, and the mean Medicare payments. The results are shown overall and then stratified by APR-DRG severity levels 1 through 4 and by MS-DRG severity level (no CCs, with CCs, with MCCs) in Tables 3-16 through 3-18. These tables illustrate different levels of medical severity for hospital discharges overall as well as for different types of cases (pneumonia versus major joint and limb procedures).
For the APR-DRG severity of illness, there are four levels (1-4) which indicate increasing severity. As discussed previously, the MS-DRG severity system stratifies cases by the presence or absence of complicating or comorbid conditions (CCs). Beneficiaries can be classified in up to 3 categories based on the presence of CCs, (although sometimes these categories will be collapsed, as will be discussed for DRG 544). For DRG 089, beneficiaries were classified into 3 categories. The lowest severity level is "No CC," the middle severity level is "CCs," and the highest severity level is "MCCs" (for "major" comorbid or complicating conditions). We must reiterate that the severity-level split for MS-DRGs is DRG-specific and may not have the same meaning across DRGs.
Post-Acute Care Episodes: All DRGs. The average post-acute episode length of stay for all post-acute users in our 2006 episode file was 81.3 days with corresponding average episode payments of over $30,000 (Table 3-13). In looking at the composition of episodes of care for post-acute users, over 60.0 percent of beneficiaries used home health services as part of their episode and nearly 48.0 percent of beneficiaries used skilled nursing facility services. Claims for beneficiaries using LTCH services were associated with the highest payments, but only a small number of beneficiaries used these services as part of their episode (2.9 percent). Looking at patterns of use for beneficiaries using post-acute care by severity level provides more specific information on how services vary by severity level (Table 3-16). When severity is measured using the APR-DRG, the majority of beneficiaries fell in to APR-DRG Level 2 (47.5 percent) and APR-DRG Level 3 (29.8 percent). When using the MS-DRG severity measure, 56.0 percent of beneficiaries were in the lowest severity level.
Post-Acute Care Episodes: DRGs 089 and 544. In looking at beneficiaries in DRGs 089 and DRG 544 overall, there are several important differences in patterns of use (Table 3-14 and Table 3-15). The average episode length of stay for beneficiaries in DRG 089 was 72.3 days compared to 64.1 days for beneficiaries in DRG 544. Though the episode length of day was longer for beneficiaries in DRG 089, the episode payments for these beneficiaries was lower than for beneficiaries in DRG 544 ($20,476 for DRG 089 vs. $23,985 for DRG 544). This difference is likely due to the services received in the inpatient setting. Beneficiaries in DRG 544 are more likely to have received surgical procedures compared to beneficiaries admitted for pneumonia and these procedures are likely reflected in the index acute hospital payments ($5,161 for DRG 089 vs. $10,532 for DRG 544). Use of post-acute services also differed for these beneficiaries. Nearly 70.0 percent of beneficiaries in DRG 544 used home health services in their episodes of post-acute care compared to over 51.0 percent of beneficiaries in DRG 089. A higher proportion of beneficiaries in DRG 089 used SNF services compared to beneficiaries in DRG 544 (53.8 percent vs. 40.2 percent). Beneficiaries in DRG 544 had significantly higher use of IRF services compared to beneficiaries in DRG 089 due as expected give the need for rehabilitative services for beneficiaries recovering from replacement procedures (20.2 percent vs. 2.8 percent).
In Table 3-16 we see that in general, episode lengths of stay and payments rise with increasing severity both when severity is measured using the APR-DRG and when severity is measured using the MS-DRG. For example in looking at episode lengths of stay across all DRGs in the healthiest MS-DRG level, "No CCs", the length of stay was 75.4 days and payments were $26,609 compared to MS-DRG level "MCCs" where length of stay was 91.3 days and payments were $39,587. Patterns of service use within episodes clearly varied by severity level as well. The proportion of beneficiaries using LTCH services increased with increasing severity reflecting the increasing medical complexity of those in the highest severity levels. Similarly, the proportion of beneficiaries using SNF services increased with increasing severity and the proportion of beneficiaries using HHA services decreased with increasing severity indicating the shift from outpatient to inpatient service use for more severely ill beneficiaries.
In the discussion below we look at differences in use and payments for beneficiaries in a medical DRG (DRG 089 Simple Pneumonia & Pleurisy Age > 17 w CC) versus beneficiaries in a rehabilitative DRG (DRG 544 Major Joint and Limb Reattachment Procedures of Lower Extremity).
Post-Acute Care Episodes: DRG 089, By APR-DRG. The majority of beneficiaries with DRG 089 are in APR-DRG severity levels 2 (51.9 percent) or 3 (42.3 percent). Table 3-17 shows that episode length of stay and payments rise with increasing APR-DRG severity. Beneficiaries with APR-DRG severity of illness level 1 had an average of post-acute episode length of stay of 62.4 days and Medicare payments of $15,383. In contrast, those in APR-DRG severity level 4 had episodes averaging 74.2 days and $27,365. These results also show that beneficiaries with pneumonia using LTCH services are more likely to be in the higher APR-DRG levels, level 3 and 4, than patients using other PAC services. For example, 4.4 percent of beneficiaries in severity level 4 had an LTCH admission, compared with less than 1.0 percent in severity group 1. Another finding highlighted in this table is related to the use of home health services, as we found that the percentage of beneficiaries using home health services decreases as APR-DRG severity increases. This result may be due to the increasing likelihood of inpatient service use for beneficiaries of higher severity.
For comparison purposes, Appendix B shows the 2005 results for the mean length of stay and payment, by claim type and APR-DRG, for DRG 089 and DRG 544. While it is useful to compare lengths of stay and rates of utilization across the 2 years, note that episode payments calculated for 2005 did not include DME, hospice, or physician services.
Post-Acute Care Episodes: DRG 089, By MS-DRG. In Table 3-17, we also present the same episode measures stratified by MS-DRG. In general, the trends observed regarding length of stay and Medicare payments are similar for both MS-DRG and APR-DRG severity groupings. The majority of beneficiaries with pneumonia are in the middle MS-DRG severity group with CCs (56.1 percent), and the smallest proportion are in the highest MS-DRG level MCC (17.7 percent). As we noted for the APR-DRG severity levels, in general, episode length of stay and payments rise with increasing MS-DRG severity levels. For example, pneumonia cases with no CCs have an average of post-acute episode length of stay of 67.7 days and Medicare payments of $17,525. In contrast, those in MS-DRG severity level MCC have episodes averaging 76.5 days in length and $24,701 in Medicare payments.
Post-Acute Care Episodes: DRG 544, By APR-DRG. As Table 3-18 shows, as a contrast to pneumonia cases, beneficiaries with DRG 544 (Major Joint and Limb Reattachment Procedures) have slightly lower APR-DRG severity, because most are in severity levels 1 (30.8 percent) and 2 (47.7 percent). In general, episode length of stay and payments rise with increasing APR-DRG severity. Joint and knee cases with APR-DRG severity of illness level 1 had an average of post-acute episode length of stay of 58.4 days and Medicare payments of $20,513. In contrast, those in APR-DRG severity level 4 had episodes averaging 99 days and $43,823.
These results also show that beneficiaries with joint and knee reattachment procedures who had acute readmissions after PAC are more likely to be in the higher APR-DRG levels, level 3 and 4, than patients using other PAC services. For example, 34.0 percent of the beneficiaries in severity level 4 had an acute readmission, compared with 10.0 percent in severity group 1. Another notable finding is that the percentage of joint and knee cases using outpatient therapy decreases with increasing APR-DRG severity levels (from 44.0 percent in the lowest severity level to 17.0 percent in the highest severity level).
Post-Acute Care Episodes: DRG 544, By MS-DRG. DRG 544 is a DRG that has only two levels of severity when grouped using MS-DRG. The highest severity level is those who have major CCs (MCCs) and the lowest is those do not have MCCs. As noted in Table 3-18, the vast majority of beneficiaries with joint and knee cases do not have MCCs (95.0 percent).
With the exception of claims for hospice and Part B therapy services, episode payments rise with increasing MS-DRG severity levels for knee and joint patients. The most notable rise was in Part B services (excluding Part B therapy), which had a mean payment per episode of $2,580 for those with no MCCs and of $4,366 for those with MCCs (higher severity). Furthermore, 70.0 percent of beneficiaries with no MCCs had home health visits, compared with 63.0 percent of beneficiaries with MCCs. Similarly, 37.0 percent of beneficiaries with no MCCs had hospital outpatient therapy, compared with 28.0 percent of beneficiaries with MCCs. It is likely that these more severe patients required more intensive services through IRF or SNF, given that the proportion using IRF or SNF increases dramatically between those with No MCCs and those with MCCs.