Results for NH use varied dramatically, depending on how use was measured. We examined four measures, each defined over the six-month intervals: any NH use; proportion of days spent in a NH, whether spent at least 30 days in a NH, and whether spent at least 90 days in a NH.
Compared to matched waiver enrollees, PACE enrollees were more likely to use a NH in almost all seven intervals, with the rate of NH use under PACE (11-17 percent) exceeding that of their matched counterparts (9-15 percent), in most intervals (Table 15). The difference of 3-4 percentage points was significant at the 1 percent level during the first four intervals, and the difference was smaller (1 percentage point or less) and not statistically significant in the last three intervals.
No such difference in NH use is observed when measured as the proportion of days during the six month interval that are spent in a NH. Proportion of days in the NH was lower for PACE enrollees compared to the matched comparison enrollees in six intervals, but only one of those differences was statistically significant--the four percentage point difference in interval six (p < 0.01). In the very first interval, PACE enrollees had a higher proportion of days in the NH (p < 0.05).
When NH use is measured by whether the sample member had a long stay in a NH during the period, the results change even more. PACE and matched waiver enrollees had similar predicted probabilities of being in a NH for at least 30 days during the seven intervals (Table 15, Panel 3), except the fifth and sixth intervals, when they had a 2-3 percentage points (p < 0.10 and p < 0.05 respectively) lower probability of spending at least 30 days in a NH. However, PACE enrollees were significantly less likely to be in a NH for at least 90 days in five of the seven intervals, by about 2-4 percentage points (Table 15, Panel 4). The difference was not statistically significant in the first and last intervals.
Results from Sensitivity Tests for Nursing Home Use
We examined the NH results after excluding New York from the study sample in order to confirm that the results were not driven by the state with the largest sample size. The findings were mostly similar with minor differences, mainly in terms of showing larger differences in predicted probabilities for some outcomes (Table 16). For instance, with New York excluded, PACE enrollees in the remaining sample had significantly lower proportion of days in the NH by 2-5 percentage points in three intervals--fourth, fifth, and sixth. Also, instead of in two intervals, PACE enrollees were now significantly less likely to be in the NH for at least 30 days in three intervals and by 2-4 percentage points (p < 0.10 in the fourth interval and p < 0.05 in the fifth and sixth intervals). Finally, as before, PACE enrollees were significantly less likely to be in a NH for at least 90 days in five of the seven intervals, but by about 2-6 percentage points, instead of 2-4 percentage points earlier.
Cumulative Risk of Nursing Home Use
In addition to the NH use outcomes reported above, we also examined the cumulative risk of being in a NH for at least 90 days over successive six-month intervals from sample entry for PACE and matched HCBS enrollees. While the outcome--whether in a NH for at least 90 days during a specific interval--described above, examines this separately for each six-month interval, the additional outcome for the cumulative risk of having been in a NH for at least 90 days offers a mechanism for examining how the aggregate risk of long-term NH use changes over time in each group. For any beneficiary, this binary outcome was coded as one for all intervals starting from the interval in which she is in a NH for at least 90 days (not necessarily consecutive). The sample sizes for examining this outcome were fixed at the number of treatment and matched comparison group members in the final matched sample for the first two intervals (since all sample members had at least 12 months of followup, with NH data available through 2009), and restricting the samples in later intervals to those whose period of sample entry would allow us to observe their cumulative risk of being in a NH for at least 90 days in a particular interval.18
There were no significant differences in the cumulative risk of being in a NH for at least 90 days over successive six-month intervals between PACE and the matched comparison group enrollees (Table 17), with all such differences being small--1 percentage point or less. Our findings remained unchanged, once New York was dropped from the study sample (results not shown). These findings differ from those reported above that showed PACE enrollees being significantly less likely to be in a NH for at least 90 days in five of the seven intervals (Table 15 and Table 16). The two sets of findings can be reconciled if there was little overlap among PACE enrollees who experienced long-term NH stays in each successive interval, while there was greater overlap across intervals among HCBS enrollees who experienced long-term NH stays, and for longer time periods in each interval than PACE enrollees.