4,761 HRS decedents who died between 1998 and 2007 (82% of 5,810 decedents with post-mortem interviews) also had linked Medicare data. In order to accurately account for EOL utilization, we excluded 1,445 decedents with any managed care enrollment during the last six months of life and 14 decedents who reported military coverage and might receive care through Veterans Health Administration facilities.
Our cohort included 3,302 decedents. Their mean age at death was 82.8. 56% were female. 70% were hospitalized at least once in the last six months of life; 41% died at in a hospital. 61% of the sample had either a living will or written DPOA, 39% of the sample completed a written, treatment-limiting advance directive. presents the characteristics of individuals with and without a treatment-limiting advance directive. Median Medicare spending in the last six months of life did not vary by treatment-limiting advance directive status. In unadjusted comparisons, those with treatment-limiting advance directives had lower rates of life-sustaining treatment (34% vs. 39%, p = 0.002), lower rates of in-hospital death (37% vs. 43%, p < 0.001) and higher rates of hospice use (40% vs. 26%, p < 0.001). Those with advance directives were more likely to be white, affluent and highly educated.
Characteristics of Decedents by Treatment-Limiting Advance Directive Statusa
We compared EOL care of decedents living in HRRs in the lowest quartile of Medicare spending, (mean unadjusted spending $8,787; range 7252 – 9707), middle half ($10,848; 10242 – 12404), and highest quartile ($15,744; 12446 – 29797). There was substantial geographic diversity in the rates of advance directives among HRRs. Decedents residing in low-spending HRRs were more likely to have an advance directive (any advance directive, 47%; treatment-limiting advance directive 42%) than decedents in high-spending HRRs (any 39%, treatment-limiting 36%; both differences between low- and high-spending HRRs significant at p < 0.001) (). After adjusting for demographic and socioeconomic characteristics, decedents in high-spending HRRs continued to face lower odds of having a treatment-limiting advance directive (OR = 0.69, 95% CI 0.54 – 0.88). Though there was considerable variation in advance directive () and median end-of-life spending () across HRRs, there was relatively little difference in cause of death or comorbidity prior to the end-of-life (). Regression-adjusted end-of-life spending was significantly lower for decedents in low-spending HRRs (predicted spending $21,741; 95% CI 19,668 – 23,816; difference $4,400, 95% CI 2,083 – 6,717) and higher for those in high-spending HRRs (predicted spending $37,841; 95% CI 34,855 – 40,107 difference $11,340, 95% CI 8,479 – 14,200) relative to those in medium-spending HRRs. Spending was considerably higher for non-white decedents (difference $6,561, 95% CI 3293 –9829)) and lower for decedents aged 90 and above relative to younger decedents (difference −$7,871, 95% CI −11,212 to −4,530). After adjusting for patient characteristics and HRR spending intensity, there was no difference in Medicare spending in the last 6 months of life for those with ($28,348, 95% CI 26,698 – 29,999) and without advance directives ($29,352, 95% CI 27,885 –30,819) (difference −$1,004, 95% CI −3,366 – 1,359) when using regressions that forced the association with advance directives to be the same for all regions.
Geographic Variation in Advance Directivesa,b
Decedent Characteristics by Level of Regional End-of-Life Spendinga
However, there was important geographic heterogeneity in the relationship between advance directives and EOL spending (). In high spending regions, adjusted spending on patients with a treatment-limiting advance directive was $33,933 (95% CI 30,233 – 37,681), whereas adjusted spending for patients without an advance directive was $39,518 (95% CI 35,871 – 43,167; difference −$5585, (95% CI −10903 to −267). Having a treatment-limiting advance directive was not associated with differences in aggregate EOL spending for decedents in low and medium spending HRRs.
Regression-Adjusted Total Medicare Spending in Last 6 Months of Life:a
Treatment-limiting advance directives were associated with site of death and palliative care for decedents in medium and high-spending regions (). Directives were associated with lower probabilities of in-hospital death in high- and medium-spending regions, but not in low spending regions. Thus, in high-spending regions, patients without an advance directive had a 47% adjusted probability of in-hospital death (95% CI 44% – 51%), whereas those with an advance directive had a 38% probability of in-hospital death (95% CI 29% – 41%; difference − 9.8%, 95% CI −16% to −3%). The equivalent results for in-hospital death for those in medium-spending regions were 42% without an advance directive (95% CI 39% – 45%) and 37% with an advance directive (95% CI 33% – 41%; difference −5.3%, 95% CI −10% to −0.4%). In high-spending regions, patients without a limiting advance directive had a 24% adjusted probability of hospice use (95% CI 21% – 28%), whereas those with a directive had an adjusted probability of hospice use of 41% (95% CI 36% – 46%; difference 17%, 95% CI 11% – 13%). Similar differences in hospice use occurred in medium-spending regions. There was no statistically significant relationship between treatment-limiting advance directive use and receipt of life-sustaining treatments during hospitalizations in the last six months of life, although the point estimates were in the same direction as for total EOL expenditures in high-spending HRRs; lower likelihood of utilization of life-sustaining treatments among those with treatment-limiting advance directives, p=0.11.
Predicted Probability of Treatments in the Last 6 Months of Life:a
The differences in Medicare spending observed among those with advance directives in high-spending regions appears to be driven mainly by lower inpatient spending ($7509 lower, 95% CI $3,404 to $11,614 lower) slightly offset by higher hospice spending ($976 higher, 95% CI $294 to $1658 higher) (eTable 1
). The differences in end-of-life spending across regions and advance directive status are concentrated among the 2,384 (72%) decedents experiencing at least one hospitalization in the last six months of life (eTable 2
). There was no evidence of heterogeneity of the advanced directive effect in high-spending region across cause of death (p=0.44 for joint test of significance; eFigure 1
3.8% of those with advance directives (1.5% of decedents overall) requested all care possible in their advance directive. There were too few such decedents in our study to reliably estimate the effects of such advance directives; these decedents are included in the no limiting directive group. On average, these decedents used $8,060 more care at the end-of-life (p= 0.02) than decedents with treatment-limiting directives.
Our results were consistent across numerous alternative specifications including an ordinary least squares regression, excluding all veterans as any VA care is unobserved in the Medicare claims, excluding disabled decedents who are under 65 but observed in the Medicare claims, excluding decedents with cancer as the cause of death, and excluding those who write advance directives in the last 6 months of life (eTable 3–6
; eFigure 1