TABLE 3.

Summary of Time-to-Death Studies

Study	Year(s) of Data	Age Group(s) Studied	Sector(s) of Health Care System Included	Baseline for Comparison	Effect of Time-to-Death	Effect of Age, Controlled for Time-to-Death	Age and Time-to-Death Combined Effect	Time Trend in Age and Time-to-Death Effects	Other Findings
Roos, Montgomery, and Roos 1987	1973–1982	45–64, 65–74, 75–84, 85+	Canadian acute care, nursing home, and primary care	9 or more years before death versus each of the last 8 years of life	More significant for nursing home days than for hospital days, especially at older ages	Age controlled for time-to-death still has a positive and significant effect with the exception of hospital days for ages 85+; the effect of age diminishes for both hospitals and nursing homes with older strata	The effect of time-to-death diminishes for both nursing home and hospital days; at ages 65–74, all eight years before death significantly different from year 9 or more; for 85+ only last year different for hospital and last four years for nursing home	Not available
Zweifel, Felder, and Meiers 1999	1981–1992, 1991–1994	All ages, 65+, deceased only	Swiss sick fund, broad multi-sector	8th quarter before death	Quarters 1–6 significantly different from 8 in first time period; in second time period only quarters 1–3 (all ages) and quarter 1 (65+) significantly different	Negative effect, statistically insignificant, for ages 65+; significant effect for all age sample (positive 1981–1992, negative 1991–1994); coefficient for Age2 is reverse sign in all cases	Quarters 1–6 significantly different from 8 in first time period; in second time period only quarters 1–3 (all ages) and quarter 1 (65+) significantly different; in second time period, effect of time-to-death appears reduced at older versus younger ages	Between first and second time period, effect of time-to-death appears reduced for all ages and older ages	In first sample, using 20th quarter before death as comparison, significant difference remains only to quarter 7; coefficients can be negative closer to quarter 20 (e.g., quarter 19 expected expenditures less than quarter 20)
Seshamani and Gray 2004b	1963–1999	Dying at ages 65+ in 1970 and after	UK data from a single hospital	16th year before death	Significant for years 1 to 13	Age is positive and significant; Age2 negative but not significant	Significant for years 1 to 13; time-to-death/expenditure curve gets flatter with older ages (i.e., time-to-death is less significant with age)	Time-to-death/expenditure curve gets flatter with more recent cohorts (i.e., time-to-death is recently less significant)
Seshamani and Gray 2004a	1963–1999	Dying at ages 65+ in 1970 and after	UK data from a single hospital	20th quarter before death	Quarters 1–3, 5, and 8 significantly different from 20; quarter 1 has negative coefficient (due to curtailed length-of-stay)	On expenditures, statistically insignificant both for Age and Age2; on probability of utilization, age is significant and positive	Quarters 1–3, 5, and 8 significantly different from 20; quarter 1 has negative coefficient (due to curtailed length-of-stay); in last quarter of life, costs peak at ages 80–85, decline thereafter	Not available	Different effects of age than Zweifel, Felder, and Meiers; age effect is parabolic, rising to age 85 and falling thereafter
Stearns and Norton 2004	1992–1998	66–99, survivors and decedents	Medicare	Not specified, assumed to be all persons 9 or more quarters from death	Significant in each quarter of the last two years of life	Remains almost as strong as uncontrolled effect of age; in both cases the coefficient for ages 66–70 through 90–95 are positive and significant relative to higher ages; age 70–75 is the highest expenditure age range	Significant in each quarter of the last two years of life; age has a negative influence on the effect of time-to-death for all quarters before death; this effect is not so much on likelihood of utilization as on intensity of utilization	Not available	The effect of age is on likelihood of use; expenditures given use are not sensitive to age; model results used in projections predict Medicare expenses in 2020 9% lower than models not using time-to-death
Seshamani and Gray 2002	1963–1999	Dying at ages 65+ in 1970 and after	UK data from a single hospital						Data from (2004b) are used to project UK hospital expenditures 2002–2026; projections using time-to-death are 12% lower than baseline; expenditures due to last year of life as share of total projected to fall for every age group
Breyer and Felder 2006	1999	All ages	Swiss sick fund, broad multi-sector	Entire population surviving 43 months or more beyond 1999	Stable (visible on graph) effect for time-to-death in each of the four years before death	Effect of Age is negative; effect of Age2 positive; significance not given	Time-to-death has a fairly consistent (rising) effect in the last four years of life on expenditures, but survivor expenses rise steadily with age, so relative comparison falls	Not available	Projections for 2050 assuming rise in life expectancy are compared using (1) time-to-death estimates, (2) age only survivor status-naïve, (3) time-to-death with medical technology growth of 1%; the technology effect in (3) dramatically outweighs the difference between (1) and (2)
Werblow, Felder, and Zweifel 2005	1999–2004	All ages	Swiss sick fund, broad multi-sector	Compared to all individuals 5 or more years from death	Time-to-death is a linear variable in this model; found to be significant for total costs, and to have greatest effect on hospital costs	Effect of Age and Age2 are of opposite sign, but signs change depending on the service measured; broad result is that age has minor effect on expenditures, peaking at around 80 for the elderly, but age is more significant and positive for social and physician care	The coefficient of the interaction of the binary dummy variable for death and age is consistently negative and significant, so that older age reduces the effect of death (except for nursing homes); interaction with time-to-death is not available	Not available	Time-to-death outweighs the effects of age for hospital costs, but age is the more important effect for long-term care and home care costs