Mean lifetime survival estimates following solid organ transplantation in the US and UK

Figures & data

Table 1. Knot placements per solid organ transplant for the US and UK analyses.

	US			UK
	k = 1	k = 2	k = 3	k = 1	k = 2	k = 3
Kidney (year)	1	2	13	1	2	12
Liver (year)	1	2	15	1	2	23
Lung (year)	2	10	16	4	10	16
Heart (year)	1	2	18	2	3	18

Abbreviation. k, knot.

Figure 1. Comparison of Kaplan–Meier plots of patient survival following SOT in the US and UK*. *Number at risk represents the number of registry patients still alive at each time point. Abbreviation. SOT, solid organ transplant.

Table 2. Patient baseline characteristics and transplant year category.^a

	All	Kidney transplants	Liver transplants	Heart transplants	Lung transplants
US
Age group (n, %)
<18	38,755 (6)	16,952 (4)	12,449 (9)	8,383 (13)	971 (3)
18–30	57,189 (9)	43,752 (11)	5,828 (4)	4,345 (7)	3,264 (9)
31–50	206,153 (33)	143,061 (37)	39,342 (29)	15,960 (25)	7,790 (21)
51–60	174,004 (28)	93,943 (25)	47,909 (35)	20,672 (32)	11,480 (32)
≥61	145,346 (23)	84,955 (22)	32,051 (23)	15,508 (24)	12,832 (35)
Transplant year category (n, %)^a
1990–1994	75,390 (12)	48,347 (13)	13,777 (10)	10,820 (17)	2,446 (7)
1995–1999	89,516 (14)	55,407 (15)	18,789 (14)	11,164 (17)	4,156 (11)
2000–2004	105,738 (17)	66,600 (17)	23,887 (17)	10,159 (16)	5,092 (14)
2005–2009	118,301 (19)	73,543 (19)	27,507 (20)	10,213 (16)	7,038 (19)
2010–2014	120,764 (19)	72,841 (19)	27,826 (20)	11,352 (17)	8,745 (24)
2015–2018	113,640 (18)	66,086 (17)	26,979 (19)	11,557 (18)	9,018 (25)
Total	621,447	382,663	137,579	64,868	36,337
UK
Age group (n, %)
<18	5,180 (9)	2,550 (6)	1,813 (13)	685 (18)	132 (5)
18–30	7,044 (12)	5,129 (13)	1,055 (8)	408 (10)	452 (16)
31–50	21,767 (36)	15,473 (39)	4,219 (30)	1,212 (31)	863 (30)
51–60	15,801 (26)	9,160 (23)	4,240 (30)	1,299 (33)	1,102 (38)
≥61	11,126 (18)	7,820 (20)	2,630 (19)	313 (8)	363 (13)
Transplant year category (n, %)^a
1995–1999	11,604 (19)	6,984 (17)	2,834 (20)	1,300 (33)	486 (17)
2000–2004	11,593 (19)	7,215 (18)	3,025 (22)	811 (21)	542 (19)
2005–2009	13,059 (21)	8,911 (22)	2,850 (20)	662 (17)	636 (22)
2010–2014	17,176 (28)	11,894 (30)	3,637 (26)	755 (19)	890 (31)
2015–2016	7,487 (12)	5,129 (13)	1,611 (12)	389 (10)	358 (12)
Total	60,918	40,132	13,957	3917	2,912

^aUS patient-level data were recorded from 1990 to 2018, while UK patient-level data were recorded from 1995 to 2017.

Abbreviation. n, number of patients.

Table 3. Fit statistics for all parametric and knot functions applied to the US and UK data.^a

	US				UK
Function	AIC	BIC	AIC rank	BIC rank	AIC	BIC	AIC rank	BIC rank
Kidney
k = 3	2,763,376	2,763,430	1	1	169,897	169,940	1	2
k = 2	2,765,451	2,765,494	2	2	169,899	169,933	2	1
Exponential	2,772,840	2,772,851	5	5	170,822	170,830	5	4
Generalized gamma	2,769,761	2,769,794	3	3	170,499	170,525	3	3
Log logistic	2,777,715	2,777,737	6	6	171,181	171,198	6	6
Log normal	2,804,791	2,804,813	7	7	172,725	172,742	7	7
Weibull	2,771,672	2,771,693	4	4	170,813	170,830	4	5
Liver
k = 3	1,043,435	1,043,484	1	1	83,890	83,928	1	1
k = 2	1,043,689	1,043,728	2	2	83,935	83,965	2	2
Exponential	1,062,790	1,062,800	7	7	86,754	86,762	7	7
Generalized gamma	1,045,150	1,045,180	3	3	84,453	84,476	3	3
Log logistic	1,050,995	1,051,015	5	5	84,981	84,996	5	5
Log normal	1,056,018	1,056,038	6	6	85,339	85,354	6	6
Weibull	1,047,619	1,047,639	4	4	84,714	84,729	4	4
Lung
k = 3	380,010	380,053	1	1	30,608	30,637	2	3
k = 2	380,100	380,134	2	2	30,611	30,635	3	2
Exponential	382,660	382,668	5	5	31,192	31,198	7	7
Generalized gamma	380,125	380,150	3	3	30,606	30,624	1	1
Log logistic	383,107	383,124	6	6	30,874	30,886	5	5
Log normal	385,587	385,604	7	7	30,972	30,984	6	6
Weibull	380,778	380,795	4	4	30,697	30,709	4	4
Heart
k = 3	603,846	603,891	1	1	33,986	34,017	1	1
k = 2	604,028	604,065	2	2	34,001	34,026	2	2
Exponential	616,671	616,680	6	6	35,957	35,963	7	7
Generalized gamma	607,292	607,319	3	3	34,404	34,422	3	3
Log logistic	616,159	616,177	5	5	34,837	34,849	5	5
Log normal	621,395	621,413	7	7	34,966	34,979	6	6
Weibull	611,410	611,428	4	4	34,626	34,639	4	4

^aGompertz function did not converge for any SOT type, therefore the fit statistics are not available.

Abbreviations. AIC, Akaike information criterion; BIC, Bayesian information criterion; k, knot.

Figure 2. Comparison of Kaplan–Meier plots of survival following SOT in the base-case (knot = 3 and life tables) and sensitivity analysis (knot = 2). (a) Kidney transplant survival in the US; (b) kidney transplant survival in the UK; (c) liver transplant survival in the US; (d) liver transplant survival in the UK; (e) lung transplant survival in the US; (f) lung transplant survival in the UK; (g) heart transplant survival in the US; (h) heart transplant survival in the UK. Abbreviations: K, knot; LT, life table; SOT, solid organ transplant.

Table 4. Mean estimated lifetime survival post-transplant.

Organ	Base-case analysis (k = 3 and LT)	Sensitivity analysis (k = 2)	Difference
US
Kidney	22.79	21.49	−1.30
Liver	20.90	24.04	+3.14
Lung	9.28	8.52	−0.76
Heart	14.82	15.57	+0.75
UK
Kidney	26.58	28.15	+1.57
Liver	20.38	25.21	+4.83
Lung	9.21	8.57	−0.64
Heart	15.85	17.60	+1.75

Abbreviations. k, knot; LT, life table.

Data availability statement

The data that support the findings of this study are available from the SRTR and UKTR registries. Restrictions apply to the availability of these data, which were used under license for this study. Data are available from https://www.srtr.org/requesting-srtr-data/data-requests/ and https://www.odt.nhs.uk/statistics-and-reports/access-data/ with permissions of the SRTR and UKTR, respectively. All analyzed data are included in this manuscript.