Interconversion of two commonly used performance tools: An analysis of 5844 paired assessments in 1501 lung cancer patients

Table 1 Karnofsky performance status categories suggested for interconversion to Eastern Cooperative Oncology Group performance status in the literature

Author, year	n and patients, assessments	Setting	KPS categories	ECOG
AJCC[34], 1977	-	-	90-100	0
			70-80	1
			50-60	2
			30-40	3
			10-20	4
Minna et al[20], 1985	-	-	100	0
			80-90	1
			60-70	2
			40-50	3
			20-30	4
Buccheri et al[10], 1996	536 (1656)	Subjects with lung cancer visiting a cancer clinic of a tertiary care centre	80-100	0-1
			60-70	2
			10-50	3-4
Ma et al[19], 2010	1385 (1385)	Subjects visiting an oncology palliative care clinic, or admitted to an acute cancer palliative care unit	100	0
			80-90	1
			60-70	2
			40-50	3
			10-30	4
de Kock et al[18], 2013	955 (674)	Subjects with advanced life-limiting illnesses (cancer and non-cancer) in acute care and community settings	60-100	1
			50	2
			30-40	3
			10-20	4
Current study	1501 (5844)	Subjects with lung cancer visiting a cancer clinic of a tertiary care center	100	0
			80-90	1
			70	2
			50-60	3
			10-40	4

AJCC: American Joint Committee on Cancer; ECOG: Eastern Cooperative Oncology Group; KPS: Karnofsky performance status; PS: Performance status.

Table 2 Baseline characteristics of the study population n (%)

Characteristic	Total, n = 1501
Age in yr	58.4 (10.8)
Males	1236 (82.3)
Smokers	1155 (76.9)
Body mass index in kg/m2	20.2 (4.2)
Histopathology
NSCLC: Squamous	553 (36.8)
NSCLC: Adeno	514 (34.2)
NSCLC: Undifferentiated	87 (5.8)
NSCLC: Other	42 (2.8)
SCLC	305 (20.3)
NSCLC/SCLC stage1
I and II	44 (2.9)
IIIA	193 (12.9)
IIIB	426 (28.4)
IV	767 (51.1)
SCLC stage
Limited disease	145 (9.7)
Extensive disease	160 (10.7)
Baseline performance status
KPS	77.6 (14.4)
ECOG PS	1.5 (1)

¹Total does not add up to 1501 as TNM staging was available for only some of the patients with SCLC. All values are mean (standard deviation) unless otherwise specified. ECOG PS: Eastern Cooperative Oncology Group performance status; KPS: Karnofsky performance status; NSCLC: Non-small cell lung cancer; SCLC: Small cell lung cancer.

Table 3 Correlation between Karnofsky performance status and Eastern Cooperative Oncology Group performance status

Visit number	Number of assessments	Spearman’s correlation coefficient1
1	1426	-0.727
2	1099	-0.890
3	957	-0.876
4	823	-0.863
5	602	-0.858
6	464	-0.867
7	270	-0.901
8	129	-0.854
9	54	-0.773
10	20	-0.972
Overall	5844	-0.840

¹P < 0.0001 for all individual visits and overall.

Table 4 Comparison of the performance of various suggested Karnofsky performance status categories (for interconversion to the Eastern Cooperative Oncology Group performance status scale) in the current cohort

Author, year	Hit rate1	κw1
AJCC et al[34], 1977	43.60%	0.376 (0.363-0.389) P < 0.0001
Minna et al[20], 1985	75.20%	0.701 (0.687-0.714) P < 0.0001
Buccheri et al[10], 1996	83.20%	0.695 (0.679-0.711) P < 0.0001
Ma et al[19], 2010	75.20%	0.701 (0.687-0.714) P < 0.0001
de Kock et al[18], 2013	43.20%	0.079 (0.068-0.090) P < 0.0001
Current study	78.10%	0.749 (0.736-0.762) P < 0.0001

¹Performance in the current cohort shown as hit rate (%) or weighted kappa (95% confidence limits) along with the P-value.