Patient factors and quality of life outcomes differ among four subgroups of oncology patients based on symptom occurrence

Figures & data

Figure 1. Flowchart of patient recruitment.

BC: breast cancer; CRC: colorectal cancer; HNC: head and neck cancer; OC: ovarian cancer.

Figure 2. Probability of symptom occurrence for each of the latent classes for the 13 symptoms on the Memorial Symptom Assessment Scale that occurred in ≥30% of the patients.

Table 1. Latent class solutions and fit indices for two- through five classes using occurrence rates for 13 symptoms on the Memorial Symptom Assessment Scale.

Model	LL	AIC	BIC	Entropy
2 Class	−4030.84	8115.69	8231.26	0.83
3 Class	−3882.91	7847.82	8023.32	0.83
4 Class^a	−3813.86	7737.72	7973.14	0.81
5 Class	−3789.00	7715.99	8011.34	0.83

AIC: Akaike Information Criterion; BIC: Bayesian Information Criterion; LL: log-likelihood.

^a The 4-class solution was selected because the BIC was smaller than the 3-class and 5-class models.

Table 2. Differences in the occurrence rates for the 13 most common symptoms among the four latent classes (n = 534).

	All low (1) 28.5% (n = 152)	Low psychological (2) 21.0% (n = 112)	High psychological (3) 22.7% (n = 121)	All high (4) 27.8% (n = 149)	p Value and pairwise
Symptom	% (N)	% (N)	% (N)	% (N)	contrasts^a
Physical symptoms
Lack of energy	12.5 (19)	91.1 (102)	47.9 (58)	97.3 (141)	<0.001 1 < 2, 3, 4 3 < 2, 4
Feeling drowsy	9.2 (14)	81.2 (91)	33.1 (40)	96.0 (143)	<0.001 1 < 2, 3, 4 3 < 2 2, 3 < 4
Pain	21.7 (33)	58.9 (66)	41.3 (50)	88.6 (132)	<0.001 1 < 2, 3, 4 3 < 2 2, 3 < 4
Difficulty sleeping	18.4 (28)	54.5 (61)	60.3 (73)	86.6 (129)	<0.001 1 < 2, 3, 4 2, 3 < 4
Dry mouth	16.4 (25)	66.1 (74)	24.8 (30)	73.8 (110)	<0.001 1, 3 < 2, 4
Problems with sexual  interest/activity	11.2 (17)	42.9 (48)	29.8 (36)	71.8 (107)	<0.001 1 < 2, 3, 4 2, 3 < 4
Feeling bloated	17.8 (27)	45.5 (51)	34.7 (42)	70.5 (105)	<0.001 1 < 2, 3, 4 2, 3 < 4
Sweats	13.8 (21)	40.2 (45)	32.2 (39)	64.4 (96)	<0.001 1 < 2, 3, and 4 2, 3 < 4
Psychological symptoms
Worrying^b	10.5 (16)	33.0 (37)	100.0 (121)	99.3 (148)	<0.001 1, 2 < 4
Feeling sad	3.9 (6)	16.1 (18)	66.1 (80)	93.3 (139)	<0.001 1 < 2, 3, 4 2 < 3 2, 3 < 4
Difficulty concentrating	0.7 (1)	36.6 (41)	45.5 (55)	85.2 (127)	<0.001 1 < 2, 3, 4 2, 3 < 4
Feeling nervous	0.7 (1)	14.3 (16)	64.5 (78)	82.6 (123)	<0.001 1 < 2, 3, 4 2 < 3 2, 3 < 4
Feeling irritable	1.3 (2)	19.6 (22)	22.7 (26)	75.8 (113)	<0.001 1 < 2, 3, 4 2, 3 < 4

^a p Value is for the omnibus test;

^b Class 3 was dropped from this analysis because all members of the class reported worrying.

Table 3. Differences in demographic characteristics among the four latent classes (n = 534).

	All low (1) 28.5% (n = 152)	Low psychological (2) 21.0% (n = 112)	High psychological (3) 22.7% (n = 121)	All high (4) 27.8% (n = 149)	p Value and pairwise
Characteristic	Mean (SD)	Mean (SD)	Mean (SD)	Mean (SD)	contrasts^a
Age (years)	62.3 (10.3)	61.0 (9.8)	59.1 (9.9)	59.1 (11.0)	0.018 4 < 1
	% (N)	% (N)	% (N)	% (N)
Gender
Men	36.8 (56)	36.6 (41)	24.8 (30)	26.8 (40)	0.060
Women	63.2 (96)	63.4 (71)	75.2 (91)	73.2 (109)
Cohabitation
Alone	27.0 (41)	21.6 (24)	23.1 (28)	25.2 (37)	0.763
With someone	73.0 (111)	78.4 (87)	76.9 (93)	74.8 (110)
Marital status
Married/partnered	69.1 (105)	69.4 (77)	68.6 (83)	67.8 (101)
Unmarried	9.2 (14)	6.3 (7)	11.6 (14)	8.7 (13)	0.696
Divorced/separated	11.2 (17)	14.4 (16)	12.4 (15)	17.4 (26)
Widowed	10.5 (16)	9.9 (11)	7.4 (9)	6.0 (9)
Education
Primary	18.9 (28)	21.6 (24)	14.9 (18)	18.6 (27)
Secondary	42.6 (63)	51.4 (57)	47.9 (58)	46.9 (68)	0.509
College/university	38.5 (57)	27.0 (30)	37.2 (45)	34.5 (50)

^a p Value is for the omnibus test.

SD: standard deviation.

Table 4. Differences in clinical characteristics among the four latent classes (n = 534).

	All low (1) 28.5% (n = 152)	Low psychological (2) 21.0% (n = 112)	High psychological (3) 22.7% (n = 121)	All high (4) 27.8% (n = 149)	p Value and pairwise
Characteristic	% (N)	% (N)	% (N)	% (N)	contrasts^a
Diagnosis
Breast	36.8 (56)	42.9 (48)	33.1 (40)	29.5 (44)
Head and neck	23.7 (36)	25.0 (28)	21.5 (26)	28.9 (43)	0.183
Ovarian	15.1 (23)	11.6 (13)	19.0 (23)	22.8 (34)
Colorectal	24.3 (37)	20.5 (23)	26.4 (32)	18.8 (28)
Treatment goal
Curative	76.3 (116)	73.2 (82)	73.6 (89)	67.1 (100)	0.338
Palliative	23.7 (36)	26.8 (30)	26.4 (32)	32.9 (49)
Metastasis
Yes	55.3 (84)	61.6 (69)	57.8 (70)	69.8 (104)	0.058
No	44.7 (68)	38.4 (43)	42.1 (51)	30.2 (45)
Number of metastatic sites (of 7)	0.8 (0.9)	0.9 (0.9)	0.9 (1.0)	1.0 (0.9)	0.136
Previous surgery (% yes)	87.5 (133)	80.4 (90)	86.0 (104)	80.5 (120)	0.254
Previous radiotherapy (% yes)	13.1 (13)	13.6 (9)	9.5 (8)	13.1 (14)	0.842
Previous chemotherapy (% yes)	37.2 (42)	44.6 (41)	34.0 (32)	43.6 (58)	0.349
Previous hormonal therapy (% yes)	5.2 (5)	9.1 (6)	6.1 (5)	4.7 (5)	0.668
	Mean/Median (SD)	Mean/Median (SD)	Mean/Median (SD)	Mean/Median (SD)
Time since diagnosis (days)	388/90 (1012)	320/94 (737)	403/79 (942)	402/96 (703)	0.868
Body mass index (kg/m^2)	25.8 (4.2)	25.5 (3.9)	25.0 (4.5)	25.1 (5.6)	0.538
Karnofsky Performance Status score	94.3 (7.4)	82.7 (13.4)	89.3 (11.6)	79.4 (12.7)	<0.001 1 > 2, 3, 4 3 > 2, 4
Number of MSAS symptoms (of 32)	2.5 (2.1)	10.5 (4.2)	8.3 (3.2)	17.7 (5.2)	<0.001 1 < 3 < 2 < 4
Number of comorbidities (of 19)	1.3 (1.2)	2.0 (1.6)	1.6 (1.7)	2.5 (1.9)	<0.001 1 < 2, 4 3 < 4
Self-Administered Comorbidity Questionnaire – 19 total score	2.3 (2.3)	3.8 (3.3)	2.9 (3.2)	4.6 (4.1)	<0.001 1 < 2, 4 3 < 4
Comorbidities	% (N)	% (N)	% (N)	% (N)
Neck/back pain	18.4 (28)	31.2 (35)	22.3 (27)	43.0 (64)	<0.001 4 > 1, 3
High blood pressure	25.7 (39)	29.5 (33)	25.6 (31)	21.5 (32)	0.532
Osteoarthritis	15.1 (23)	16.1 (18)	19.0 (23)	21.5 (32)	0.487
Headache	5.3 (8)	12.5 (14)	5.8 (7)	18.8 (28)	<0.001 4 > 1, 3
Depression	0.7 (1)	7.1 (8)	10.7 (13)	22.1 (33)	<0.001 1 < 2, 3, 4 2 < 4
Bowel disease	7.9 (12)	9.8 (11)	9.1 (11)	10.1 (15)	0.919
Skin disease	5.3 (8)	8.0 (9)	5.0 (6)	12.1 (18)	0.086
Heart disease	6.6 (10)	9.8 (11)	4.1 (5)	10.7 (16)	0.175
Diabetes	4.6 (7)	10.7 (12)	8.3 (10)	4.0 (6)	0.101
Lung disease	2.0 (3)	8.9 (10)	5.0 (6)	7.4 (11)	0.069
Rheumatoid arthritis	2.6 (4)	8.0 (9)	2.5 (3)	8.1 (12)	0.045^b
Disease in muscle/connective tissue	2.0 (3)	5.4 (6)	4.1 (5)	6.0 (9)	0.334
Liver disease	4.6 (7)	4.5 (5)	3.3 (4)	4.7 (7)	0.942
Ulcer/stomach disease	1.3 (2)	4.5 (5)	3.3 (4)	5.4 (8)	0.268
Kidney disease	1.3 (2)	1.8 (2)	1.7 (2)	2.7 (4)	0.843
Anemia/blood disease	0.0 (0)	0.9 (1)	0.8 (1)	4.0 (6)	0.024^b

^a p Value is for the omnibus test;

^b no significant post hoc contrasts.

MSAS: Memorial Symptom Assessment Scale; SD: standard deviation.

Table 5. Differences in quality of life scores among the four latent classes (n = 534).

	All low (1) 28.5% (n = 152)	Low psychological (2) 21.0% (n = 112)	High psychological (3) 22.7% (n = 121)	All high (4) 27.8% (n = 149)	p Value and pairwise contrasts^a
Quality of life scores	Mean (SD)	Mean (SD)	Mean (SD)	Mean (SD)
Short Form – 12
Physical component   summary score	50.9 (8.4)	39.6 (10.6)	47.7 (10.4)	38.2 (10.5)	<0.001 1, 3 > 2, 4
Mental component   summary score	54.7 (7.3)	48.5 (10.2)	44.7 (10.3)	39.4 (9.8)	<0.001 1 > 2 > 3 > 4
Multidimensional Quality of  Life Scale – Cancer
Total quality of life   score	8.7 (0.8)	7.3 (1.2)	7.9 (1.1)	6.6 (1.2)	<0.001 1 > 3 > 2 > 4

^a p Value is for the omnibus test.

SD: standard deviation.