Cross-sectional survey of factors influencing treatment adherence in elderly cancer patients in rural mountainous Guangyuan, China

Table 1 Distribution of demographic characteristics, n (%)

Characteristics	n = 103
Median age, years, mean ± SD	68.2 ± 7.8
Age
60-69	54 (52.4)
70-79	44 (42.7)
≥ 80	5 (4.9)
Gender
Male	58 (56.3)
Female	45 (43.7)
Treatment modality
Chemotherapy	65 (63.1)
Targeted therapy	22 (21.4)
Immunotherapy	11 (10.7)
Radiotherapy	5 (4.9)

Table 2 Patient symptom burden characteristics

Symptom category	Symptom	Grade 1 (n)	Grade 2 (n)	Grade 3 (n)	Grade 4 (n)	Total (n)	Moderate-to-severe symptom proportion (%)
Gastrointestinal symptoms	Nausea	38	19	7	2	66	13.6
	Vomiting	44	14	3	1	62	6.5
	Diarrhea	49	5	2	3	59	8.5
	Constipation	33	25	4	0	62	6.5
Systemic symptoms	Fatigue	27	18	17	6	71	32.4
	Fever	49	10	0	1	60	1.7
Skin/mucosal symptoms	Oral mucositis	41	6	3	3	53	11.3
	Hand-foot syndrome	39	11	4	0	54	7.4
Neurological symptoms	Peripheral neuropathy	39	10	6	1	56	12.5
	Headache	28	16	6	3	55	16.4

Table 3 Classification of patient treatment adherence levels

Adherence level	Score range	n (%)	Cumulative percentage (%)	Evaluation result
Good adherence	8 points	12 (11.80)	11.80	Fully compliant
Medium adherence	6-7.9 points	35 (34.30)	46.10	Partially compliant, needs intervention
Poor adherence	< 6 points	55 (53.90)	100.00	Severely non-compliant, urgent intervention needed
Total	0-8 points	102 (100.00)	100.00	Average score: 4.12 ± 1.85 points

Table 4 Correlation analysis between Supportive Care Needs Survey-Short Form 34 dimension scores and 8-item Morisky Medication Adherence Scale total score

Need dimension	Correlation coefficient (r) with MMAS-8 total	P value	Correlation strength	Correlation evaluation
Health information needs	-0.324	0.001	Moderate negative	Higher needs, lower adherence
Psychological needs	-0.287	0.004	Moderate negative	Higher needs, lower adherence
Physical and daily living needs	-0.351	< 0.001	Moderate negative	Higher needs, lower adherence
Care and support needs	-0.298	0.003	Moderate negative	Higher needs, lower adherence
Sexuality needs	-0.158	0.116	Weak negative	Not statistically significant
Overall supportive care needs	-0.336	< 0.001	Moderate negative	Higher needs, lower adherence

MMAS-8: 8-item Morisky Medication Adherence Scale.

Table 5 Multiple linear regression analysis results (dependent variable: 8-item Morisky Medication Adherence Scale total score)

Independent variables	Standardized coefficient (β)	t-value	P value	95%CI
Supportive care needs (n = 103, adjusted R2 = 0.142, F = 4.128, P = 0.001)
Physical and daily living needs	-0.183	-2.456	0.016	-0.942 to -0.100
Health information needs	-0.162	-2.134	0.035	-0.815 to -0.031
Psychological needs	-0.143	-1.987	0.049	-0.768 to -0.002
Care and support needs	-0.102	-1.423	0.158	-0.712 to 0.116
Sexuality needs	-0.052	-0.724	0.471	-0.501 to 0.233
Symptom burden (n = 71-81, adjusted R2 = 0.168, F = 4.782, P < 0.001)
Fatigue severity	-0.254	-3.128	0.002	-0.412 to -0.096
Nausea severity	-0.186	-2.245	0.027	-0.351 to -0.021
Oral mucositis severity	-0.172	-2.078	0.040	-0.337 to -0.007
Vomiting severity	-0.134	-1.618	0.108	-0.298 to 0.030
Diarrhea severity	-0.098	-1.182	0.240	-0.262 to 0.066
Financial toxicity (n = 103, adjusted R2 = 0.243, F = 6.892, P < 0.001)
Direct medical costs	-0.312	-3.456	0.001	-0.498 to -0.126
Indirect medical costs	-0.268	-2.978	0.004	-0.445 to -0.091
Medication costs	-0.234	-2.598	0.011	-0.415 to -0.053
Treatment interruption	-0.198	-2.198	0.030	-0.376 to -0.020
Debt situation	-0.175	-1.943	0.055	-0.354 to 0.004
Psychological status (n = 49, adjusted R2 = 0.268, F = 5.784, P < 0.001)
Social support (SSRS)	0.312	3.102	0.003	0.109-0.515
Anxiety symptoms (HADS-A)	-0.286	-2.845	0.007	-0.489 to -0.083
Depression symptoms (HADS-D)	-0.234	-2.326	0.025	-0.438 to -0.030
Life event impact (DT)	-0.198	-1.968	0.056	-0.402 to 0.006

β is standardized regression coefficient. All models were checked for multicollinearity (all variance inflation factors < 3.0), residual normality (Shapiro-Wilk test P > 0.05), and influential observations (Cook’s distance < 0.5 for all cases). Variable selection used stepwise regression with entry criterion P < 0.10 and removal criterion P > 0.15.

CI: Confidence interval; SSRS: Social Support Rating Scale; HADS-A: Hospital Anxiety and Depression Scale-Anxiety; HADS-D: Hospital Anxiety and Depression Scale-Depression; DT: Distress Thermometer.

Table 6 Association analysis between symptom severity and treatment adherence (8-item Morisky Medication Adherence Scale score), mean ± SD

Symptom type	Sample size	Moderate-to-severe symptom proportion (%)	Average MMAS-8 score of patients with symptom	P value vs patients without symptom
Fatigue	71	32.4	3.85 ± 1.78	0.008
Nausea	66	13.6	4.02 ± 1.82	0.023
Vomiting	62	6.5	4.15 ± 1.79	0.045
Diarrhea	59	8.5	4.28 ± 1.76	0.087
Constipation	62	6.5	4.32 ± 1.74	0.124
Oral mucositis	53	11.3	3.91 ± 1.81	0.015

MMAS-8: 8-item Morisky Medication Adherence Scale.

Table 7 Relationship between financial toxicity grade and treatment adherence, mean ± SD

Financial toxicity score grade	Number of patients	Percentage (%)	Average MMAS-8 score	Proportion with poor adherence (%)
0-10 points (low toxicity)	18	17.5	5.42 ± 1.23	22.2
11-20 points (moderate toxicity)	47	45.6	4.18 ± 1.45	48.9
21-30 points (high toxicity)	29	28.2	3.25 ± 1.68	75.9
> 30 points (severe toxicity)	9	8.7	2.18 ± 1.32	88.9

MMAS-8: 8-item Morisky Medication Adherence Scale.

Table 8 Patient psychological status scale assessment results (n = 49), mean ± SD

Psychological status dimension	Average score	Abnormal proportion (%)	Score range
Anxiety symptoms (HADS-A)	8.62 ± 3.45	42.9	3-16 points
Depression symptoms (HADS-D)	7.89 ± 3.28	38.8	2-15 points
Life event impact (DT)	2.78 ± 1.12	51	1-5 points
Total social support (SSRS)	32.45 ± 6.78	24.5	18-45 points
Treatment adherence (MMAS-8)	4.23 ± 1.82	53.1	1.5-7.5 points

HADS-A: Hospital Anxiety and Depression Scale-Anxiety; HADS-D: Hospital Anxiety and Depression Scale-Depression; DT: Distress Thermometer; SSRS: Social Support Rating Scale; MMAS-8: 8-item Morisky Medication Adherence Scale.

Table 9 Relationship between multiple factors and patient treatment adherence in linear regression analysis

Influencing factor dimension	Specific variable	Standardized coefficient (β)	t-value	P value	Independent contribution rank
Financial toxicity	Direct medical costs	-0.312	-3.456	0.001	1
	Indirect medical costs	-0.268	-2.978	0.004	4
	Medication costs	-0.234	-2.598	0.011	5
Symptom burden	Fatigue severity	-0.254	-3.128	0.002	2
	Nausea severity	-0.186	-2.245	0.027	6
Psychological status	Social support	0.234	2.895	0.005	3
	Anxiety symptoms	-0.158	-2.015	0.047	8
Supportive care needs	Physical and daily living needs	-0.183	-2.456	0.016	7
	Health information needs	-0.162	-2.134	0.035	9

Model statistics: R² = 0.518, adjusted R² = 0.482, F = 14.267, P < 0.001.

Table 10 Relative importance and incremental explanatory power of each dimension on treatment adherence

Influencing factor dimension	Relative weight (%)	Importance rank	Hierarchical regression ΔR2	Cumulative explanatory power (%)
Financial toxicity	28.40	1	0.157	37.00
Symptom burden	24.70	2	0.127	21.30
Psychological status	22.50	3	0.082	45.20
Supportive care needs	13.40	4	0.066	51.80
Demographic and disease characteristics	11.00	5	0.086	8.60