Frailty, Illness Perception and Lung Functional Exercise Adherence in Lung Cancer Patients After Thoracoscopic Surgery

Figures & data

Figure 1 The Hypothetical model about explanatory factors used in mediation analysis.

Notes: In this hypothetical model: 1. The influence coefficient of influence of frailty X on disease perception M is a; 2. The influence coefficient of disease perception M on lung function exercise adherence Y is b; 3. The influence coefficient of frailty X on lung function exercise adherence Y is c’. Exploring the mediation model will involve two regression equations of the influence coefficient: 1.M = Constant 1+a × X 2.Y = Constant 2 +b × M +c’ × X Therefore, 1. The indirect effect of frailty X on lung function exercise adherence Y through illness perception M is ab; 2. The direct influence of frailty X on lung function exercise adherence Y is c’; 3. The total effect of frailty X on lung function exercise adherence (Y) c=c’+ ab.

Figure 2 The enrollment of study samples.

Table 1 Baseline Characteristics of the Study

Variates		Mean ± SD/n(%)	Adherence (mean ± SD)	t/z/F/r	p	Low Illness Perception(n=109)	High Illness Perception(n=109)	z/χ^2	P
		218(100)	36.93±12.053			24.70±5.672	44.87±7.471	−12.763	<0.001
Age		60.27±13.008	36.93±12.053	−0.171*	0.012	60.86±13.675	59.67±12.339	−1.296	0.195
Sex				0.201	0.841			0.019	0.891
	Male	93(42.7)	36.40±1.315			46(42.2)	47(43.1)
	Female	125(57.3)	37.33±1.037			63(57.8)	62(56.9)
Culture				1.23	0.3			1.316	0.725
	Primary school and below	70(32.1)	35.34±1.372			36(33.0)	24(31.2)
	Junior high school	80(36.7)	37.36±1.326			42(38.5)	38(34.9)
	High school	34(15.6)	36.12±2.142			17(15.6)	17(15.6)
	University and above	34(15.6)	40.00±2.242			14(12.8)	20(18.3)
Money				−0.934	0.35			0.130	0.719
	Cash	8(3.7)	38.75±5.975			3(2.8)	5(4.6)
	Health care	210(96.3)	36.68±0.820			106(97.2)	104(95.4)
BMI				0.78	0.46			0.214	0.898
	<18.5	11(5.0)	33.18±13.068			5(4.6)	6(5.5)
	18.5–25	139(63.8)	36.72±12.530			71(65.1)	68(62.4)
	≥25	68(31.2)	37.93±10.874			33(30.3)	35(32.1)
Hypertension				0.318	0.751			2.298	0.130
	No	129(59.2)	37.15±1.063			59(54.1)	70(64.2)
	Yes	89(40.8)	36.62±1.282			50(45.9)	39(35.8)
Diabetes				0.419	0.676			0.000	1.000
	No	196(89.9)	37.05±0.867			98(89.9)	98(89.9)
	Yes	22(10.1)	35.91±2.438			11(10.1)	11(10.1)
Double nodules				0.134	0.894			0.394	0.530
	No	164(75.2)	36.99±0.959			80(73.4)	84(77.1)
	Yes	54(24.8)	36.74±1.557			29(26.6)	25(22.9)
Time from diagnosis to surgery				2.623	0.075			1.368	0.504
	<1 month	68(31.2)	34.72±1.476			30(27.5)	38(34.9)
	1 month-1 year	91(41.7)	36.86±1.287			48(44.0)	43(39.4)
	>1 year	59(27.1)	39.59±1.459			31(28.4)	28(25.7)
Cancer				10.482*	0.033			8.788	0.058
	Adenocarcinoma in situ	61(28.0)	35.90±1.556			23(21.1)	38(34.9)
	Microinvasive adenocarcinoma	66(30.3)	40.68±1.557			41(37.6)	25(22.9)
	Invasive adenocarcinoma	64(29.4)	35.88±1.409			30(27.5)	34(31.2)
	Squamous cell carcinoma	23(10.6)	32.17±2.021			12(11.0)	11(10.1)
	Mucinous adenocarcinoma	4(1.80)	35.00±7.036			3(2.8)	1(0.9)
Location of surgery				3.537	0.618			7.121	0.208
	Left upper lung	50(22.9)	35.16±1.848			24(22.0)	26(23.9)
	Left lower lung	35(16.1)	39.51±1.621			16(14.7)	19(17.4)
	Right upper lung	71(32.6)	37.23±1.470			33(30.3)	38(34.9)
	Right middle lung	7(3.2)	33.71±6.221			2(1.8)	5(4.6)
	Right lower lung	44(20.2)	36.36±1.739			25(22.9)	19(17.4)
	Other cases	11(5.0)	39.18±3.567			9(8.3)	2(1.8)
Lymphatic clearance				1.838	0.067			7.390**	0.007
	No	118(54.1)	38.31±1.109			69(63.3)	49(45.0)
	Yes	100(45.9)	35.31±1.192			40(36.7)	60(55.0)
Postoperative fever				4.305**	<0.001			3.185	0.074
	No	169(77.5)	38.75±0.928			90(82.6)	79(72.5)
	Yes	49(22.5)	30.65±1.394			19(17.4)	30(27.5)
Postoperative stool				−1.526	0.127			4.788*	0.029
	No	94(43.1)	35.70±1.171			39(35.8)	55(50.5)
	Yes	124(56.9)	37.86±1.125			70(64.2)	54(49.5)
Pain		2.98±1.472	36.93±12.052	−0.177**	0.009	2.71±1.356	3.26±1.536	−2.648**	0.008
Sleep				−3.24**	0.001			3.233	0.072
	Good	131(60.1)	38.99±1.032			72(66.1)	59(54.1)
	Bad	87(39.9)	33.83±1.265			37(33.9)	50(45.9)
Preoperative time		3.57±2.857	36.93±12.054	−0.131	0.053	3.53±3.299	3.61±2.349	−1.029	0.304
Postoperative time		6.41±2.917	36.93±12.055	−0.297**	<0.001	6.00±2.357	6.83±3.347	−1.818	0.069
The first day of drainage		128.09±130.177	36.93±12.056	−0.148*	0.029	129.55±133.886	126.63±126.962	−0.086	0.931
Total postoperative drainage,		645.22±609.348	36.93±12.057	−0.283**	<0.001	611.32±549.044	679.13±665.041	−0.412	0.680
Time to drain tube placement,		4.89±2.762	36.93±12.058	−0.308**	<0.002	4.32±1.948	5.46±3.299	−2.624**	0.009
frailty				−4.58**	<0.001			17.929**	<0.001
	No	123(56.4)	40.36±0.976			77(70.6)	46(42.2)
	Yes	95(43.6)	32.49±1.248			32(29.4)	63(57.8)
frailty	frailty total	3.40±2.661	36.93±12.052	0.439**	<0.001	2.48±2.371	4.33±2.621	−5.343**	<0.001
	Health	1.58±1.924				1.09±1.681	2.07±2.031	−3.999**	<0.001
	Cognition	0.47±0.500				0.43±0.498	0.51±0.502	−1.218	0.223
	Society	0.4±0.799				0.32±0.744	0.49±0.846	−1.815	0.069
	Mental	0.95±0.790				0.64±0.752	1.27±0.702	−5.861**	<0.001
Illness perception		34.78±12.084	36.93±12.052	−0.327**	<0.001
Exercise adherence		36.93±12.052				39.65±11.554	34.21±11.977	−3.280**	0.001

Notes: *p<0.05; **p<0.01.

Abbreviations: SD, standard deviation, BMI, body mass index.

Table 2 Descriptive Statistics for Illness Perception

	Mean	SD
Illness perception	34.784	12.084
Consequences	4.752	2.566
Timeline	4.528	2.491
Personal control	4.683	2.556
Treatment control	1.986	1.516
Identity	4.014	2.433
Concern	6.858	2.244
Illness coherence	3.583	2.317
Emotional response	4.528	2.362
Cognitive dimensions	19.917	8.813
Emotional dimensions	11.344	4.018
Illness comprehensibility	3.592	2.323

Abbreviation: SD, standard deviation.

Table 3 Linear Regression Model for Frailty and Illness Perception on Exercise Adherence

	Model 1				Model 2				Model 3
	B	t	p	VIF	B	t	p	VIF	B	t	p	VIF
Age	−0.023	−0.362	0.717	1.241	−0.122	−2.004*	0.046	1.162	−0.055	−0.872	0.384	1.303
Pain	−0.363	−0.65	0.516	1.284	−0.363	−0.641	0.522	1.29	−0.235	−0.424	0.672	1.297
Postoperative time	0.019	0.045	0.964	2.935	−0.121	−0.282	0.778	2.926	−0.024	−0.057	0.955	2.941
The first day of drainage	0.004	0.553	0.581	2.125	0.002	0.282	0.778	2.117	0.004	0.502	0.616	2.126
Total postoperative drainage	−0.002	−0.818	0.414	4.501	−0.002	−0.596	0.552	4.478	−0.002	−0.84	0.402	4.501
Time to drain tube placement	−0.12	−0.211	0.833	4.681	−0.201	−0.35	0.727	4.663	0.008	0.014	0.989	4.724
Adenocarcinoma in situ	0				0				0
Microinvasive adenocarcinoma	1.695	0.864	0.389	1.552	1.019	0.507	0.613	1.592	0.954	0.486	0.628	1.592
Invasive adenocarcinoma	−0.648	−0.331	0.741	1.514	−0.596	−0.301	0.764	1.517	−1.037	−0.535	0.594	1.525
Squamous cell carcinoma	−3.112	−1.078	0.282	1.501	−2.173	−0.75	0.454	1.477	−3.393	−1.188	0.236	1.503
Mucinous adenocarcinoma	−1.022	−0.183	0.855	1.073	−1.465	−0.259	0.796	1.079	−2.134	−0.385	0.701	1.08
Postoperative fever(no)	0				0				0
Postoperative fever(yes)	−5.264	−2.696**	0.008	1.269	−5.071	−2.568	0.011*	1.269	−5.188	−2.686**	0.008	1.269
Sleep(good)	0				0				0
Sleep(bad)	−2.348	−1.395	0.164	1.297	−2.542	−1.495	0.136	1.293	−2.203	−1.323	0.187	1.298
Frailty	−1.398	−4.506**	<0.001	1.297					−1.084	−3.239**	0.001	1.541
Illness perception					−0.257	−3.894**	<0.001	1.184	−0.167	−2.366*	0.019	1.406
R^2	0.261				0.244				0.281
Adjusted R^2	0.214				0.196				0.232
F	5.554				5.068				5.674
P	< 0.001				< 0.001				< 0.001
Durbin-Watson	1.512				1.622				1.542

Notes: *p<0.05, **p<0.01. Dependent variable: lung functional exercise adherence. Model 1: confounding variable (age, pain, cancer, postoperative fever, sleep, postoperative time, the first day of drainage, total postoperative drainage, time to drain tube placement)+frailty; Model 2: confounding variable+illness perception; Model 3: confounding variable+frailty+illness perception.

Table 4 Correlates of Illness Perception, Frailty, Exercise Adherence

	Illness Perception	Exercise Adherence	Frailty
Illness perception	1
Exercise adherence	−0.327**	1
Frailty	0.439**	−0.398**	1

Notes: ** p<0.01.

Table 5 Bootstrap Results for the Mediation Analysis

Variables	Effect Size	Standard Error	Bootstrap 95% CI		Rate
			Lower Limit	Upper Limit
Frailty on exercise adherence (total effect)	−1.398**	0.309	−2.008	−0.788
Frailty on exercise adherence (direct effect)	−1.061**	0.332	−1.716	−0.406	75.86%
Illness perception on exercise adherence (indirect effect)	−0.338**	0.148	−0.651	−0.064	24.14%

Notes: **p < 0.01. After controlling for age, pain, cancer, postoperative fever, sleep, postoperative time, the first day of drainage, total postoperative drainage, time to drain tube placement.

Figure 3 The established structural equation model for frailty and illness perception on exercise adherence.

Notes: **p<0.01. The structural model is checked with Model number 4 and number of bootstrap samples are 5000. Covariates: age, pain, cancer, postoperative fever, sleep, postoperative time, the first day of drainage, total postoperative drainage, time to drain tube placement.