Background factors influencing postgastrectomy syndromes after various types of gastrectomy

Table 1 Relationship of the domains and main outcome measures of the Postgastrectomy Syndrome Assessment Scale

Domain	Main outcome measures
Symptom	Esophageal reflux subscale
	Abdominal pain subscale
	Meal-related distress subscale
	Indigestion subscale
	Diarrhea subscale
	Constipation subscale
	Dumping subscale
	Total symptom score
Living status	Change in body weight
	Ingested amount of food per meal
	Necessity for additional meals
	Quality of ingestion subscale
	Ability for working
Quality of life	Dissatisfaction with symptom
	Dissatisfaction at the meal
	Dissatisfaction at working
	Dissatisfaction for daily life subscale
	Physical component summary of SF-8
	Mental component summary of SF-8

Table 2 Background factors for each surgical procedure

	TGRY	DGBI	DGRY	PG	PPG	LR
Number of patients	393	909	475	193	313	85
Postoperative period, mo	35.0 ± 24.6	40.7 ± 30.7	31.7 ± 18.0	40.5 ± 28.1	38.4 ± 27.7	42.9 ± 34.2
Age, yr	63.4 ± 9.2	61.6 ± 9.1	62.0 ± 9.1	63.7 ± 7.7	61.5 ± 8.7	60.8 ± 9.8
Sex: Male/female	276/113	594/311	318/154	139/53	183/126	48/37
Approach laparoscope/open	97/293	415/489	152/320	33/159	136/173	52/33
Celiac branch: Saving/cut	12/371	133/754	28/442	83/105	213/96	84/0

Values are presented as mean ± SD. TGRY: Total gastrectomy with Roux-en-Y reconstruction; DGBI: Distal gastrectomy with Billroth I reconstruction; DGRY: Distal gastrectomy with Roux-en-Y reconstruction; PG: Proximal gastrectomy; PPG: Pylorus preserving gastrectomy; LR: Local resection of the stomach.

Table 3 Multiple regression analysis exploring independent factors affecting the Postgastrectomy Syndrome Assessment Scale scores for total gastrectomy with Roux-en-Y reconstruction

	Postop period		Age		Sex [female]		Approach [laparo]		Celiac branch [saved]
MOMs	β1	P	β	P	β	P	β	P	β	P	R22	P
Esophageal reflux SS											0.015	> 0.10
Abdominal pain SS					0.129	0.0141					0.02	> 0.10
Meal-related distress SS							0.094	0.0849			0.014	> 0.10
Indigestion SS							0.093	0.0813			0.0493	0.00213
Diarrhea SS	-0.089	0.0978			-0.143	0.0057					0.028	0.0588
Constipation SS			0.145	0.0056							0.023	> 0.10
Dumping SS			-0.1633	0.00263							0.0453	0.00793
Total symptom score											0.015	> 0.10
Change in BW					-0.095	0.0751					0.018	> 0.10
Ingestion amount of food			-0.111	0.0361							0.017	> 0.10
Need of additional food			0.1263	0.01593			0.092	0.0928			0.0303	0.04513
Quality of ingestion SS			-0.1343	0.01063	-0.102	0.0516					0.0323	0.0363
Ability for working			0.1333	0.0120	0.1183	0.0253			0.1313	0.01243	0.0483	0.00403
Dissatisfaction: symptom							0.099	0.0677			0.0343	0.02653
Dissatisfaction: meal							0.116	0.0327			0.026	0.0813
Dissatisfaction: working											0.016	> 0.10
Dissatisfaction SS							0.106	0.0508			0.0303	0.04763
PCS of SF-8			-0.174	0.00073					-0.1453	0.00453	0.0593	0.00043
MCS of SF-8									-0.125	0.016	0.02	> 0.10

¹β: standardized regression coefficient. If β is positive, then the score of the main outcome measures (MOMs) of the patient in the category in [brackets] is higher when the factor has a nominal scale, and the score of the MOMs of the patient with a larger value is higher when the factor has a numeric scale;

²R²: coefficient of determination;

³Significantly independent factors with a small effect size. Change in body weight, ingestion amount of food, quality of ingestion subscale, physical component summary, and mental component summary indicate higher scores (i.e., better conditions). Other outcome measures indicate higher scores (i.e., worse conditions). Interpretation of effect size: None or very small (β < 0.100, R² < 0.020); Small (β ≥ 0.100, R² ≥ 0.020); Medium (β ≥ 0.300, R² ≥ 0.130); Large (β ≥ 0.500, R² ≥ 0.260). MOMs: Main outcome measures; SS: Subscale; PCS: Physical component summary; MCS: Mental component summary; BW: Body weight; postop: Postoperative; laparo: Laparoscopic.

Table 4 Multiple regression analysis exploring independent factors affecting the Postgastrectomy Syndrome Assessment Scale scores for the cases of distal gastrectomy with Billroth I reconstruction

	Postop period		Age		Sex [female]		Approach [laparo]		Celiac branch [saved]
MOMs	β1	P	β	P	β	P	β	P	β	P	R22	P
Esophageal reflux SS			0.064	0.0633							0.015	0.0224
Abdominal pain SS					0.1213	0.00043	-0.086	0.0175			0.0283	0.00023
Meal-related distress SS					0.1223	0.00033			-0.087	0.0111	0.0343	< 0.00013
Indigestion SS					0.067	0.0519			-0.096	0.0057	0.014	0.0305
Diarrhea SS			-0.1553	< 0.00013					-0.1303	0.00023	0.0423	< 0.00013
Constipation SS					0.068	0.0472					0.008	> 0.10
Dumping SS			-0.1413	< 0.00013	0.1413	< 0.00013	-0.066	0.0837	-0.067	0.0657	0.0563	< 0.00013
Total symptom score			-0.083	0.0258	0.1053	0.00473	-0.071	0.0677	-0.1023	0.00613	0.0373	< 0.00013
Change in BW									0.099	0.0049	0.016	0.02
Ingestion amount of food			-0.086	0.0125							0.009	> 0.10
Need of additional food	-0.1143	0.00123	0.074	0.030	0.102	0.00283	-0.1153	0.00143			0.0343	< 0.00013
Quality of ingestion SS			-0.07	0.0437							0.01	> 0.10
Ability for working			0.1773	< 0.00013	0.098	0.0046	-0.067	0.0632			0.0423	< 0.00013
Dissatisfaction: symptom					0.1283	0.00023					0.0233	0.00133
Dissatisfaction: meal	-0.077	0.0296			0.086	0.0125					0.017	0.0117
Dissatisfaction: working					0.095	0.0054	-0.071	0.0499			0.015	0.0193
Dissatisfaction SS					0.119	0.0005					0.019	0.0067
PCS of SF-8			-0.065	0.0591	-0.1233	0.00033	0.076	0.0355			0.0253	0.00053
MCS of SF-8					-0.1203	0.00053	0.1093	0.00263			0.0273	0.00033

¹β: standardized regression coefficient. If β is positive, then the score of the main outcome measures (MOMs) of the patient in the category in [brackets] is higher when the factor has a nominal scale, and the score of the MOMs of the patient with a larger value is higher when the factor has a numeric scale;

²R²: coefficient of determination;

³Significantly independent factors with a small effect size. Change in body weight, ingestion amount of food, quality of ingestion subscale, physical component summary, and mental component summary indicate higher scores (i.e., better conditions). Other outcome measures indicate higher scores (i.e., worse conditions). Interpretation of effect size: None or very small (β < 0.100, R² < 0.020); Small (β ≥ 0.100, R² ≥ 0.020); Medium (β ≥ 0.300, R² ≥ 0.130); Large (β ≥ 0.500, R² ≥ 0.260). MOMs: Main outcome measures; SS: Subscale; PCS: Physical component summary; MCS: Mental component summary; BW: Body weight; postop: Postoperative; laparo: Laparoscopic.

Table 5 Multiple regression analysis exploring independent factors affecting the Postgastrectomy Syndrome Assessment Scale scores for distal gastrectomy with Roux-en-Y reconstruction

	Postop period		Age		Sex [female]		Approach [laparo]		Celiac branch [saved]
MOMs	β1	P	β	P	β	P	β	P	β	P	R22	P
Esophageal reflux SS					0.094	0.0439					0.017	> 0.10
Abdominal pain SS	-0.1033	0.02863			0.2263	< 0.00013					0.0663	< 0.00013
Meal-related distress SS			-0.085	0.0660	0.1973	< 0.00013					0.0533	0.00013
Indigestion SS	-0.091	0.0567			0.093	0.0456					0.0293	0.02003
Diarrhea SS											0.007	> 0.10
Constipation SS											0.015	> 0.10
Dumping SS			-0.094	0.0556	0.1963	< 0.00013					0.058	0.00023
Total symptom score					0.1363	0.00623					0.0313	0.02513
Change in BW			-0.1123	0.01993	-0.085	0.073					0.0263	0.03623
Ingestion amount of food											0.007	> 0.10
Need of additional food	-0.1133	0.01903			0.1323	0.00463					0.0323	0.01063
Quality of ingestion SS			-0.1653	0.00053			-0.082	0.0919			0.0313	0.01423
Ability for working	-0.1053	0.03033	0.1813	0.00013							0.0523	0.00033
Dissatisfaction: symptom	-0.1123	0.01963			0.1283	0.00593	-0.1003	0.03993			0.0323	0.01073
Dissatisfaction: meal	-0.1493	0.00203			0.078	0.0911					0.0283	0.02413
Dissatisfaction: working	-0.1183	0.01383			0.1053	0.02413					0.0253	0.03853
Dissatisfaction SS	-0.1483	0.00223			0.1273	0.00673					0.0363	0.00553
PCS of SF-8											0.013	> 0.10
MCS of SF-8	0.094	0.0506			-0.084	0.074					0.020	0.0977

¹β: standardized regression coefficient. If β is positive, then the score of the main outcome measures (MOMs) of the patient in the category in [brackets] is higher when the factor has a nominal scale, and the score of the MOMs of the patient with a larger value is higher when the factor has a numeric scale;

²R²: coefficient of determination;

³Significantly independent factors with a small effect size. Change in body weight, ingestion amount of food, quality of ingestion subscale, physical component summary, and mental component summary indicate higher scores (i.e., better conditions). Other outcome measures indicate higher scores (i.e., worse conditions). Interpretation of effect size: None or very small (β < 0.100, R² < 0.020); Small (β ≥ 0.100, R² ≥ 0.020); Medium (β ≥ 0.300, R² ≥ 0.130); Large (β ≥ 0.500, R² ≥ 0.260). MOMs: Main outcome measures; SS: Subscale; PCS: Physical component summary; MCS: Mental component summary; BW: Body weight; postop: Postoperative; laparo: Laparoscopic.

Table 6 Multiple regression analysis exploring independent factors affecting the Postgastrectomy Syndrome Assessment Scale scores for proximal gastrectomy

	Postop period		Age		Sex [female]		Approach [laparo]		Celiac branch [saved]
MOMs	β1	P	β	P	β	P	β	P	β	P	R22	P
Esophageal reflux SS											0.019	> 0.10
Abdominal pain SS											0.005	> 0.10
Meal-related distress SS											0.018	> 0.10
Indigestion SS											0.009	> 0.10
Diarrhea SS					-0.131	0.082					0.030	> 0.10
Constipation SS			0.159	0.037							0.032	> 0.10
Dumping SS											0.009	> 0.10
Total symptom score											0.016	> 0.10
Change in BW	0.128	0.0905									0.027	> 0.10
Ingestion amount of food	0.151	0.0437									0.035	> 0.10
Need of additional food											0.015	> 0.10
Quality of ingestion SS											0.031	> 0.10
Ability for working	-0.123	0.094	0.2843	0.00023					-0.1463	0.04703	0.1123	0.00103
Dissatisfaction: symptom											0.009	> 0.10
Dissatisfaction: meal	-0.153	0.0439									0.029	> 0.10
Dissatisfaction: working									-0.160	0.0334	0.035	> 0.10
Dissatisfaction SS									-0.125	0.0963	0.027	> 0.10
PCS of SF-8	0.19	0.0115	-0.138	0.0666							0.052	0.0849
MCS of SF-8											0.021	> 0.10

¹β: standardized regression coefficient. If β is positive, then the score of the main outcome measures (MOMs) of the patient in the category in [brackets] is higher when the factor has a nominal scale, and the score of the MOMs of the patient with a larger value is higher when the factor has a numeric scale;

²R²: coefficient of determination.

³Significantly independent factors with a small effect size. Change in body weight, ingestion amount of food, quality of ingestion subscale, physical component summary, and mental component summary indicate higher scores (i.e., better conditions). Other outcome measures indicate higher scores (i.e., worse conditions). Interpretation of effect size: None or very small (β < 0.100, R² < 0.020); Small (β ≥ 0.100, R² ≥ 0.020); Medium (β ≥ 0.300, R² ≥ 0.130); Large (β ≥ 0.500, R² ≥ 0.260). MOMs: Main outcome measures; SS: Subscale; PCS: Physical component summary; MCS: Mental component summary; BW: Body weight; postop: Postoperative; laparo: Laparoscopic.

Table 7 Multiple regression analysis exploring independent factors affecting the Postgastrectomy Syndrome Assessment Scale scores for pylorus-preserving gastrectomy

	Postop period		Age		Sex [female]		Approach [laparo]		Celiac branch [saved]
MOMs	β1	P	β	P	β	P	β	P	β	P	R22	P
Esophageal reflux SS											0.019	> 0.10
Abdominal pain SS	-0.116	0.0707									0.025	> 0.10
Meal-related distress SS	-0.134	0.0353									0.029	> 0.10
Indigestion SS											0.01	> 0.10
Diarrhea SS							0.11	0.0929			0.012	> 0.10
Constipation SS			0.108	0.0611	0.2003	0.00063					0.0503	0.00963
Dumping SS	-0.122	0.0752									0.030	> 0.10
Total symptom score											0.025	> 0.10
Change in BW											0.009	> 0.10
Ingestion amount of food					-0.135	0.0220					0.026	> 0.10
Need of additional food	-0.119	0.0625			0.1563	0.00753					0.0403	0.03743
Quality of ingestion SS	-0.1323	0.03913	-0.129	0.02783							0.0473	0.01603
Ability for working			0.1793	0.00233	0.1533	0.00903					0.0563	0.00553
Dissatisfaction: symptom	-0.127	0.0477							-0.106	0.0754	0.033	0.0792
Dissatisfaction: meal	-0.1643	0.01013					-0.114	0.0789	-0.1293	0.02953	0.0443	0.02153
Dissatisfaction: working											0.008	> 0.10
Dissatisfaction SS	-0.145	0.0238							-0.111	0.0631	0.031	> 0.10
PCS of SF-8	0.1633	0.01083	-0.103	0.0785			0.1503	0.02213			0.0443	0.02413
MCS of SF-8											0.009	> 0.10

¹β: standardized regression coefficient. If β is positive, then the score of the main outcome measures (MOMs) of the patient in the category in [brackets] is higher when the factor has a nominal scale, and the score of the MOMs of the patient with a larger value is higher when the factor has a numeric scale;

²R²: coefficient of determination;

³Significantly independent factors with a small effect size. Change in body weight, ingestion amount of food, quality of ingestion subscale, physical component summary, and mental component summary indicate higher scores (i.e., better conditions). Other outcome measures indicate higher scores (i.e., worse conditions). Interpretation of effect size: None or very small (β < 0.100, R² < 0.020); Small (β ≥ 0.100, R² ≥ 0.020); Medium (β ≥ 0.300, R² ≥ 0.130); Large (β ≥ 0.500, R² ≥ 0.260). MOMs: Main outcome measures; SS: Subscale; PCS: Physical component summary; MCS: Mental component summary; BW: Body weight; postop: Postoperative; laparo: Laparoscopic.

Table 8 Multiple regression analysis exploring independent factors affecting the Postgastrectomy Syndrome Assessment Scale scores for local resection of stomach

	Postop period		Age		Sex [female]		Approach [laparo]
MOMs	β1	P	β	P	β	P	β	P	R22	P
Esophageal reflux SS									0.048	> 0.10
Abdominal pain SS			-0.3474	0.00124	0.194	0.0695			0.1604	0.00694
Meal-related distress SS									0.037	> 0.10
Indigestion SS									0.031	> 0.10
Diarrhea SS			-0.218	0.0481					0.072	> 0.10
Constipation SS									0.027	> 0.10
Dumping SS									0.008	> 0.10
Total symptom score									0.035	> 0.10
Change in BW									0.095	> 0.10
Ingestion amount of food									0.001	> 0.10
Need of additional food									0.051	> 0.10
Quality of ingestion SS	0.3044	0.00764	-0.2153	0.04373					0.1674	0.00664
Ability for working	-0.2213	0.05143							0.1163	0.04103
Dissatisfaction: symptom									0.036	> 0.10
Dissatisfaction: meal									0.038	> 0.10
Dissatisfaction: working									0.078	> 0.10
Dissatisfaction SS									0.037	> 0.10
PCS of SF-8									0.056	> 0.10
MCS of SF-8			0.229	0.0386					0.083	> 0.10

¹β: standardized regression coefficient. If β is positive, then the score of the main outcome measures (MOMs) of the patient in the category in [brackets] is higher when the factor has a nominal scale, and the score of the MOMs of the patient with a larger value is higher when the factor has a numeric scale;

²R²: coefficient of determination;

³Significantly independent factors with a small effect size;

⁴Significantly independent factors with a medium effect size. Change in body weight, ingestion amount of food, quality of ingestion subscale, physical component summary, and mental component summary indicate higher scores (i.e., better conditions). Other outcome measures indicate higher scores (i.e., worse conditions). Interpretation of effect size: None or very small (β < 0.100, R² < 0.020); Small (β ≥ 0.100, R² ≥ 0.020); Medium (β ≥ 0.300, R² ≥ 0.130); Large (β ≥ 0.500, R² ≥ 0.260). MOMs: Main outcome measures; SS: Subscale; PCS: Physical component summary; MCS: Mental component summary; BW: Body weight; postop: Postoperative; laparo: Laparoscopic.

Table 9 Summary of the effects of the background factors for the main outcome measures of Postgastrectomy Syndrome Assessment Scale-45 according to the type of surgery

Method	Domain	Postop period	Age	Sex (female)	Approach (laparo)	Celiac branch (saved)
TGRY	Symptoms		+1
	Living status or QoL		-4	-1		-2
DGBI	Symptoms		+2	-4		+2
	Living status or QoL	+1	-1	-4	+2
DGRY	Symptoms	+1		-4
	Living status or QoL	+6	-3	-4	+1
PG	Symptoms
	Living status or QoL		-1			+1
PPG	Symptoms			-1
	Living status or QoL	+1	-2	-2	+1	+1
LR	Symptoms		+1			-
	Living status or QoL	+2	-1			-

Numbers in each column are the aggregate number of main outcome measures of Postgastrectomy Syndrome Assessment Scale. The main outcome measures having positive effects independently by each background factor were counted as + 1, and the main outcome measures having negative effects independently by each background factor were counted as - 1. TGRY: Total gastrectomy with Roux-en-Y reconstruction; DGBI: Distal gastrectomy with Billroth I reconstruction; DGRY: Distal gastrectomy with Roux-en-Y reconstruction; PG: Proximal gastrectomy; PPG: Pylorus preserving gastrectomy; LR: Local resection of the stomach; Postop: Postoperative; laparo: Laparoscopic; QoL: Quality of life.