Developing a nomogram for predicting the depression of senior citizens living alone while focusing on perceived social support

Table 1 General characteristics of subjects

Characteristics	n (%)
Age, mean ± SD	67.9 ± 5.5
Gender
Male	695 (44.6)
Female	863 (55.4)
Occupation (ISCO)
Managers	20 (1.3)
Professional	12 (0.8)
Clerical support workers	6 (0.4)
Service workers	97 (6.2)
Sales workers	166 (10.7)
Skilled agricultural, forestry and fishery workers	88 (5.6)
Craft and related trades workers	77 (4.9)
Plant and machine operators, and assemblers	9 (0.6)
Elementary occupations	130 (8.3)
Housewives	553 (35.5)
Unemployed persons	399 (25.6)
Alcohol use disorder (AUDIT)
Normal drinker	817 (52.4)
High-risk drinker	278 (17.8)
Alcohol use disorder	13 (0.8)
Self-esteem, the experience of suicidal urge over the past year
No	1418 (91.0)
Yes	140 (9.0)
Subjective loneliness
Very rare	687 (44.1)
Occasionally lonely	639 (41.0)
Often lonely	210 (13.5)
Mostly lonely	22 (1.4)
Self-esteem scale, mean ± SD	28.7 ± 3.4
Depression
No	1438 (92.3)
Yes	120 (7.7)

ISCO: International Standard Classification of Occupations; ADUIT: Alcohol Use Disorders Identification Test.

Table 2 The characteristics of the subjects according to the prevalence of depression, n (%)

Variables	Depression		P
	No (n = 1438)	Yes (n = 120)
Age, mean ± SD	67.75 ± 5.53	70.95 ± 4.99	< 0.0001
Self-esteem scale, mean ± SD	29.06 ± 3.26	25.01 ± 3.43	< 0.0001
Subjective frequency of communication with other family members, mean ± SD	2.54 ± 0.95	2.05 ± 0.94	< 0.0001
Subjective frequency of communication with neighbors and friends, mean ± SD	2.25 ± 1.05	2.05 ± 1.11	0.05
Alcohol use disorder			< 0.001
Normal drinker	766 (93.8)	51 (6.2)
High-risk drinker	258 (92.8)	20 (7.2)
Alcohol use disorder	6 (46.2)	7 (53.8)
Self-esteem, the experience of suicidal urge over the past year			< 0.001
No	1349 (95.1)	69 (4.9)
Yes	89 (63.6)	51 (36.4)
Subjective trust satisfaction with neighbors			< 0.001
No	163 (76.9)	49 (23.1)
Yes	1275 (94.7)	71 (5.3)
Subjective satisfaction with help from neighbors			< 0.001
No	420 (85.7)	70 (14.3)
Yes	1018 (95.3)	50 (4.7)
Subjective satisfaction of the living environment of the neighborhood			0.08
No	245 (89.7)	28 (10.3)
Yes	1193 (92.8)	92 (7.2)
Subjective satisfaction of the safety level of the neighborhood			< 0.001
No	230 (84.3)	43 (15.7)
Yes	1208(94.0)	77 (6.0)
Subjective satisfaction of the medical service of the region			< 0.001
No	386 (88.5)	50 (11.5)
Yes	1,438 (92.3)	120(7.7)
Regular club activities			< 0.001
No	975 (90.5)	103(9.5)
Yes	463 (96.5)	17(3.5)
Subjective loneliness			< 0.001
Very rare	685 (99.7)	2 (0.3)
Occasionally lonely	617 (96.6)	22 (3.44)
Often lonely	131 (62.4)	79(37.6)
Mostly lonely	5 (22.7)	17(77.3)

Table 3 A model for predicting the depression of senior citizens living alone: Odds ratio and 95% confidence interval

Variables	Crude model	Adjusted model	VIF
Alcohol use disorder
Normal drinker	1.00	1.00
High-risk drinker	1.16 (0.68, 1.99)	1.08 (0.45, 2.59)	1.14
Alcohol use disorder	17.52 (5.67, 54.06)a	1.54 (0.16, 14.80)	1.20
Self-esteem, the experience of suicidal urge over the past year
No (Ref)
Yes	12.83 (7.74, 21.26)a	3.57 (1.55, 8.22)a	1.27
Subjective trust satisfaction with neighbors
No (Ref)	1.00	1.00
Yes	0.20 (0.12, 0.32)a	1.02 (0.43, 2.40)	1.37
Subjective satisfaction with help from neighbors
No (Ref)	1.00	1.00
Yes	0.24 (0.15, 0.39)a	0.29 (0.13, 0.66)a	1.40
Subjective satisfaction of the living environment of the neighborhood
No (Ref)	1.00	1.00
Yes	0.41 (0.25, 0.66)a	0.51 (0.23, 1.10)	1.19
Subjective satisfaction of the safety level of the neighborhood
No (Ref)	1.00	1.00
Yes	0.32 (0.20, 0.53)a	0.46 (0.21, 1.04)	1.19
Subjective satisfaction of the medical service of the region
No (Ref)	1.00	1.00
Yes	0.46 (0.28, 0.73)a	0.56 (0.26, 1.20)	1.19
Regular club activities
No (Ref)	1.00	1.00
Yes	0.38 (0.20, 0.70)a	2.04 (0.81, 5.15)	1.31
Subjective loneliness
Very rare (Ref)	1.00	1.00
Occasionally lonely	12.21 (2.86, 52.14)a	5.04 (0.58, 43.39)	6.87
Often lonely	206.54 (50.13, 850.86)a	187.19 (23.17, 1512.13)a	7.89
Mostly lonely	1164.50 (210.83, 6431.88)a	758.12 (56.44, 10183.32)a	3.10
Subjective frequency of communication with other family members	0.55 (0.49, 0.61)a	0.95 (0.71, 1.27)	2.16
Subjective frequency of communication with neighbors and friends	0.59 (0.53, 0.66)a	1.10 (0.81, 1.48)	2.12
Age	0.89 (0.85, 0.93)a	1.17 (1.07, 1.26)a	1.42
Self-esteem scale	0.70 (0.65, 0.74)a	0.81 (0.72, 0.91)a	1.33

^aP < 0.05.

VIF: Variance Inflation Factor.

Table 4 Validating a nomogram for predicting the depression of senior citizens living alone

Measure	Description	Value
TP		1012
TN		49
FP		29
FN		18
AUC		0.96
Accuracy	(TP + TN)/(TP + TN + FP + FN)	0.95
Balanced accuracy	[TP/(TP + FN) + TN/(TN + FP)]/2	0.80
Sens	TP/(TP + FN)	0.98
Spec	TN/(TN + FP)	0.62
FPR	FP/(TN + FP)	0.37
FNR	FN/(TP + FN)	0.01
F1 score	2/(1/Sens + 1/PPV)	0.97

TP: True positive; TN: True negative; FP: False positive; FN: False negative; AUC: Area under the curve; FPR: False positive rate; FNR: False negative rate; PPV: Potential path volume; Sens: Sensitivity; Spec: Specificity.