A multidimensional risk factor model for suicide attempts in later life

Figures & data

Table 1 Multidomain comparison of female subjects

	Suicide attempters (N=43)	Comparison subjects (N=59)	Test statistics	df	P-value (2-sided)
Sociodemography and life circumstances
Age (SD)	74.88 (7.46)	76.95 (8.43)	t=−1.28	100	0.205
Being married (%)	15 (34.9)	10 (17.2)	χ^2=4.13	1	0.042
Living alone (%)	4 (9.3)	15 (25.9)	χ^2=4.43	1	0.035
Recipient of social welfare subsidy (%)	11 (25.6)	23 (39.7)	χ^2=2.19	1	0.20
Level of education (%)
No formal education	20 (46.5)	23 (39.7)	χ^2=5.3	2	0.071
Primary or below	21 (48.8)	24 (41.4)
Secondary and above	2 (4.65)	9 (15.5)
LE-12 (SD)	1 (0.72)	0.28 (0.49)	t=6.00	100	<0.001
Physical health status (SD)
Age-adjusted CVRFs	10.56 (5.46)	7.24 (4.04)	t=3.52	100	0.001
CIRS	6.26 (3.05)	4.41 (2.8)	t=3.15	100	0.002
PSMS	3.35 (4.15)	0.38 (0.9)	t=5.286	100	<0.001
Age-adjusted CVRFs (in subjects with current DSM-IV depressive disorders)a	11 (5.41)	5.33 (3.98)	t=2.451	43	0.018
Psychopathology
DSM-IV major depressive disorder (current) (%)	39 (90.1)	5 (8.6)	χ^2=64.5	1	<0.001
Any lifetime DSM-IV psychiatric diagnosis excluding current psychiatric diagnosis (%)	23 (53.5)	8 (13.8)	χ^2=10.1	1	<0.001
Past suicide attempt (excluding the index attempt) (%)	6 (14)	0 (0)	χ^2=8.64	1	0.005
NEO-FFI percentile score (SD)
Neuroticism	61 (24.6)	46.3 (26.3)	t=2.8	100	0.006
Extraversion	41 (23.2)	49.7 (27.6)	t=−1.63	100	0.106
Conscientiousness	43.5 (15.7)	50.0 (22)	t=−1.603	100	0.112
NEO-Anger-Hostility (N2) facet percentile score (SD)	46.8 (26.2)	40.7 (28.9)	t=1.092	100	0.278
NEO-Impulsiveness (N5) facet percentile score (SD)	24 (22.9)	13 (15.6)	t=2.831	100	0.006
Cognitive domain
MCST
No of categories	3.28 (1.7)	4.24 (1.67)	t=−2.84b	100	0.006
Percentage of perseverative error	35.8 (24.7)	25 (22.8)	t=2.27	100	0.025
C-MMSE	23.6 (3.6)	26 (3.1)	t=−3.47	100	0.001

Notes:

a N=39 in attempters group and six in comparison group

b equal variance not assumed.

Abbreviations: df, degrees of freedom; SD, standard deviation; t, independent sample t-test; χ², chi-square test; LE-12, total number of life events in the past 12 weeks; age-adjusted CVRFs, summative score of cerebrovascular risk factors calculated from criteria of the American Heart Association minus the age-related subscore; CIRS, Cumulative Illness Rating Scale; PSMS, Physical Self-Maintenance Scale; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; NEO-FFI, NEO Five Factor Inventory; N2, NEO-Anger-Hostility; N5, NEO-Impulsiveness; MCST, Modified Wisconsin Card Sorting Test; C-MMSE, Chinese version of the Mini-Mental State Examination.

Table 2 Logistic regression models on risk factors predicting suicide attempt in women subjects

Variables in equation	Exp(B)	95% CI	P-valuea
Model 1 (Nagelkerke R^2: 0.844)c
Age-adjusted CVRFs	1.289	1.02–1.63	0.033
Depressive disorder (current)	348	25.2–4795	<0.001
LE-12	10.4	2.61–41.6	0.001
Being marriedb	12.86	1.03–160	0.047
Model 2 (Nagelkerke R^2: 0.844)d
Age-adjusted CVRFs	1.289	1.02–1.63	0.033
Depressive disorder (current)	348	25.2–4795	<0.001
LE-12	10.4	2.61–41.6	0.001
Being marriedb	12.86	1.03–160	0.047

Notes: Dependent variable: suicide attempt status (recent suicide attempt vs no attempt ever).

a P-values are from regression with df=1

b categorical variable

c in model 1, independent variables removed in backward Wald logistic regression: living alone, PSMS, CIRS, psychiatric diagnosis (lifetime)

d in model 2, independent variables removed in backward Wald logistic regression: living alone, PSMS, CIRS, psychiatric diagnosis (lifetime), C-MMSE, category, perseverative err, N, n2, and n5.

Abbreviations: Exp(B), exponentiation of the B coefficient, which is an odds ratio; CI, confidence interval; age-adjusted CVRFs, summative score of cerebrovascular risk factors calculated from criteria of the American Heart Association minus the age-related subscore; LE-12, total number of life events in the past 12 weeks; C-MMSE, Cantonese version of the Mini-Mental Status Examination; category, number of categories achieved in Modified Card Sorting Test; Perseverative err, percentage of perseverative error in Modified Card Sorting Test; PSMS, Physical Self-Maintenance Scale; CIRS, Cumulative Illness Rating Scale; N, NEO-Neuroticism; n2, NEO-Anger-Hostility; n5, NEO-Impulsiveness.

Table 3 Multidomain comparison of male subjects

	Suicide attempters (N=34)	Comparison subjects (N=40)	Test statistics	df	P-value (2-sided)
Sociodemography and life circumstances
Age (SD)	76.8 (6.71)	77.5 (6.23)	t=−0.46	72	0.65
Being married (%)	25 (73.5)	21 (51.2)	χ^2=3.9	1	0.04
Living alone (%)	6 (17.6)	2 (4.9)	χ^2=3.18	1	0.13
Recipient of social welfare subsidy (%)	10 (29.4)	17 (41.5)	χ^2=0.28	1	0.20
Level of education (%)
No formal education	5 (14.7)	4 (9.8)	χ^2=8.99	2	0.10
Primary or below	22 (64.7)	19 (46.3)
Secondary and above	7 (20.6)	18 (43.9)
LE-12 (SD)	1.12 (0.77)	0.17 (0.44)	t=6.67	72	<0.001
Physical health status (SD)
Age-adjusted CVRFs	7.74 (3.92)	7.71 (4.86)	t=0.027	72	0.98
CIRS	6.79 (3.5)	5.02 (3.57)	t=2.15	72	0.035
PSMS	2.15 (2.94)	0.24 (0.77)	t=4.00	72	<0.001
Psychopathology
DSM-IV major depressive disorder (current) (%)	26 (76.5)	0 (0)	χ^2=48	1	<0.001
Any lifetime DSM-IV psychiatric diagnosis excluding current psychiatric diagnosis (%)	9 (26.5)	4 (9.8)	χ^2=3.62	1	0.055
Past suicide attempt (excluding the index attempt) (%)	9 (26.5)	0 (0)	χ^2=12.3	1	<0.001
NEO-FFI percentile score (SD)
Neuroticism	61.9 (25.5)	37.8 (23.9)	t=4.19	72	<0.001
Extraversion	39.4 (23.6)	53.2 (26.3)	t=−2.36	72	0.021
Openness to experience	44.1 (22.1)	38.1 (20)	t=1.24	72	0.211
Agreeableness	45.3 (17.4)	52.8 (25.1)	t=−1.35	72	0.181
Conscientiousness	43.3 (17.4)	52.5 (20.4)	t=−2.06	72	0.043
NEO-Anger-Hostility (N2) facet percentile score (SD)	60 (25.5)	41.2 (25.7)	t=2.63	72	0.01
NEO-Impulsiveness (N5) facet percentile score (SD)	30.7 (25.8)	16.5 (21.1)	t=2.61	72	0.011
Cognitive domain
MCST
No of categories	3.5 (1.72)	4.8 (1.5)	t=−3.41	72	0.001
Percentage of perseverative error	8.3 (10.3)	3.4 (6.2)	t=2.4a	72	0.02
C-MMSE	25.3 (3.2)	27.2 (2.7)	t=−2.88	72	0.005

Note:

a Equal variance not assumed.

Abbreviations: df, degrees of freedom; SD, standard deviation; t, independent sample t-test; χ², chi-square test; LE-12, total number of life events in the past 12 weeks; age-adjusted CVRFs, summative score of cerebrovascular risk factors calculated from criteria of the American Heart Association minus the age-related subscore; CIRS, Cumulative Illness Rating Scale; PSMS, Physical Self-Maintenance Scale; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; NEO-FFI, NEO Five Factor Inventory; N2, NEO-Anger-Hostility; N5, NEO-Impulsiveness; MCST, Modified Wisconsin Card Sorting Test; C-MMSE, Chinese version of Mini-Mental State Examination.

Table 4 Logistic regression model on risk factors predicting suicide attempt in older men

Variables in equationa	Exp(B)	95% CI	P-valueb
NEO-Neuroticism	1.028	1.00–1.056	0.049
LE-12	9.164	2.92–28.78	<0.001
Category	0.646	0.434–0.963	0.032

Notes: Dependent variable: suicide attempt status (recent suicide attempt vs no attempt ever).

a Independent variables removed in backward Wald logistic regression: being married, PSMS, psychiatric diagnosis (lifetime);

b P-values are from regression with df=1, Nagelkerke R²=0.611.

Abbreviations: Exp(B), exponentiation of the B coefficient, which is an odds ratio; CI, confidence interval; LE-12, total number of life events in the past 12 weeks; category, number of categories achieved in Modified Card Sorting Test; PSMS, Physical Self-Maintenance Scale.