Construction of a prediction model for fall risk in older patients with osteoporosis and comorbid with psychiatric disorders

Table 1 Comparison of general demographic data between the two groups, mean ± SD/n (%)

Variable	Fall group (n = 58)	Non-fall group (n = 72)	Statistic	P value
Age (years)	73.58 ± 6.91	69.53 ± 6.28	t = 3.482	0.001
Sex			χ2 = 2.341	0.126
Male	19 (32.76)	32 (44.44)
Female	39 (67.24)	40 (55.56)
Years of education	8.12 ± 3.41	8.73 ± 3.15	t = 1.067	0.288
Marital status			χ2 = 4.523	0.033
Married	31 (53.45)	51 (70.83)
Widowed/divorced	27 (46.55)	21 (29.17)
Living status			χ2 = 5.872	0.015
Living with family	37 (63.79)	59 (81.94)
Living alone	21 (36.21)	13 (18.06)
BMI (kg/m2)	23.28 ± 3.56	23.98 ± 3.31	t = 1.168	0.245

BMI: Body mass index.

Table 2 Comparison of clinical data and medication status between the two groups, mean ± SD/n (%)

Variable	Fall group (n = 58)	Non-fall group (n = 72)	Statistic	P value
Duration of osteoporosis (years)	5.68 ± 3.42	4.97 ± 3.18	t = 1.229	0.221
History of falls	35 (60.34)	18 (25.00)	χ2 = 16.731	< 0.001
Number of comorbidities, median (interquartile range)	4.00 (2.00, 5.00)	2.00 (1.00, 4.00)	Z = -2.937	0.003
Medication
Benzodiazepines	24 (41.38)	13 (18.06)	χ2 = 8.646	0.003
Antidepressants	8 (13.79)	5 (6.94)	χ2 = 1.713	0.191
Antipsychotics	3 (5.17)	2 (2.78)	χ2 = 0.074	0.786
Calcium supplementation	32 (55.17)	48 (66.67)	χ2 = 1.814	0.178
Vitamin D supplementation	28 (48.28)	44 (61.11)	χ2 = 2.142	0.143
Antihypertensive agents	41 (70.69)	43 (59.72)	χ2 = 1.680	0.195
Antidiabetic agents	19 (32.76)	21 (29.17)	χ2 = 0.196	0.658

Table 3 Comparison of bone metabolism markers between the two groups, mean ± SD

Variable	Fall group (n = 58)	Non-fall group (n = 72)	Statistic	P value
Blood calcium (mmol/L)	2.26 ± 0.18	2.29 ± 0.16	1.007	0.316
Serum inorganic phosphorus (mmol/L)	1.13 ± 0.21	1.16 ± 0.19	0.861	0.391
ALP (U/L)	89.47 ± 23.68	83.92 ± 21.45	1.408	0.162
25-hydroxyvitamin D (ng/mL)	18.36 ± 5.72	22.84 ± 6.31	4.196	< 0.001
PTH (pg/mL)	52.38 ± 18.46	47.65 ± 16.92	1.531	0.128

ALP: Alkaline phosphatase; PTH: Parathyroid hormone.

Table 4 Comparison of physical function and cognitive function between the two groups, mean ± SD

Variable	Fall group (n = 58)	Non-fall group (n = 72)	t value	P value
Grip strength (kg)	21.34 ± 5.86	24.78 ± 6.23	3.243	0.002
TUGT (second)	15.68 ± 4.73	11.94 ± 3.86	4.962	< 0.001
BBS score (points)	41.53 ± 7.26	47.82 ± 6.54	5.234	< 0.001
SPPB score (points)	8.16 ± 2.34	9.73 ± 2.18	3.966	< 0.001
MMSE score (points)	25.37 ± 3.14	26.82 ± 2.86	2.773	0.006

TUGT: Timed Up and Go Test; BBS: Berg Balance Scale; SPPB: Short Physical Performance Battery; MMSE: Mini-Mental State Examination.

Table 5 Comparison of psychiatric and psychological assessment indicators between the two groups, mean ± SD/n (%)

Variable	Fall group (n = 58)	Non-fall group (n = 72)	Statistic	P value
GDS score (points)	7.43 ± 3.26	4.68 ± 2.85	t = 5.138	< 0.001
Positive depressive symptoms	35 (60.34)	21 (29.17)	χ2 = 12.746	< 0.001
GAD-7 score (points)	6.87 ± 3.52	4.21 ± 2.94	t = 4.691	< 0.001
Positive anxiety symptoms	28 (48.28)	16 (22.22)	χ2 = 9.873	0.002
FES-I score (points)	38.46 ± 9.87	27.53 ± 8.64	t = 6.749	< 0.001

GDS: Geriatric Depression Scale; GAD-7: Generalized Anxiety Disorder-7; FES-I: Falls Efficacy Scale-International.

Table 6 Variable assignment table for multivariate logistic regression analysis

Variable	Assignment	Variable	Assignment
Fall (dependent variable)	0 = no fall, 1 = fall occurred	Grip strength	Continuous variable
Age	Continuous variable	TUGT	Continuous variable
Marital status	0 = married, 1 = widowed/divorced	BBS score	Continuous variable
Living status	0 = living with family, 1 = living alone	SPPB score	Continuous variable
History of falls	0 = no, 1 = yes	MMSE score	Continuous variable
Number of comorbidities	Continuous variable	GDS score	Continuous variable
Benzodiazepine use	0 = no use, 1 = use	GAD-7 score	Continuous variable
25-hydroxyvitamin D	Continuous variable	FES-I score	Continuous variable

TUGT: Timed Up and Go Test; BBS: Berg Balance Scale; SPPB: Short Physical Performance Battery; MMSE: Mini-Mental State Examination; GDS: Geriatric Depression Scale; GAD-7: Generalized Anxiety Disorder-7; FES-I: Falls Efficacy Scale-International.

Table 7 Multivariate logistic regression analysis of fall risk factors in older patients with osteoporosis

Variable	β	SE	Wald χ2	OR	95%CI	P value
History of falls	1.464	0.398	13.527	4.326	1.987-9.416	0.001
GDS score	0.294	0.089	10.912	1.342	1.127-1.598	0.002
GAD-7 score	0.252	0.088	8.214	1.287	1.082-1.531	0.005
TUGT	0.197	0.068	8.394	1.218	1.065-1.393	0.004
BBS score	-0.115	0.038	9.136	0.891	0.826-0.961	0.003
25-hydroxyvitamin D	-0.092	0.033	7.776	0.912	0.855-0.973	0.006
Constant	-2.867	1.724	2.767	0.057		0.096

OR: Odds ratio; CI: Confidence interval; GDS: Geriatric Depression Scale; GAD-7: Generalized Anxiety Disorder-7; TUGT: Timed Up and Go Test; BBS: Berg Balance Scale.