Drug Burden Index associated with function in community-dwelling older people in Finland: A cross-sectional study

Figures & data

Table I. Base-line study characteristics (n = 700).

Characteristics	Value^a
Mean (median) age, years	81.3 (80.0) ± 4.6
Education, years
>6	340 (49.9)
Gender
Female (%)	486 (69.4)
Mean (median) number of regularly prescribed drugs	4.9 (4.0) ± 3.2
Mean (median) DBI score	0.33 (0.00) ± 0.55
Exposed to DBI drugs (%)	257 (36.6)
Exposure to DBI subgroups (%)
0	443 (63.4)
>0 <1	166 (23.7)
≥1	91 (13.0)
Cognitive impairment (MMSE <25) (%)	174 (24.9)
Mean (median) modified FCI score	2.5 (2.0) ± 1.7
Self-rated health (%)
Good/very good	301 (43.1)
Moderate	294 (42.1)
Poor/very poor	103 (14.8)
Mean (median) 10-m walking speed, m/s	1.3 (1.3) ± 0.4
Mean (median) time taken to complete chair stands test, seconds	16.7 (14.7) ± 7.8
Mean (median) time taken to complete TUG, seconds	13.9 (10.6) ± 9.3
Mean (median) grip strength, kg	20.0 (19.0) ± 10.2
Mean (median) IADL score	6.4 (7.0) ± 2.1
Mean (median) Barthel Index score	95.1 (100.0) ± 12.1

Data are reported as number (percentage) or mean (median) ± SD.

^aData were missing for the following variables and number of participants: education (n = 18); MMSE (n = 1); self-rated health (n = 2); 10-m walking speed (n = 127); chair stands test (n = 138); TUG (n = 71); grip strength (n = 50); IADL score (n = 1).

DBI = drug burden index; FCI = Functional Comorbidity Index; IADL = instrumental activities of daily living; MMSE = mini-mental state examination; TUG = timed up and go test.

Table II. The most common DBI medications used in the GeMS population.

Medication name	ATC code	Minimum daily dose (mg)^a	No of participants (%)^b
Oxybutynin	G04BD04	5	14 (2.0)
Tolterodine	G04BD07	4	7 (1.0)
Tamsulosin	G04CA02	0.4	27 (3.9)
Codeine, combinations	N02AA59	30	9 (1.3)
Tramadol	N02AX02	150	7 (1.0)
Gabapentin	N03AX12	900	6 (0.9)
Levodopa, combinations	N04BA02	300 levodopa/75 carbidopa	11 (1.6)
Selegiline	N04BD01	5	6 (0.9)
Pericyazine	N05AC01	5	5 (0.7)
Thioridazine	N05AC02	25	5 (0.7)
Melperone	N05AD03	20	10 (1.4)
Risperidone	N05AX08	0.5	10 (1.4)
Oxazepam	N05BA04	15	17 (2.4)
Temazepam	N05CD07	10	33 (4.7)
Zopiclone	N05CF01	3.75	56 (8.0)
Zolpidem	N05CF02	5	5 (0.7)
Amitriptyline	N06AA09	10	8 (1.1)
Citalopram	N06AB04	10	26 (3.7)
Mianserin	N06AX03	10	5 (0.7)
Mirtazapine	N06AX11	15	19 (2.7)
Amitriptyline and psycholeptics	N06CA01	10 amitriptyline/5 chlordiazepoxide	9 (1.3)
Ipratropium	R03BB01	0.5	9 (1.3)
Tiotropium	R03BB04	0.018	5 (0.7)

ATC = Anatomical Therapeutic Chemical.

^aRegistered by the Finnish product medication information.

^bDBI medications reported by less than five participants are not included in Table II.

Table III. Unadjusted and adjusted analysis of covariance for association of DBI with outcomes.

	Parameter estimate (95% CI)	No. of participants with DBI >0	P value	F value
10-m walking speed, m/s
Unadjusted model (n = 573)	−0.23 (−0.29, −0.16)	198	<0.0001	46.9
Adjusted model (n = 558)	−0.13 (−0.19, −0.08)	191	<0.0001	59.7
Chair stands test, seconds^a
Unadjusted model (n = 562)	1.18 (1.12, 1.24)	188	<0.0001	35.8
Adjusted model (n = 549)	1.11 (1.05, 1.16)	182	0.0001	24.4
Hand grip strength, kg
Unadjusted model (n = 650)	−2.60 (−4.01, −1.19)	236	0.0003	13.1
Adjusted model (n = 634)	−0.98 (−2.05, 0.08)	228	0.07	92.5
TUG, seconds^a
Unadjusted model (n = 629)	1.26 (1.18, 1.34)	226	<0.0001	46.7
Adjusted model (n = 615)	1.13 (1.07, 1.19)	219	<0.0001	57.3
IADL score
Unadjusted model (n = 699)	−1.05 (−1.33, −0.77)	257	<0.0001	54.3
Adjusted model (n = 678)	−0.61 (−0.84, −0.39)	246	<0.0001	72.3
Barthel Index score
Unadjusted model (n = 700)	−5.68 (−7.26, −4.11)	257	<0.0001	50.2
Adjusted model (n = 679)	−3.21 (−4.68, −1.75)	246	<0.0001	24.1

Models adjusted for age, sex, education, comorbidites, self-reported status and cognitive impariment. 10-m walking speed: higher scores indicated faster speed; chair stands test and TUG: lower score indicated better performance; grip strength, IADL, and Barthel Index: higher score indicating better performance.

DBI = drug burden index; CI = confidence intervals; IADL = instrumental activities of daily living; TUG = timed up and go.

n represents the number of participants with available data for each model.

^a Variables log₁₀-transformed before analysis.

Figure 1. Adjusted means of functional outcome measures according to the DBI exposure. 10-m walking speed: higher scores indicated faster speed; chair stands test and TUG: lower score indicated better performance; grip strength, IADL, and Barthel Index: higher score indicating better performance. Models adjusted for age, sex, education, comorbidites, self-reported status and cognitive impariment. The y-axis does not consistently start at 0. Error bars represent standard error. DBI = drug burden index; IADL = instrumental activities of daily living; TUG = timed up and go.