Table 3.

Variation between the 41 nursing homes in drug use and drug-related problems and the differences between the quartile of nursing homes using highest and lowest number of drugs

Variables	All NHs (n = 41) Mean (range)	Differences between the NHs using highest (n = 10) and lowest (n = 10) number of drugs
		Mean Q4	Mean Q1	Diff (95%CI)a	P-value
Drug use
Drugs/patient	6.8 (4.8–9.3)	7.7	5.7	2.0 (1.6, 2.6)	< 0.001
Proportion of patients using:
≥ 9 drugs	34.2 (15.9–52.2)	44.2	22.0	22.2 (18.5, 25.9)	< 0.001
Opioids	33.1 (0.0–65.2)	42.1	22.0	20.1 (8.7, 31.4)	0.002
Paracetamol	43.5 (15.8–73.9)	44.7	34.0	10.6 (−1.5, 22.7)	0.08
Antipsychotics	19.1 (3.0–50.0)	20.3	20.9	- 0.6 (−12.3, 11.0)	0.9
Benzodiazepines	52.8 (23.7–98.6)	57.8	45.7	12.1 (−4.9, 29.1)	0.2
Antidepressants	37.8 (9.1–75.0)	38.2	35.3	2.8 (−10.2, 15.9)	0.6
Antidementia drugs	11.4 (0.0–41.7)	10.7	12.0	- 1.3 (−10.6, 8.1)	0.8
Drug-related problems (DRPs)
Proportion of patients with DRPs	84.1 (31.8–100.0)	85.2	86.2	- 1.0 (−14.9, 12.8)	1.0
DRPs/patient	2.0 (0.5–3.4)	2.2	1.8	0.4 (−0.3, 1.0)	0.2
Categories of DRPs:
- Unnecessary drug	0.6 (0.1–1.3)	0.6	0.6	0.0 (−0.2, 0.3)	1.0
- Excessive dosage	0.3 (0.1–0.6)	0.3	0.3	0.0 (−0.1, 0.2)	0.2
- Monitor use required	0.3 (0.0–0.7)	0.3	0.3	0.0 (−0.1, 0.2)	0.9
- Need for new drug	0.2 (0.0–0.4)	0.2	0.1	0.1 (−0.01, 0.1)	0.1
- Drug-drug interaction	0.2 (0.0–0.5)	0.2	0.1	0.1 (0.01, 0.2)	0.03
- Adverse drug reaction	0.1 (0.0–0.4)	0.2	0.1	0.1 (− 0.04, 0.2)	0.2
- Inappropriate drug	0.1 (0.1–0.5)	0.1	0.2	- 0.1 (−0.1, 0.1)	0.9
Demographics
Mean age, years	85.9 (61.3–90.0)	84.6	84.5	0.1 (−6.4, 6.7)	1.0
Proportion of males	25.8 (13.6–47.4)	27.5	24.5	3.0 (−6.0, 12.0)	0.5

^aThe mean of the lower quartile (Q₄) was compared to the mean of the lower quartile (Q₁) using the Independent samples T test, with difference in means with 95% CI and p-value