Effects of an antimicrobial restriction system on appropriate carbapenem use in a hospital without infectious diseases consultation

Figures & data

Table 1 Patient characteristics

Characteristics	Number of prescriptions (%)		p-value
	Before (n=180)	After (n=180)
Sex
Male	108 (60)	116 (64.4)	0.384
Female	72 (40)	64 (35.6)
Age (years)
18–30	3 (1.7)	9 (5)	0.194
31–60	64 (35.5)	56 (31.1)
>60	113 (62.8)	115 (63.9)
Length of stay, median (min–max)	16 (1–122)	12 (1–161)	0.001
Wards prescribing carbapenem
Medical ward	150 (83.3)	169 (93.9)	0.001
Surgical ward	21 (11.7)	3 (1.7)
Orthopedic ward	4 (2.2)	4 (2.2)
Neurologic ward	5 (2.8)	3 (1.7)
Obstetric ward	0 (0)	1 (0.6)

Table 2 Clinical data of patients

Characteristics	Number of prescriptions (%)		p-value
	Before (n=180)	After (n=180)
Underlying disease
Orthopedic disease	4 (4.12)	2 (2.67)	<0.001
Neurologic disease and CNS	4 (4.12)	2 (2.67)
Lower respiratory tract disease	11 (11.34)	11 (14.66)
Other	78 (80.41)	60 (80.00)
Type of infection
Bone and joint infection	4 (2.20)	2 (1.10)	<0.001
Lower respiratory tract infection	45 (24.20)	48 (25.90)
Central nervous system infection	11 (5.90)	3 (1.62)
Urinary tract infection	53 (28.60)	49 (26.49)
Sepsis	20 (10.70)	36 (19.45)
Bacteremia	13 (6.90)	6 (3.24)
Skin and soft tissue infection	5 (2.70)	2 (1.10)
Neutropenia	0 (0.00)	2 (1.10)
Intra-abdominal infection	16 (8.60)	4 (2.16)
Septic shock	16 (8.60)	23 (12.43)
Unknown	3 (1.60)	10 (5.41)

Note: Other: cancer, liver disease, cardiovascular disease, renal disease.

Abbreviation: CNS, central nervous system.

Table 3 Types of prescriptions and clinical outcomes

Parameter	Number of prescriptions (%)		Unadjusted OR (95% CI)	p-value	Adjusted ORa (95% CI)	p-value
	Before (n=180)	After (n=180)
Type of prescription			2.162 (1.417–3.300)	0.000	2.329 (1.425–3.805)	0.001
Empiric therapy	81 (45.00)	117 (65.00)
Specific therapy	99 (55.00)	63 (35.00)
Clinical outcome			0.575 (0.178–0.973)	0.005	0.594 (0.153–1.036)	0.008
Complete response	0 (0.00)	46 (25.60)
Partial response	90 (50.00)	49 (27.20)
Failure	90 (50.00)	85 (47.20)

Note:

a Adjusted for length of stay, wards, underlying disease, and type of infection.

Abbreviations: CI, confidence interval; OR, odds ratio.

Table 4 Incidence rates of nosocomial infections caused by resistant organisms before and after using the antimicrobial restriction system

Microorganism	Number of infections per 1,000 patient days		p-value
	Before	After
Enterobacteriaceae
Ertapenem (R) Enterobacteriaceae	2.78	0.63	1.000
Meropenem (R) Enterobacteriaceae	2.02	0.32	1.000
CRE	4.80	0.95	1.000
Pseudomonas aeruginosa
Meropenem (R) P. aeruginosa	3.53	1.28	1.000

Notes: Before: 3,961 patient days. After: 3,132 patient days.

Abbreviations: CRE, Carbapenem (R) Enterobacteriaceae; R, resistant.

Table 5 Appropriateness of prescribing

Parameter	Number of prescriptions (%)		Unadjusted OR (95% CI)	p-value	Adjusted ORa (95% CI)	p-value
	Before (n=180)	After (n=180)
Appropriateness of prescribing			1.966 (1.292–2.993)	0.002	2.150 (1.351–3.423)	0.001
Appropriate	69 (38.3)	99 (55.0)
Inappropriate	111 (61.7)	81 (45.0)

Note:

a Adjusted for length of stay, wards, underlying disease, and type of infection.

Abbreviations: CI, confidence interval; OR, odds ratio.

Table 6 Inappropriate prescribing

Inappropriate prescribing	Number of prescriptions (%)		Unadjusted OR (95% CI)	p-value	Adjusted ORa (95% CI)	p-value
	Before (n=180)	After (n=180)
Indication	40 (22.3)	28 (15.6)	0.800 (0.468–1.367)	0.414	0.811 (0.456–1.445)	0.478
Improper dose	88 (48.9)	67 (37.2)	1.613 (1.060–2.456)	0.026	1.879 (1.173–3.011)	0.009

Note:

a Adjusted for length of stay, wards, underlying disease, and type of infection.

Abbreviations: CI, confidence interval; OR, odds ratio.

Table 7 Amount of carbapenem in dose prescribed per 1,000 bed days (DDD/1,000 bed days)

Drug	Mean DDD (g)/1,000 bed days		% difference between before and after	p-value
	Before (n=180)	After (n=180)
Carbapenem	616.71	638.20	+3.48	0.611
Meropenem*	597	642.05	+7.54	0.972
Ertapenem**	761.86	609.07	−20.05	0.220

Notes:

* Mapenem^® (meropenem) from Siam Pharmaceutical, Bangkok, Thailand.

** Invanz^® (ertapenem) from Merck & Co., Inc., Kenliworth, NJ, USA.

Abbreviation: DDD, defined daily dose.

Table 8 Prescription drug expenses in average value of baht per patient

Drug	Average value of baht per patient (min–max)		% difference between before and after	p-value
	Before (n=180)	After (n=180)
Carbapenem	5,030.5 (204.4–41,344.8)	3,202.9 (204.4–14,766.0)	−36.33	0.001
Meropenem	4,320.4 (204.4–35,560.4)	3,023.8 (204.4–12,262.2)	−30.01	0.014
Ertapenem	9,888.7 (1,968.8–41,344.8)	4,558.5 (984.4–14,766.0)	−53.90	0.005