A systematic review and meta-analysis of the effects of antibiotic consumption on antibiotic resistance

BMC Infectious Diseases

Table 1 Explanatory variables

Variable	Number (percentages in parenthesis) total sample = 243
Outcome	Positive	164 (67%)
Outcome	Negative or equivocal	79 (33%)
Level of sampling	Individual	72 (30%)
	Region/Country	124 (51%)
	Other	47 (19%)
Level of analysis	Individual	178 (73%)
	Region/Country	53 (22%)
	Other	12 (5%)
Children/Adults	Children	88 (36%)
	Adults	62 (26%)
	Both	93 (38%)
Bacteria*	Streptococcus	132 (54%)
	Staphylococcus	50 (21%)
	Enteric Bacteria	69 (28%)
	Haemophilus	24 (10%)
	Other	17 (7%)
Most common bacteria/Drug combinations**	B-lactam resistant S pneumonia	104 (43%)
	Macrolide resistant S pneumonia	56 (23%)
	Quinolone resistant E coli	41 (17%)
	B-lactam resistant E coli	35 (14%)
	Sulphonamide resistant E coli	31 (13%)
	Methicillin-resistant S aureus	38 (16%)
Most common antibiotics consumed***	B-lactams	132 (54%)
	Macrolides	93 (38%)
	Sulphonamides	59 (24%)
	Quinolones	52 (21%)
	Antibiotic not specified	65 (27%)
Time between consumption and resistance^	Six months or less	129 (53%)
	More than 6 months	57 (23%)
	Same time	43 (18%)
	Not specified	14 (6%)
How antibiotic consumption was assessed#	Self report	99 (41%)
	Medical records	92 (38%)
	Sales/Prescriptions	65 (27%)
	Direct application of antibiotic	14 (6%)
Region where study was conducted##	Northern Europe	66 (27%)
	Southern Europe	45 (18%)
	US	67 (28%)
	Other	61 (25%)
Type of study	Cross-sectional	101 (42%)
	Ecological	56 (23%)
	Case–control	35 (14%)
	Quasi-experiment	21 (9%)
	Other	30 (12%)

*Percentages do not equal 100% as any given study may have examined more than one type of bacteria.
**Percentage do not equal 100% as any given study may have examined more than one combination; resistant and non-susceptible strains of S pneumonia are combined under the resistant label for this bacterium.
***Percentages do not equal 100% as any given study may have examined more than one antibiotic.
^This variable represents the maximum time interval in any given study between when consumption occurred and resistance was measured. Studies classified as ‘same time’ tended to be ecological studies where the precise interval separating consumption and resistance could not be determined, these studies often simply reported consumption and resistance occurring together over some multi-year interval.
#Percentages do not equal 100% as any given study may have used more than one method.
##The total equals 239 as three studies were conducted in both southern Europe and northern Europe and one study was coded as not applicable.

ISSN: 1471-2334