Volume 18, Number 4—April 2012
Research
Comparison of Escherichia coli ST131 Pulsotypes, by Epidemiologic Traits, 1967–2009
Table 8
Outcome variable, significant predictor variables† | Odds ratio (95% CI) | p value | Nagelkerke R2 for model‡ |
---|---|---|---|
Pulsotype 968 | 0.18 | ||
Human source | 0.20 (0.09–0.46) | <0.001 | |
FQ-R | 55.04 (10.63–285.03) | <0.001 | |
ESBL production | 0.63 (0.41–0.90) | 0.03 | |
Pulsotype 800 | 0.31 | ||
Human source | 10.61 (1.32–85.48) | 0.03 | |
FQ-R | 46.50 (3.75–576.74) | .003 | |
ESBL production | 0.10 (0.05–0.19) | <0.001 | |
Pulsotype 812 | 0.21 | ||
Year of isolation/submission | 1.47 (1.07–2.03) | 0.02 | |
ESBL production | 17.53 (4.02–76.07) | <0.001 | |
High-prevalence pulsotypes | 0.16 | ||
Year of isolation/submission | 1.09 (1.03–1.55) | 0.003 | |
FQ-R | 4.04 (2.22–7.34) | <0.001 | |
ESBL production | 0.47 (0.32–0.70) | <0.001 | |
Multiple-isolate pulsotypes | 0.13 | ||
Year of isolation/submission | 1.07 (1.02–1.13) | 0.009 | |
FQ-R | 3.42 (1.76–6.66) | <0.001 | |
ESBL production | 0.42 (0.24–0.71) | 0.001 |
*ST, sequence type; FQ-R, fluoroquinolone resistance/resistant; ESBL, extended-spectrum β-lactamase; high-prevalence pulsotypes, 12 pulsotypes that contained >6 isolates (>1% of population) each; multiple-isolate pulsotypes, 65 pulsotypes that contained >1 isolate each.
†Variables shown are those that yielded p values of <0.05. With 1 exception, each model included the following candidate predictor variables: human source (vs. other sources), US origin (vs. Canada or other international locale origin), year of isolation/submission, FQ-R, and ESBL production. All pulsotype 812 isolates were FQ-R; thus, FQ-R could not be included in that model.
‡Nagelkerke R2 provides an estimate of the total amount of variance accounted for by the model, i.e., the model's explanatory power. Values range from 0 (no explanatory power) to 1.0 (complete prediction).
1MASTER (Macrorestriction Analysis of ST131 for Epidemiologic Research) Investigators who contributed data are listed at the end of this article.