Table 5.
Multivariable Analysis of Risk Factors for Acquired Resistance to Crucial Second-line Drugs, Controlling for Demographic, Social, and Clinical Characteristics, Hospitalizations, and Baseline Drug Resistance, 2005–2010, in 9 Countries
| Characteristic | Category | XDR: aOR (95% CI) | P Value | FQ: aOR (95% CI) | P Value | SLI: aOR (95% CI) | P Value |
|---|---|---|---|---|---|---|---|
| Green Light Committee | Yes | 0.21 (.07–.62) | .004 | 0.23 (.09–.59) | .001 | 0.74 (.29–1.87) | .53 |
| No | Ref | Ref | Ref | ||||
| No. of hospitalizations for this episode of tuberculosis | 0 | Ref | Ref | Ref | |||
| 1 | 1.36 (.43–4.25) | .77 | 0.78 (.31–1.99) | .35 | 1.48 (.54–4.06) | .50 | |
| 2 | 2.34 (.69–7.91) | .12 | 1.19 (.45–3.13) | .43 | 3.73 (1.44–9.69) | .002 | |
| No. of SLDs to which the isolate was susceptible | 0–2 | 32.03 (14.47–70.89) | <.0001 | 13.95 (7.42–26.22) | <.0001 | 15.53 (2.84–84.79) | .005 |
| 3–4 | 4.47 (2.12–10.62) | .58 | 2.25 (1.13–4.48) | .10 | 1.97 (1.09–3.57) | .16 | |
| 5 | Ref | Ref | Ref | ||||
| Baseline ethambutol resistance | Res | 1.98 (.95–4.13) | .07 | 1.54 (.84–2.81) | .16 | 1.40 (.69–2.84) | .35 |
| Sus | Ref | Ref | Ref | ||||
| Baseline streptomycin resistance | Res | 3.26 (1.25–8.48) | .02 | 1.54 (.75–3.15) | .24 | 1.33 (.65–2.73) | .43 |
| Sus | Ref | Ref | Ref | ||||
| Baseline fluoroquinolone resistance | Res | 7.51 (2.83–19.94) | <.0001 | … | 2.40 (1.11–5.20) | .02 | |
| Sus | Ref | … | |||||
| Baseline KAN or AMK resistance | Res | 13.59 (4.72–39.09) | <.0001 | 6.32 (2.58–15.49) | <.0001 | … | |
| Sus | Ref | Ref | … | ||||
| Baseline capreomycin resistance | Res | 1.65 (.62–4.39) | .32 | 1.65 (0.68–4.02) | .27 | 1.15 (.23–5.67) | .87 |
| Sus | Ref | Ref | Ref | ||||
| Baseline ethionamide resistance | Res | 0.89 (.37–2.09) | .78 | 1.09 (.52–2.30) | .82 | 1.45 (.71–2.96) | .30 |
| Sus | Ref | Ref | Ref | ||||
| Baseline PAS resistance | Res | 0.76 (.28–2.07) | .60 | 0.60 (.19–1.91) | .39 | 0.98 (.36–2.63) | .96 |
| Sus | Ref | Ref | Ref | ||||
| Propensity score | 0.98 (.70–1.38) | P = .93 | 0.932 (.70–1.25) | P = .63 | 0.85 (.62–1.16) | .30 |
Propensity scores included terms for the following variables: human immunodeficiency virus status, employment, marital status, education, high-risk occupation, alcohol abuse, diabetes, chronic renal insufficiency, history of treatment with any first-line drugs, history of treatment with ethambutol or streptomycin, history of treatment with SLIs, history of treatment with PAS or cycloserine, outcome of previous treatment, unilateral vs bilateral disease and cavitary vs non-cavitary disease radiographically, sputum microscopy results for acid-fast bacilli, number of drugs tested locally for drug susceptibility before treatment, and hospitalization at enrollment. Coefficients and tests of statistical significance for these variables do not appear individually in the final multivariable models for acquired resistance.
Abbreviations: AMK, amikacin; aOR, adjusted odds ratio; CI, confidence interval; FQ, fluoroquinolone; KAN, kanamycin; PAS, para-aminosalicylic acid; Ref, reference group; Res, resistant; SLD, second-line drug; SLI, second-line injectable drug; Sus, susceptible; XDR, extensively drug-resistant.