Criteria for an extensively drug-resistant tuberculosis:
(1) resistance to >= 2 multidrug-resistant drugs (rifampicin, isoniazid)
(2) resistance to any fluoroquinolone
(3) resistance to >= 1 injectable antituberculous drugs: capreomycin, kanamycin, amikacin
Risk factors for extensive drug resistance:
(1) previous antituberculous therapy (relapse; adjusted odds ratio 10.5)
(2) HIV infection (adjusted odds ratio 3.1)
(3) homelessness (adjusted odds ratio 2.7)
(4) alcohol abuse (adjusted odds ratio 2.0)
Risk factors for multi-drug but not extensive drug resistance:
(1) previous antituberculous therapy (relapse; adjusted odds ratio 4.1)
(2) age < 65 years (adjusted odds ratios 2.1 to 2.6 depending on age strata)
Risk factors for multi-drug resistance if less than 25 years of age:
(1) female sex (adjusted odds ratio 6.2)
(2) immigrant (born outside of Estonia; adjusted odds ratio 82.0)
