Relationship Between Isoniazid Resistance and Initial Drug Regimens
Among the 21 counties in New Jersey, 17 had a percentage of isoniazid resistance of 4% or more; these counties contributed 98% of all TB cases reported in the state. The remaining four counties had a total of 17 cases tested for drug susceptibility during 1994 and 1995, and none of their isolates were resistant to isoniazid. The proportion of isoniazid resistance ranged from 4.4% to 19.7% in the 16 counties with 10 or more cases tested for drug susceptibility. The proportion of TB patients who were initially treated with fewer than four drugs varied from 23% to 71% among the same 16 counties. At the county level, there was no significant relationship between the proportion of isoniazid-resistant cases and the proportion of TB patients who were initially treated with fewer than four drugs (Spearman correlation coefficient=0.23; p=0.31). Presumably, the higher the level of isoniazid resistance observed in a county, the less likely it was that a patient in that county had initially been treated with fewer than four drugs. In other words, a negative correlation should have been observed between the two variables if physicians had used the proportion of isoniazid resistance to guide their treatment decisions, but no such correlation was found here.
Factors Associated With Patients Treated With Fewer Than Four Drugs Initially
Table 2 shows the prevalence of drug resistance and the proportion of TB patients who were initially treated with fewer than four drugs according to selected patient characteristics. ORs and 95% CIs for patients who were initially treated with fewer than four drugs also are shown in Table 2. In certain groups, a high proportion of drug resistance was not always associated with a high proportion of four-drug regimens, and vice versa. The proportion of isoniazid resistance was almost identical in male and female patients, yet female patients were more likely to be treated with fewer than four drugs than were male patients. Physicians were more likely to prescribe fewer than four drugs for younger and older TB patients than for middle-aged patients (not significant after adjusting for other factors as listed in Table 2). Although the rate of drug resistance did not differ significantly between non-Hispanic white and non-Hispanic black patients, the former were about twice as likely to be treated with fewer than four drugs as were the latter after adjusting for other potential risk factors. In spite of a high level of isoniazid resistance (17.3%), Asians were also more likely to be treated with fewer than four drugs than were non-Hispanic black patients. canadian helth& care mall

Table 2—Prevalence of Drug Resistance and ORsfor TB Patients Initially Treated With Fewer Than Four Drugs in New Jersey, 1994 to 1995, According to Patient Characteristics

Drug Resistance, %* Initial Drug Regimen
Factor No. of Cases Isoniazid Isoniazid+Rifampin <4 Drugs, % ORcf ORa (95% Cl)
Sex
Male 778 10.4 3.3 32.3 1.0* 1.0
Female 452 10.2 2.4 41.2 1.47 1.21 (0.93-1.59)
Age group, yr
<15 26 11.5 0 53.9 2.84 1.67 (0.72-3.88)
15 to 24 101 12.9 0 32.7 1.18 0.84 (0.51-1.36)
25 to 44 622 10.9 3.5 29.1 1.0* 1.0
45 to 64 281 8.9 2.5 35.6 1.35 0.99 (0.71-1.38)
>65 200 9.0 4.0 54.5 2.92 1.22 (0.82-1.80)
Raee/ethnieity
Non-Hispanic black 558 8.1 2.7 25.8 1.0* 1.0
Non-Hispanic white 237 8.4 2.1 57.0 3.81 1.97(1.37-2.84)
Hispanic 227 11.5 4.4 30.0 1.23 1.03 (0.68-1.56)
Asian 208 17.3 3.4 43.3 2.19 1.49 (0.94-2.38)
Country of origin
United States 786 8.3 2.7 34.9 1.0* 1.0
Foreign 444 14.0 3.6 36.7 1.08 0.66 (0.46-0.94)
Recurrent TB
No 1,184 9.1 2.4 36.1 1.0* 1.0
Yes 46 41.3 19.6 21.7 0.49 0.48 (0.22-1.02)
Excessive alcohol use
No 899 11.0 3.1 38.4 1.0* 1.0
Yes 178 7.9 2.3 18.5 0.37 0.61 (0.38-0.97)
Unknown 153 9.2 3.3 38.6 1.01 0.95 (0.35-2.59)
Injecting drug use
No 979 10.7 3.1 37.4 1.0* 1.0
Yes 108 8.3 2.8 15.7 0.31 1.20 (0.63-2.31)
Unknown 143 9.1 2.8 37.8 1.02 1.12 (0.40-3.13)
HIV status
Seronegative 306 9.2 2.0 34.0 1.0* 1.0
Seropositive 348 10.3 4.6 14.9 0.34 0.38 (0.25-0.59)
Unknown 576 10.9 2.6 48.8 1.85 1.45 (1.05-1.99)
Initial care provider
UMDNJ-MS 134 4.5 0.8 8.2 1.0* 1.0
Hospitals 885 9.6 3.1 36.8 6,52 4.33 (2.25-8.34)
Chest clinics 93 21.5 1.1 41.9 8.08 5.05 (2.31-11.06)
Private physicians 118 13.6 6.8 51.7 12.0 5.67 (2.64-12.17)
Total 1,230 10.3 3.0 35,5