Table 4 Subgroup analyses of 24 observational studies on the association between diabetes mellitus and multi-drug-resistant-tuberculosis among tuberculosis patients co-morbid with diabetes mellitus
Study characteristics | Studies that adjusted for at least one covariate | Studies that did not adjustment for covariates | ||||||
|---|---|---|---|---|---|---|---|---|
No. of studies | Pooled OR (95% CI) | I2 (%) | P value¥ | No. of studies | Pooled OR (95% CI) | I2 (%) | P value¥ | |
Study design | ||||||||
 Case control | 5 | 2.89 (2.02, 4.12) | 0.0 | 0.773 | 4 | 1.39 (0.79, 2.45) | 0.0 | 0.459 |
 Cohort | 4 | 3.36 (1.82, 6.20) | 40.2 | 0.171 | 3 | 1.47 (0.93, 2.34) | 0.0 | 0.501 |
 Cross sectional | 4 | 1.72 (1.23, 2,41) | 19.1 | 0.250 | 4 | 1.45 (0.68, 3.09) | 73.2 | 0.011 |
Type of TB | ||||||||
 Both or not defined | 7 | 2.72 (1.88, 3.94) | 38.4 | 0.136 | 7 | 1.90 (1.40, 2.60) | 0.0 | 0.492 |
 New | 5 | 2.36 (1.59, 3.51) | 3.8 | 0.385 | 2 | 1.64 (0.99, 2.71) | 0.0 | 0.436 |
 Previously treated | 1†|  |  |  | 2 | 0.77 (0.36, 1.67) | 35.4 | 0.115 |
Diagnosis of TB | ||||||||
 Culture confirmed | 8 | 1.97 (1.51, 2.57) | 0.0 | 0.831 | 8 | 1.60 (1.08, 2.38) | 43.6 | 0.088 |
 Sputum smear test only | 5 | 3.73 (2.33, 5.97) | 28.0 | 0.235 | 3 | 1.03 (0.58, 182) | 0.0 | 0.736 |
Type of DM | ||||||||
 Type 2 | 6 | 2.67 (1.82, 3.93) | 40.7 | 0.134 | 3 | 1.12 (0.52, 2.42) | 67.3 | 0.047 |
 Type 1 and type 2 | 5 | 2.22 (1.31, 3.76) | 35.8 | 0.183 | 3 | 1.77 (1.08, 2.89) | 35.5 | 0.212 |
 Not defined | 2 | 2.37 (1.29, 4.34) | 0.0 | 0.872 | 5 | 1.46 (0.84, 2.51) | 0.0 | 0.428 |
Diagnosis of DM | ||||||||
 HbA1c or FBS | 3 | 2.42 (1.49, 3.93) | 0.0 | 0.981 | 1†|  |  |  |
 Only FBS | 6 | 2.68 (1.45, 4.96) | 53.5 | 0.056 | 6 | 1.50 (0.93, 2.42) | 51.6 | 0.066 |
 Self-report/unspecified | 4 | 2.33 (1.65, 3.29) | 21.5 | 0.282 | 4 | 1.49 (0.77, 2.89) | 21.9 | 0.279 |
Country income level* | ||||||||
 Lower middle income | 4 | 2.95 (1.69, 5.16) | 40.6 | 0.168 | 1†|  |  |  |
 Upper middle income | 4 | 2.32 (1.65, 3.28) | 0.0 | 0.418 | 7 | 1.27 (0.80, 2.01) | 56.9 | 0.031 |
 High income | 5 | 2.13 (1.29, 3.52) | 34.6 | 0.191 | 3 | 1.88 (1.07, 3.29) | 0.0 | 0.963 |
 Overall | 13 | 2.43 (1.90, 3.12) | 19.1 | 0.250 | 11 | 1.45 (1.05, 2.02) | 35.4 | 0.115 |