Table 5.
Effect of diabetes (DM) on rate of tuberculosis, modification by consultation rate, consultation number, age, time since diagnosis of diabetes and ethnicity
| Strata | Exposure status | TB cases/PYa | Unadjusted rate | Unadjusted rate ratio | Adjusted rate ratiob | P-value for interactionc |
|---|---|---|---|---|---|---|
| (95 % CI) | (95 % CI) | (95 % CI) | ||||
| Consultation rated | ||||||
| 1st tertile | DM | 5/0.93 | 5.35 (2.23–12.86) | 0.91 (0.37–2.22) | 1.80 (0.64–5.01) | |
| Non-DM | 141/23.94 | 5.89 (4.99–6.95) | 1.0 | 1.0 | ||
| 2nd tertile | DM | 39/4.61 | 8.46 (6.18–11.59) | 0.65 (0.46–0.91) | 1.01 (0.63–1.62) | 0.535 |
| Non-DM | 273/20.92 | 13.05 (11.59–14.69) | 1.0 | 1.0 | ||
| 3rd tertile | DM | 146/6.19 | 23.60 (20.01–27.76) | 0.83 (0.68–1.00) | 0.94 (0.69–1.27) | |
| Non-DM | 265/12.81 | 28.50 (25.72–31.57) | 1.0 | 1.0 | ||
| Consultation numbere | ||||||
| 1st tertile | DM | 48/0.35 | 138.41 (104.31–183.67) | 5.14 (3.78–7.00) | 2.99 (1.68–5.31) | |
| Non-DM | 254/9.43 | 26.93 (23.82–30.46) | 1.0 | 1.0 | ||
| 2nd tertile | DM | 70/1.97 | 35.61 (28.17–45.01) | 2.42 (1.86–3.14) | 2.88 (1.96–4.24) | 0.003 |
| Non-DM | 285/19.37 | 14.71 (13.10–16.53) | 1.0 | 1.0 | ||
| 3rd tertile | DM | 72/9.42 | 7.65 (6.07–9.63) | 0.92 (0.71–1.20) | 1.26 (0.87–1.83) | |
| Non-DM | 240/28.87 | 8.31 (7.32–9.43) | 1.0 | 1.0 | ||
| Age in years | ||||||
| 0- < 45 | DM | 10/1.10 | 9.07 (4.88–16.86) | 1.23 (0.61–2.45) | 0.97 (0.32–2.93) | |
| Non-DM | 41/5.54 | 7.40 (5.45–10.04) | 1.0 | 1.0 | ||
| 45- < 70 | DM | 103/6.11 | 16.85 (13.89–20.45) | 1.71 (1.37–2.14) | 1.62 (1.14–2.31) | 0.228 |
| Non-DM | 295/29.93 | 9.86 (8.79–11.05) | 1.0 | 1.0 | ||
| 70+ | DM | 77/4.51 | 17.0 (13.64–21.32) | 0.85 (0.67–1.09) | 1.08 (0.76–1.55) | |
| Non-DM | 443/22.20 | 19.95 (18.18–21.90) | 1.0 | 1.0 | ||
| Time since index date | ||||||
| 0- < 1 years | DM | 56/2.07 | 27.07 (20.83–35.17) | 1.83 (1.35–2.48) | 1.48 (0.86–2.56) | |
| Non-DM | 165/11.16 | 14.78 (12.69–17.22) | 1.0 | 1.0 | ||
| 1- < 5 years | DM | 80/5.72 | 13.99 (11.24–17.41) | 0.99 (0.78–1.26) | 1.24 (0.88–1.74) | 0.375 |
| Non-DM | 407/28.81 | 14.13 (12.82–15.57) | 1.0 | 1.0 | ||
| 5- < 10 years | DM | 41/3.08 | 13.32 (9.80–18.08) | 1.05 (0.75–1.48) | 1.13 (0.68–1.87) | |
| Non-DM | 177/14.01 | 12.64 (10.91–14.64) | 1.0 | 1.0 | ||
| 10+ years | DM | 13/0.86 | 15.11 (8.77–26.02) | 1.86 (0.97–3.57) | 2.66 (1.12–6.35) | |
| Non-DM | 30/3.70 | 8.11 (5.67–11.61) | 1.0 | 1.0 | ||
| Ethnicity | ||||||
| White | DM | 74/6.74 | 10.98 (8.74–13.79) | 0.88 (0.69–1.13) | 1.27 (0.95–1.69) | |
| Non-DM | 380/30.57 | 12.43 (11.24–13.75) | 1.0 | 1.0 | ||
| South Asian | DM | 38/0.27 | 139.40 (101.43–191.58) | 1.39 (0.91–2.12) | 1.34 (0.79–2.28) | 0.894 |
| Non-DM | 49/0.49 | 100.58 (76.02–133.08) | 1.0 | 1.0 | ||
| Black, Mixed or Other | DM | 5/0.20 | 24.41 (10.16–58.65) | 0.57 (0.22–1.49) | 1.65 (0.55–4.93) | |
| Non-DM | 26/0.61 | 42.74 (29.10–62.77) | 1.0 | 1.0 |
aPY: 100,000 person years at risk
bModel adjusted for: age, ethnicity, BMI, alcohol status, smoking and IMD
c P-value from likelihood ratio test
dConsultation rate defined as number of face to face consultations per year of follow-up; tertiles in order of increasing consultation rate
eConsultation number defined as total number of face to face consultations during patient follow-up; tertiles in order of increasing number of consultations
BMI body mass index, CI confidence interval, IMD index of multiple deprivation, TB tuberculosis