Univariate | Multivariate | ||||
OR | 95% CI | p-value | OR | 95% CI | |
Analysis 1a – Contact with any potential source, newly diagnosed infection | |||||
Age at infection | 1.00 | 0.97–1.03 | 0.806 | Not in final model | |
Male sex | 0.93 | 0.44–1.94 | 0.844 | Not in final model | |
Current smoking | 1.63 | 0.58–4.54 | 0.351 | Not in final model | |
BCG | 0.65 | 0.24–1.75 | 0.391 | Not in final model | |
Residing with a person with smear-positive disease | 2.03 | 0.67–6.14 | 0.208 | Not in final model | |
Total exposures | 1.09 | 1.05–1.14 | <0.0005 | 1.11 | 1.06–1.16 |
Persons per room# | 1.12 | 0.98–1.28 | 0.086 | 1.18 | 1.04–1.34 |
Analysis 1b – Contact with any potential source, tuberculin skin test conversion only | |||||
Age at infection | 1.01 | 0.98–1.04 | 0.593 | Not in final model | |
Male sex | 0.72 | 0.31–1.67 | 0.442 | Not in final model | |
Current smoking | 2.19 | 0.61–7.90 | 0.231 | Not in final model | |
BCG | 1.30 | 0.33–5.21 | 0.707 | Not in final model | |
Residing with a person with smear-positive disease | 3.17 | 0.85–11.79 | 0.085 | 0.27 | 0.02–4.59 |
Total exposures | 1.12 | 1.06–1.18 | <0.0005 | 1.14 | 1.08–1.21 |
Persons per room# | 1.13 | 1.00–1.28 | 0.056 | ||
Persons per room# when not residing with a person with smear-positive disease | 1.15 | 1.03–1.28 | |||
Persons per room# when residing with a person with smear-positive disease | 1.49¶ | 1.06–2.10 |
BCG: Bacillus Calmette–Guérin. #: For comparability to [6], persons per room scaled such that the odds ratio corresponds to a one-person increase in a five-person house. ¶: p=0.027 for interaction between persons per room and residing with a person with smear-positive disease; this odds ratio represents the joint effect of adding one person to a five-person house when residing with an individual with smear-positive disease. Age and persons per room are centred at the overall mean for analysis 1a, at 20.8 years and 1.7 persons per room, respectively. Total exposures centred at 1, as all individuals had at least one contact.