{
  "abstract": "Background Silicosis is caused by the inhalation of respirable crystalline silica. Silica-exposed individuals have a two-fold, and those with silicosis a four-fold, increased risk of tuberculosis (TB). 1 To determine if these groups also experience worse TB outcomes, we reviewed studies that described TB-related mortality and TB treatment outcomes among individuals with silica exposure or silicosis.Methods Medline, Embase, Cinahl, Web of Science and Scopus were searched on 6 March 2025. Studies including TB treatment success, failure, relapse or mortality outcomes from adult populations described as silica-exposed or with a radiologically confirmed diagnosis of silicosis were included. We pooled standardised mortality ratios (SMR) using a random effects meta-analysis. Methodological and outcome differences precluded meta-analysis for TB treatment outcomes.Results Of 26 eligible studies, 13 contributed SMR data from 264,617 workers. The pooled SMR for silicosis-exposed studies was 3.54 (95% confidence interval (CI) 1.95, 6.42, n = 10) ( figure 1). Outlier analysis demonstrated that very high heterogeneity (I2 = 99%) was largely attributable to two studies. SMRs for three silicosis studies were 76.5 (95% CI 63.6, 89.1), 27.0 (95% CI 18.8, 38.8) and 2.9 (95% 2.2, 3.8). TB treatment success rates ranged from 23% to 99% in 11 silica-exposed groups, and 3% to 99% in 7 silicosis groups; 13/18 (72%) study groups reported treatment success rates below the 90% World Health Organisation benchmark. There was a greater relative risk of unfavourable outcomes in four of six studies that directly compared higher to lower exposures or silica-exposed to non-silica exposed groups.Abstract M46 Figure 1Forest plots displaying pooled SMR value for silica-exposed and silicosis groupDiscussion Despite study heterogeneity, TB-related mortality appears more common among silica-exposed individuals than the general population, with a higher risk among those with silicosis. This excess TB mortality, greater than expected from increased incidence alone, and poor treatment success suggest silica exposure and silicosis lead to worse TB outcomes. Reducing silica exposures would lead to lower TB incidence and, to a greater extent, improve TB outcomes, including mortality.Reference Ehrlich R, et al. The association between silica exposure, silicosis and tuberculosis: a systematic review and meta-analysis. BMC Public Health. 2021 May 20;21(1).",
  "authors": [
    {
      "affiliations": [
        "Faculty of Medicine, Imperial College London, London, UK"
      ],
      "name": "A Dunlop"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College London, London, UK",
        "Royal Brompton Hospital, London, UK"
      ],
      "name": "J Feary"
    },
    {
      "affiliations": [
        "National Heart and Lung Institute, Imperial College London, London, UK"
      ],
      "name": "P Howlett"
    }
  ],
  "title": "M46 A meta-analysis of TB treatment outcomes in individuals with silicosis and silica exposure",
  "uid": "78c64823-79e7-536a-950e-c1b69ce1d656"
}