Cannabis hospitalization and tuberculosis rates overlapped geographically in Thailand but causal link unconfirmed | Research

The takeaway

In Thailand, cannabis-related and tuberculosis hospital admissions shared a geographic hotspot in the Northeast, and prior cannabis hospitalization showed a non-significant 48% higher TB hazard.

People interested in respiratory health effects of cannabis, particularly in countries with high TB prevalence.

HR 1.48 for TB after cannabis hospitalization (not significant)

What the researchers found

Cannabis-related admissions increased while TB admissions declined during 2017-2022. Both shared a hotspot in Northeastern Thailand. In matched cohorts of 6,773 patients, the TB incidence rate was 267.6 per 100,000 person-years in those with prior cannabis admission versus 165.9 in those without. The adjusted hazard ratio was 1.48 but did not reach significance (P=0.268).

Why it matters

Thailand legalized recreational cannabis in 2022. Understanding whether cannabis use could exacerbate its existing TB burden is a public health priority, even though this study found the association was not statistically significant.

The numbers in context

2017-2022 data period. 6,773 matched pairs. TB incidence: 267.6 vs. 165.9 per 100,000 person-years. Hazard ratio: 1.48 (P=0.268). Shared hotspot in Northeastern Thailand.

How the study worked

National in-patient database analysis in Thailand (2017-2022). Spatiotemporal correlation between cannabis-related and TB admissions examined with line plots and choropleth maps. Matched cohort analysis (6,773 per group) compared subsequent TB admission rates with Cox regression.

What this study cannot tell us

Hospital admission data misses outpatient cannabis use. The non-significant result could reflect insufficient power. Cannabis hospitalization is a proxy for heavy use, not representative of all users. Ecological correlation between geographic hotspots does not imply causation.

How to read the evidence

National database analysis with matched cohorts, but the non-significant primary finding and reliance on hospital admission data limit conclusions.

When this study was published

Published in 2024 using Thai national data from 2017-2022.

The bigger picture

In countries with high TB prevalence, any factor that might increase respiratory vulnerability is worth monitoring. While this study did not find a statistically significant link between cannabis hospitalization and TB, the geographic overlap and elevated (if non-significant) hazard ratio suggest the question deserves further study.

Questions still open

Would a larger study with more power detect a significant cannabis-TB association? Does the method of cannabis use (smoking vs. other) matter for TB risk? Is the geographic overlap explained by shared socioeconomic factors?

Common questions

Does cannabis increase tuberculosis risk?

This Thai study found a non-significant 48% higher TB risk among people previously hospitalized for cannabis-related reasons. The result did not reach statistical significance, so the question remains open.

Why study cannabis and TB together?

Cannabis smoking causes airway inflammation that could theoretically increase TB susceptibility. In countries like Thailand where TB is common and cannabis was recently legalized, understanding this potential connection is a public health priority.

Read the original research

Relationship between hospitalization from cannabis usage and pulmonary tuberculosis in Thailand from 2017 to 2022.

PloS one, 19(12), e0312139

View on PubMed ↗Publisher’s paper ↗

Citation

Chumchuen, Kemmapon; Wichaidit, Wit; Chongsuvivatwong, Virasakdi. (2024). Relationship between hospitalization from cannabis usage and pulmonary tuberculosis in Thailand from 2017 to 2022.. PloS one, 19(12), e0312139. https://doi.org/10.1371/journal.pone.0312139