Cohort studyindependent cross-checkfull text checked★ key study I-ODD-116 in-depth review

Fournier gangrene on SGLT2 drugs: very rare, any extra risk uncertain

Association of Sodium-Glucose Cotransporter 2 Inhibitor Treatment With Risk of Hospitalization for Fournier Gangrene Among Men.

Overview

Dave CV et al.. JAMA Intern Med 2019 · PMID 31479145 · DOI 10.1001/jamainternmed.2019.2813

15.0 vs 9.7 cases per 100,000 person-years; HR 1.73 (0.87-3.42).

Does the study support the specific claim? Partly · Methodological quality: moderate

Study explained simply

What did the researchers want to find out?: Measure Fournier gangrene risk in men starting SGLT2i.
How was the study done?: Claims-data cohort vs DPP-4i.
How many people, animals or samples were studied?: About 500,000 men.
What was actually found?: Very rare; possible but non-significant increase.
How large was the observed effect?: HR 1.73 (0.87-3.42).
What do the results mean in everyday life?: This severe infection is very rare; genital pain with fever needs urgent care.
What are the study's limitations?: Few events.
What does it say about Elawady's specific claim?: Shows the FDA numbers cannot establish a risk ratio.
Do the results apply to Germany and Europe?: High.
What can explicitly not be concluded from this study?: Causality.

Authors: Dave CV et al.
Journal: JAMA Intern Med
Year: 2019
Identifier: PMID 31479145 DOI 10.1001/jamainternmed.2019.2813
Verification: verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
Retracted: no
Corrections: none
Extent checked: full text
Conflicts of interest and funding: Brigham and Women's Hospital and NIA career grant; senior authors report grants from industry outside the submitted work.

Is initiation of an SGLT2 inhibitor associated with hospitalisation for Fournier gangrene in men?

Study design: Cohort study – Cohort study (research letter) of new users with propensity-score weighting, US claims data
Population: Men >=18 years with type 2 diabetes initiating SGLT2i or DPP-4i
Country: USA
Period: After SGLT2i approval (2013) onward; mean follow-up about 7.7 months
Sample size: 138,158 SGLT2i and 360,685 DPP-4i initiators
Inclusion and exclusion criteria: Excluded nursing home care, type 1 or secondary diabetes, ESRD, cancer, HIV

Exposure / intervention: SGLT2 inhibitor initiation
Comparator: DPP-4 inhibitor initiation
Endpoints: Hospitalisation for Fournier gangrene (ICD code plus surgery)
Statistical methods: Stabilised IPTW from propensity score with 37 covariates

Results: 13 cases with SGLT2i (15.0 per 100,000 PY) vs 24 with DPP-4i (9.7 per 100,000 PY); adjusted rate difference 6.7 per 100,000 PY (-2.8 to 16.1); adjusted HR 1.73 (0.87-3.42).
Absolute risks: 15.0 vs 9.7 per 100,000 person-years; adjusted difference 6.7 per 100,000 PY (not significant).
Authors' conclusion: Fournier gangrene occurred rarely; among men initiating an SGLT-2 inhibitor there was a potential increase of approximately 1 case per 10,000 men treated, which was not statistically significant; limitation: lack of randomisation and potential residual confounding.

HR CI log-symmetric; CI includes both no effect and a tripling (stats/C-ODD-08.py). If causal, about 1 extra case per 15,000 person-years.

Provides incidence data that the FDA report counts in the claim cannot: the condition is very rare and any excess is uncertain.

RCT meta-analysis (I-ODD-12) MH-OR 0.41 (0.09-1.82).

High.

Possible small excess, not established.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	moderate
Risk of bias	some concerns
Precision of results	low
Directness	direct
Reproducibility	partly replicated
Consistency with the overall evidence	mixed
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable

Risk in women; true causality.