Testosterone lab testing and initiation in the United Kingdom and the United States, 2000 to 2011.
Level 3 - non-randomized controlled study
Retrospective observational cohort study using claims and electronic health records
PubMed 24423353 · doi:10.1210/jc.2013-3570
What was done
Researchers performed a retrospective incident user cohort study analyzing US commercial and Medicare claims and UK general practitioner electronic health records from 2000 to 2011. They evaluated 410,019 US men and 6,858 UK men initiating testosterone formulations (injections, implants, transdermal, or oral), alongside 1,114,329 US men and 66,140 UK men undergoing a new testosterone laboratory measurement.
What was found
Testosterone testing and supplementation increased substantially over the decade, especially in the US. UK testing primarily identified men with low testosterone, whereas US testing increasingly captured men with normal levels. Men in the US were more likely to start treatment despite having normal testosterone levels, and a substantial proportion initiated therapy without recent laboratory testing. Transdermal gels emerged as the predominant initial formulation in both countries. Exact numerical rates and proportions were not reported in the abstract.
Why it matters
This study documents widespread international increases in testosterone therapy and highlights major practice gaps, particularly in the US where treatment was frequently initiated without documented biochemical deficiency or preceding lab tests.
Limits
The abstract reports no exact percentages, effect sizes, or laboratory threshold values. The study relies on administrative claims and primary care records, which may miss unbilled care, cash purchases, or specific clinical indications.
Cited by
- supports Testosterone prescriptions in the United States increased by 300% over a 10-year period.