Background/Purpose: A recent study based on data from a gout specialty clinic (N=706) found that patients with tophi (N=215) had a two-fold increased risk of mortality compared to those without tophi.  However, no population-based data are available on the topic.  We evaluated the mortality impact of tophaceous gout in a general population context.

Methods: Using an electronic medical record database representative of the UK general population, we identified tophaceous gout cases (based on physician diagnosis) and up to 5 non-tophaceous gout controls matched on sex, age, gout duration, and entry time between January 1, 1995 and December 31, 2015.  We calculated mortality rates and hazard ratios (HRs) using a Cox proportional hazard model to adjust for demographics, lifestyle factors, comorbidities, medications, and healthcare use.  We conducted subgroup analyses based on age (≤70 and >70) and sex.  

Results: Among 618 patients with tophaceous gout (55% men, mean age=73 years), the mortality rate was 64.7 deaths/1000 person-years, whereas among 2850 matched gout patients (56% men, mean age=73 years), the corresponding mortality rate was 45.5 deaths/1000 person-years.  Tophaceous gout was associated with a 60% increased risk of mortality (HR=1.60; 95% CI, 1.29-1.97) compared to those without tophi.  After adjusting for covariates, these estimates remained similar (HR=1.60; 95% CI, 1.28-1.99).  Those in the younger age group (≤70 years) and who were male tended to have a larger HR (Table 1).

Conclusion: This general population-based cohort study indicates that tophaceous gout is associated with an increased risk of death among gout patients, particularly among those who are younger (≤70) or male.  Total urate burden as well as morbidity and functional decline associated with chronic tophaceous gout may explain the increased mortality.  

Table 1. Mortality Rates and Hazard Ratios among Gout Patients according to Tophi Status