Objective

We aimed to assess systemic sclerosis (SSc) mortality by age in the general population over the past five decades.

Methods

This is a population-based study using a national mortality database and census data of all United States residents. We calculated the proportions of deaths for SSc and for all other causes (non-SSc) by age, and calculated age-standardized mortality rate (ASMR) for SSc and non-SSc, and the ratio of SSc-ASMR to non-SSc-ASMR by age groups for each year from 1968 through 2015. We performed joinpoint regression to estimate average annual percent change (AAPC) for each of these parameters.

Results

SSc was recorded as the underlying cause of death in 5,457 decedents aged ≤44 years, 18 395 aged 45-64, and 22 946 aged ≥65 from 1968 through 2015. At ages ≤44, the proportion of annual deaths decreased more for SSc than for non-SSc: AAPC, -2.2% (95% CI, -2.4% to -2.0%) for SSc vs -1.5% (-1.9% to -1.1%) for non-SSc. Consistently, SSc-ASMR decreased from 1.0 (95% CI, 0.8-1.2) in 1968-0.4 (0.3-0.5) per million persons in 2015, a cumulative decrease of 60% at an AAPC of -1.9% (95% CI, -2.5% to -1.2%) at ages ≤44. The ratio of SSc-ASMR to non-SSc-ASMR ratio also decreased (cumulative -20%; AAPC -0.3%) in ≤ 44-year group. In contrast, those aged ≥65 experienced a steep increases in SSc-ASMRs (cumulative 187.0%; AAPC 2.0% [95% CI, 1.8-2.2]) and SSc-ASMR: non-SSc-ASMR ratio (cumulative 395.4%; AAPC 3.3% [95% CI, 2.9-3.7]).

Conclusion

Mortality for SSc has steadily decreased at younger ages over the past five-decades.

Objective

Male sex and black race incur poor prognosis in systemic sclerosis (SSc). There is no nationwide population-based assessment of premature SSc death burden by sex and race.

Methods

This is a population-based study comprising all recorded SSc deaths across the United States. We constructed histograms depicting the number of SSc deaths for each age by sex and race, and calculated the cumulative percent death at each age and the median age of death. We determined the odds ratios for the risk of premature death from SSc by sex and race. We then calculated the percent of total SSc deaths for different age groups by sex and race from 1970 to 2015. We performed chi-square test with Yates's correction and quantified the odds ratio (OR) with 95% confidence interval (CI).

Results

The median age of SSc death was 63 years in males versus 68 years in females, and 57 years in blacks versus 70 years in whites. The odds for SSc death before 65 years age was 1.8 (95% CI, 1.6-2.0) for males compared with females and 5.1 (95% CI, 4.4-6.0) for blacks compared with whites. The higher odds for premature death in males than in females was similar for both races. Differences in the proportions of premature deaths from 1970 to 2015 increased between males and females (-5% to 17%) and between blacks and whites (14% to 36%).

Conclusion

Males and black persons die of SSc at younger ages. The worsening premature death burden gap between the two sexes and races over the last five decades is troublesome.