Background/Purpose:

Survival is decreased in patients with connective tissue diseases (CTDs) and vasculitis, however few studies have compared the mortality between the specific diseases prospectively by similar methods for patient’s selection. Here, we aimed to compare survival, standard mortality rates (SMR) and premature mortality between diagnoses of CTDs and vasculitis .

Methods:

All patients included in NOSVAR diagnosed from January 1, 1999 to December 31, 2016, in total 2148 patients were followed up until death or study end. Fifteen controls matched for each individual patient for year of birth, sex and residence area was randomly selected from the Norwegian Central Public Population Register. All controls were alive at time of patients diagnosis. Kaplan-Meier survival probabilities and curves were used to determine survival, and the difference between patients and controls was estimated by the log-rank test (Mantel Cox). In the Standardized mortality ratio (SMR) the number of deaths was divided by number of years of observation for each diagnosis and calculated as the ratio between the observed and expected numbers of death. The years of potential life lost (YPLL) was defined as the years a person would have lived if he or she had not died prematurely (here defined as 60 years of age). The YPLL for each death in patients are summed to represent the total years of potential life lost for all patients in each patient-group. The YPLL (60) rate is found by dividing YPLL by years of observation under the age of 60 in each group.

Results:

During a mean (SD) follow-up time of 9,2 years (4,7), 280/2148 (13%) patients deceased compared to 2885/32186 (9%) of the controls (p<0.001). Patient’s characteristics and demographics are shown in Table 1. Compared to controls, the lowest 5-and 10 years survival was seen in diffuse cutaneous systemic sclerosis (dcSSc) (79 % and 60%), (p<0.001), Antisynthetase syndrome (86% and 73%), (p<0.001), and limited systemic sclerosis, (89% and 75%), (p<0.001) Figure 1). For ANCA vasculitis and controls 5 years survival was 91% vs 95% and 10 years survival was 80 % vs 87%., (p=0.030). Highest SMR was observed for dSSc (5,8) and Antisynthetase syndrome (4,1)(Figure 2) The sum of YPLL60 among patients was 493 years and in matched controls 115 years, indicating a four-fold increase in premature deaths among the patients. The mean YPLL60 was highest in SLE and Takayasu with 19 and 15 years lost, respectively. Both lcSSc and dcSSc had a mean of 7 years lost YPLL60. The ranking of annual rate of YPLL60 for each disease is shown in (Figure 3)

Conclusion:

We show that there is a difference in survival, mortality and YPLL60 among the different CTDs and vasculitis. Methods used supplement each other and highlights the different aspects of outcome among the diagnoses. Systemic sclerosis and Antisynthetase syndrome had the lowest 5 and 10 years survival and the highest rate of premature mortality, but the mean loss of years before 60 years of age were higher in individuals with Takayasus and SLE.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/survival-and-years-of-potential-life-lost-in-connective-tissue-disease-and-vasculitis-data-from-the-norwegian-connective-tissue-diseases-and-vasculitis-registry-nosvar/