This study aims to examine the associations between comorbid conditions and healthcare utilization, medical charges, or mortality of patients with rheumatoid arthritis (RA). Nebraska state emergency department (ED) discharge, hospital discharge, and death certificate data from 2007 to 2012 were used to study the comorbid conditions of patients with RA. RA was defined using the standard International Classification of Diseases (ICD-9-CM 714 or ICD-10-CM M05, M06, and M08). There were more comorbid conditions in patients with RA than in patients without RA. Comorbid conditions were majorly related to healthcare utilization and mortality of patients with RA. In addition to injury, fracture, sprains, and strains, symptoms of cardiovascular and digestive systems, respiratory infection, and chronic obstructive pulmonary disease (COPD) were common comorbid conditions for ED visits. In addition to joint replacement and fracture, infections, COPD and cardiovascular comorbidities were common comorbid conditions for hospitalizations. Cardiovascular, cerebrovascular, and respiratory comorbidities, dementia, malignant neoplasm, and diabetes mellitus were common comorbid conditions for deaths of patients with RA. In addition, the numbers of comorbid conditions were significantly associated with the length of hospital stay and hospital charges for patients with RA. The findings in this study indicated that comorbid conditions are associated with healthcare utilization, medical charges, and mortality of patients with RA.

Seatbelt use is the most effective way to save lives and reduce severe injuries. However, the percentage of non-seatbelt use is still high among drivers and passengers. Although the factors related to non-seatbelt use among drivers have been widely studied, the factors associated with non-seatbelt use among passengers have not been well documented. In addition, recent surveys showed that the driver's attitude has a significant impact on the passenger's seatbelt use. However, the lower response rate and less accurate of self-reported seatbelt use in survey studies, especially among participants who had a high level perception of penalty for non-seatbelt use. Therefore, we examined the association between passenger's seatbelt use and driver's seatbelt use with a statewide injury surveillance system. 36,012 passengers who were involved in motor vehicle crashes (MVC) in 2004-2013 were included in this study. Our results showed that if a driver wore a seatbelt, 92.6% of his/her passengers also wore seatbelts while if a driver did not wear a seatbelt, only 19.1% of his/her passengers wore seatbelts. Compared to the passenger whose driver wore a seatbelt, the passenger had a significantly higher probability of non-seatbelt use (odds ratio = 46.7; 95% confidence intervals, 42.7-51.1) if his/her driver did not wear a seatbelt. The driver has the greatest influence on the passenger's seatbelt use. The findings will provide important information for future public health practices to increase seatbelt use at the highest possible rate for passengers, such as educational interventions for drivers and seatbelt reminders use.