Assessment of cumulative health risk in the World Trade Center general responder cohort.

BACKGROUND: Multiple comorbidities have been reported among rescue/recovery workers responding to the 9/11/2001 WTC disaster. In this study, we developed an index that quantifies the cumulative physiological burden of comorbidities and predicts life expectancy in this cohort. METHODS: A machine learning approach (gradient boosting) was used to model the relationship between mortality and several clinical parameters (laboratory test results, blood pressure, pulmonary function measures). This model was used to construct a risk index, which was validated by assessing its association with a number of health outcomes within the WTC general responder cohort. RESULTS: The risk index showed significant associations with mortality, self-assessed physical health, and onset of multiple chronic conditions, particularly COPD, hypertension, asthma, and sleep apnea. CONCLUSION: As an aggregate of several clinical parameters, this index serves as a cumulative measure of physiological dysregulation and could be utilized as a prognostic indicator of life expectancy and morbidity risk.

The association between body mass index and gastroesophageal reflux disease in the World Trade Center Health Program General Responder Cohort.

BACKGROUND: There is increasing concern about the obesity epidemic in the United States. Obesity is a potential risk factor for a number of chronic diseases, including gastroesophageal reflux disease (GERD). This analysis examined whether body mass index (BMI) was associated with physician-diagnosed GERD in World Trade Center (WTC) general responders. METHODS: 19,819 WTC general responders were included in the study. Cox proportional hazards regression models were used to compare time to GERD diagnosis among three BMI groups (normal (<25 kg/m(2) ), overweight (≥25 and <30 kg/m(2) ), and obese (≥30 kg/m(2) )). RESULTS: Among the responders, 43% were overweight and 42% were obese. The hazard ratio for normal versus overweight was 0.81 (95% Confidence Interval (CI), 0.75-0.88); normal versus obese 0.71 (95%CI, 0.66, 0.77); and overweight versus obese 0.88 (95%CI, 0.83-0.92). CONCLUSION: GERD diagnoses rates were higher in overweight and obese WTC responders. Am. J. Ind. Med. 59:761-766, 2016. © 2016 Wiley Periodicals, Inc.

Sex differences in asthma and gastroesophageal reflux disease incidence among the World Trade Center Health Program General Responder Cohort.

BACKGROUND: Asthma and gastroesophageal reflux disease (GERD) are two common conditions among the responders to the WTC attacks. This study examined whether the cumulative incidence rates of asthma and GERD differed by sex among 24,022 and 23,557 WTC responders, respectively. METHODS: Cox proportional hazards regression was used to examine the sex difference in the rate of onset of physician-diagnosed asthma or GERD, from 9/12/2001 through 12/31/2015. RESULTS: The cumulative incidence of asthma reached 23% for women and 17% for men by the end of 2015, and the cumulative incidence of GERD reached 45% for women and 38% for men. Comparing women to men, the hazard ratio was 1.48 (95% confidence interval (CI): 1.27, 1.74) for asthma, and 1.25 (95% CI: 1.13, 1.38) for GERD. CONCLUSIONS: WTC general responders have a substantial burden of asthma and GERD, with higher incidence in women. Am. J. Ind. Med. 59:815-822, 2016. © 2016 Wiley Periodicals, Inc.