Associations with chest illness and mortality in chronic spinal cord injury

Outcome measures: Logistic regression assessing relationships with chest illness at baseline and Cox regression assessing the relationship between chest illness and mortality.

Objective: Identify factors associated with chest illness and describe the relationship between chest illness and mortality in chronic spinal cord injury (SCI).

Design: Cross-sectional survey assessing chest illness and a prospective assessment of mortality.

Methods: Between 1994 and 2005, 430 persons with chronic SCI (mean ± SD), 52.0 ± 14.9 years old, and ≥4 years post SCI (20.5 ± 12.5 years) underwent spirometry, completed a health questionnaire, and reported any chest illness resulting in time off work, indoors, or in bed in the preceding 3 years. Deaths through 2007 were identified.

Results: Chest illness was reported by 139 persons (32.3%). Personal characteristics associated with chest illness were current smoking (odds ratio =2.15; 95% confidence interval =1.25-3.70 per each pack per day increase), chronic obstructive pulmonary disease (COPD) (3.52; 1.79-6.92), and heart disease (2.18; 1.14-4.16). Adjusting for age, subjects reporting previous chest illness had a non-significantly increased hazard ratio (HR) for mortality (1.30; 0.88-1.91). In a multivariable model, independent predictors of mortality were greater age, SCI level and completeness of injury, diabetes, a lower %-predicted forced expiratory volume in 1 second, heart disease, and smoking history. Adjusting for these covariates, the effect of a previous chest illness on mortality was attenuated (HR = 1.15; 0.77-1.73).

Conclusion: In chronic SCI, chest illness in the preceding 3 years was not an independent risk factor for mortality and was not associated with level and completeness of SCI, but was associated with current smoking, physician-diagnosed COPD, and heart disease history.