Risk factors for chest illness in chronic spinal cord injury: a prospective study

Chest illnesses commonly cause morbidity in persons with chronic spinal cord injury. Risk factors remain poorly characterized because previous studies have not accounted for factors other than spinal cord injury.

Between 1994 and 2005, 403 participants completed a respiratory questionnaire and underwent spirometry. Participants were contacted at a median of 1.7 yrs [interquartile range: 1.3-2.5 yrs] apart over a mean (SD) of 5.1 +/- 3.0 yrs and asked to report chest illnesses that had resulted in time off work, spent indoors, or in bed since prior contact.

In 97 participants, there were 247 chest illnesses (0.12/person-year) with 54 hospitalizations (22%). Spinal cord injury level, completeness of injury, and duration of injury were not associated with illness risk. Adjusting for age and smoking history, any wheeze (relative risk = 1.92; 95% confidence interval: 1.19, 3.08), pneumonia or bronchitis since spinal cord injury (relative risk = 2.29; 95% confidence interval: 1.40, 3.75), and physician-diagnosed chronic obstructive pulmonary disease (relative risk = 2.17; 95% confidence interval: 1.08, 4.37) were associated with a greater risk of chest illness. Each percent-predicted decrease in forced expiratory volume in 1 sec was associated with a 1.2% increase in risk of chest illness (P = 0.030).

In chronic spinal cord injury, chest illness resulting in time spent away from usual activities was not related to the level or completeness of spinal cord injury but was related to reduced pulmonary function, wheeze, chronic obstructive pulmonary disease, a history of pneumonia and bronchitis, and smoking.