Changes in Pulmonary Function During the Early Years After Inpatient Rehabilitation in Persons With Spinal Cord Injury: A Prospective Cohort Study

Abstract

ObjectiveTo describe changes in pulmonary function (PF) during the 5 years after inpatient rehabilitation in persons with spinal cord injury (SCI) and to study potential determinants of change. DesignProspective cohort study. SettingEight rehabilitation centers with specialized SCI units. ParticipantsPersons with SCI (N=180). InterventionsNot applicable. Main Outcome MeasuresPF was determined by forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) as a percentage of the predicted value, at the start of rehabilitation, at discharge, and 1 and 5 years after discharge from inpatient rehabilitation. The population was divided into 3 subgroups on the basis of whether their PF declined, stabilized, or improved. ResultsFVC improved on average 5.1% over the whole period between discharge of inpatient rehabilitation and 5 years thereafter, but changes differed largely between persons. FVC declined in 14.9% of the population during the first year after discharge. During this year, body mass index, inspiratory muscle strength, change in peak power output, and change in peak oxygen uptake differed significantly between subgroups. FVC declined in 28.3% of the population during the following 4 years, but no differences were found between the subgroups for this period. Subgroups based on changes in FEV1 differed only with respect to change in peak oxygen uptake the first year after discharge. ConclusionsIn our study, many persons with SCI showed a decline in PF, larger than the normal age-related decline, during the 5 years after inpatient rehabilitation. Results suggest that a decline in PF during the first year after inpatient rehabilitation is associated with higher body mass index, lower inspiratory muscle strength, and declined physical fitness.