Knight-Madden, Jennifer M.; Reid, Marvin E.; Younger, Novie O.; Forrester, Terrence E.; Greenough, Anne
Author Affiliation, Ana.
Tropical Medicine Research Institute
Comparison between two spirometers in the measurement of pulmonary function in adults and children with sickle cell disease and controls
West Indian Medical Journal
Date of Publication
53 (Supplement 5)
Presented at the 13th Annual Research Conference and Workshop on Violence and Violence prevention. November 10-12, 2004. Faculty of Medical Sciences. University of the West Indies, Mona. Kingston, Jamaica.
Objective: To determine whether the pulmonary function tests (PFTs) obtained using the Vitalograph pneumotachograph based spirometer varied significantly from those obtained using the Morgan TLC rolling seal spirometer in adults and children with sickle cell disease (SCD) and AA controls. This comparison can determine whether spirometer measurements in patients with SCD accrued using different spirometers should be pooled for analysis. Method: Eighty subjects were recruited to each of the four subjects groups: adults (age 24.7 ± 2.4 years) and children (7.7 ± 1.3 years) with SCD and controls. Pulmonary function tests were performed pre and post exercise or bronchodilator challenges using both the Vitalograph and the Morgan TLC spirometers. Forced vital capacity (FVC), forced expiratory low in one second (FEV1) and peak flow (PF) data were analyzed by correlation and random effects models using the Stata SE8. Results: Measured values of FVC and FEV1 on each spirometer correlated well ( r > 0.93, p < 0.05). Random effects modeling demonstrated that the Vitalograph yielded significantly lower values of FVC and FEV1 in adults and children of both genotypes in pre and post tests (p<0.001) and lower values of PF in children only (p=0.028). There was no interaction between spirometer and genotype in children. In adults, the difference between the values of FVC and FEV1 yielded by the two spirometers was less in patients with SCD. Conclusion: The FVC and FEV1 were lower when measured by the Vitalograph than when measured by the Morgan TLC in all patient groups.....