Examining Web Equivalence and Risk Factor Sensitivity of the COPD Population Screener

Objectives: The primary aim was to assess the equivalence of an Internet-based chronic obstructive pulmonary disease-population screener (COPD-PS) relative to a validated paper-and-pencil version. A secondary aim was to compare groups based on known COPD risk factors, such as smoking status and gender. Methods: Using an online panel survey organization, participants were randomized to internet or paper-and-pencil assessment where they completed the COPD-PS and other study forms. A subset of respondents also completed a test-retest reliability assessment. Finally, several thousand additional online respondents completed the COPD-PS for risk factor analyses. Results: A total of 1006 adults completed the randomized study (N = 504 online, N = 502 by mail). There were no differences between the arms in mean COPD-PS scores (mean difference: 0.12; 95% confidence interval: -0.14-+0.37; P = 0.365). In the web arm, 106/504 (21.0%) exceeded the screening cut-off compared to 101/502 (20.1%) in the paper-administration arm (difference in proportions: 0.9%; 95% confidence interval: -4.1%-+5.9%; P = 0.720). Subgroup analyses on a separate cohort of 3001 adults demonstrated hypothesized differences between groups defined by smoking status, presence of COPD, and shortness of breath. Conclusion: The methods of administration that were evaluated in this study (internet vs. paper and pencil) resulted in no significant differences in COPD-PS mean scores. Furthermore, the predictive utility of the COPD-PS was not different between methods of administration, even after accounting for age and smoking status.