Patients may respond differently to paper and electronic versions of the same questionnaires

AIM: To adapt the Asthma Quality of Life Questionnaire (AQLQ(S)), the Asthma Control Questionnaire (ACQ) and the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ(S)) for a personal digital assistant (Palm TX) and to examine the validity of the electronic versions by comparing them with the original paper versions. METHODS: 84 adults with asthma and 32 with rhinitis were randomised to complete either the paper or the electronic version first. After 2h, they completed the other version. RESULTS: 68 asthma and 27 rhinitis patients provided analysable data. For the AQLQ(S) and RQLQ(S) differences between paper and electronic were significant. Concordance between paper and electronic, evaluated using an intraclass correlation coefficient were: AQLQ=0.92, ACQ=0.90 and RQLQ=0.85. Concordance for the individual domains of the AQLQ and RQLQ ranged from 0.52 to 0.94. These levels of concordance did not reach the a priori defined requirement for validity. CONCLUSIONS: The significant bias between paper and electronic versions and only modest concordance provides evidence that patients may respond differently to questionnaires in different formats and show that different formats must not be used interchangeably.