Further Validation and Responsiveness Assessment of the Herpes Outbreak Impact Questionnaire and Herpes Symptom Checklist

Abstract

Objective The Herpes Outbreak Impact Questionnaire (HOIQ) and Herpes Symptom Checklist (HSC) are patient-completed questionnaires for assessing genital herpes outbreaks. This report describes the validation of paper-and-pencil versions of the scales and responsiveness assessments in an Australian clinical trial. Methods Acceptability of the language of the original UK versions was tested with Australians. The HOIQ and HSC were then field-tested with patients. The new versions were validated using patients' daily responses to the questionnaires in a famciclovir study. Results The HOIQ and HSC were readily adapted into Australian English and were acceptable to patients. Psychometric sample: N = 151; 81 (54%) male; mean age 39.9 ± 11.6 years; mean outbreaks 5.1 ± 3.0 per year. Internal consistency was good (alphas at outbreak 1 ranged 0.84–0.90 HOIQ and 0.73–0.87 HSC). Rasch analysis showed item stability over time. Correlations between HOIQ and HSC ranged from 0.46 to 0.60. Both scales distinguished outbreak healing presence or absence at day 6 ( P = 0.001), and the HOIQ scale distinguished between symptom severity groups ( P < 0.001). Scale scores declined significantly over study duration, exhibiting large effect sizes. Conclusions The paper-and-pencil HOIQ and HSC were reliable, valid, and responsive in a clinical trial setting. These instruments are recommended for use in clinical studies.