Telephone validation of the Quality of Life in Epilepsy Inventory-89 (QOLIE-89).

PURPOSE

To assess the psychometric properties of the Quality of Life in Epilepsy Inventory-89 (QOLIE-89) administered via telephone and to compare these properties with data gathered through self-administration.

METHODS

A study of 139 patients with epilepsy was undertaken at three clinical sites in the United States. Patients participated in both telephone interview (T) and self-administration (S). Order effect was controlled through randomization (T-S and S-T). Twenty-eight S-T subjects participated in an assessment of the 2-week reproducibility of telephone interviews.

RESULTS

Internal consistency and test-retest reliability levels of the QOLIE-89 overall score were very high across method of administration (T = 0.98; S = 0.98; ICC of T = 0.96). Scores were significantly related to mood (Profile of Mood States, r = -0.76, for both methods, p<0.001) and two indicators of epilepsy severity (seizure frequency in the past month, T: r = 0.52, p<0.0001; S: r = 0.54, p<0.0001; days since last seizure, T: r = 0.28, p<0.001; S: r = 0.25, p<0.01), with no significant differences in coefficients by method of administration. Performance of the measure was consistent for patients with unimpaired and impaired memory, using the Rivermead Behavioural Memory Test, and across level of education.

CONCLUSIONS

Results of this study indicate telephone interview is a viable option for evaluating HRQL in persons with epilepsy and support the reliability and validity of the QOLIE-89 regardless of method of administration.