The purpose of this study was to assess the psychometric properties of the Patient Perception of Migraine Questionnaire (PPMQ), which measures patient satisfaction with migraine therapy.
The PPMQ was administered to 940 patients as part of a 3-month, multinational, open-label, clinical trial comparing the effects of oral naratriptan 2.5 mg with the patient's customary therapy for the treatment of migraine. Psychometric properties of the PPMQ were evaluated in terms of its latent factor structure, validity, reliability, sensitivity, and development of a scoring method. Classical Test theory and Item Response theory (IRT) modeling were both used to measure reliability.
The PPMQ was able to detect treatment differences (P > .001), and all items significantly correlated with diary ratings of headache pain (r = .18−.51, p > .0001) and the Medical Outcomes Short Form-36 pain scale (r = .27, p > .0001). A principal components factor analysis revealed that the items on the PPMQ were psychometrically distinct and unidimensional (loadings, 0.74–0.91), with the exclusion of two items. The reliability (i.e., internal item consistency) of the PPMQ post-trial was high in both treatment groups (Cronbach's α = 0.96). An IRT analysis also ensured the formation of homogenous items, which were stable on repeat administration. Items did not require weighting and can be simply summed to yield a total score.
Based on the data from this one clinical trial, the 15-item PPMQ was shown to be a valid and reliable instrument that seems to efficiently and comprehensively measure patient perception of drug attributes in relation to the treatment of symptoms associated with migraine headaches.