Does treatment with Lyrica lower FIQ scores?
Science: Yes, in three trials of pregabalin (Lyrica,) 8% more of those using Lyrica for three months obtained at least a 14% reduction in FIQ vs. those using placebo.
Conclusion: You have an 8% better chance of seeing meaningful improvement after three months of using Lyrica vs. using nothing. Lyrica use results in a modest but statistically significant reduction in FIQ.
Determining the minimum significant change in the FIQ score.
The data from three clinical trials of pregabalin (Lyrica) in the treatment of fibromyalgia were analyzed. These trials involved over 2,200 patients.
Because these trials assessed each patient using multiple tests, analysis of the data allowed for the comparison of FIQ score changes with other changes in other measures, especially the patient global impression of change.
The patient global impression of change (PGIC) is a commonly used instrument in fibromyalgia, in part because there are few objective measures of fibromyalgia severity. Patients are asked to rate their improvement on a seven point scale: 1 = very much improved; 2 = much improved; 3 = minimally improved; 4 = no change; 5 = minimally worse; 6 = much worse; 7 = very much worse.
By evaluating the change in FIQ in relation to the change in PGIC, it was determined that a 14% change in FIQ was equivalent to a single ‘step’ category change in the PGIC.
Did the FIQ improve as a result of treatment with pregabalin?
The FIQ scores improved slightly on pregabalin. Some of these changes were statistically significant. Others were not.
After 13 weeks of treatment with pregabalin, 46% of those in the placebo group had at least a 14% decrease in their FIQ. In comparison, among those taking pregabalin (at various dosages) the number who had at least 1 14% decrease in FIQ ranged from 48% to 54%.
So it seems that by using pregabalin (the 450 mg./day dose) for 13 weeks you increase your chance for a 14% decrease in FIQ by about 8%.
The 8% increase in response on pregabalin was determined to be statistically significant.
Minimal clinically important difference in the fibromyalgia impact questionnaire.
Summary of the Abstract
The Fibromyalgia Impact Questionnaire (FIQ) is a measure of fibromyalgia severity.
In order to makes the IQ more useful, we wanted to determine the minimum change in FIQ score that represented a significant change for the patient. We also wanted to determine severity categories based on FIQ scores.
To do this, we investigated the results of over 2,200 patients. Over 90% of these patients were female, average age was 49, average duration of fibromyalgia was 9.7 years, average number of tender points was just over 17, and the average FIQ before the start of treatment was 62.
We determined the minimum significant change to be a change in FIQ score of 14%.
In the severity analysis we determined that an FIQ score of from 0 to 38 represented mild fibromyalgia; that from 39 to 58 represented moderate fibromyalgia and that a score of 59 or more represented severe fibromyalgia.