|dc.description.abstracteng||Individual patient data from three randomised, double blind, placebo-controlled, 13 or 14 week long trials of pregabalin for fibromyalgia had been provided by Pfizer Inc. 2228 such datasets were available for analysis. Study participants had been treated with pregabalin (300 mg, 450 mg or 600 mg per day) or placebo.
During these trials the study participants had filled in a number of questionnaires. In the doctoral thesis presented here scores of the Short Form 36 Health Survey (SF-36), the Fibromyalgia Impact Questionnaire (FIQ), and data on pain intensity as assessed by the visual analogue scale (VAS) were analysed.
The aim of this analysis of component questions from these questionnaires was to explore the relationship between chronic pain and the ability to work (with work ability possibly being impaired by physical health or emotional problems), and to explore how these parameters were affected by successful pain therapy. Furthermore it was of interest whether the ability to work measured as ‘workdays missed per week at trial end’ and ‘improvement of the ability to work during the trial’ would be suitable as a novel trial outcome in pain studies. Important results were:
• An analysis of treatment group mean values revealed similar results in all treatment groups (placebo or 300 mg, 450 mg, or 600 mg of pregabalin per day) concerning the improvements in the physical or emotional aspects of the ability to work.
• Substantial improvements in the physical or emotional aspects of the ability to work were achieved when there was at the same time a reduction in pain intensity over the duration of the trial, and a low pain state at trial end.
• Overall there were greater improvements in the physical (than in the emotional) aspects of the ability to work.
• If pain was analysed in relation to workdays missed, it was apparent that the greatest reduction in pain intensity over the duration of the trial was associated with the lowest number of workdays missed at trial end, and with the largest reduction in the number of workdays missed over the course of the trials.
• Workdays missed at trial end and the change in workdays missed over the duration of the trials reflected treatment success with regard to other domains of life.
• The lower the number of workdays missed at trial end or the greater the reduction in workdays missed was, the bigger were the differences between trial beginning and end in pain intensity, the FIQ total score and the scores of the eight domains of the Short Form 36 Health Survey.
• Role-Emotional (SF-36): scores of study participants without workdays missed at the trial end almost achieved population reference values.
• An effective pain treatment was reflected in the ability to work and in the number of workdays missed.
In the doctoral thesis presented here the relationship between pain and ability to work is described for patients with fibromyalgia who are treated with pregabalin. The greater the reduction in pain over the duration of the trial and the lower the pain intensity at trial end was, the greater was the improvement in the ability to work. Therefore an effective pain treatment is reflected in the outcome of the ability to work.
Furthermore, the ability to work (workdays missed at trial end, and change in workdays missed over the duration of the trials) appears to be a new and promising outcome for trials in the pain field. This doctoral thesis only focussed on the chronic pain disorder fibromyalgia; future analysis, possibly making use of trial data already in existence, should address the relationship between pain related and work related trial outcomes in trials of other painful disorders and their treatments.
Patients with fibromyalgia experience limitations due to their disease in a number of domains of life. There are also substantial costs because of disease-related workdays missed. An improvement in the ability to work, which can be achieved with successful pain treatment, means not only a better quality of life for the individual patient, but should also have a considerable economic impact.||de