FM has multiple symptom domains, like pain, fatigue, sleep disturbance, depression and anxiety. They could be assessed individually or using a global scale or a composite scale (Silverman & Martin, 2005). Pain is usually measured by Numerical rating scale or Visual analogue scale. They are shown to be effective in clinical studies (Arnold, et al., 2002). Multi-dimensional pain assessment tools like Short-form McGill Pain Questionnaires (SF-MPQ) have been used in drug trials (Vitton, et al., 2004). Tenderness is assessed using manual tender point score (MTPS) and it is used in antidepressant trials (Arnold, et al., 2000).

Fibromyalgia Impact Questionnaire (FIQ) is a widely used multi- dimensional measure. It is self-administered and extensively used in clinics and trials of drugs/non-drug therapies (Burckhardt, et al., 1991). Fatigue could be measured using VAS and as a part of FIQ. Specific fatigue scales are also used for assessment. Similarly, sleep is assessed using VAS or specific sleep scales like Sleep Assessment Questionnaire (SAQ) and MOS-sleep scale (Hays & Stewart, 1992). Patient and physician global assessments are also used in trials (Crofford, et al., 2005).

FM severity at presentation and follow-up could be assessed using following tools: pain diagram, pain VAS, FIQ and Sleep fatigue scales. The Hospital Anxiety and Depression Scale (HADS) is a simple tool to assess the presence of depression.

REFERENCES
1. Silverman SL, Martin SA. Assessment tolls and outcome measures used in the investigation of fibromyalgia. In Wallace DJ, Clauw DJ (eds). Fibromyalgia and other pain syndromes. LWW. 2005; 309-19.
2. Arnold LM, Hess EV, Hudson JI, et al. A randomized, placebo-controlled, double-blind, flexible-dose study of fluoxetine in the treatment of women with fibromyalgia. Am J Med. 2002; 112(3):191-7.
3. Vitton O, Gendreau M, Gendreau J, et al. A double-blind placebo-controlled trial of milnacipran in the treatment of fibromyalgia. Hum Psychopharmacol. 2004; 19 Suppl 1:S27-35.
4. Arnold LM, Keck PE, Welge JA. Antidepressant Treatment of Fibromyalgia: A Meta-Analysis and Review. Psychosomatics.2000; 41(2):104-13.
5. Burckhardt CS, Clark SR, Bennett RM. The fibromyalgia impact questionnaire: development and validation. J Rheumatol. 1991; 18(5):728-33.